JYFL Accelerator News
Accelerator Laboratory, Department of Physics
University of Jyväskylä, Finland
Volume 18, No. 1
March 2010
New Time-of-Flight-Energy spectrometer for materials
characterization
Raw TOF-E histogram (left) and depth profiles that were calculated from the elemental energy
spectra (right). The sample was atomic layer deposited Al2O3 + TiO2 nanolaminate and a density of
3.5 g/cm3 was used in converting areal densities to nanometers.
In December 2009 first spectra were
collected with the EU-funded Time-ofFlight Elastic Recoil Detection Analysis
(TOF-ERDA) spectrometer in the Pelletron
Laboratory. This spectrometer was designed
by Mikko Laitinen and it provides a tool for
depth profiling all sample elements including
hydrogen with a depth resolution better than
2 nm at the surface. The performance of the
spectrometer has been demonstrated in the
analysis of 35 nm thick AlxTiyOz film on Si
substrate. As a part of the project, a new
sputtering ion source for heavy ions was
installed to the injector of the Pelletron
accelerator.
Mikko Laitinen holding the first timing gate of
the spectrometer just before installation.
First commissioning runs for SAGE spectrometer
The first commissioning runs for the
combined gamma-ray and conversion
electron spectrometer SAGE were carried
out in the last week of January and
again in the last week of February. The
SAGE spectrometer consists of a ninetyelement annular silicon detector to which
conversion electrons are transported via
a solenoidal magnetic field. The electron
spectrometer operates in conjunction with
the JUROGAMII array of germanium
detectors and the RITU gas-filled recoil
separator. All detector signals are read out
with digital electronics and the Total Data
Readout acquisition system, developed at
STFC Daresbury. The device was designed
and constructed in a collaborative effort
of the University of Liverpool, STFC
Daresbury and JYFL. Funding for the device
came from the UK STFC and the European
Research Council.
Philippos Papadakis and Rodi Herzberg mounting the SAGE silicon detector.
2
JYFL Accelerator News
March 2010
Benchmarking experimental equipment for FAIR at
IGISOL
A November campaign of experiments
at IGISOL successfully benchmarked the
performance of equipment intended to be
used at the future FAIR facility, GSI. A
Spanish led collaboration involving groups
from Barcelona, Valencia and Madrid,
utilized the powerful combination of the
IGISOL-JYFLTRAP system in order to
provide pure sources of selected fission
fragments for post-trap spectroscopy. Nuclei
of interest for nuclear structure, astrophysics
and reactor technology were targeted,
specifically those with a large beta decay
energy window and a moderate probability
of neutron emission. Two detectors were
used in the studies, a Total Absorption
Spectrometer to measure the beta decay
probability distribution, and a 4π neutron
detector (see figure) to efficiently measure
the neutron emission probability that follows
the beta decay. In the future the use of a
Time-of-Flight neutron detector is planned
in order to measure the energy of the emitted
neutrons, thus providing a complete picture
of the decay strength distribution over the
entire energy window.
The 4π neutron detector located after JYFLTRAP. The setup consisted of a block of polyethylene
with an open bore in the centre, surrounded by two rings of 3He proportional counters. A beta
detector situated inside the hole, a tape station to remove unwanted buildup of daughter activity
and a Ge detector (far left) completed the system.
New limit reached for in-beam studies of heavy nuclei
8
40
Pb( Ar, 2n)
246
Fm "Online" Preliminary
+
+
(16 - 14 )
+
+
+
+
(14 - 12 )
+
(12 - 10 )
+
+
+
4
(6 − 4 )
Fm X-rays
Pb X-rays
Counts / keV
6
(10 - 8 )
+
+
(8 - 6 )
208
2
0
100
200
300
400
Gamma-ray Energy (keV)
Recoil-decay tagged spectrum of gamma-rays in 246Fm.
500
The combination of digital electronics
with JUROGAM II enables low crosssection in-beam experiments at high total
gamma-ray counting rates for heavy nuclei.
Nuclei such as 256Rf can be populated with
cross-sections of the order of 10 nb, and
are now accessible with the current set-up
of JUROGAM II combined with RITU
and GREAT. In December 2009 an attempt
was made to produce 256Rf through the
208
Pb(50Ti,2n) reaction. Unfortunately, the
intensity of the 50Ti beam was not sufficient
to ensure a successful experiment, and
the beam requires further development.
As a back-up, 246Fm was produced using
the 208Pb(40Ar,2n) reaction (cross-section
approximately 15 nb). Up to 70 pnA of beam
were used, an unprecedented level for this
type of study. The resulting recoil-decay
tagged spectrum of gamma-rays is shown
in the figure. The experiment was attended
by participants from IHPC Strasbourg,
University of Liverpool, CEA Saclay, GSI
and Argonne National Laboratory. The
TNT2 digital electronics were provided
on loan by the GABRIELA project of
CNRS/IN2P3.
March 2010
JYFL Accelerator News
3
JYFL researchers give advanced postgraduate course in
Thailand
Jyväskylä and Chiang Mai PhD student Nitipon Puttaraksa
instructing the students from Kasetsart in the use of the PIXE
system in Chiang Mai.
An advanced postgraduate course
on Elemental Analysis was held during
February in Kasetsart University, Thailand
under the auspices of JYFL, the Thai
Centre of Excellence in Physics and
The Department of Chemistry, Kasersart
University. The course which was funded
by an ASEM-DUO grant was run by Assoc.
Prof. Orapin Chienthavorn, Department
of Chemistry, Kasetsart University, Assoc.
