Tuesday 9 July 2013, Strathblane & Cromdale Halls, 16:30-18:30
Poster session A - Instruments – inelastic
P.045 Progress on the cold three-axis spectrometer ThALES at the Institut Laue Langevin
M Boehm1, P Cermak2, S Roux1, J Kulda1, V Sechovsky2, P Svoboda2, J Saroun3 and P Steffens1
1
Institut Laue-Langevin, France, 2Faculty of Mathematics and Physics, Charles University, Czech Republic, 3Nuclear
Physics Institute AS CR, Czech Republic
The new cold neutron spectrometer ThALES at the Institut Laue Langevin, Grenoble will be optimized for exploring
correlated magnetic systems beyond the experimental possibilities of its predecessor IN14 spectrometer [1,2] in
terms of data collection rate and experimental possibilities as the increase in the dynamical range with/without high
magnetic fields. The project has entered its fabrication phase in 2012. On-site installation and commissioning is
planned for 2014.
We will present the present status of the project and very recent results obtained from ray-tracing simulations, where
we studied the interplay between an elliptically shaped guide end with two double focusing monochromators pyrolytic graphite PG002 and bent Si111. The primary aim of these calculations has been the optimization of the
neutron optics of ThALES, the successor of the IN14 spectrometer at the Institut Laue-Langevin, Grenoble. The
obtained results are, nevertheless, general and independent of the specific geometry of ThALES. The beam
characteristics in terms of flux, real space and angular distribution and energy resolution at the sample position are
presented for both cases.
The ThALES project is a collaboration between ILL and Charles University, financed by the Czech Ministry of Science
and Education (Project no. LM2010001).
[1]
[2]
Boehm M., Roux S., Hiess A., Kulda J., JMMM 310 (2007), e965-e967
Boehm M., Roux S., Hiess A., Kulda J., I. Saroun, Meas. Sci. Technol 19 (2008), p.034024
P.046 Focusing optics upgrade for the thermal triple axis beamline at LLB
J-P Castellan, F Weber, D Lamago and L Pintshovius
Karlsruhe Institute of Technology, Germany
Abstract unavailable
P.047 Implementation and use of the deep inelastic neutron scattering technique at a low intensity neutron source
J Dawidowski1, L R Palomino2 and J J Blostein2
1
Centro Atómico Bariloche, Argenitina, 2Consejo Nacional de Investigaciones Científicas y Técnicas, Argentina
In this work, we show that it is feasible to perform DINS experiments in a neutron source based on a low intensity
LINAC. We describe the two detector banks built at the Neutron Laboratory at Bariloche Atomic Center (Argentina).
They are constructed respectively on the basis of 10- and 12- helium-3 detector rings, so as to cover two different
scattering angles, in forward and backward positions. The performance of the instrument is described. In the first
step we show the calibration process that involves the determination of the incident spectrum, calibration of flight
lengths, dead-time, electronic delay of the data acquisition line, and detector banks efficiencies. In the second step
we show the data processing procedure that comprises a Monte Carlo simulation code, and the steps to determine
cross sections in an absolute scale. As a result, we show the neutron scattering cross sections of Hydrogen,
Deuterium, Carbon and Oxygen determined in light water, heavy water and polyethylene samples.
ICNS 2013 International Conference on Neutron Scattering
P.048 Direct geometry spectroscopy at the European Spallation Source
P Deen1, T Bruckel2, F Sachetti3 and K Andersen1
1
European Spallation Source, Sweden, 2Forschungszentrum Juelich GmbH Germany, 3Dipartimento di Fisica,
Universita di Perugia, Italy
The European Spallation Facility (ESS) will be operational before the end of the decade with world leading
spectroscopic instrumentation in the cold and thermal neutron regime. The novel nature of long pulsed sources
provides the neutron community an opportunity to redesign, optimise and develop new spectroscopic techniques.
Large gains can be found by exploiting the latest technology in neutron optics and instrument design that would
match the scientific needs of the future.
