ABSTRACTS SUBMITTED IN SESSION 9
Low and Intermediate Energy Proton and Ion Accelerators and Sources
1654 - Beam Optics with Strong Space Charge Effects:
Comparing Beam Measurements with 3D Simulations
A. Adelmann, S. Adam, S. Humbel, PSI, Villigen
In the PSI high intensity proton accelerator facility the
870 keV beam line connects the Cockcroft Walton
preaccelerator to the Injector II cyclotron. The beam
transported in this line is initially a 12 mA DC beam with
an increasing 50 MHz time structure after the buncher.
The 12 pairs of wire profile monitors and 5 pairs of light
profile monitors mounted in this beamline provide
detailed information on the transverse beam properties. In
the part after the buncher, due to the dispersion produced
by the 90 degree bending magnet, some information on
the momentum distribution is available as well. We use
Mad9p (methodical accelerator design version 9 parallel) to model the optical properties in this beam line
including a full 3D space charge simulation. For the
comparison between measured and simulated beam
properties a Simulated Annealing based stochastic fit
algorithm is used to establish the initial conditions to be
entered into the simulation. The good agreement between
measurements and simulations in the beamline increses
our confidence that the full 3D simulation is also able to
predict the phase space transformations dominated by
space charge effects on the first few turns in the Injector
II cyclotron.
Type of presentation requested : Poster
Speaker :
Dr. Stefan Adam
Classification : [A04] Low- and Intermediate-Energy
Circular Accelerators
1164 - An Inverted Plasma Sheath for the Simulation
of the Extraction of Volume Produced HR. Becker, IAP, Frankfurt-am-Main
For the extraction of positive ions from plasmas well
established computer programs are available, which are
based on the simple Bohm sheath theory. In general the
results of such simulations agree very well with
experimental data. The situation is completely different,
however, for the simulation of the extraction of volume
produced H- ions. No simple theory exists for the
formation of an inverted sheath, connecting the quasineutral plasma in a self-consistent manner with the field
provided by the positive extraction voltage. Based on a
formulation of the space charge of the virtual cathode,
caused by reflected protons in the extraction aperture, a
linear model for an inverted plasma sheath will be
presented, which allows to discuss the influence of most
physical processes in the formation and extraction of Hand may become the basis of a correct simulation
program.
Type of presentation requested : Poster
Classification : [A04] Low- and Intermediate-Energy
Circular Accelerators
1341 - A New Generation of EBIS: High Current
Devices for Accelerators and Colliders*
E. Beebe, J.G. Alessi, A. Kponou, A.I. Pikin, K. Prelec,
BNL, Upton, Long Island, New York
With the advent of heavy ion colliders, such as RHIC at
BNL and LHC at CERN, the demand for high charge
state ion beam intensities was raised by more than an
order of magnitude compared to fixed target operation of
existing accelerators.[1] RHIC, for example, requires 3.4
E9 gold 32+ particles per ion source pulse, or about 85 nC
total positive charge yield, assuming a 20% abundance of
the selected charge state in the ion source beam. An EBIS
is capable of producing the required ion intensities in
beams of a low emittance and pulses as short as 10us,
which is quite advantageous for colliders. However, for
the colliders, the EBIS requires electron beam currents of
the order of 10 A, about 20 times higher than electron
beams utilized in devices at accelerators at Dubna, Saclay,
and Stockholm for fixed target and low intensity atomic
physics experiments. At BNL, we have constructed a test
EBIS, designed for the full electron beam power but with
only half of the trap solenoid magnet length required for
RHIC. Electron and ion beam currents in our test EBIS
have exceeded values obtained with previous EBIS
devices by more than an order of magnitude, in a stable
and quiet mode of operation. For operation with gold, ion
spectra with dominant charge state of 34+ have been
observed; and, even with only half the trap length
required by RHIC, 55nC ion pulses have been obtained at
the source exit after a confinement time of only 30 ms.
By extending the confinement time in a RHIC EBIS from
30 ms to 200 ms we should be able to produce Pb54+ ions
required by the LHC at CERN, which would eliminate
several preacceleration, stripping and accumulation stages
envisaged in the present scheme, using an ECR ion
source.
*This work is performed under the auspices of the U.S.
Department of Energy.
[1] H. Haseroth and K. Prelec "Possible Application of an
EBIS in Preinjectors for Large Heavy Ion Colliders",
Physica Scripta T71, 23 (1997).
Type of presentation requested : Invited Paper
Classification : [A04] Low- and Intermediate-Energy
Circular Accelerators
556 - Layout of a New Experimental Storage Ring
NESR at GSI
P. Beller, K. Beckert, A. Dolinskii, B. Franzke, F. Nolden,
M. Steck, GSI, Darmstadt
A new experimental storage ring (NESR) is part of the
new beam facility proposed recently for GSI. Due to the
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very high intensity of rare isotope beams envisaged by the
new facility nuclear physics experiments with these
beams will become feasible. Besides experiments using
an internal gas target, the NESR offers the possibility to
collide circulating bunches of rare isotope ions with
electron bunches counter-propagating in a small 500 MeV
electron storage ring. The goal of the electron scattering
experiments is the determination of nuclear charge
distributions and charge radii. The conceptual design of
electron facility and interaction region was done in
collaboration with BINP in Novosibirsk. The lattice
design has to take into account, that the NESR shall be
capable to accumulate 7×1010 antiprotons per hour at 4
GeV/c by applying stochastic cooling. This contribution
presents the principle ring design and lattice studies
relevant for the different tasks of the ring.
* An International Accelerator Facility for Beams of Ions
and Antiprotons, Conceptual Design Report, GSI,
November 2001
** A. Koop et. al., Conceptual Design of an ElectronNucleus Scattering Facility at GSI, Final Report,
BINP/GSI, August 2001, to be published
Type of presentation requested : Poster
Speaker :
P.Beller
Classification : [A04] Low- and Intermediate-Energy
Circular Accelerators
408 - A High Precision Model of AGS Booster Tune
Control*
K.A. Brown, W. Meng, BNL, Upton, Long Island, New
York; W. van Asselt, Kernfysich Versneller Institute,
Groningen, the Netherlands
The AGS Booster is used as the pre-injector to the AGS
for heavy ion, polarized proton, and high intensity proton
operations. In addition, the Booster is currently being
modified to supply slow extracted beams to the Booster
Applications Facility (BAF). The Booster is capable of
accelerating these various beams up to a maximum
rigidity of 17 T-m. However, for AGS injection, the
Booster never operates higher than about 10 T-m. For
BAF the Booster will operate up to the highest rigidity for
heavy ion beams and up to 13 T-m for proton beams. In
this note we will give a full description of the Booster
tune quadrupoles and the arc dipoles. We will describe
magnetic measurements and actual bare tune
measurements. We will describe a 3 dimensional model
we developed in order to understand various aspects of
the tune quadrupole magnets that were not or could not
be measured directly. We will present data on tune shifts
caused by B-dot effects (e.g., vacuum chamber eddy
currents) and results of a 3 dimensional model of eddy
currents. Finally we will describe a high precision MAD
model of the Booster tunes and the predicted tune control
ranges at the highest Booster rigidities.
*Work performed under the auspices of the U.S. Dept. of
Energy.
Type of presentation requested : Poster
Classification : [A04] Low- and Intermediate-Energy
Circular Accelerators
414 - IEEE 1394 Camera Imaging System for
Brookhaven's Booster Application Facility Beam
Diagnostics*
K.A. Brown, D. Gassner, L. Hoff, S. Tepikian, BNL,
Upton, Long Island, New York
Brookhaven's Booster Applications Facility (BAF) will
deliver resonant extracted heavy ion beams from the AGS
Booster to short exposure fixed target experiments located
at the end of the BAF beam line. The facility is designed
to deliver a wide range of heavy ion species over a range
of intensities from 10^3 to over 10^8 ions/pulse, and over
a range of energies from 0.1 to 1.1 GeV/nucleon Fe +26.
With these constraints we have looked to design
instrumentation packages which can deliver the maximum
amount of dynamic range at a reasonable cost. Through
the use of high quality optics systems and neutral density
light filters we will achieve 4 to 5 orders of magnitude in
light collection. By using all digital ieee1394 camera
systems we are able to eliminate the frame-grabber stage
in processing and directly transfer data at maximum rates
of 400 Mb/sec. In this note we will give a detailed
description of the system design and discuss the
parameters used to develop the system specifications. We
will also discuss the ieee1394 camera software interface
and the high level user interface.
*Work performed under the auspices of the U.S. Dept. of
Energy.
Type of presentation requested : Poster
Classification : [A04] Low- and Intermediate-Energy
Circular Accelerators
416 - A Heavy Ion Microbeam Facility using Micron
Resolution Detectors for 3 GeV/nucleon beams.*
K.A. Brown, R. Fliller III, Zheng Li, S. Peggs, R. Prigl, V.
Radeka, M.E. Vazquez, BNL, Upton, Long Island, New
York
The ability to place discrete numbers of particles in
defined cellular and extracellular locations is now
possible by using microbeam irradiation facilities. Such
facilities permit heavy-ion radiobiology to address
specifically the impact of signal transduction between
cellular compartments as well as issues related to
intercellular communication at limiting low fluences
where not all the cells in a population have been traversed
by even a single particle. Higher energetic heavy ion
microbeams will permit investigations of an important
unanswered question: whether neurons that survive
traversal by HZE particles develop changes as a late
consequence of the damage they incurred. Therefore,
these low-fluence studies promise to aid in our
understanding of the consequences of exposure to highLET radiation such as encountered in the space radiation
environment. In this paper we will discuss the technical
issues related to creating microbeams of heavy ions (e.g.
iron) at energies higher than at existing microbeam
facilities (up to 3 GeV/nucleon) and related to developing
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an electronic position sensitive detector for heavy ions
with a position resolution better than 1 micrometer. The
experimental requirements define microbeams to be
beams which will have a sufficiently small diameter to
localize the ions to a single cell. A facility such as this
will require specialized cell culture systems to evaluate
the performance of the heavy ion microbeam, and the
micro-resolution detector. For the cell studies employing
these tools, the necessary infrastructure will include a
micro positioning stage with a microscope and auxiliary
detectors. This project will advance significantly the stateof-the art of high-energy heavy ion microbeams and of
high-resolution heavy ion detectors. The system will
allow us to critically determine the response of human
cells to the single-particle traversals typically encountered in space environmental exposures, avoiding the
confounding effect of the Poisson distribution of particle
traversals inherent in conventional exposure systems.
During long-term space flight mission, it is estimated that
virtually no cell receives more than one Fe ion traversal in
3-year Mars mission scenario. Thus the use of the
microbeam will aim to produce data for direct input into
the analysis of human health risks during long-term space
flights exposures involving exposure to low fluences of
charged particles.
*Work performed under the auspices of the U.S. Dept. of
Energy and supported by the National Space Biomedical
Research Institute.
Type of presentation requested : Poster
Classification : [A04] Low- and Intermediate-Energy
Circular Accelerators
984 - The RCMS Optic Lattice
J. Cardona, J. Kewish, S. Peggs, BNL, Upton, Long
Island, New York
The Rapid Cycling Medical Synchrotron is designed to be
a very light and inexpensive accelerator. This is possible
due to the small beam size that has been chosen early
during the design stage. This choice has implications in
the design of the optic lattice. In this paper we will
present an overview of the RCMS optics lattice, the kind
of magnets to be used and also a description of a special
optic module that matches the rotating gantry with the rest
of the fixed accelerator. Techniques developed to win
additional space between quadrupoles without
significantly disturbing the lattice functions will also be
presented.
Type of presentation requested : Poster
Speaker :
Dr. Steve Peggs
Classification : [A04] Low- and Intermediate-Energy
Circular Accelerators
477 - Proposed New Facilities for Proton Therapy at
iThemba LABS
P. Celliers, L. Conradie, D. Fourie, N. Fredericks, P.
Fördelmann, M.J. Hogan, M. Jakoet, D. Jones, I. Kohler,
Y. Manjoo, M. Murphy, J. Pilcher, P. Rohwer, J. SharpeySchafer, J. Symons, E. de Kock, G. de Villiers, IThemba
LABS, Somerset West; F. Vernimmen, Tygerberg
Hospital, Tygerberg
New facilities, based on a commercial 230 MeV
cyclotron, for proton therapy are proposed for iThemba
LABS (previously National Accelerator Centre, NAC,
South Africa). In addition to the existing two vaults for
proton therapy three further vaults will be provided. Four
of these vaults will be equipped, respectively, with an isocentric spot-scanning system, a fixed horizontal line for
spot-scanning and two fixed lines for scattering systems
enabling treatment from two angles each. Proton beams
from the new cyclotron will be switched between the
different vaults. It is estimated that about 1000 patients
will be treated annually with the new facilities, which will
be operated on a commercial basis. The existing 200
MeV cyclotron will be retained for nuclear physics
research, production of radioisotopes, neutron therapy and
will in future also be used for eye treatment with protons
in one of the existing vaults for proton therapy. The
rationale for and the layout of the facilities will be
presented.
Type of presentation requested : Poster
Classification : [A04] Low- and Intermediate-Energy
Circular Accelerators
1841 - LEIR: The Low Energy Ion Ring at CERN
M. Chanel, CERN, Geneva
Amongst all the modifications of the PS Complex to
produce the LHC ion beams, the conversion of the old
Low Energy Antiproton Ring (LEAR) into the Low
Energy Ion Ring (LEIR) is a major issue. The
accumulation in LEIR of 9*108 Lead ions in normalized
transverse emittances of 0.7 mm allows the production of
4 of the 608 bunches needed in one LHC ring, in one
LEIR cycle. Then, it will take around 10 min to fill one
LHC ring. The requested luminosity of 1027 cm-2s-1 for
Lead ion collisions is reachable and is ~1000 times more
that the actual chain (Linac3, PSB) can do. The
production of Lead ion beams is described, with particular
attention to electron cooling, the injection system and the
beam lifetime.