Prof. Somsorn Singkarat, Chiang Mai
University and Prof. Harry J. Whitlow
JYFL. The course included a study visit
to the Plasma and Beam Physics Research
Facility at Chiang Mai University where
the students performed laboratory exercise
work.
Course participants at the Chiang Mai 1.7 MV Tandetron control panel. Back row (L to R):
Rattanporn Norarat (JYFL PhD student), Assoc. Prof. Orapin Chienthavorn (Kasetsart), Prof.
Harry J. Whitlow (JYFL), Assoc. Prof. Somsorn Singkarat (Chiang Mai), Teerasak (Chiang Mai),
Nitipon Puttaraksa (JYFL and Chiang Mai PhD student), Jeerasak Jitpaiboon (Kasetsart)
Commissioning of the MCC30/15
cyclotron soon ready
SAB-CoE Meeting
A day for the Scientific Advisory
Board (SAB) meeting and for an open
seminar of the Centre of Excellence (CoE)
in Nuclear and Accelerator Based Physics
was organised on 7 December 2009. The
CoE covers the experimental activities
at the JYFL Accelerator Laboratory and
theoretical nuclear physics activities carried
out at JYFL. In addition to the presentations
of many highlights of 2008-2009, strategies
for a possible continuation of the CoE
beyond 2011 were discussed. The year
2009 was scientifically very successful for
the CoE. The number of the peer reviewed
publications was more than 100 including
10 high-impact letter-type of reports.
Sergey Grigorenko, NIIEFA, shows how to change the filament in the ion source.
Since the arrival of the MCC30/15
cyclotron in August, 2009, the team from
the Efremov Institute (FSUE NIIEFA) has
installed and tested the cyclotron. The first
beam tests were carried out in November
2009, in pulsed mode (10 Hz, 300 µs pulse
length, duty cycle 0.3 %). In pulses the
maximum extracted proton intensity was
205 µA and 140 µA for 18 MeV and 30
MeV, respectively, the guaranteed value
being 100 µA. For deuterons (15 MeV) the
extracted current was 62 µA, the guaranteed
value being 50 µA.
During testing it turned out that the RFfeeder had to be redesigned due to heating.
A new feeder was installed in February,
2010, and it worked without problems.
The RF amplifier needs an additional HV
capacitor which will be installed in the
middle of March. The programming of the
computer control system is still underway.
It is assumed to be ready by April.
The users will be trained to use the
cyclotron. Training on the electric system,
cooling system and the ion source with
injection has been done already.
4
JYFL Accelerator News
March 2010
Next Call for Proposals
Deadline: March 15, 2010
The next deadline for submission of
proposals and letters of intent is March
15, 2010. Proposals should include an
abstract/summary. A justification of
the beam time requested, based on crosssections, detector efficiencies, etc. should
be given. If a proposal is the continuation
of an existing experimental program at the
JYFL Accelerator Laboratory, a summary of
the status of the project should be included.
Proposals and letters of intent should be sent
(preferably as a postscript or pdf file) to the
Program Advisory Committee secretary Iain
Moore (address: see below) and include
the Proposal Summary Sheet mailed with
this Newsletter. This form is also available
from the JYFL WWW-pages. You are
encouraged to contact anyone in the Contact
List at the end of this Newsletter for more
information.
All publications resulting from work done
at the Accelerator Laboratory should also
contain the following acknowledgement:
This work has been supported by the
Academy of Finland under the Finnish
Centre of Excellence Programme 20062011 (Nuclear and Accelerator Based
Physics Programme at JYFL).
How to contact us:
Name
Rauno Julin
Matti Leino
Juha Uusitalo
Juha Äystö
Pauli Heikkinen
Iain Moore
Ari Jokinen
Paul Campbell
Wladyslaw Trzaska
Ari Virtanen
Harry J. Whitlow
Timo Sajavaara
Hannu Koivisto
Arto Lassila
Jaana Kumpulainen
Responsibility
Scientific Director,
γ- and e--spectroscopy
RITU
RITU
IGISOL
Technical Director
Beam-time schedule,
PAC secretary
Ion beam cooler and trap
Laser spectroscopy
HENDES, LSC, dE/dx
Applications
Accelerator based materials
physics
Accelerator based materials
physics
ECR ion sources
Control system
Radiation safety
e-mail
rauno.julin@jyu.fi
matti.e.leino@jyu.fi
juha.uusitalo@jyu.fi
juha.h.e.aysto@jyu.fi
pauli.heikkinen@jyu.fi
iain.d.moore@jyu.fi
ari.s.a.jokinen@jyu.fi
paul.campbell_3@manchester.ac.uk
wladyslaw.h.trzaska@jyu.fi
ari.virtanen@jyu.fi
harry.j.whitlow@jyu.fi
timo.sajavaara@jyu.fi
The Programme Advisory Committee
Mike Bentley (University of York, UK)
Klaus Blaum (University of Heidelberg, Germany)
Lorenzo Corradi (INFN-LNL, Legnaro, Italy)
Jacek Dobaczewski (University of Warsaw, Poland)
Günther Dollinger (Universität der Bundeswehr
München, Germany)
Mark Huyse (Katholieke Universiteit Leuven, Belgium)
Iain Moore, Scientific Secretary (JYFL)
hannu.koivisto@jyu.fi
arto.lassila@phys.jyu.fi
jaana.k.kumpulainen@jyu.fi
Department of Physics
P.O. Box 35 (YFL)
FI-40014 University of Jyväskylä
Finland
Fax: +358 (14) 260 2351
2401
https://www.jyu.fi/physics
Accelerator News editor: Pauli Heikkinen