The dominant trend in materials research is towards increasing complexity. Emergent complex phenomena impacts
on the dynamic behaviour over broad energy scales with small variations in energy and spatial lineshapes. In
addition, increased complexity comes at the cost of weak and broadened neutron scattering signals concomitant
with reduced sample sizes. To address these scientific needs the instrumentation for direct geometry spectroscopy
will incorporate bispectral extraction and instrumentation optimised for small single crystals. In particular the
instruments under consideration include a wide bandwidth bispectral chopper spectrometer, a narrow bandwidth
high resolution cold chopper spectrometer, a high resolution thermal chopper spectrometer and a rotating
monochromator time focussing spectrometer. The technical design of these concepts are provided by the in-kind
contributions and collaborations from Germany and Italy respectively in addition to in-house contributions. A brief
overview of the various designs will be given and placed within the context of the scientific needs of the materials
research community and thus the ESS instrument suite.
P.049 A wide bandwidth bispectral chopper spectrometer at the European Spallation Source
P Deen1, A Vickery2 and K Andersen1
1
European Spallation Source, Sweden, 2Niels Bohr Institute, University of Copenhagen, Denmark
Emergent complex phenomena present dynamic behaviour over broad energy scales. In addition the increased
complexity that are commonly addressed in the scientific fields probed by neutron scattering; soft matter,
hydrogenous materials and correlated phenomena, arrive with weak and broadened neutron scattering signals
concomitant with reduced sample sizes. To address these scientific needs the instrumentation for direct geometry
spectroscopy at the European Spallation Source will incorporate bispectral direct chopper spectrometers optimised
for small single crystals.
A bispectral design, currently under consideration, is a 20 m instrument, moderator to sample, that gives the
possibility to measure dynamics simultaneously over a very extended energy range (0.4 - 80 meV) via repetition
rate multiplication. This is not possible at present day facilities. The instrument concept allows the energy resolution
to relax from the high resolution set-up ∆E/E ∼ 1% to the lowest resolutions, ∆E/E ∼ 10%. This will enable the
user to trade flux for resolution and thus optimise for the scattering signal and energy resolutions required. The
guide design will be optimised for samples as small as a few mm3 in size. Scattering from liquids or biological
samples and single crystals in complex sample environments will become routine. An outline of the proposed
instrument, simulated analytically and via McStass simulations, will be given in terms of signal to noise, beam
divergence, beam homogeneity and energy lineshapes as a function of the tremendous energy bandwidth.
ICNS 2013 International Conference on Neutron Scattering
P.050 Effective use of the flexible multianalyser system at PUMA
G Eckold1, O Sobolev1 and N Juenke2
1
University of Goettingen, Germany, 2 Forschungs-Neutronenquelle Heinz Maier-Leibnitz, Germany
Abstract unavailable
P.051 The next step forward in high resolution NSE spectroscopy
B Farago and P Falus
Institut Laue-Langevin, France
NSE resolution is limited by the magnetic field homogeneity, which is dictated by the quality of the correction
elements. While a lot of effort was invested in improving the correction coils at all NSE spectrometers, progress
seems to be very limited. Instead of further tuning of the corrections we took a new direction by re-optimizing the
shape of the main solenoids, to decrease the amount of correction needed. Our calculations show a possible gain
of factor two, which means even keeping our present correction elements a factor two increase in field integral is
realistic. Taking into account another factor two, which we could already use at short wavelengths, we are aiming at
a four fold field integral increase. The goal of the IN15 upgrade is to stretch the boundaries of the Neutron Spin
Echo technique by significantly improving stability and resolution, as well as achieving a much higher effective flux.
This shall allow extending the useful q-range to probe smaller structures and increasing the useful Fourier times in
the µs-range. The improvements in resolution and effective flux are foreseen to be achieved by minimizing field
inhomogeneities by a novel design of the precession magnets and compensation elements. Some of these novel
elements has been tested already ae results will be presented. While IN15 has already reached a demonstrative 1
µs fourier time with 27.5Å wavelength, with these improvements we expect to offer the same performance with ten
times higher flux at 18Å.