Type of presentation requested : Poster
Classification : [A04] Low- and Intermediate-Energy
Circular Accelerators
821 - One-Dimensional Ordering in a Heavy-Ion Beam
H. Danared, A. Källberg, K.-G. Rensfelt, A. Simonsson,
MSL, Stockholm
Some years ago, it was found at GSI that the momentum
spread of electron-cooled beams of highly charged ions
dropped abruptly to very low values when the particle
number decreased to below about 5000 ions. This has
been interpreted as an ordering of the ions, such that they
line up after one another without being able to pass their
neighbours. Such transitions have also been observed at
CRYRING, and it has been seen how the drop in
momentum spread is accompanied by a similar drop in
Schottky-noise power. Using a model for the particle
distribution in a beam with string-like order, theoretical
3 /22
calculations of Schottky-noise power have been
performed. It is found that the model can reproduce the
reduction in noise power, and the good agreement with
the experimental data can be interpreted as evidence for
spatial ordering of the ions.
Type of presentation requested : Poster
Classification : [A04] Low- and Intermediate-Energy
Circular Accelerators
1 - Possibilities to Increase the Nuclotron's Intensity
D. Dinev, INRNE, Sofia
The superconducting heavy ion synchrotron Nuclotron is
under operation in JINR - Dubna since 1993. The ways to
increase the intensities of the accelerated ion beams are
discussed in this paper. As the polarized beams are of
special interest the stripping injection of polarized protons
and deuterons has been considered above all both
analytically and by computer simulations. Building a
booster has been debated for many years and now a
superconducting booster with Dubna-type magnets has
been proposed. We have simulated different schemes for
injection into the booster: multiturn injection, RF
stacking, charge exchange injection and stacking by
means of electron cooling. A comparison between the
results of the simulations is given as well.
Type of presentation requested : Poster
Classification : [A04] Low- and Intermediate-Energy
Circular Accelerators
129 - Design of a Collector Ring for Antiproton and
Rare Isotope Beams
A. Dolinskii, K. Beckert, P. Beller, B. Franzke, F. Nolden,
M. Steck, GSI, Darmstadt
Efficient collection and fast cooling of secondary beams
are major objectives of the new accelerator/storage ring
facility recently proposed at GSI [1]. Present ideas
concerning the lattice design for operation of a large
acceptance Collector Ring (CR) are presented. The CR
has to be optimized for fast stochastic cooling, its lattice
designed for three different optical modes. One is
necessary for rare isotopes (RI) and another one for
antiprotons, both requiring fast stochastic cooling. RI
beams shall be injected to the CR at 740 MeV/u with
transverse emittance of 50 mm*mrad and momentum
spread of 5% (FW). For 3 GeV antiprotons the transverse
and momentum acceptances will be 240 mm*mrad and
6%, respectively. Furthermore, the ring shall be operated
in the isochronous mode (i.e. at transition energy) for time
of flight (TOF) mass spectrometry of short-lived RI.
Tracking simulations for the different optics, taking into
account higher order field effects, have been carried out.
In addition, some aspects of beam injection and extraction
are discussed.
[1] "An International Accelerator Facility for Beams of
Ions and Antiprotons", Conceptual Design Report, GSI,
November 2001
Type of presentation requested : Poster
Classification : [A04] Low- and Intermediate-Energy
Circular Accelerators
1246 - Conceptual Design of a Facility for Internal
Target Experiments with Antiprotons up to 15 GeV/c
B. Franzke, K. Beckert, P. Beller, A. Dolinskii, F. Nolden,
M. Steck, GSI, Darmstadt
A major objective of the new beam facility recently
proposed for GSI [1] is to permit high luninosity internal
target experiments with stored and cooled antiprotons in
the momentum range 1.8-15 GeV/c. The concept includes
suitable accelerator/storage ring designs as well as
adequate techniques for efficient production, fast
stochastic cooling and accumulation of antiproton beams.
It must fit properly into the complete project: optimal
efficiency and extensive time/instrument sharing with
heavy ion acceleration and rare isotope beam production.
A new linac has to be developed delivering 100 MeV
protons in pulses of 60 mA, 0.1 ms duration, and 5 Hz
repetition frequency for injection to the existing SIS18.
The latter shall serve as intensity and energy booster for
fast cycled 100 Tm synchrotron accelerating 3×10**13
protons per cycle to 30 GeV. A net accumulation rate of
about 1×10**8 antiprotons every 5 s is aimed at, allowing
for experiments at correspondingly high luminosity of up
to 2×10**32/cm**2/s. The preliminary layout of a "High
Energy Storage Ring" HESR is presented. Results of
numerically simulated equilibrium beam properties taking
into account intra-beam scattering, internal target effects
and electron cooling are discussed.
[1]
"An International Accelerator Facility for Beams
of Ions and Antiprotons", Conceptual Design Report,
GSI, November 2001
Type of presentation requested : Poster
Classification : [A04] Low- and Intermediate-Energy
Circular Accelerators
718 - New Results on Electron Cooling at the TSR
Heidelberg
M. Grieser, M. Beutelspacher, D. Schwalm, A. Wolf, MPIK, Heidelberg; T. Shirai, ICR, Kyoto
At the heavy ion storage ring TSR. the longitudinal
cooling force can be measured with stochastic heating and
with the aid of an induction accelerator as well. So it is
possible to compare the results of these techniques. As
the ion current in such measurements is high, the
influence of the ion density has to be taken into
account.The results on the longitudinal cooling time
measurements will be presented.
Type of presentation requested : Poster
Classification : [A04] Low- and Intermediate-Energy
Circular Accelerators
1767 - Multiturn Injection Using Coupling Resonance
into the Nuclotron Booster
I. Issinsky, A. Butenko, A. Kovalenko, O. Kozlov, V.
Mikhailov, B. Vasilishin, V. Volkov, JINR, Dubna,
Moscow Region
Multi-turn beam injection process into the Nuclotron
booster with filling both horizontal and vertical
acceptance is considered. Numerical simulation of
4 /22
particle moving with using a coupling resonance Qx = Qz
exited by longitudinal solenoidal magnetic field shows
one posibility to reduce considerably losses of particles
and to raise injection efficiency. Optimum system
parameters and conditions for matching extracted beam
emittance with Nuclotron acceptance are determined, and
requirements for tolerances are evaluated. Particularities
and advantages of such injection way in comparison with
the other ones are discussed.
Type of presentation requested : Poster
Classification : [A04] Low- and Intermediate-Energy
Circular Accelerators
1768 - Separated Orbit Cyclotron with Magnet System
Cooled by the Liquid Nitrogen
I. Issinsky, A. Butenko, H. Khodzhibagiyan, O. Kozlov, B.
Vasilishin, JINR, Dubna, Moscow Region
Advantage of separated orbit cyclotrons, which efficiency
of injection, acceleration and extraction are close to
100%, requires construction of compact bending and
focusing magnetic systems using superconductivity. For
reducing the expenses of both the accelerator
manufacturing and operation a version of the SOC
magnetic system cooled by the liquid nitrogen with using
standard copper for windings is proposed. On the example
of earlier developed superferric cyclotron is shown
possibility of construction of such cryogenic systems at
their advantage comparatively with use of liquid helium.
Type of presentation requested : Poster
Classification : [A04] Low- and Intermediate-Energy
Circular Accelerators
958 - Magnetic Field Design and Beam Optics Study
for a 250 MeV Proton Radiotherapy Cyclotron
J. Kim, H. Blosser, F. Marti, NSCL, East Lansing; A.
Geisler, M. Schillo, ACCEL, Bergisch Gladbach
A 250 MeV superconducting cyclotron for radiation
therapy with a proton beam is under construction at the
ACCEL Instruments to be installed at the PSI by 2004.
The design of the cyclotron is in many aspects based on
the conceptual design work performed at the NSCL in
early 90's. The previous magnetic design has been
recently refined in the process of finalizing the magnet
configuration using 2D and 3D magnetic field programs,
resulting in new hill-edges, valley shims, and etc. For the
design of central and extraction regions extensive beam
optics simulations were used to ensure a well-behaving
beam. The layout of extraction elements essentially
remains the same as in the earlier design. The magnetic
field and rf electrode shapes in the central region have
been modified to achieve adequate vertical focusing for a
beam extracted from an internal PIG source. A
collimation system is to be placed in the center region to
remove unwanted beam phase space. The optics
simulation with computed electric and magnetic fields has
confirmed that the extraction efficiency above 80 % can
be achieved for a beam with a broad initial phase, and the
beam loss is being investigated in light of alleviating
radiation problem.
Type of presentation requested : Poster
Classification : [A04] Low- and Intermediate-Energy
Circular Accelerators
819 - Progress and Development of the CRYRING
Facility*
A. Källberg, MSL, Stockholm
The ECR source now delivers beams to experiments and
the beamline to the ring is completed. The EBIS source,
CRYSIS, has been used with some radioactive species
such as tritium, and uranium. The research groups
studying molecules and molecular clusters often request
ions that can only be produced in small amounts. Thus,
weak beams, less than 1 nA from the ion source, have
been successfully injected into the ring and stored
currents down to 5 nA have been measured. Furthermore,
new ways of running the storage ring, such as fast
ramping of the magnets during acceleration is reported as
well as development of beam diagnostics.
A. Källberg for the CRYRING Group
Type of presentation requested : Poster
Classification : [A04] Low- and Intermediate-Energy
Circular Accelerators
126 - Progress in the Nuclotron Booster Design
V. Mikhailov, A. Butenko, I. Issinsky, H. Khodzhibagiyan,
A. Kovalenko, I. Meshkov, V. Monchinsky, A. Sidorin, A.
Smirnov, E. Syresin, V. Volkov, JINR, Dubna, Moscow
Region; V. Anguelov, D. Dinev, INRNE, Sofia
New results of the Nuclotron booster design, a 250
MeV/Amu rapid cycling superconducting synchrotron at a
1 Hz repetition rate and a circumference of 84 m, are
presented. The paper describes different options of heavy
ion accumulation in the booster for upgrading the
Nuclotron beam intensities. They are a traditional
multiturn injection, a "skew" injection, accumulation of
protons, deuterons, polarized deuterons and heavy ions up
to carbon by charge exchange, acceleration of ions with
filled K and L shells, their stripping at the booster exit and
trasfer into the main ring. Numerical estimations of the
injection efficiency are given. The application of electron
cooling at the superconducting accelerator is considered
for the first time.
Type of presentation requested : Poster
Classification : [A04] Low- and Intermediate-Energy
Circular Accelerators
1087 - Development of Compact FFAG Accelerator
for Heavy Ion Radiotherapy
T. Misu, T. Fujisawa, T. Furukawa, S. Hojo, T. Honma, Y.
Iwata, M. Kanazawa, A. Kitagawa, K. Kono, M. Kumada,
N. Miyahara, T. Murakami, M. Muramatsu, K. Noda, Y.
Sakamoto, Y. Sato, M. Suda, A. Sugiura, E. Takada, M.
Torikoshi, S. Yamada, M. Yoshimoto, NIRS, Chiba City
During the past several years of successful clinical trial at
the Heavy Ion Medical Accelerator in Chiba (HIMAC),
the heavy-ion accelerator has proven to be a powerful tool
5 /22
for cancer treatment. Due to our satisfactory clinical
records at HIMAC, a medical Fixed-Field AlternatingGradient (FFAG) accelerator, which is more compact and
cost-effective, is being proposed so as to establish the
medical standards for a carbon-beam cancer therapy. In
this study we present our current accelerator design
scheme.
Type of presentation requested : Poster
Classification : [A04] Low- and Intermediate-Energy
Circular Accelerators
641 - S-ring Project at NIRS
K. Noda, M. Kanazawa, T. Murakami, E. Takada, S.
Yamada, NIRS, Chiba City; S. Shibuya, Sumitomo Heavy
Industries, Tokyo
The small ring (S-ring) project has been started since
April, 2001 at NIRS for the following purposes: (1)
Development of key-technologies for a compact heavyion synchrotron for the cancer therapy, (2) Study of the
radical behavior in a living body, (3) Bio-physics
experiment with high LET beam for the estimation of the
radiation risk in space and (4) Accelerator physics. The Sring will deliver heavy-ion beams with energies from 1 to
28 MeV/n, s bunch length of 10 to 1000 ns and a small
emittance, while the circumference is as small as 25 m.
The lattice structure of the ring is based on a double-bend
achromatic structure. Applying a bunch rotation method
to the high quality beam generated by an electron cooler,
we will obtain a short bunched beam through a fast
extraction method. An un-tuned RF cavity is adopted to
accelerate the beams, which has been tested at a lowpower level. A switching type power-supply has been
developed as that for a main magnet has been developed,
and its tracking accuracy and stability are estimated to be
around 1e-4 and 1e-6 order, respectively. The design and
R&D result will be presented.
Type of presentation requested : Poster
Classification : [A04] Low- and Intermediate-Energy
Circular Accelerators
100 - Computer Simulation of Space Charge
Dominated Beam Dynamics for External Injection into
Phasotron
L. Onischenko, E. Samsonov, JINR, Dubna, Moscow
Region
Capture efficiency for external injection into Phasotron is
under consideration. Computer simulation of the space
charge dominated beam dynamics shows the possibility of
external injection into Phasotron with sufficient capture
efficiency and the permisible emittance growth.
Type of presentation requested : Poster
Speaker :
Leonid Onischenko
Classification : [A04] Low- and Intermediate-Energy
Circular Accelerators
468 - Upgrading of ALPI Resonator by Nb Sputtering
A.M. Porcellato, INFN-LNL, Legnaro, Padova
ALPI is the superconductiong linac for heavy ions in
operation at Legnaro. Its average beta section used to be
composed by Pb/Cu QWRs. The replacement of Pb by a
Nb sputtered film allowed improving the resonator
performance substantially at very low cost. The average
accelerating field of the cavity rose from about 2.5 MV/m
to 4 MV/m. The upgraded resonators maintain the same
thermal and mechanical stability typical of copper-based
resonators, keeping their lock in field and phase easy and
reliable. At present 2/3 of the resonators have been
upgraded and installed without interfering with ALPI
beam time schedule.
* INFNLNL
Type of presentation requested : Poster
Classification : [A04] Low- and Intermediate-Energy
Circular Accelerators
1305 - Calculations of Beam Lifetimes in CELSIUS
D. Reistad, Y.-N. Rao, V. Ziemann, TSL, Uppsala
We have made computations of beam lifetimes due to the
interaction between the stored proton and ion beams and
the internal targets (hydrogen pellet target and cluster-jet
target with target materials ranging from hydrogen to
xenon) and with the electron cooling system in CELSIUS.