P.052 New possibilities for neutron backscattering with inelastic fixed window scans
B Frick1, J Combet2, L van Eijck3, A Remhof4, M Appel1 and D Morineau5
1
Institut Laue-Langevin, France, 2Institut Charles Sadron - CNRS - UdS Strassbourg, France, 3Technical University
Delft, The Netherlands, 4EMPA Switzerland, Switzerland, 5University Rennes, France
We report on the first experience with a new type of inelastic fixed window scans (IFWS) [1] in neutron
backscattering spectroscopy using the flexibility of linear motor Doppler drives to choose the velocity profile. We
discuss more generally the information content obtained from such scans and show some application examples.
Simultaneous scans at a few different energy offsets, including elastic scans (EFWS), lead to a large improvement in
statistics compared to full quasielastic spectroscopy and to a higher sensitivity for the temperature dependence of
the scattering law. The statistical advantage may allow for kinetic IFWS in future. We show on one example how
IFWS, EFWS and full spectra can be combined in a simultaneous fitting procedure and point out how such scans
might in future be used to find, may be even computer controlled, the optimum parameter range for the more time
consuming measurements of full spectra.
[1]
B. Frick et al. Nuclear Instruments & Methods in Physics Research A 669 (2012) 7-13
ICNS 2013 International Conference on Neutron Scattering
P.053 Elliptic focusing - new perspectives for three axis measurements
R Georgii, G Brandl and P Böni
FRM II, TU München, Germany
Neutron three axis spectroscopy is still the main experimental method for inelastic measurements throughout the
whole Brillouin zone. One of its major limitations is the amount of singe crystal material necessary for obtaining a
good inelastic signal, as large single crystals are difficult to grow in sufficient good quality.
We will present a dedicated system consisting of a set of elliptic focusing guides, which can be easily and
reproducible mounted on a triple axis instrument. An enhancement of the inelastic signal by a factor of 30 has been
shown by an inelastic phonon measurement in lead with and without such a system at the triple axis spectrometer
MIRA at the FRM II. This will open new possibilities in triple axis spectroscopy using much smaller single crystals in
future experiments.
P.054 Performance of the upgraded cold triple axis spectrometer FLEXX at BER II
K Habicht1, M Duc Le1, M Skoulatos2, F Groitl1, D Lucia Quintero-Castro1 and R Toft-Petersen1
1
Helmholtz-Zentrum Berlin für Materialien und Energie, Germany, 2Present adress: Paul Scherrer Institute, Villigen,
Switzerland
The cold triple axis spectrometer Flex was recently upgraded with new m=3 guides with a converging elliptical
section to focus neutrons onto a virtual source, which is subsequently imaged on a new double focussing
monochromator, ensuring an increase in neutrons reaching the sample. In addition, a new velocity selector is used
to remove higher order scattering which eliminates the need for filters. A polarizing S-bender may be translated into
the beam before the elliptical guide section where the beam is relatively well collimated, allowing the gains from
focussing neutrons onto the sample to be realized for polarized measurements also. Furthermore new compact
NRSE arms with new coils and shielding have been constructed.
The improved coil design permits a larger beam cross-section to be transmitted, and also larger coil tilt angles to be
reached allowing measurements of steeper dispersions.
We present first experimental results from the upgraded instrument, which confirm overall large intensity gains
ranging from 2 to 10 as predicted in the design phase from Monte Carlo simulations and analytical considerations.
We have obtained flipping ratios of around 20 with the S-bender polarizer and a supermirror polarization analyzer.
The velocity selector has also proved highly satisfactory with a second order transmission of less than 0.01%. After
commissioning the triple-axis spectrometer FLEXX is now back in normal operation and the first user experiments
have been successfully completed.
P.055 Instrument concepts for indirect geometry spectroscopy at ESS
A Hiess
ESS AB, Sweden
The unparalleled neutron brightness and the unique long pulse structure of ESS combined with innovative
instrument concepts will significantly expand the scientific possibilities of neutron spectroscopy. Here the
collaborative work for indirect geometry spectroscopy is presented, which covers the concept development of
spectrometers in which the final energy is determined using crystal analysers or filters.
The cold crystal-analyser spectrometer [J. O. Birk, M. Marko, P. G. Freeman, F. Juranyi, C. Niedermayer, N. B.
Christensen, K. Lefmann, H. M. Ronnow; to be published] uses graphite crystals to cover a quasi-continuous range
ICNS 2013 International Conference on Neutron Scattering
of scattering angles in the horizontal plane as imposed by extreme sample environment. The instrument for
vibrational spectroscopy [M. Zoppi; to be published] will have variable resolution to allow measurements up to 300
meV, with a variable energy resolution down to 2% with very little energy-dependence. The backscattering
spectrometer [R. Lechner, N. Tsapatsaris, K. Andersen, H. Bordallo; to be published] provides access to a unique
combination of high energy resolution, intermediate Q, and large dynamic range. Phase space transformers [K.
Habicht, T. Keller, L. Cussen; to be published] combine moving crystals with the TOF to increase the monochromatic
flux. Concepts for S(Q,E) selective instruments using one single beam tube and guide system are under
investigation [A. Hiess; to be published].
The instrument concepts are a collective effort involving a multitude of colleagues at different institutes such as CNR
Italy, DTU Denmark, EPFL Switzerland, HZB Germany, KU Denmark, PSI Switzerland. We also thank our colleagues
from the scientific and technical advisory panel.
P.056 The multi-purpose ESS test beamline at BER II
T Hofmann1, M Bulat1, M Strobl2 and K Habicht1
1
Helmholtz-Zentrum Berlin, Germany, 2European Spallation Source ESS AB, Sweden
The Helmholtz-Centre Berlin commissions a new cold-neutron spectrometer (V20) in the neutron guide hall of the
research reactor BER II. The instrument is a German in-kind contribution to the planned European Spallation Source
(ESS) in Lund, Sweden. It shall provide a suited platform to test and develop conceptual hardware, neutron
instrumentation and novel scattering methods, which are of immediate interest for the planned spallation source. As
a main feature of V20, a specially tailored double chopper will be employed to provide a pulsed neutron beam,
which mimics the time structure of the ESS neutron pulse (14Hz, 2.86ms). Additionally, a sophisticated chopper
cascade will allow studying wavelength frame multiplication as a main approach to benefit efficiently from the long
ESS pulse in elastic scattering applications. Here we report on the actual status of the instrument. We discuss
envisioned fields of applications in detail and present very first measurements performed at V20.
P.057 Development and design of optimised magnetic field components for the polarisation option of the TOF
spectrometer FOCUS
L Holitzner1, J Peter Embs2, T Fennell2 and U Filges1
1
Laboratory for Developments and Methods, Paul Scherrer Institut, Switzerland, 2Laboratory for Neutron Scattering,
Paul Scherrer Institut, Switzerland
The time-of-flight spectrometer FOCUS[1] at the neutron spallation source SINQ at Paul Scherrer Institut (PSI) will
be extended by a polarisation option. The current activities concentrate on the components for the primary
polarisation.
The authors present the result of the CAD simulation (finite elements method, FEM) of the guide field, which
contains the neutron polarizer (remanent supermirror, PSI-developed, using FeCoV) and the neutron spin flipper. The
model covers the complete area between monochromator and Fermi chopper.
A favourable space-saving method will be shown, to host a neutron polarizer in an iron-containing monochromator
shielding. The special feature of this design is the creation of a permanent, homogeneous magnetic field, which is
strong enough to permanently magnetize the slot-in polarizer. This depends on an optimized Halbach arrangement
of NdFeB permanent magnets. The current state of the device design will be shown.