These computations are presented, and compared with
measurements.
Type of presentation requested : Poster
Classification : [A04] Low- and Intermediate-Energy
Circular Accelerators
1780 - A Double Electrostatic Ion Ring, DESIREE
K.-G. Rensfelt, L. Bagge, H. Danared, L. Liljeby, A.
Simonsson, Ö. Skeppstedt, MSL, Stockholm
The first storage ring with only electrostatic elements
used for physics experiments (ELISA) was designed and
taken in operation some years ago in Aarhus. The
advantages compared to magnetic elements, small size,
cheap construction and easy operation was demonstrated.
Other projects based on that idea has been implemented
and are underway. At CRYRING an increasing number of
experiments asks for beams of singly charged, high mass
and low energy ions. Many of these experiments could
also be done at a small electrostatic ring. The double
electrostatic ring Desiree will give these experiments
more beam time but it will also open new fields of
experiments in atomic, molecule and biophysics. Beams
of negative and positive ions will be merged so low
energy collisions can be studied. The equipment will be
cooled to 10 - 20 K in order to relax internal degrees of
freedom in circulating molecules. The paper will shortly
review the physics programme and describe the status of
the design work.
Type of presentation requested : Poster
Classification : [A04] Low- and Intermediate-Energy
Circular Accelerators
867 - Status of ITEP Powerful Ion AcceleratorAccumulator Facility TWAC
B. Sharkov, N. Alexeev, D. Koshkarev, ITEP, Moscow
6 /22
The TWAC (TeraWatt Accumulator) project at ITEPMoscow takes advantage of a heavy ion accelerator
facility based on two existing synchrotron rings and using
a special stripping technique for stacking pulses
accelerated in the UK booster into the U-10 storage ring.
A bunch of carbon-4+ ions from the laser ion source was
pre-accelerated in the new U-3 pre-injector, injected and
accelerated in the UK booster ring to 300 MeV per
nucleon, stripped down to 6+ and stacked into the U-10
storage ring. After fast extraction the beam has been
transported to the beam-target interaction area via a new
86 long beamline. This marks completion and
commissioning of the new facility's main systems - ion
source, ion pre-injector, RF and power supply for the
booster ring, beam transport lines and pulsed magnetic
elements. Together with the upgrading of the main
accelerator-accumulator systems and with implementation
of the pulse compression system, the intensity of the
heavy ion beam will then reach the maximal (target)
values:In ion acceleration mode supplying up to 4.3
GeV/nucleon and up to 1011 particles/s;In ion
accumulation mode, 300-700 GeV/nucleon and1012 ?
1013 particles per ca.100 ns pulse;In medical application
mode, some 250 MeV/nucleon , 10 9 - 10 10 particles/s.
Type of presentation requested : Poster
Classification : [A04] Low- and Intermediate-Energy
Circular Accelerators
1244 - Design of New Compact Cooler Ring for
Crystalline Beams
T. Shirai, H. Fadil, Y. Iwashita, A. Morita, A. Noda, H.
Tongu, A. Yamazaki, ICR, Kyoto; K. Okabe, H. Okamoto,
Y. Yuri, Hiroshima University, Higashi-Hiroshima; M.
Grieser, MPI-K, Heidelberg
The compact ion cooler ring project has been started in
Kyoto University. It will have an electron cooler and a
laser cooling system. One of the main subject is a
realization of crystalline beams by cooling techniques.
The circumference is 19.2 m and the maximum magnetic
rigidity is 1 Tm. It has six superperiods. The design of the
ring satisfies the so-called "maintenance condition" [1]. It
can also be operated with the betatron phase advance
below 90 degrees per a superperiod. We plan to test the
three-dimensional laser cooling in this ring [2]. The
cooler ring design and the cooling systems will be
presented in the conference.
[1]. J. Wei, X.-P. Li, A. M. Sessler, Phys. Rev. Lett. 73
(1994) 3089
[2]. T. Kihara, H. Okamoto, Y. Iwashita, K. Oide, G.
Lamanna, J. Wei, Phys. Rev.E, 59, 3594
Type of presentation requested : Poster
Classification : [A04] Low- and Intermediate-Energy
Circular Accelerators
1325 - Double Synchrotron Complex SIS100/200 for a
New Research Facility at GSI
P. Spiller, K. Blasche, O. Boine-Frankenheim, B.
Franczak, P. Huelsmann, G. Moritz, P. Schuett, GSI,
Darmstadt
In 2001 a new international research facility has been
proposed by GSI. The proposed facility consists of two
superconducting synchrotrons SIS100/200 and three
cooler storage rings for radioactive ions and antiproton
beams. The two stage synchrotron facility SIS100/200
provides for fast acceleration of high intensity uranium
ions (U28+) to energies between 0.4 and 2.7 GeV/u and
for acceleration of fully stripped uranium ions to at least
23 GeV/u. By using the second stage synchrotron as a
stretcher ring, beams of up to 100 duty cycle can be
generated. In addition, high intensity proton beams of 29
GeV can be provided for the production of antiproton
beams. Specific technical features of the synchrotrons are
a)rapid cycling superconducting magnets for the operation
at 4 T/s up to 2 T in SIS100 and 1 T/s to at least 4 T in
SIS200, b)rf systems for beam acceleration with a total rf
voltage of 350 kV and for bunch compression with a
voltage of 1000 kV in SIS100 ( the latter is required to
generate a short bunch with a pulse length of 50 ns), and
c)a well designed vacuum system for the operation at an
extremely low pressure of about 10-12 mbar in warm and
cold beam tubes. Especially theoretical and experimental
studies of dynamic vacuum instabilities are discussed. In
addition the layout of the synchrotron with respect to
bunch compression and impedance is addressed.
Type of presentation requested : Poster
Classification : [A04] Low- and Intermediate-Energy
Circular Accelerators
757 - Developments at the Cooler Synchrotron COSY
H. Stockhorst, U. Bechstedt, J. Dietrich, R. Gebel, K.
Henn, A. Lehrach, B. Lorentz, R. Maier, D. Prasuhn, A.
Schnase, H. Schneider, R. Stassen, J. Stein, R. Tölle, P.
von Rossen, FZJ, Jülich
The Cooler Synchrotron COSY at the Forschungszentrum
Juelich delivers polarized and unpolarized protons in the
momentum range 600 MeV/c up to 3.3 GeV/c. COSY
offers routinely different modes of operation to serve
internal experiments with solid targets as well as with gas
cluster or atomic beam targets. Stochastic cooling in the
longitudinal and transverse phase space has been applied
for internal target experiments to preserve the high beam
quality. Polarized and unpolarized protons are slowly
extracted with high efficiency to external target stations
with the method of stochastic feeding. Here, brilliant
beams at the external target areas can be prepared with
electron cooling. For short pulse experiments also a single
turn extraction of an electron cooled proton beam bunch
is available. Machine experiments proved that the beam
momentum could be increased to 3.65 GeV/c, i.e.beyond
the design momentum 3.3 GeV/c.
Type of presentation requested : Poster
Classification : [A04] Low- and Intermediate-Energy
Circular Accelerators
290 - An Electron Beam Target/Cooler for Extremely
Low-Energy Ion Beams at the Electrostatic Storage
Ring
Tetsumi Tanabe, S. Lee, KEK, Ibaraki-ken; E. Syresin,
7 /22
JINR, Dubna, Moscow Region; K. Noda, NIRS, Chiba
City; I. Watanabe, Toshiba, Yokohama
An electrostatic storage ring for studying atomic and
molecular science has been operational at KEK since
May, 2000. The ring has a circumference of 8 m and can
store light-to-heavy ions with an E/q of up to 30 keV [1].
Light ions are produced with an ECR ion source, while
macro-molecular ions like bio-molecules are produced
with an electrospray ion source. The measured 1/elifetimes are 10 ~ 50 s for light ions and 12 ~ 20 s for biomolecular ions. These lifetimes are long enough to cool
vibrationally excited molecular ions, and their intensities
are tolerable for practical use, like atomic collision
experiments. So far, we have stored bio-molecules [2]
with a mass of up to 66,000. In order to study electronion collisions, an electron beam target has been designed,
which will be installed in a straight section of the ring.
The structure of the target is almost the same as an
electron cooler consisting of an adiabatically expanded
electron beam; the target can also function as an electron
cooler for light-mass ions. Main parameters are: the
electron energy, 0.1~100 eV; the interaction length, 20
cm; the electron beam diameter at the interaction region,
20 mm; the expansion factor, 10~100; the solenoid field
at the gun region and at the interaction regions, 1000 G
and 10~100 G, respectively. The device will be completed
in coming spring. The design and the first experimental
results will be presented.
[1] T.Tanabe et al., Nucl. Instr. and Meth. A (2002) in
press.
[2] T.Tanabe et al., Proc. Int. Symp. on Dissociative
Recombination of Molecules with Electrons, Aug. 26-30,
Chicago (2001), in press.
Type of presentation requested : Poster
Classification : [A04] Low- and Intermediate-Energy
Circular Accelerators
127 - Lattice and Beam Dynamics of the Isochronous
Cyclotron with Separate Orbits and Particle Motion
Simulation
B. Vasilishin, A. Glasov, I. Issinsky, V. Mikhailov, JINR,
Dubna, Moscow Region
The method and results of calculation of the lattice and
beam dynamics in the isochronous cyclotron with
separate orbits (SOC) for a 240 MeV proton energy are
described. An energy gain during one turn must cause
sufficient orbit separation to place the magnetic structure
elements. Each part of path between accelerating cavities
(period with increasing length)involves focusing and
defocusing lenses and two dipole magnets. The bending
angles in magnets are calculated to provide such lengths
of periods which the beam passes for equal intervals of
time (the isochronism condition). Decreasing the orbit
separation during acceleration can be compensated by the
corresponding increase of the energy gain. We achieve it
by shifting the accelerating voltage equilibrium phase
from 45 degree at the beginning to 90 degree at the end.
This shift is achieved by a small increasing of the period
lengths against lengths determined by the isochronism
condition (corresponding increase of the bending angles
in dipoles). The computing simulation of particle motion
and the parameters errors and nonlinearities influence on
the beam stability has been performed. The limit proton
current is about 0.2 mA. SOC permits the acceleration of
nuclei with Z/A near to 0.5. The final energy in this case
is 46 MeV/amu. The work was performed by the request
of Laboratory Director's Research and Development
Funds from Oak Ridge National Laboratory.
Type of presentation requested : Poster
Classification : [A04] Low- and Intermediate-Energy
Circular Accelerators
1070 - Status of 1MV Tandem Proton Accelerator
Development*
Y.-S. Cho, W.S. Song, KAERI, Daejon
For industrial applications such as high-energy
implantation, nano-structure fabrication, and explosive
detection, a 1MV 10mA tandem proton accelerator is
being developed. The proton accelerator consists of a
10mA negative hydrogen ion source, two Einzel lenses,
accelerating tubes, a gas stripper, a 1MV 30mA CockroftWalton high voltage power supply, vacuum system with 4
cryo-pumps, and a high pressure insulating gas system.
The simple straight optical geometry is adapted for the
optics design for the accelerator.
The 2MV/m
accelerating tubes are developed for this accelerator and
tested. The accelerator is being constructed. The details
of the accelerator developments will be reported.
* This work is supported by the Korea Ministry of
Science and Technology.
Type of presentation requested : Poster
Classification : [A07] Electrostatic Accelerators
792 - High Current Tandem Accelerator for Intense
Monochromatic Gamma Rays Generation
A. Krivenko, L. Barkov, Y. Belchenko, G. Derevyankin, G.
Dimov, G. Kraynov, R. Salimov, V. Shirokov, G.
Silvestrov, I. Sorokin, S. Taskaev, M. Tyunov, BINP,
Novosibirsk
Original 2 MeV proton tandem accelerator with current
up to 40 mA for monochromatic 9.17 MeV gammaquantum production on Carbon-13 target for contraband
detection is described. The tandem is supplied by a
powerful sectioned rectifier from ELV type industrial
accelerator providing high stability of the proton beam in
the region of maximum gamma rays production at protons
energy 1.76 MeV. The description of working ion source
with current up to 10 mA, variants of gas stripper system
and design of 100 kW Carbon-13 target with liquid metal
cooling are presented. Also the results of optics
calculation for focussing on stripper of high current (1040 mA) compensated H(-) beam with heterogeneous
density and transverse energy about 1 eV are given.
Type of presentation requested : Poster
Classification : [A07] Electrostatic Accelerators
8 /22
66 - Layout of an Electrostatic Storage Ring
C. Welsch, A. Schempp, IAP, Frankfurt-am-Main; H.
Schmidt-Böcking, INP, Frankfurt-am-Main
An electrostatic storage ring can be seen as a cross
between an electrostatic trap and magnetic rings. It
combines small size, relatively low costs with a high
flexibility in terms of the ions that can be stored and beam
parameters. From the point of view of particle dynamics
important differences to "classical" storage rings are the
mass-independence of the fields and a coupling between
the different planes of motion. At IAP the design of a
small ring for ions of energies up to 50 keV has been
made and a quarter ring section is presently being build
up. Different possible geometrical shapes of the machine
will be discussed and the corresponding particle dynamics
will be shown. Limitations to storage times and envisaged
experiments will be presented.
Type of presentation requested : Poster
Classification : [A07] Electrostatic Accelerators
68 - Analysis of Field Perturbation in an Electrostatic
Storage Ring
C. Welsch, C. Glaessner, A. Schempp, IAP, Frankfurt-amMain; H. Schmidt-Böcking, INP, Frankfurt-am-Main
At IAP in Frankfurt the design of a small ring for ions of
energies up to 50 keV has been made and a quarter ring
section is presently being build up. The setup of optical
elements consist of quadrupole doublets, parallel plate 10
deflectors and 70 cylindrical bends. An important
question during the design of such a device is the
positioning and manufacturing accuracy needed for the
optical elements. The dependence of the electric field on
electrode displacements and mechanical errors is
discussed and the effects on particle dynamics shown.