Strong attention has been devoted to adjust the magnetic field in the transient region between polarizer, spin flipper
and Fermi chopper, in order to make it suitable for a maximum possible neutron energy range and flipping ratio. The
ICNS 2013 International Conference on Neutron Scattering
neutron guide field properties were verified by simulating the adiabatic rotation with 3-dimensional FEM
calculations.
[1]
J.Mesot, S.Janssen, L.Holitzner, R.Hempelmann, J. Neutr. Res. 3 (1996) 293-310
P.058 Parameters of the NERA spectrometer at cold and thermal modes of moderators of the IBR-2M pulsed
reactor
N Ireneusz, C Dorota, H Łukasz, K Viatcheslav Yu., K Jan, I L Sashin and Z Sławomir
Frank Laboratory of Neutron Physics, JINR, Russia
The NERA inverted geometry time-of-flight spectrometer is located on 110 m flight path at the IBR-2M high flux
pulsed reactor. The new cold moderator and mirror guide for incoming neutrons have been constructed during
modernization period of the IBR-2 reactor. Crystal analyzers of the NERA spectrometer, pyrolitic graphite – PG(002)
reflection at 45o, were optimized for thermal neutron flux from water moderator working at 330 K. The new cold
moderator working at 30 K significantly shift incoming neutrons spectrum to longer wavelength and allow effectively
use PG(002) reflections up to back scattering. We compare the resolution and intensity of the NERA spectrometer at
both moderators for selected modes of the PG(002) reflections at 45o, 60o, and 87.5o. Separate and simultaneous
use of different PG analyzers for measurements of inelastic (INS) and quasi-elastic (QENS) neutron scattering
spectra are discussed and illustrated by experimental results.
P.059 Neutron brillouin scattering on high resolution chopper spectrometer, HRC
S Itoh1, T Yokoo1, D Kawana1 and Y Endoh2
1
High Energy Accelerator Research Organization, Japan, 2Tohoku University, Japan
Inelastic neutron scattering for spin excitations from powder samples is usually not easy. In order to overcome this
difficulty we apply the neutron Brillouin scattering (NBS) by using sub eV high energy pulsed spallation neutrons
which is required to cover meV range energy transfer due to the kinematic constrain. To access the energy
momentum space close to (000), scattered neutrons should be detected at low angles with high energy resolution
as well as low background eliminated unwanted forward scattering. We could develop this traditional but not yet
established NBS experiments on the High Resolution Chopper Spectrometer (HRC) installed at the Material and Life
Science Facility (MLF) in Japan Proton Accelerator Research Complex (J-PARC). It was demonstrated by observing
well defined ferromagnetic spin waves from La0.8Sr0.2MnO3 powders, whose dispersion curve can be extended to
lower q from reported results. Then we apply SrRuO3 powders which are not synthesized large single crystalline form
at present. Then novel result is coming out that a large spin wave energy gap emerges in this crystal suggesting the
robust spin orbit coupling in this unusual ferromagnetic metal. We now try to perform NBS experiments on various
polycristalline samples and liquids. For instance a strong permanent magnet of Nd2Fe14B, Neomax, and D2O show
good agreement with previous results with improved S/N ratio.
P.060 Lagrange- the new vibracional spectrometer at the ILL for the study of complex materials
M Jimenez-Ruiz and A Ivanov
Institut Laue-Langevin, France
Vibrational spectroscopic techniques provides unique information about the high-energy atomic and molecular
vibrations in condensed matter systems. The Inelastic Neutron Scattering has proven to be a powerful and unique
tool for studies of dynamical properties of solids and is used as an important source of supplementary data for
computational techniques dealing with the dynamics of complex systems.
ICNS 2013 International Conference on Neutron Scattering
The Lagrange project was launched with the goal to create a new spectrometer for studies of lattice and molecular
excitations in the extended energy range up to several-hundred-meV typical for materials containing light chemical
elements, in particular hydrogen. Lagrange replaces the Be filter spectrometer placed on the hot neutron
spectrometer IN1 at the Institute Laue-Langevin and is fully operational since 2012. Lagrange provides much higher
sensitivity to extremely small or low scattering samples through substantially increased detector count rate
combined with considerably improved energy resolution. Unique at the ILL by the combination of high energy range
(1-1000 meV), high count rate and flexible energy resolution variation.
With these characteristics Lagrange opens new possibilities for the spectroscopic studies of complex materials. The
new instrument permits investigation of much smaller samples that are inherent in novel materials studies,
recording of well-resolved vibration spectra and a more detailed probing of external parameters like temperature,
pressure, chemical composition, magnetic field, time-dependent processes etc.
P.061 Upgrade program for neutron triple-axis spectrometers in the research reactor JRR-3
K Kaneko, S Wakimoto, T Osakabe, H Yamauchi, Y Shimojyo, M Kubota and M Takeda
QuBS, Japan Atomic Energy Agency, Japan
Two major neutron sources, pulsed neutron source MLF/J-PARC and continuous one JRR-3, locate in the Tokai site
of Japan Atomic Energy Agency (JAEA). In the research reactor JRR-3, three triple-axis spectrometers TAS-1, TAS-2
and LTAS with different characteristics have been run by JAEA. Advantages of TAS-1 installed at the reactor hall are
intense neutron flux up to high energy and its availability of modern polarised neutron devices like CRYOPAD. TAS-2
has clean neutron beam with low background, thanks to its location at the end of the thermal guide tube, and has
availability to accommodate various extreme sample environments, such as a high-field magnet with a dilution
refrigerator. In contrast, LTAS installed at a cold guide tube have higher energy resolution of 70 μeV, and accepts
wide range of accessories as TAS-2.
A complementary use of these triple-axis spectrometers in combination with J-PARC offers an optimum performance
in inelastic neutron scattering experiments to study dynamics of materials in wide Q- space. We will present an
overview of our upgrade project for these TASs taking advantage of a reactor source, in particular, to enhance
availability of polarised neutron and extreme sample environment.
P.062 A single-crystal inelastic sample component for McStas
M D Le
Seoul National University, Korea
We present a new single crystal sample component for the neutron Monte-Carlo ray tracing package McStas which
can handle coherent inelastic scattering. In order to be generally applicable, the component requires only a table of
S(q,ω) values and the sample lattice parameters, which are provided in an input file. This may be generated from a
spin wave model, for example, using the McPhase mean-field random-phase approximation package[1].
The algorithm employed first picks, for each neutron trajectory which intersects the sample, an energy transfer by
inverse transform sampling of the (interpolated) input scattering function. This thus fixes the magnitude of the
scattered neutron wavevector and defines a sphere in reciprocal space on which the kf wavevector must lie. The
component then computes where the dispersion surfaces, interpolated from the input scattering function, intersects
this sphere. The direction of the scattered neutron is then determined by sampling these intersections, broadenned
by a Gaussian distribution to model sample mosaicity and lattice spacing spreads.
Absorption by the sample is handled if an absorption cross-section is provided, but incoherent scattering is not
modeled at present.
ICNS 2013 International Conference on Neutron Scattering
[1]
M. Rotter, M. D. Le, A. T. Boothroyd and J. A. Blanco, J. Phys. Condens. Matter 24 (2012) 213201
P.063 A Si Crystal Analyzer near Backscattering TOF Spectrometer at the Spallation Neutron Source of J-PARC, DNA
-Design and Current Performance M Matsuura1 K Shibata2, N Takahashi2, T Yamada1, K Kamazawa1, Y Kawakita2, W Kambara2, K Nakajima2, Y
Inamura2, T Nakatani2, K Aizawa2, M Arai2 and K Soyama2.