The resulting fields have been used to trace particles
through realistic field distributions and to compare
trajectories with particles following an idealized orbit.
Possible countermeasures are presented and acceptable
tolerances given.
Type of presentation requested : Poster
Classification : [A07] Electrostatic Accelerators
1837 - Linac Complex in the JAERI-KEK Joint RNB
Facility
S. Arai, y. Arakaki, K. Niki, M. Okada, Y. Takeda, M.
Tomizawa, KEK, Ibaraki-ken; S. Takeuchi, JAERI,
Ibaraki-ken
Construction of the JAERI-KEK joint RNB facility has
started from 2001 at JAERI-Tokai tandem cite. The
facility comprises a tandem accelerator, an ISOL and a
heavy-ion linac complex. The radioactive nuclei,
produced by bombarding a thick target with a 36-MeV 3microA proton beam from the tandem accelerator, are
ionized in an ion source, mass-analyzed by the ISOL, and
are accelerated up to 1-MeV/u by the heavy-ion linac
complex. The linac complex comprises a 26-MHz split
coaxial RFQ (SCRFQ) and a 52-MHz IH linac, which
were developed at KEK-Tanashi. The SCRFQ accelerates
ions with a charge-to-mass ratio (q/A) greater than 1/30
from 2 to 172 keV/u. The IH linac accelerates ions with a
q/A greater than 1/10, and is able to vary the output
energy continuously in the range of 0.17 through 1.05
MeV/u. We have a plan to extend the linac system in
near future. The present linac complex can be connected
to the JAERI superconducting tandem booster linac, if an
additional 2 MeV/u linac is newly set between them. The
extended linac system is able to provide the RNB energies
higher than the Coulomb barrier.
Type of presentation requested : Poster
Classification : [A08] Linear Accelerators
1809 - Frequency Change of IH-Linac to Accelerate an
Unstable-Nuclei Beam
Y. Arakaki, S. Arai, K. Niki, M. Okada, Y. Takeda, M.
Tomizawa, KEK, Ibaraki-ken
The heavy ion Linac complex which comprises a
25.5MHz RFQ and a 51MHz linac had been used for
accelerating unstable beam and for testing performance of
accelerator at KEK-Tanashi campus. These linacs will be
moved to tandem facility at JAERI-Tokai,and are
connected to an existing super conducting linacs in order
to accelerate the unstable beam up to the energy region
beyond the Coulomb barrier by setting up an additional
IH-Linac(IH2). Since the existing-super conducting linac
has an resonant frequency of 129.8 MHz, that of IH-Linac
must be changed from 51MHz to 51.92MHz. We
performed a test of frequency change by using a half size
model of IH-Linac, 3D calculation by using MAFIA code
was carried out, and is compared to the measured results.
Type of presentation requested : Poster
Classification : [A08] Linear Accelerators
536 - Results from the ISIS RFQ Test Stand
C. Bailey, A. Letchford, J. Thomason, CLRC RAL,
Chilton, Didcot
Results are described of studies on the LEBT matching
section of the RFQ test stand at the Rutherford Appleton
Laboratory.
Comparisons are made between
measurements on the beam line and theoretical
predictions, and an assessment is presented of the extent
to which the LEBT is successful in matching a beam with
unequal transverse emittances from the ion source into the
RFQ.
In addition, the degree of space charge
compensation present is evaluated, and its evolution with
time during the beam pulse is described.
Type of presentation requested : Poster
Classification : [A08] Linear Accelerators
1471 - Possibility Ion Acceleration on Higher Modes at
the Linear Accelerator with Interdigital-H
Accelerating Structure
V. Bomko, A. Kobets, B. Rudjak, B. Zajtsev, KIPT,
Kharkov
Heavy ion linear accelerators based on interdigital-H
accelerating structure has latent resources of particle
acceleration at non-conventional modes of excitation of
HF power. The results of investigations demonstrate that
in the structures of prestripping (PS) and main section
9 /22
(MS) on the Kharkov heavy ion linear accelerator
(MILAC) there is a real possibility to accelerate ions on
the higher modes of H-type. The investigations were
carried out on the models of accelerating structures PS
and MS built in the scale 1:3. In the MS cavity the wave
Н-120 was excited that corresponds to Н121 for unloaded cavity. In the PS cavity having a
rectangular shape, Н-300 is an analogue of this
wave (that corresponds to Н-301 for unloaded
cavity). In each of the given cases we managed to obtain
the required distribution of the accelerating field using
local and end resonant adjusting elements. With that there
was essential difference in frequencies of excited waves.
In the PS cavity the frequency increased by a factor of
1.6, while in the MS cavity the frequency only increased
by a factor of 1.08. The frequency changes obtained allow
to enhance accelerated particles energy in PS and MS
without essential changes of the accelerating structure by
a factor of 2.56 and 1.16, respectively.
Type of presentation requested : Poster
Classification : [A08] Linear Accelerators
1842 - Fast Chopper Structure for the CERN
Superconducting Proton Linac
F. Caspers, A. Mostacci, CERN, Geneva; S. Kurennoy,
LANL, Los Alamos
The SPL chopper is a traveling wave device, which
deflects a slow beam (beta value of 0.08) by its transverse
electric field. We discuss the chopper deflecting structure
based on a meander line printed on an alumina substrate.
This concept profits from the radiation resistance of
alumina, its excellent out-gassing properties as well as
good thermal conductivity. The use of well-established
MIC (Microwave Integrated Circuit) thick film
technology allows easy implementations of prototypes;
the thickness of the printed layers was further increased
by electrochemical deposition method. The topology of
the structure has been chosen from standard MIC layouts
and was subsequently optimized using numerical
simulations. Several prototypes have been manufactured
and their preliminary measurements showed encouraging
results.
Type of presentation requested : Poster
Classification : [A08] Linear Accelerators
670 - Study of Separated Function RFQ Structure*
C.E. Chen, J. Fang, X. Yan, IHIP, Beijing; Y. Wu, IPP,
Hefei
The accelerating field in the conventional RFQ is
originated from the surface modulation of the quadrupole
electrodes. However, the axial field gradient Ez generated
in this way is quite limited. Since the enhancement of the
modulation would result in less Ez if it's maximum is
already reached, and the higher the axial field maximum
means the less the focusing power. For this reason, the
energy gain of the conventional RFQ is rather limited,
especially when the energy of the accelerated ions is
higher than 2-3 MeV per nucleon. To improve the
situation, the structures of a new type RFQ, the Separated
Function RFQ (SFRFQ), have been proposed and studied.
In these structures, RF accelerating field mainly occurs at
the gaps between cells, while the RF transverse focusing
with electrical quadrupole field exists inside the cells.
Two kinds of SFRFQ structures, with diaphragms and
with rods, have been studied respectively. The energy
gain is improved for both cases if comparing with the
conventional one. All the preliminary results of analysis,
calculations and measurements are presented and
discussed in the paper.
*Supported by NSFC(19975004)
Type of presentation requested : Poster
Classification : [A08] Linear Accelerators
255 - Finite Element Analysis And Frequency Shift
Studies for The Bridge Coupler of The Coupled
Cavity Linear Accelerator of The Spallation Neutron
Source*
Z. Chen, LANL, Los Alamos
The Spallation Neutron Source (SNS) is an acceleratorbased neutron scattering research facility. The linear
accelerator (linac)is the principal accelerating structure
and divided into a room-temperature linac and a
superconducting linac. The normal conducting linac
system that consists of a Drift Tube Linac (DTL) and a
Coupled Cavity Linac (CCL) is to be built by Los Alamos
National Laboratory. The CCL structure is 55.36-meters
long. It accelerates H- beam from 86.8 Mev to 185.6 Mev
at operating frequency of 805 MHz. This side coupled
cavity structure has 8 cells per segment, 12 segments and
11 bridge couplers per module, and 4 modules total. A 5MW klystron powers each module. The number 3 and
number 9 bridge coupler of each module are connected to
the 5-MW RF power supply. The bridge coupler with
length of 2.5 bl is a three-cell structure and located
between the segments and allows power flow through the
module. The center cell of each bridge coupler is excited
during normal operation. To obtain a uniform
electromagnetic filed and meet the resonant frequency
shift, the RF induced heat must be removed. Thus, the
thermal deformation and frequency shift studies are
performed via numerical simulations in order to have an
appropriate cooling design and predict the frequency shift
under operation. The center cell of the bridge coupler also
contains a large 4-inch slug tuner and a tuning post that
used to provide bulk frequency adjustment and field
intensity adjustment, so that produce the proper total field
distribution in the module assembly.
* Work supported by the Office of Basic Energy Science,
Office of Science of the US Department of Energy, and
by Oak Ridge National Laboratory.
Type of presentation requested : Poster
Classification : [A08] Linear Accelerators
1355 - Study of a New PARRNe Experimental Area
using an Electron LINAC close the Tandem of Orsay
S. Essabaa, J. Arianer, P. Ausset, J.P. Baronick, J.-B.
Bergot, G. Bienvenu, J. Bourdon, F. Clapier, L. Coacolo,
F. Dupong, D. Gardès, D. Grialou, F. Ibrahim, T.
10 /22
Junquera, S. Kandri, J. Le Scornet, J. Lesrel, A. Mueller,
N. Rouvière, A. Tkatchenko, B. Waast, IPN, Orsay; L.
Rinolfi, CERN, Geneva; T. Garvey, B. Jacquemard, M.
Omeich, LAL, Orsay
The production of neutron-rich radioactive nuclei through
fission is currently prime research interest for the future
radioactive beam facilities. For example in the
EURISOL* project, photo-fission and fast neutron
induced fission are proposed. The photo-fission crosssection for 238U is about 0.16 barn (against 1.6 barn for
fast neutrons of MeV) but the conversion
electrons/gammas is much more efficient than that of
deutons/neutrons. It was then necessary, to test this new
method of production, to carry out, in equivalent
conditions, an experiment of the type PARRNe 1 using a
50 MeV electron beam. In April 2001, production of
fission fragments induced by gammas proved to be
successful. Bremsstrahlung gamma rays were produced
by the few nA - 50 MeV electron beam delivered by the
CERN LEP pre-injector (LIL). This promising alternative
has stimulated the studies of a new experimental area at
IPNO based on an electron Linac closed to the tandem,
through a collaboration with LAL and CERN PS groups.
* http://www.ganil.fr/eurisol/
Type of presentation requested : Poster
Classification : [A08] Linear Accelerators
1245 - Studies on a 100 MeV/A Superconducting
Reaccelerator Linac for EURISOL
A. Facco, M. Comunian, A. Pisent, F. Scarpa, V.
Zviagintsev, INFN-LNL, Legnaro, Padova; Z. Lipeng,
CIAE, Beijing; D. Berkovits, SOREQ, Yavne, Israel
A superconducting linac for radioactive beam acceleration
up to 100 MeV/u (for 132Sn) has been studied in the
framework of the EURISOL collaboration. The linac, fed
by a high charge state breeder, is based on high gradient
superconducting quarter- and half-wave resonators and
includes superconducting RFQs; it was designed for
acceleration of ions of all masses and especially studied
for ions with mass number around 132. In order to
maximize the acceleration efficiency, two stripping stages
are foreseen along the linac; multiple charge beam
transport is then used to maximize the transport
efficiency.
Beam dynamics simulations have been
performed with the code LANA, which includes realistic
field distribution in quarter- and half-wave resonators.
Type of presentation requested : Poster
Classification : [A08] Linear Accelerators
940 - Beam Dynamics Studies at NSCL of the RIA
Superconducting Driver Linac*
D. Gorelov, T.L. Grimm, W. Hartung, F. Marti, H.
Podlech, X. Wu, R.C. York, NSCL, East Lansing
Extensive studies have been done of the longitudinal and
transverse beam dynamics of the high power, cw
superconducting linac for the proposed Rare Isotope
Accelerator (RIA). The linac is to accelerate light and
heavy ions to energies of ~400 MeV/u or more with beam
powers of 100 to 400 kW. For the heavier ions,
simultaneous acceleration of several charge states will be
used to meet the beam power requirement and to
minimize the required accelerating voltage. The multicharge state acceleration scheme does, however, present
some challenges in the preservation of beam quality. A
linac design with a beginning frequency of 80.5 MHz in
lieu of a proposed design using 57.5 MHz [1,2] was
evaluated. The higher frequency option simplifies the
geometry, decreases the number of different resonators
types required, and reduces the microphonics problem.
On the other hand, the higher frequency solution would
require a somewhat larger number of accelerating
structures. In both cases, superconducting solenoid
magnets at the lower energies and room-temperature
quadrupole doublets at the higher energies are used to
provide the transverse focusing and beam matching. The
performance characteristics of both scenarios were found
to be similar. The results of the beam dynamics
optimization are discussed as well as a comparative
analysis of the two possible linac designs.
* Work supported by Michigan State University and NSF
PHY 0110253.
[1] K.W. Shepard and T.E. Tretyakova, "Superconducting
Accelerating Structures for a Multi-Beam Driver Linac
for RIA", LINAC'2000, Monterey, CA, August 2000.
[2] D. Gorelov et al., "Superconducting Driver Linac
Beam Dynamics Optimization for RIA", Proceedings of
PAC'2001, Chicago, IL, June 2001.
Type of presentation requested : Poster
Speaker :
Dr. X. Wu
Classification : [A08] Linear Accelerators
1361 - High Current Positron Source for Novel Ion
Accelerator
V. Gorev, RRC, Moscow
The theoretical investigations and conceptual design of a
high current positron sources and beams,as a carrier of
positive charge and energy for novel proton and ion
accelarator scheme, is discused.We are going to
describe:1.low density electron-positron-proton plasma
open traps,as an accumulator and high current impulse
source of positrons.,2.generation of high current and
power quasimonoenergetical positron impulses by
bremsstrahlung.
Type of presentation requested : Poster
Speaker :
prof.V.V.Gorev
Classification : [A08] Linear Accelerators
699 - Design of a 200MHz Proton RFQ
Z. Guo, C.E. Chen, J. Fang, Y. Lu, X. Yan, C. Zhang,
IHIP, Beijing
A 200MHz RFQ was designed to accelerate proton beam
to more than 2MeV. A mini-vane four-rod structure was
adopted and a 200MHz 400kW RF amplifier will be used
as its RF power source. The basic consideration was
presented. The design of particle dynamics was performed
with PARMTEQ and the preliminary results were given.