1
CROSS-Tokai, Japan, 2J-PARC Center, JAEA, Japan
We report the design and current performance of the Si crystal analyzer near backscattering spectrometer (DNA), a
TOF near backscattering spectrometer built at the spallation neutron source of the Japan Proton Accelerator
Research Complex (J-PARC). DNA is the first Si crystal analyzer backscattering spectrometer with pulse shaping
chopper installed at a spallation neutron source. In addition to high S/N ratio, it offers a high-energy resolution of
about 3.0 meV at currently, about 1.8 meV at final design goal.
P.064 A cold-neutron disk-chopper spectrometer AMATERAS
K Nakajima, S Ohira-Kawamura, T Kikuchi, Y Inamura and Y Kawakita
J-PARC Center, Japan
AMATERAS is a cold-neutron disk-chopper spectrometer installed at Materials and Life Science Experimental Facility
(MLF) of J-PARC. By using a series of high-speed (f < 350Hz) disk-choppers and owing to the high peak intensity
from a coupled moderator source at MLF, AMATERAS is designed to realizes high-intensity and fine and flexible
energy resolution measurements in quasielastic and inelastic neutron scattering experiments from cold to thermal
neutron energy region. AMATERAS started the user program from the end of 2009 in parallel to commissioning work.
In this presentation, we will show the current status of AMATERAS including the highlight of scientific outputs.
P.065 Construction of polarisation analysis neutron chopper spectrometer POLANO at J-PARC
K Ohoyama1, T Yokoo2, S Itoh3, K Iwasa4, T J Sato5, T Ino2 and T Oku6
1
Institute for Materials Research, Tohoku Univesity, Japan, 2Neutron Science Division, High Energy Accelerator
Research Organization, Japan, 3Neutron Science Division, High Energy Accelerator Research Organization,
Japan, 4Graduate School of Science, Tohoku University, Japan, 5Institute of Multidisciplinary Research for Advanced
Materials, Tohoku University, Japan, 6Japan Atomic Energy Agency, Japan
Polarisation analysis neutron spectroscopy is indispensable for investigations of spin correlations in novel material
science. We are constructing a polarisation analysis spectrometer at J-PARC/MLF as a collaboration project
between KEK and Tohoku Univ. along with international collaborations. The spectrometer, named POLANO, is a
compact chopper spectrometer (L1=17.5 m, L2=2.5 m) installed at a decoupled H2 moderator. One of the main
scientific targets is observations of magnetic excitations in the range of
100 meV; thus, direct guide tubes will
be adopted. As a main polariser, a SEOP 3He spin filter system will be installed. The flux of the polarised beam at
the sample is expected to be 1.2E+5 (n/sec/cm2/meV/MW) at =100 meV for an optimised SEOP condition in
terms of neutron polarisation and transmission. As a practical solution of analysers, we plan to approach the target
energy range via phased approaches, while simultaneously developing the analyser devices. In the first phase, we
choose a fan-type supermirror bender system. Consequently, the focus of our researches in the first phase will be in
the energy range of 25meV. In the second phase, 3He spin filters with large solid-angles will be installed as
analysers for experiments over 100meV. As an ambitious challenge to cover reduction of flux, we are considering
to use the cross correlation method for elastic scattering experiments. The construction will begin in the summer of
2013.
ICNS 2013 International Conference on Neutron Scattering
P.066 Numerical simulations and optimizations of the focusing prototype at the TOFTOF spectrometer (FRM-II)
N Rasmussen1, K Lefmann1 and G Simeoni2
1
Niels Bohr Institute, University of Copenhagen, Denmark, 2Technische Universitaet Muenchen - Neutron Source
Heinz Maier-Leibnitz (FRM II) and Physics Department, Germany
Small sample sizes are often needed due to the restrictions posed by the use of sample environment for extreme
conditions, such as magnetic fields, pressure cells and electrostatic and electromagnetic levitators. However, not all
instruments can meet these strict requirements to the size of the beamspot. At the TOFTOF spectrometer, this is
solved by exchanging the last piece of the guide with a focusing neutron guide. It benefits from both supermirror
coating and adaptive optics technology, and is the first prototype in the world suitable for neutron spectroscopy,
working in a broad thermal and cold neutron region (1.4 - 14 Å).