11 /22
Type of presentation requested : Poster
Classification : [A08] Linear Accelerators
640 - KTF RFQ Linac
J.-M. Han, Y.-S. Cho, B.-H. Choi, H.-J. Kweon, H.H. Lee,
K.-Y. Seo, KAERI, Daejon
The 350MHz KTF RFQ constructed to accelerate 20mA
proton beam from 50keV to 3MeV. The basic electrical
characteristic for an operaton of the RFQ are testing and
will extensively studied for an operation condition with
pulsed and cw beam current.
Type of presentation requested : Poster
Speaker :
Jang-Min Han
Classification : [A08] Linear Accelerators
624 - Injection into RFQ Using Beams with Different
Energies
V. Kapin, K. Noda, NIRS, Chiba City
An alternative way of beam injection into RFQ linac is
discussed. In the low energy part of an ion accelerator, a
monochromatic beam extracted from ion source is
transported to the entrance of RFQ by the low energy
beam transport system (LEBT). RFQ has a high current
limit. A beam current is often limited by LEBT or an ion
source. A possible way to increase the beam current is to
combine several beams at the entrance of RFQ. Beams
can be generated by a set of ion sources or a miltiplebeam ion source. A longitudinal acceptance of RFQ has a
large energy spread (up to 30-40%), and can be filled by
monochromatic beams with different energies. A total
combined beam has a discrete energy spectrum within
RFQ energy spread. Beams can be combined using a
bending magnet acting as an inverse spectrometer. In the
case of a linac with a short-pulse operation, a
conventional long-pulse ion source can be used. An
extracted long-pulse ion beam is cut to the set of shortpulse beams, which are stored on separated orbits of a
supplementary ring. The injection scheme is studied for
the HIMAC RFQ. Parameters of beam-line and
simulation results are presented.
Type of presentation requested : Poster
Classification : [A08] Linear Accelerators
242 - Acceleration of Radioactive Ion Beams at REXISOLDE*
O. Kester, F. Ames, S. Emhofer, D. Habs, K. Reisinger, K.
Rudolph, T. Sieber, LMU-München, Garching; O.
Forstner, F. Wenander, B. Wolf, CERN, Geneva; J.
Cederkäll, R. Repnow, D. Schwalm, R. von Hahn, MPI-K,
Heidelberg
In 2001 the linear accelerator of the Radioactive beam
Experiment (REX-ISOLDE)delivered for the first time
accelerated radioactive ion beams with a beam energy of
2 MeV/u. REX-ISOLDE uses the method of charge state
breeding, in order to enhance the charge state of the ions
before injection into the LINAC [1]. Radioactive singly
charged ions delivered by the on-line mass separator
ISOLDE are first accumulated in a Penning trap, then
charge bred to an A/q = 4.5 in an electron beam ion
source (EBIS) and finally accelerated in a LINAC from 5
keV/u to the final energy between 0.8 and 2.2 MeV/u [2].
Measurements of the interplay between the REXTRAP,
the transfer line and the EBIS have been done as well as
the first commissioning of the whole accelerator. The
properties of the different elements could be determined
and a first optimisation of the system could be carried out.
In two test beam times in 2001 stable and radioactive Na
isotopes(23Na-26Na) have been accelerated and
transmitted to a preliminary target station. There
$^{58}Ni$ and Be targets have been used to populate
exited states via Coulomb excitation and nuclear transfer
reactions. First results of the commissioning and of the
beam times will be presented.
* supported by the BMBF under 06LM974 and
06HD802I
* supported by the EU under HPRI-CT-1999-50003
[1] O. Kester and D. Habs, Charge breeding of intense
radioactive beams, Proc. of the 8th Symposium on EBIS
sources, 6-8 November, Brookhaven National Laboratory,
USA, 2000, AIP conference proceedings 572, p.217
[2] O. Kester et al., Hyperfine Interactions 129 (2000) 43
Type of presentation requested : Poster
Classification : [A08] Linear Accelerators
254 - A short IH-cavity for the Energy Variation of
Radioactive Ion Beams
O. Kester, H. Bongers, D. Habs, LMU-München,
Garching
In order to perform experiments with radioactive ions at
the Coulomb barrier energy variation of the ion beams
over a wide range is required. Short linac structures are
suitable for that puspose, like the 7-gap resonators for
REX-ISOLDE [1]. For the Munich Accelerator for
Fission Fragments (MAFF) 7-gap IH-resonators are
designed to vary the final beam energy between 3.7 and
5.9 MeV/u. This kind of resonator operates at 202.56
MHz and with 10% duty cycle [2]. A prototyp f that
cavity is being built and will be tested with beam in the
Munich tandem laboratory. Therefore a test beam line
with an emittance rig, an analysing magnet and a fast
Farday cup has been established. In addition a
modification of the drift tube structure is planned in order
to use the cavity as an additional booster for the REXISOLDE LINAC. This new design and the test
measurements will be presented.
[1] H. Podlech et al., Nucl. Instrum and Meth. B 139
(1998) 447
[2] H. Bongers et al., The IH-7-Gap Resonators of the
Munich Accelerator for Fission Fragments(MAFF) Linac,
proceedings of the PAC2001, Chicago, June 2001, p.3945
Type of presentation requested : Poster
Classification : [A08] Linear Accelerators
1560 - New Potential Function for RFQ Accelerator
Cells
S. Koscielniak, TRIUMF, Vancouver
12 /22
The performance of a rf quadrupole (RFQ) accelerator
design is assessed (in advance of construction) by
computer tracking of particles, from one cell to the next,
through a model of the electric fields that transport the
beam. Most computer models are based on the potential
of Kapchinskii and Tepliakov which assumes a perfectly
periodic structure, whereas an RFQ accelerator is only a
quasi-periodic device; the cells are typically adapted to
accept a d.c. beam, bunch, and then accelerate. A
particular problem with the two-term potential is that
there are only two free parameters, whereas three are
required to guarantee continuity at the cell boundaries. In
this paper we introduce a new potential and unit cell,
with independently variable bore radius and minimum
and maximum radii to pole tip, that should better
approximate the real-world fields. We also suggest a
potential function for a triplet of similar, but not
identical, adjacent cells.
Type of presentation requested : Poster
Classification : [A08] Linear Accelerators
384 - Increasing of Phase Capture for a Multi-Charge
Beam in a Heavy-Ion RFQ
G. Kropachev, A. Balabin, ITEP, Moscow
An opportunity to increase phase capture for a copper
beam with different charge states ions from an
electrostatic injector at ITEP heavy-ion 27 MHz RFQ
input without use of extra devices for ion velocity
equalization is considered. High phase capture efficiency
is achieved by arrangement of longitudinal emittances
for different charge states ions in the corresponding
maximum longitudinal acceptances located inside the
RFQ channel. Up to this moment the ions move outside
of separatrixes. Analytical and numerical approaches are
developed to describe a phase capture process for a
multi-charge beam. Both approaches predict a maximum
of total phase capture efficiency on an injection voltage at
fixed inter-vane voltage. According to the numerical
approach the total phase capture efficiency can be more
than 90%. In this case two-charge-states ions of the
copper beam (Cu2+ and Cu3+) are fully captured.
Type of presentation requested : Poster
Classification : [A08] Linear Accelerators
723 - Development of a FDT-Cavity *
K.-U. Kuehnel, A. Schempp, IAP, Frankfurt-am-Main
To achieve a better focussing at higher energies the RFQ
principle is combined with a drift tube cavity. In a
Focussing Drift Tube cavity this is done by adding small
electrodes with quadrupole symmetry to the accelerating
gaps of a spiral loaded cavity. The cavity will first be used
as a booster for the new RFQ-injector for COSY at FZ
Jülich.
* work supported by BMBF
Type of presentation requested : Poster
Classification : [A08] Linear Accelerators
1551 - Field Tuning of the TRASCO RFQ
G. Lamanna, INFN-Sezione di Bari, Bari; P. Antonio, S.
Fu, A. Pisent, INFN-LNL, Legnaro, Padova
In the frame of the TRASCO/ADS project, the Italian
study for an accelerator driven system for nuclear waste
transmutation, a 5 MeV CW RFQ is under construction at
LNL. In view of the field tuning of such structure we have
built and developed a 3 m aluminum RFQ cold model,
operated at 352 MHz (as the accelerator). This paper
presents the results of tuning the RFQ structure up to an
error of 2 %. The tuning procedure and the new
algorithm, based on the analysis of the second derivative
of the measured bead-pull data, will be described in
detail.
Type of presentation requested : Poster
Classification : [A08] Linear Accelerators
1738 - Beam Commissioning and Operation of the
ISAC Post Accelerator at TRIUMF
R. Laxdal, Z.T. Ang, I.V. Bylinsky, G. Dutto, M. Pasini,
R.L. Poirier, TRIUMF, Vancouver
The ISAC facility at TRIUMF has been producing intense
beams of low energy radioactive ions for experiment over
the last three years. A post accelerator comprising a 35
MHz RFQ and 106MHz DTL has been installed and
recently commissioned and is now delivering radioactive
ions to experiment in an energy range fully variable
between 0.15 and 1.5MeV/u. Beam measurements taken
during commissioning confirm the initial design goals;
the acceleration of low intensity beams with high final
beam quality and good efficiency. Delivery of beams for
experiment has been relatively straightforward and
dependable. We will present the results of the beam
commissioning studies and summarize the accelerator
performance and operational experience.
Type of presentation requested : Poster
Classification : [A08] Linear Accelerators
986 - Error Effects and a Tolerance Budget for the
Prestripper Section of the RIA Driver Linac*
E. Lessner, P. Ostroumov, ANL, Argonne
Distortions on the beam dynamics are discussed and a
tolerance budget is established for the prestripper section
of the RIA driver linac. The prestripper linac contains 85
superconducting (SC) independently phased rf cavities,
distributed in ten cryostat modules, that accelerate a 2charge-state (28 and 29) uranium from 0.17 MeV/u to 9.4
MeV/u. Transverse focusing is provided by 44 SC
solenoids. The increase in current gained by the multicharge beam comes at a cost of larger final emittance than
that of a
single-charge beam of the same initial
emittance. Minimization of emittance growth of the 2charge-state beam is obtained by transverse and
longitudinal phase-space matching at the lattice
transitions. Construction errors and misalignments of the
magnetic components introduce
further effective
emittance growth and trajectory distortions. The effects of
such errors on the beam parameters are studied by
numerical simulations that include three-dimensional
13 /22
electric and magnetic field distributions in the rf cavities
and solenoids. Error tolerances are determined to
minimize radiation losses and maintain the beam quality
in the high-energy section of the linac.
* Work supported by the U. S. Department of Energy
under contract W-31-109-ENG-38.
Type of presentation requested : Poster
Classification : [A08] Linear Accelerators
774 - Measured Performance of the ISIS RFQ
A. Letchford, C. Bailey, J. Duke, D. Findlay, J.
Thomason, CLRC RAL, Chilton, Didcot
The ISIS RFQ is a 665 keV, 202.5 MHz, 4-rod RFQ
intended as a replacement pre-injector for the ISIS
spallation neutron source at RAL. A test stand has been
constructed for soak testing and characterisation of the
RFQ before installation. Results are presented for
measurements of the principal parameters of the RFQ
together with its performance characteristics. A
comparison is made between the measurements and the
results from computer simulations.
Type of presentation requested : Poster
Classification : [A08] Linear Accelerators
82 - Using of RF Undulators for Ion Beam
Acceleration in Linac
E. Masunov, MEPhI, Moscow
RF undulator can be realized in periodical rf-structure
where the field has no space harmonic in synchronism
with the beam. The accelerating force is produced by a
combination of two or more space harmonics of RF field.
Hamilton's equation of particles motion in polyharmonic
RF field are devised by means of smooth approximation.
The analysis of 3D effective potential allows to find the
conditions under which focusing and acceleration of the
particles occur simultaneously. The new approach to RF
acceleration channel parameters choice is suggested. The
relationship between 4D phase space volume of the bunch
and trasmission coefficient is studied by means
Hamiltonian analysis. Examples illustrating the efficiency
of the proposed method acceleration are given for cases
when RF field has a different phase advances per period
of structure. The results are compared with a conventional
RF ion linac where the beam is accelerated by a
synchronous wave and focusing by a nonsynchronous
one.
Type of presentation requested : Poster
Classification : [A08] Linear Accelerators
1427 - Design of the RIA Driver Linac Switchyard*
P. Ostroumov, S. Kim, J. Nolen, ANL, Argonne; V. Aseev,
INR, Moscow
The Rare Isotope Accelerator Facility currently being
designed in the U.S. will use both heavy ion and light ion
beams to produce radionuclides via the fragmentation and
spallation reactions, respectively. Driver beam power of
up to 400 kW will be available so that beam sharing
between target stations is desirable. Design of the
switchyard for the driver beams of RIA is a unique task
due to the following features: 1) Distribution of various
ion species accelerated to wide range of energies to four
target stations; 2) Delivery of beams to two target stations
simultaneously; 3) Providing high quality beam optics
with higher order corrections for multiple charge state
beams to produce small beam spots at the entrance of the
fragment separators. A rf sweeper is used for beam
delivery to two targets simultaneously. The rf-sweeper is
followed by two DC septum magnets. A room
temperature IH-type cavity operating at 115 MHz is
proposed for the rf-sweeper and it provides fourmilliradian beam deflection. The time of flight of
different ion species in the rf-sweeper is close to 180
degree of the rf cycle to minimize fringing field effects.
*Work supported by the U. S. Department of Energy
under contract W-31-109-ENG-38.
Type of presentation requested : Poster
Classification : [A08] Linear Accelerators
766 - Optimization of Acceptance for the High
Current Proton Linac *
A. Pashenkov, INR, Moscow
The method of optimization of the acceptance for high
intensity proton Linac with transition section (TS)
between low and high energy parts - choosing of the
synchronous phase, accelerating field and length - is
presented. A computer code
has been written to
numerically integrate the longitudinal beam dynamic in
the Linac with TS. Basic concepts are applicable to any
type of the proton Linac. As an example the problems of
the beam acceptance and particle losses in the 600 MeV
Moscow Meson Factory proton Linac is considered.
* Institute for Nuclear Research, Moscow
Type of presentation requested : Poster
Classification : [A08] Linear Accelerators
1733 - Beam Dynamics Studies on the ISAC-II PostAccelerator at TRIUMF
M. Pasini, R. Laxdal, TRIUMF, Vancouver; P.
Ostroumov, ANL, Argonne
The TRIUMF/ISAC facility, now a world leader in rare
isotope production and acceleration, is constructing
ISAC-II, that will allow the acceleration of ion beams
with 3<A/q<7 to an energy of at least 6.5 MeV/u for
masses up to 150. The upgrade will include the addition
of a superconducting heavy-ion linac delivering an
effective voltage of 43MV. The design of the new postaccelerator has been optimized to provide simultaneous
acceleration of multiple charge states. This feature can be
used either to reduce the loss in beam intensity after a
single stripping stage or to make possible the addition of
multiple stripping sections to increase the final beam
energy without a significant overall beam loss. The
quarter wave resonators providing the acceleration have
inherent rf electric and magnetic steering components that
complicate multi-charge acceleration and can lead to
transverse emittance growth. We will present a detailed
beam dynamics study throughout the whole accelerator
including matching sections, with realistic field
14 /22
simulations of the steering fields and techniques to
compensate transverse emittance growth for multi-charge
beams.
Type of presentation requested : Poster
Classification : [A08] Linear Accelerators
1424 - Design of a 40 MeV Linear Accelerator for
Protons and Deuterons using Superconducting Half
Wave Resonators
M. Pekeler, K. Dunkel, C. Piel, H. Vogel, P. vom Stein,
ACCEL, Bergisch Gladbach
ACCEL currently investigates the design of a 40 MeV cw
linac based on independently phased superconducting
cavities. The linac is optimized for Protons and Deuterons
with a maximum current of 4 mA. The particles will be
injected from a ECR source into a normal conducting
RFQ, which is capable of cw operation. The transition
energy between RFQ and the following superconducting
accelerator section is 1.5 MeV/amu. The superconducting
section is equipped with half wave resonators to avoid
emittance growth by deflecting rf field components on
beam axis. The average energy gain per cavity will be
0.65 MeV.
Type of presentation requested : Poster
Speaker :
Mr. Christian Piel
Classification : [A08] Linear Accelerators
446 - High-Current Multicharge Heavy Ions Injector
Linac for ITEP-TWAC Project
V. Pershin, D. Kashinsky, A. Kolomiets, S. Minaev, B.
Sharkov, T. Tretjakova, R. Vengrov, S. Yaramishev, ITEP,
Moscow
The TeraWatt Accumulator (TWAC) at Moscow Institute
of Theoretical and Experimental Physics (ITEP-Moscow)
is under commissioning now. In order to reach the TWAC
target parameters it is necessary to build up the new highcurrent injector linac providing 10 to power 11 particles/s
instead of existing simple injector for the commissioning
with output beam energy 1.2 MeV/u. The new injector
should deliver the heavy ion beam with 15-20 mA current
of the necessary charge to mass ratio and energy of about
7-8 MeV/u. For this purpose an RF field focused linac
which accelerates the Al11+ or Co25+ ions from the laser
ion source to the synchrotron injection was developed.
Since the normalized emittance produced by the source is
expected as large as 4pimm.mrad, the high acceptance 81
MHz RFQ structure has been designed for the first stage
of the linac, where the beam energy of 1.6 MeV/u is
gained at the length of 6m. The charge state mixture with
the total current of about 100 mA is injected directly to
the RFQ channel because the beam separation is not
efficient behind of the laser source due to high value of
initial energy spread. Nevertheless, 85% transmission of
the main charge state component whose current is around
of 20 mA is reached in the beam dynamics simulations.
Four-vane RFQ structure supplied with the coupling interchamber windows provides both the moderate cavity
diameter and the operating mode stability. A new type of
the RFQ structure with the period length of 2 beta.lambda
is proposed for the second stage of acceleration.
Preliminary simulated 2 beta.lambda RFQ section
following the conventional RFQ gains the energy at the
second stage to 7 MeV/m without beam losses providing
the effective accelerating gradient of around 3.5 MV/m.
The first RFQ section is under manufacturing now.
Type of presentation requested : Poster
Classification : [A08] Linear Accelerators
1531 - Study of a Superconducting 100 MeV Linear
Accelerator for Exotic Beam
A. Pisent, M. Comunian, A. Facco, F. Scarpa, V.
Zviagintsev, INFN-LNL, Legnaro, Padova
An ISCL (Independent Superconducting Cavity Linac)
able to accelerate a 5 mA CW proton beam up to 100
MeV has been studied at LNL. Such a linac can be used
as the first stage of a high energy proton linac or as a
stand alone machine. The first application is considered
for the 1 GeV primary linac of a European facility for the
production of exotic beams (EURISOL project), while a
stand alone machine can be used as primary linac of a
facility to be built at LNL (SPES project). The main
advantages of this linac (respect to a normal conducting
accelerator) are the low power consumption and the
possibility to accelerate ions with different M/q (up to 34) with almost the same final energy per charge.
Type of presentation requested : Poster
Classification : [A08] Linear Accelerators
812 - Electromagnetic Design of an 80.5 MHz RFQ for
the RIA Driver Linac*
H. Podlech, D. Gorelov, W. Hartung, F. Marti, X. Wu,
R.C. York, NSCL, East Lansing
The Rare Isotope Accelerator (RIA) [1] requires a high
power driver linac capable of accelerating all ions through
uranium to energies >= 400 MeV/u with a beam power of
100 to 400 kW. The first accelerating structure would be
an RFQ. Electrodynamic simulations using the MAFIA
code [2] have been performed to optimize the RFQ
Resonator. We present the design of an IH-RFQ
(Interdigital H-Type) and a 4-rod RFQ. The operating
frequency is 80.5 MHz and the resonator has a length of
523 cm. Because of the specified cw operation,
optimization of the shunt impedance and the cooling
requirements are major issues. It was determined that an
RF power of 17 kW/m (IH-RFQ) and 21 kW/m (4-rod
RFQ) would be required to reach the design voltage of 55
kV.
* Work supported by Michigan State University and NSF
PHY 0110253
[1] http://srfsrv.jlab.org/ISOL/
[2] http://www.cst.de
Type of presentation requested : Poster
Speaker :
Dr. Holger Podlech
Classification : [A08] Linear Accelerators
15 /22
831 - RIA RFQ Beam Dynamic Studies*
H. Podlech, D. Gorelov, W. Hartung, F. Marti, X. Wu,
R.C. York, NSCL, East Lansing
In this paper we present an analysis of the beam dynamics
of a possible RFQ for the Rare Isotope Accelerator (RIA)
driver linac [1]. We investigated an 80.5 MHz and a 57.5
MHz RFQ. Both RFQs are designed for U28+ with an
input energy of 12.4 keV/u. The output energy is 169
keV/u for the 57.5 MHz RFQ and 292 keV/u for the 80.5
MHz RFQ. To increase the total beam power of the driver
linac, the RFQ must be capable of accelerating two charge
states (28,29) simultaniously. Two charge state
acceleration increases the longitudinal emittance
significantly. Therefore, one major design issue was the
minimization of the longitudinal emittance. To optimize
the RFQ accelerator subject to a variety of design criteria
(emittance growth, tank length, transverse acceptance) an
optimization program has been developed. We present a
new method of generating RFQ parameter curves (i.e.
modulation and phase) and of optimizing RFQ
accelerators.
* Work supported by Michigan State University and NSF
PHY 0110253
[1] H. Podlech et al., Electromagnetic Design of an 80.5
MHz RFQ for the RIA Driver Linac, these Proceedings
Type of presentation requested : Poster
Speaker :
Dr. Holger Podlech
Classification : [A08] Linear Accelerators
838 - Design of a 40 MHz RFQ for a Post Accelerator
at the Coupled Cyclotron Facility at NSCL*
H. Podlech, D. Gorelov, W. Hartung, F. Marti, X. Wu,
R.C. York, NSCL, East Lansing
Since 2001 the Coupled Cyclotron Facility with its new
A1900 fragment separator has been in operation at the
National Superconducting Cyclotron Laboratory (NSCL)
at Michigan State University [1]. Presently a helium gas
cell is being commissioned to stop the fragmentation
products [2]. As a consequence, a preliminary evaluation
has been done of a post accelerator that could deliver rare
isotope beams with an energy up to 5 MeV/u. The post
accelerator could consist of an RFQ, an IH drift tube
structure, and 36 superconducting Quarter Wave
Resonators. A cw RFQ capable of accelerating ions with a
charge to mass ration of 1:40 to 120 keV/u was specified.
Electrodynamic simulations using the MAFIA code [3]
have been performed to optimize the RFQ resonator. We
present the results of the MAFIA simulations and of the
beam dynamics of an IH-type RFQ and a Split Ring RFQ
with an operating frequency of 40 MHz and a length of
717 cm.
* Work supported by Michigan State University and NSF
PHY 0110253
[1] P. Miller et al., Commissioning of the Coupled
Cyclotron Facility at NSCL, Proceedings of the
PAC2001, Chicago, USA, 2001
[2] S. Schwarz et al., The LEBT Project at NSCL/MSU,
European Physical Journal, submitted 2001
[3] http://www.cst.de
Type of presentation requested : Poster
Speaker :
Dr. Holger Podlech
Classification : [A08] Linear Accelerators
914 - Investigation of a Normal-Conducting 175 MHz
Linac Design for IFMIF
A. Sauer, H. Deitinghoff, H. Klein, U. Ratzinger, R. Tiede,
IAP, Frankfurt-am-Main
The work for the project study of an International Fusion
Material Irradiation Facility (IFMIF) has been continued.
The linac part of the facility has to provide a 40 MeV, 125
mA D+ beam for the homogenous irradiation of a Li
target to produce very high neutron fluxes for fusion
chamber wall material tests. The linac consists of a Radio
Frequency Quadrupole (RFQ) accelerator followed by a
Drift Tube Linac (DTL). To different rf structures have
been investigated for the DTL: the well known Alvarez
type and the IH-type, both operating succesfully at several
large laboratories. Moderate rf power losses in the
structure has been one main aspect in the design with
respect to the required cw operation. Results of
multiparticle beam dynamics simulations demonstrate the
capability of each structure to handle the very high
currents without particle losses and at moderate emittance
growth. While the Alvarez DTL design shows less
emittance growth with and without errors, the IH-DTL is
attractive with respect to its compactness and mechanical
robustness.
Type of presentation requested : Poster
Classification : [A08] Linear Accelerators
1429 - An Fully Automated Test Bench for the
Measurement of the Field Distribution in RFQ and
Other Resonant Cavity
F. Simoens, F. Ballester, A. France, J. Gaiffier, A.
Sinanna, CEA, Gif-sur-Yvette
As part of the RF studies of the resonant cavities of the
"IPHI" accelerator project ("Injector of Proton High
Intensity"), a fully computer controlled bench for the field
distribution measurement has been developped. Based on
the perturbation method, the acquisition of the s21
transmission coefficient phase shift is synchronized with
the displacement of a bead. A systematic study of the
noise and uncertainties reduction has lead to a clearly
enhanced signal over noise. The measured raw data are
then converted to a quantity proportional to the
electromagnetic field magnitude. Specifically for the RFQ
tuning study, different transverse section positions where
to guide the perturbing object have been tested on our
RFQ cold-model.
Type of presentation requested : Poster
Classification : [A08] Linear Accelerators
109 - A Superconducting Injector LINAC for COSY
R. Tölle, U. Bechstedt, N. Bongers, J. Dietrich, O. Felden,
R. Gebel, K. Henn, H. Jungwirth, A. Lehrach, R. Maier,
N. Markgraf, U. Pfister, D. Prasuhn, P. von Rossen, A.
16 /22
Schnase, H. Schneider, Y. Senichev, R. Stassen, H.
Stockhorst, E. Zaplatin, FZJ, Jülich; A. Schempp, IAP,
Frankfurt-am-Main; A. Facco, V. Zviagintsev, INFNLNL, Legnaro, Padova
For the Cooler Synchrotron COSY at the Research Center
Jülich a superconducting linear accelerator will replace
the existing cyclotron which presently serves as an
injector for COSY. The new injector will have to deliver
polarized H- ions and polarized D- ions for injection into
COSY with an energy of at least 50 MeV. The number of
particles accepted in COSY is to be risen up to the space
charge limit, which is a significant improvement
especially for polarized ions. The polarized ions will be
generated in a colliding beams source with magnetic
extraction and subsequent electrostatic deflection. After
the RFQ stage (up to 2.5 MeV/u) the particles will be fed
into the LINAC section which consists of about 44
independently phased superconducting 2-gap resonators.
The ions are finally guided to the COSY injection point.
The main characteristics of the LINAC operation will be
2 mA peak current, 2 Hz repetition rate, 500 us ion source
pulse length. A facility description is given and designs
are discussed. The status of the project is reported.
Type of presentation requested : Poster
Classification : [A08] Linear Accelerators
1408 - The 7-Gap-Resonators for REX-ISOLDE
R. von Hahn, M. Grieser, H. Podlech, R. Repnow, D.
Schwalm, MPI-K, Heidelberg
REX-ISOLDE (Radioactive Beam Experiment at
ISOLDE)- a European collaboration of 22 institutions
aims to study the structure of very neutron rich light
nuclei using radioactive beams. Radioactive nuclei
delivered by the mass separator ISOLDE at CERN are
accelerated to 2.2 MeV/u using a novel concept. First the
radioactive beams from ISOLDE are accumulated in a
Penning trap (REXTRAP), then they are converted to
highly charged ions in an Electron Beam Ion Source
(REX-EBIS), cleaned by a high resolution mass
spectrometer and finally accelerated by a LINAC up to
2.2 MeV/u. A first successfully accelerated radioactive
ion beam was delivered to the target in autumn 2001 with
a preliminary final energy of 2 MeV/u. This paper
presents the first tests and successful acceleration of
radioactive ions in the 7-gap-resonator section.
Type of presentation requested : Poster
Classification : [A08] Linear Accelerators
1614 - Controls and Diagnostics for the High Current
EBIS at BNL*
E. Beebe, J.G. Alessi, O. Gould, D. Graham, A. Kponou,
R. Lockey, A.I. Pikin, K. Prelec, J. Ritter, V. Zajic, BNL,
Upton, Long Island, New York
The BNL testEBIS, is a full electron beam power, half ion
trap length prototype for an Electron Beam Ion Source
that could meet requirements for a RHIC preinjector. [1].
The testEBIS uses a 10A, ~50ms pulsed electron beam to
produce intense pulses of highly charged ions, of ~55nC
total positive charge yield and as short as 10us duration.
An auxiliary ion source is used to inject primary low
charged Au ion into the testEBIS in ~500us pulses. The
EBIS controller handles all the digital timing and many
analog control signals used for power supply and device
control necessary, for stable, low loss EBIS operation.
Diagnostics used to monitor the electron and ion beams
include Faraday cups, current transformers, an inline
time-of-flight (TOF) spectrometer to accept and analyze
the full ion beam, a Mamyrin TOF for providing high
resolution of ion spectra for highly charged heavy ions
(e.g., Au34+) at 20kV extraction energy, harp-type beam
profile monitors and a compact emittance head. The
design and operation of these devices will be discussed.
*This work is performed under the auspices of the U.S.
Department of Energy.
[1] E. Beebe, et.al., Rev. Sci. Instrum. 71 (2000) 893.
Type of presentation requested : Poster
Classification : [T01] Proton and Ion Sources
869 - Operation Experience of the Alice Ion Source
M. Cavenago, INFN-LNL, Legnaro; T. Kulevoy, S.
Petrenko, ITEP, Moscow
The ion source Alice, a compact 14.4GHz ECRIS, was
stably operated over its high voltage platform, capable of
reaching 350 kV, to provide several beams for ion
transport studies, and for injection of
accelerators. To further improve reliable operation, two
independent microwave power systems were installed;
moreover two alternative oven systems are being used (rf
oven) or possible (Mevva, ohmic oven); the elaborate
hierarchy of hardware interlocks coordinating platform
operation (independently from computer assistance) is
described. Details of the optical elements installed with
the accelerator tube, the platform voltage stability and
source upgrading plans are also discussed.
Type of presentation requested : Poster
Classification : [T01] Proton and Ion Sources
875 - Vapor Sources for ECR Ion Sources
M. Cavenago, INFN-LNL, Legnaro; T. Kulevoy, S.
Petrenko, ITEP, Moscow
An rf oven system was inserted and tested in the ECR ion
source Alice. The test bench performance of this oven
were similar to a previously described one [1], but it has
space for a larger copper sample and can be mounted at a
large angle with the vertical. Oven electronics proved to
work even in the ECR source enviroment, that is, both
power and pickup transformers stand the 11 kV dc source
voltage (and the occasional Paschen discharges);
influence on the source voltage stability is also discussed.
By placing oven at some distance from actual ECR
plasma, initial oven outgassing is made tolerable for rapid
ECR operation. Details of extracted copper beam are
given. A new ohmic oven was also prepared, using most
of the materials and technical simplification introduced by
the rf oven (glued crucible, zirconia covering, stress relief
in the heating element).
[1] M.Cavenago, T.Kulevoy and S.Petrenko, Rev. Sci.
Instrum., 2002
17 /22
Type of presentation requested : Poster
Classification : [T01] Proton and Ion Sources
1177 - Electron String Source of Highly Charged Ions:
Studies and First Tests on a Synchrotron*
E.D. Donets, D.E. Donets, E.E. Donets, V.V. Salnikov,
V.B. Shutov, Y. Tumanova, V. Vadeev, JINR, Dubna,
Moscow Region; J.G. Alessi, E. Beebe, A.I. Pikin, BNL,
Upton, Long Island, New York; L. Liljeby, K.-G. Rensfelt,
MSL, Stockholm
Operation of EBIS in the reflex mode of operation at
certain conditions leads to formation of the so called
electron string state of one component electron plasma,
which similar to electron beam can be used for production
of highly charged ions in Electron String Ion Source
(ESIS). We describe the experiments and results on
studies of electron string features, such as electron density
distribution and B-dependence of string density and of
ESIS ion output, obtained using 4 different EBIS sources
since the EPAC'98 conference. The results of the first
tests of ESIS "Krion-2" on injection of C6+ and Ar16+
ions in JINR Nuclotron also will be presented.
* The work is supported in part by US CRDF (Grant RP12110) and by the Swedish Royal Academy of Science.
Type of presentation requested : Poster
Speaker :
Professor Evgueni. D. Donets
Classification : [T01] Proton and Ion Sources
1189 - Status Report on Development of Tubular
Electron Beam Ion Source (TEBIS)*
E.D. Donets, E.E. Donets, JINR, Dubna, Moscow Region;
R. Becker, IAP, Frankfurt-am-Main
The tubular version of EBIS with off-axis injection and
extraction of ions was proposed to provide a significant
increase of interacting electrons and ions compared to the
usual linear version. The small ion beam emittance,
peculiar to EBIS, should be conserved, nevertherless.
Here we describe the results of a conceptual analytic and
computer simulations of TEBIS in the direct current and
in the reflex modes of operation, which predict that
effective electron current can reach more than 100 A at a
current density of about 300 - 400 A/cm^2 and an energy
of the electron beam in the region of several KV with a
correspondingly increased ion output of such highly
charged ions as, for example, C6+, Ar16+ and Pb54+.
The first results of simulation of ion extraction from
TEBIS in the off-axis mode also will be presented.
* The work is supported in part by US Civilian Research
and Development Foundation.
Type of presentation requested : Poster
Speaker :
Professor Evgueni D. Donets
Classification : [T01] Proton and Ion Sources
102 - A New Superconducting ECR Ion Source for the
Future Accelerator Facilities
S. Gammino, L. Andò, L. Celona, G. Ciavola, M. Menna,
L. Torrisi, INFN-LNS, Catania; A. Girard, D. Guillaume,
D. Hitz, G. Melin, P. Seyfert, CENG, Grenoble
A new electron cyclotron resonance ion source (ECRIS)
running at high frequency has been designed in
collaboration between INFN LNS and CEA Grenoble.
The source, named GyroSERSE, aims to the production
of very high charge states (up to U60+) at intensities so
far never obtained and of medium charge states at high
intensities (»1 emA). Both goals are of paramount interest
for future accelerators and require high-frequency
superconducting ECR ion sources. This means a
significant step to achieve with respect to the technology
of copper coils and permanent magnets, and also with
respect to the new projects of hybrid or fully
superconducting magnets. The expected performances of
the new source are presented: the latter are based on
existing scaling laws and have been demonstrated
recently by experiments performed with SERSE at 28
GHz"*,**". The technological aspects related to highfrequency operation and to cryogenic systems (in
particular mechanical stresses, helium consumption and
autonomous cryocooler) are briefly discussed, with a
particular emphasis on the possibility of having an
independent machine placed on a HV platform. In
particular we show that this kind of source is as versatile
as the sources of the previous generation but shows
performances typically ten times higher.
"*" Operation of the SERSE superconducting electron
cyclotron resonance ion source at 28GHz, S. Gammino,
G. Ciavola, L. Celona, D. Hitz, A. Girard, and G. Melin,
Review of Scientific Intruments 72 (2001) 4092.
"**" Results and interpretation of high frequency
experiments at 28 GHz in ECR ion sources, future
prospects, D. Hitz, A. Girard, G. Melin, G. Ciavola, S.
Gammino, L. Celona. Review of Scientific Intruments 73
(2002).
Type of presentation requested : Poster
Classification : [T01] Proton and Ion Sources
1141 - A New Room Temperature ECR Ion Source for
Accelerator Facilities
D. Hitz, D. Cormier, J.-M. Mathonnet, CEA, Grenoble
Magnetic scaling laws have recently been determined for
the optimization of any Electron Cyclotron Resonance Ion
Source (ECRIS)"*". According to these scaling laws, a
new 18 GHz room temperature ECRIS has been built to
deliver intense beams of medium and high charge states.
To achieve an efficient electron heating, additional
frequencies could be used at the same time. The effect of
these additional frequencies will be presented for cw and
pulsed operation of the source.
"*" Results and Interpretation of High Frequency
Experiments at 28 GHz in ECR Ion Sources, future
prospects, D. Hitz, A. Girard, G. Melin, G. Ciavola, S.
Gammino, L. Celona, Review of Scientific Instruments
(2002)
Type of presentation requested : Poster
Classification : [T01] Proton and Ion Sources
18 /22
1834 - Investigation of Formation of Spectra of Twoelement (Tb_2O_3, Dy_2O_3, Lu_2O_3) Laser
Produced Plasma as a Source of Ions
R. Khaydarov, IAP, Frankfurt-am-Main; G. Berdiyorov,
U. Kunishev, N.U. Uzbekistan-IAP, Uzbekistan
In this work the mass-charge, energy spectra of low
energy multiply charged ions O and Tb, Dy, Lu in twoelement laser produced plasma
has been studied.
Experiments were carried out on laser mass-spectrometer
with mass resolution of 100 and time-of-flight distance of
particles 100 cm. The power density of solid state
neodymium glass laser radiation is q=5E10 W/cm^2. In
experiments targets Tb_2O_3, Dy_2O_3, Lu_2O_3 with
density ~4,4 g/cm^3 were used. It was found
experimentally that mass-charge spectra of ions of twoelement plasma, basically, consists of ions O and Tb, Dy,
Lu in different ionized conditions. We found that
increasing of power density of laser radiation from
q=1E9 to q=5E10 W/cm^2 leads to increasing of charge
of ions as O so and Tb, Dy, Lu of two-element plasma.
Maximum charge of O and Tb, Dy, Lu in plasma are
reached under q=5E10 W/cm^2 and they equal to
Z_max=2 and 3, respectively. It was also shown that with
increasing of q of laser radiation, spectra of ions are
changed basically in the field of minimum energy, where
highly charged ions is formed. It was found
experimentally that both single charged and multiply
charged ions have a wide energy spectrum. For example,
energy ranges of O ions (Z=1,2) and Tb (Z=1-3) are 10150eV and 20-850 eV, respectively. It was found mutual
influence of multiply charged ions O and Tb, Dy, Lu on
formation of spectra of plasma ions by comparison of
mass-charge and energy spectra of O and Tb, Dy, Lu of
two-element plasma in the wide interval of power density
of laser radiation. The experimental data are under
discussion, taking into account their use in the program of
Inertial Fusion Energy.
Type of presentation requested : Poster
Speaker :
Dr.Khaydarov Rajabboy
Classification : [T01] Proton and Ion Sources
1462 - PIG Detachable Lithium Ion Source for
Cyclotron
A. Kolosov, A. Demyanov, U. Kamushnikov, KINR, Kiev
The description presents the design of internal lithium ion
source for cyclotron and also the experimental results for
testing device of Cyclotron U-240. The detachable ion
source have a heating crucible mounted to anticathod.
Sufficiently allows to improve the operational technology
and obtain Li+, Li2+ and Li3+ ions. In the ion source the
operation condition of discharge to minimum impurity
into lithium vapour is implemented. The construction and
operation condition of crucible prevent lithium ejection
from the ion source to cyclotron accelerator volume.
Type of presentation requested : Poster
Speaker :
Mr. A.Kolosov
Classification : [T01] Proton and Ion Sources
5 - Laser Ion Source for High Current Injection into
Synchrotrons
S. Kondrashev, A. Balabaev, V. Balanutsa, K. Konukov,
A. Lozhkin, A. Marchenko, N. Mescheryakov, V. Nikolaev,
S. Savin, B. Sharkov, A. Shumshurov, R. Sydykov, E.
Zahodnov, ITEP, Moscow; K. Makarov, V. Roerich, Y.
Satov, Y. Smakovskii, A. Stepanov, TRINITI, Troitsk
The results of more than one year operation of Laser Ion
Source (LIS) on injection of intense C^+4 beam into
booster synchrotron of ITEP Terra Watt Accumulator
(TWAC) facility are presented. Further improvements of
LIS performance will be based on using of 100 J/1 Hz
CO2-laser. Recently such laser became operational and it
will be used in LIS development for LHC (CERN) and
TWAC(ITEP) projects. In order to specify LIS parameters
for ITEP-TWAC project generation and yield of highly
charged ions for different elements have been investigated
experimentally by using CO2-laser with output energy 75
J. The yield of 10-15 mA/ 80 mks Pb^+4 ion beam was
optimized to meet the requirements of GSI heavy ion
injector.
Type of presentation requested : Poster
Classification : [T01] Proton and Ion Sources
1838 - Charge Breeding Method Results with The
PHOENIX Booster ECR Ion Source
T. Lamy, J.-C. Curdy, R. Geller, P. Sole, P. Sortais, T.
Thuillier, ISN, Grenoble; K. Jayamanna, M. Olivo, P.
Schmor, D. Yuan, TRIUMF, Vancouver
The charge breeding method using an ECRIS has already
shown interesting results when injecting a 1+ ion beam
into the dedicated PHOENIX Booster Ion source
developed at ISN-Grenoble with a 10 GHz RF
transmitter. New results have been obtained with a 14
GHz RF transmitter and new elements have been studied
to get reliable efficiencies and charge breeding times
suitable for an easy and daily production of multi-charged
Radioactive Ion Beams [1],[2]. The c.w. regime is
suitable for cyclotron acceleration. With the Electron
Cyclotron Resonance Ion Trap one fulfils the
requirements of pulsed accelerators such as linacs and
synchrotrons. The trapping time measurements performed
with the ECRIT process give a better understanding of the
physical processes involved in the ECR-plasma
production of highly charged ions and could lead to
improvements of ECR ion source efficiencies.
[1] TRIUMF/IN2P3 contract nb. CS2000/11
[2] EU-RTD contract HPRI-CT-1999-50003
Type of presentation requested : Poster
Speaker :
Thierry LAMY
Classification : [T01] Proton and Ion Sources
1930 - Role of the Biased Electrode for Producing the
Highly Charged Ions from DECRIS 14-3 Ion Source
M. Leporis, S. Bogomolov, A. Efremov, V. Loginov, V.
Mironov, JINR, Dubna, Moscow Region
19 /22
ECR ion sources are used for the production of highly
charge ions in a various accelerator facilities. Most of
them usually use biased electrode to increase the ion
yield. Physical processes in the plasma of an ion source
are quite complicated and the role of biased electrode is
not clear. To investigate the effect of the biased electrode
on the intensity of extracted highly charged ions the
axially movable electrode was placed into the plasma
chamber of the DECRIS 14-3 ion source. It was found
that the intensity of Ar ions depends on the position of the
biased electrode and negative biased voltage. The optimal
position of the biased electrode was found near the pick of
the magnetic field. Experiments with the pulsed biased
electrode were also carried out. The influence of the
negative pulse on the ion yield depends on the ion charge
state.
Type of presentation requested : Poster
Classification : [T01] Proton and Ion Sources
710 - Internal versus External RF Coupling into a
Volume Source
J. Peters, DESY, Hamburg
RF sources have the advantage of a cleaner plasma and a
longer lifetime compared to filament sources. Hminus
Ions can be produced by RF driven volume sources.
These sources are often designed with an internal antenna.
A present example is the RF Hminus source for the
spallation accelerator SNS. A similar source is considered
for the European spallation source ESS. At DESY a new
development took place. The internal antenna of the
HERA RF Hminus source was replaced by an external RF
coupling. This system has been running for more than 25
000 h without any degradation. This is a significant
improvement compared to the 980 h average lifetime of
internal antenna systems. Six basic reasons are given why
external RF coupling is superior to internal coupling.
Type of presentation requested : Poster
Classification : [T01] Proton and Ion Sources
495 - Multipass RF Accelerator for Acceleration of
Protons and Deuterons
M. Petrichenkov, V. Abdulmanov, V. Auslender, A.
Panfilov, V.V. Parkhomchuk, G. Silvestrov, V. Volkov,
BINP, Novosibirsk
Here the project of 12-15 MeV proton-deyton accelerator
is described. It is proposed to be used as acceleratorinjector, or neutron source and also can be utilized for
isotopes production for PET. The accelerator is 30 MHz
RF cavity with four 1-1.5 MeV accelerating gaps and drift
tubes of corresponding length. The beam from ion source
will be pre-accelerated up to 0.5-1 MeV and bunched
before injection into accelerator. After the direct passage
of first four accelerating gaps the beam is bent by 225
deg. and returned again into the cavity on the next level.
After the next passage of four accelerating gaps the beam
is bent again by 225 deg. and returned into the cavity.
Thus, it crosses the cavity four times perpendicular to its
axis on different levels with corresponding change of drift
tubes length. As a result protons and deytons can achieve
12-15 MeV energy in the same structure,
correspondingly. The design of cavity was calculated
using special computer code SLANS, developed at BINP.
The effective shunt impedance of accelerating structure is
about 1 MOhm with Q-factor about 20000. The pulsed
power of high-frequency losses does not exceed 1.5 MW.
Type of presentation requested : Poster
Classification : [T01] Proton and Ion Sources
1641 - Recent Results with Highly Charged Au Ions
Extracted from a 10A Electron Beam EBIS at BNL*
A.I. Pikin, J.G. Alessi, E. Beebe, O. Gould, D. Graham, A.
Kponou, K. Prelec, J. Ritter, V. Zajic, BNL, Upton, Long
Island, New York
All design goals [1] have been reached in the operation of
the BNL Electron Beam Ion Source (EBIS), which is a
prototype for an EBIS that could meet requirements for a
RHIC preinjector. RHIC requires 3.4 E9 gold 32+
particles per ion source pulse, or about 85 nC total
positive charge yield, assuming a 20% abundance of the
selected charge state. Stable operation of the 10 A, 50ms
electron beams through the EBIS trap have been
achieved. Ion injection of low charge gold ions from a
low energy vacuum ion source (LEVA) [2] and
subsequent extraction of high charge state Au has been
demonstrated with electron beams up to 10A. Gold
spectra with dominant charge state 34+ and total ion
charge 55nC measured on current transformer at the EBIS
exit has been obtained after a 30ms confinement period.
This corresponds to ~85% of the theoretical ion trap
capacity and exceeds our goal of 50% neutralization.
Time-of-flight spectra indicate that 20% of the gold
charge is concentrated in charge state 34+. The collected
ion charge is proportional to the electron current and the
gold charge state scales with the electron current density.
Details of the EBIS configuration, total charge, TOF and
emittance measurements will be presented.
*This work is performed under the auspices of the U.S.
Department of Energy.
[1] E. Beebe, et.al., Rev. Sci. Instrum. 71 (2000) 893.
[2] I.G. Brown, et.al., Rev. Sci. Instrum. 65 (1994) 1260.
Type of presentation requested : Poster
Classification : [T01] Proton and Ion Sources
1235 - Influence of Different Inner Hexapole Radius
on Construction of ECR Ion Source Hexapoles: New
Results*
J. Pivarc, IP SAS, Bratislava; A. Tikhomirov, JINR,
Dubna, Moscow Region
The paper presents new data concerning dimentions of
permanent magnets which are used for construction of
suitable hexapoles for Electron Cyclotron Resonance Ion
Sources (ECR IS). Permanent magnets are made from
FeNdB magnetic materials. The main attention is given to
hexapoles with hexapole thickness of 2.8 cm at different
inner diameters of (3.6 - 12) cm. It is investigated an
influence of inner radius of hexapole to the maximum
value of the magnetic field inside hexapole.
20 /22
* Work supported by the Deutsche Bank AG, AdolphPrior-Strasse 11, D-65936 Frankfurt/Main, Germany.
Type of presentation requested : Poster
Classification : [T01] Proton and Ion Sources
Work supported in part by RIKEN
[1] T. Takeuchi et al., NIMB, in print.
[2] T. Takeuchi et al., RSI, in print.
Type of presentation requested : Poster
Classification : [T01] Proton and Ion Sources
684 - Latest Results of the Cadarache 1 MV SINGAP
Experiment and Application of the SINGAP
Accelerator Concept to the ITER Neutral Beam
Injection System
L. Svensson, CEA, St Paul lez Durance; D. Boilson, R.S.
Hemsworth, A. Krylov, P. Massmann, H.P.L. de Esch,
Association EURATOM-CEA Cadarache, DRFC/SCCP,
St Paul lez Durance
The SINGAP (SINGle APerture - SINgle GAP)
acceleration concept has been developed as a simplified
alternative to the multi-aperture, multi-grid accelerator of
the ITER Neutral Beam reference design. The objective
of the present experiments is to demonstrate reliable
multi-second acceleration of a D- beam to 1 MeV (~100
mA, 200 A/m2), relevant to the ITER Neutral Beam
Injection (NBI) requirements. During previous studies it
has been demonstrated that the SINGAP concept works
and good quality 860 keV H- beams (43 mA, 1 s) and
630 keV D- beams (106 mA, 1s) have been produced. In
the present campaign another attempt has been made to
reach the full beam energy with a refurbished 1 MV
epoxy insulator / bushing. Refurbishment had become
necessary after the top 2 of the 9 epoxy rings making up
the insulator had been perforated and carbonised due to
high voltage discharges. The best parameters achieved
during the present campaign are 911 keV D- beams ( 58
mA, 1 s) with a current density of 30 A/m2 and 600 keV
D- beams ( 100 mA, 1s) with a current density of 70
A/m2. The paper will describe the actual accelerator layout and present the results of the ongoing experimental
campaign. The planned development to reach the Dcurrent density ( 200 A/m2) and beam optics required for
ITER will also be described.
Type of presentation requested : Poster
Classification : [T01] Proton and Ion Sources
1265 - Direct Nd:YAG Laser Plasma Injection Scheme
in to RFQ
T. Takeuchi, T. Katayama, CNS, Saitama; R. Jameson, M.
Okamura, S. Ozawa, A. Sakumi, RIKEN, Saitama; T.
Hattori, N. Hayashizaki, H. Kashiwagi, Tokyo Institute of
Technology, Tokyo
A heavy ion production and acceleration system, which
consists of a laser ion source and a radio frequency
quadrupole (RFQ) LINAC, has been established at Tokyo
Institute of Technology [1-2]. This new system is based
on a principle of the direct plasma injection scheme into
RFQ LINAC. Using a conventional Nd:YAG laser,
instruments (target chamber and the isolator, etc.) could
be simplified than the that of CO2 laser. Additionally, the
production of more intense beam is expected. We carried
out the acceleration test of carbon ion beams by using
Nd:YAG laser. The comparison of results for CO2 and
Nd:YAG laser is described.
77 - Performance of the H minus Ion Source
Development Rig at RAL
J. Thomason, R. Sidlow, M. Whitehead, CLRC RAL,
Chilton, Didcot
A dedicated ion source development rig (ISDR) has been
constructed at Rutherford Appleton Laboratory (RAL) to
fully characterise the ISIS ion source and then produce
sources with enhanced performances suitable for next
generation projects such as the European Spallation
Source (ESS). The ISDR has been designed to replicate
the beam transport configurations on both the present ISIS
pre-injector and the ISIS RFQ. Experiments will be
described which investigate the intrinsic differences
between these two configurations. Initial results from the
ISDR have shown that space charge neutralisation in the
accelerated H minus beam is sub-optimal due to the
relatively low residual gas pressure in the diagnostics
chamber. The effect of introducing buffer gas atoms in
order to artificially raise the residual pressure and increase
space charge neutralisation will be detailed.
Type of presentation requested : Poster
Classification : [T01] Proton and Ion Sources
78 - The RFQ Test Stand Ion Source at RAL
J. Thomason, P. Barratt, C. Barton, J. Kerr, C.
Lambourne, A. Letchford, G. Murdoch, M. Perkins, J.
Saunders, R. Sidlow, C. Viswanathan, M. Whitehead,
CLRC RAL, Chilton, Didcot
The RFQ test stand at Rutherford Appleton Laboratory
(RAL) is now being operated with an ion source identical
to that used on ISIS. This is a surface plasma source of
the Penning type, and routinely produces 35 mA of H
minus ions during a 200 micro second pulse at 50 Hz for
uninterrupted periods of up to 50 days. A new ion source
vacuum chamber which is compatible with the low energy
beam transport for the RFQ has been constructed, and the
layout of power supplies and other essential services has
been reconfigured in order to ensure that the RFQ will fit
the space available when it is eventually installed on ISIS.
An extensive redesign of many power supplies, where
exact duplication of the ISIS equipment has proved
impossible because of component obsolescence, has been
necessary. In addition a new timing system and control
systems using fibre optic ethernet have been developed
specifically for this application.
Type of presentation requested : Poster
Classification : [T01] Proton and Ion Sources
1845 - High Intensity Ion Beams For Accelerators
T. Thuillier, J.-L. Bouly, J.-C. Curdy, T. Lamy, C.
Peaucelle, P. Sole, P. Sortais, J. Vieux-Rochaz, ISN,
Grenoble
21 /22
The classical PHOENIX 28 GHz ECRIS has been
developed to prospect high pulsed multicharged lead ion
beams for the LHC [1,2]. The goal of the experiment is to
reach 1 mAe pulses of Pb 27+ during 0.4 ms with a 10 Hz
repetition rate. This high beam current is one order of
magnitude higher than the ones available today. The
strategy to take up this challenge is based on an increase
of the RF frequency to 28 GHz and an increase of the RF
power density (up to 8 kW/liter, limited by the present
gyrotron characteristics). Preliminary results have been
obtained with Xenon in the late 2001. As a first step, 0.5
mAe of Xenon 22+ has been measured in the afterglow
with a time structure that matches LHC requirements.
However, this result was obtained with a low beam
transmission (around 60 %). As a second step, a new
dedicated high current beam line has been setup and
coupled to PHOENIX in order to increase beam
transmission and ion charge state separation. This line has
been designed by computer simulation which shows a 100
% transmission factor. The new results with Xe and Pb
are presented and discussed.
[1] Grant CERN/GSI/CEA/IN2P4 K598/PS
[2] EU RTD HPRI-1999-50019
Type of presentation requested : Poster
Speaker :
Dr. Thomas Thuillier
Classification : [T01] Proton and Ion Sources
285 - Neutral Beams Generation by Laser Irradiation
of Thin Foils
Y. Wada, D. Fukuta, T. Kubota, A. Ogata, Hiroshima
University, Higashi-Hiroshima
Ion generation has been reported in these several years by
high-power (>10TW), short pulse (<1ps) with solid
targets[1][2][3]. We have performed similar experiments
irradiating thin (<10micron) plastic and metal foils by a
laser with smaller power (1TW) and smaller pulse width
(50fs). What we have observed is generation of neutral
beams. The foil was set 45degree to the laser direction.
The neutral particles were observed at the rear side of the
laser injection. To the contrary, ion beams were observed
in the direction of reflection of the laser, at the same side
of the foil with the laser injection. Differences between
these neutral particles and those usually obtained by a
sputtering process are in small divergence and high
momentum as measured by CR39 track detectors, so we
conclude that these particles make neutral beams.
[1]A.Maksimchuk et al., Phys. Rev. Lett. 84(2000)4108.
[2]E.L.Clark et al., Phys. Rev. Lett. 85(2000)1654.
[3]R.A.Snavely et al.,Phys. Rev. Lett. 85(2000)2945.
Type of presentation requested : Poster
Classification : [T01] Proton and Ion Sources
1935 - New Program FEFI for Easer Construction and
Definition of Boundaries for IGUN
A. Zelenak, JINR, Dubna, Moscow Region
A program IGUN has been developed for simulation of
the extraction of positive ions from a plasma and many
users have used this program. Also has been developed a
preprocessor GPED to IGUN for definition of boundaries
of extraction. GPED was written with FORTRAN a long
time ago for MS_DOS system and now it seems to be not
too much comfortable device for users working on PC
with Windows 95 and higher. And for this reason has
been written a new program FEFI on C++ that work on
PC with Windows 95 and higher and offer for users
gently ambient known from operating system Windows.
Type of presentation requested : Poster
Classification : [T01] Proton and Ion Sources
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