To get a deeper understanding of the experimental results, numerical simulations of the device were conducted by
the use of McStas. Furthermore, optimizations of alternative solutions, including different lengths, geometries and
coatings have been executed for wavelengths of 1.5, 3, 6, 9 and 12Å. The optimizations were aimed at achieving
the highest brilliance of neutrons with a maximal divergence of 3 degrees at a 5×5mm2 sample. In addition the
effect of counter-rotating choppers was investigated.
The simulations of the focusing device were found to be in agreement with the experimental results. It was found
that constructing a longer, parabolic device can increase the brilliance while decreasing the size of the beam spot.
Furthermore the simulations revealed that the counter-rotating choppers cause irregularities in the divergence
distribution.
P.067 Self-modelling curve resolution in neutron spectroscopy: applications of solid acids in chemical
manufacturing
S Richards1, M Krzystyniak1 and F Fernandez-Alonso2
1
Nottingham Trent University, UK, 2ISIS Facility, Rutherford Appleton Laboratory, UK
Bulk solid acids, and those based on micelle-templated silicas and other mesoporous high surface area support
materials are beginning to play a significant role in fuel cells for electrolytes and in the greening of fine and
speciality chemicals manufacturing processes. A wide range of important organic reactions can be efficiently
catalyzed by these materials, which can be designed to provide different types of acidity as well as high degrees of
reaction selectivity. Neutron Compton Scattering (NCS) is a unique neutron spectroscopic technique. In simple
terms, NCS can be regarded as a mass-spectroscopic technique in which each atomic mass contributes to the
overall time of flight (TOF) spectrum in a form of a Doppler-broadened recoil peak. NCS was originally developed to
probe the nuclear momentum distribution and the effective binding potentials of nuclei.
Here, a model free approach, Self-Modelling Curve Resolution (SMCR) has been applied to experimental NCS data
on a solid acid (proton conductor) caesium hydrogen sulphate (CsHSO4). The motivation of this work is to improve
the accuracy of the computation of the nuclear momentum distribution by the removal of unwanted caesium
gamma nuclear resonances appearing in the NCS spectra. The novel NCS data treatment protocol based on SMCR
involves successive data transformations from TOF into Y and energy-transfer spaces leading to the removal of
unwanted nuclear resonances. SMCR is shown to offer more flexibility than traditional data-analysis methodologies
e.g., Gram-Charlier-type expansions. These results have important consequences for further theoretical modelling of
nuclear momentum distributions in solid acid systems.
ICNS 2013 International Conference on Neutron Scattering
P.068 Recent developments for Taipan at ANSTO
K Rule1, P Imperia2, W T Lee2, S Danilkin2, A Stampfl2 and G Deng2
1
ANSTO - Bragg Institute, Australia, 2ANSTO, Australia
Taipan is the thermal triple axis spectrometer (TAS) at the OPAL reactor. TAS instruments are typically used to
investigate dynamics such as phonons and magnons however due to the high neutron flux, Taipan has also been
used to investigate weak magnetic and structural features. Taipan started full user service in November 2010 and
since then has successfully measured a broad range of samples including single crystals, powders, thin films, and
co-aligned multi-crystal arrays [1,2].
Recent commissioning has seen a number of new options now available to Taipan users. These options are geared
to improve the instrument and sample environment capabilities, increasing the number of materials that we can
study. From a sample perspective, new sample environments have been commissioned and are ready for use in the
next proposal round. These include the high temperature furnace capable of accessing temperatures up to 1600°C
and the new ANSTO 12T magnet. We have also commissioned the He3 polarisation analysis option for Taipan
which will allow users to define the 3D polarization state of the incident and scattered neutrons. From this we will
be able to study complex magnetic structures such as chiral spin states.
This poster will outline these new options as well as recent improvements to Taipan that will benefit the entire user
community.
[1]
[2]
S. A. Danilkin, M. Yethiraj, TAIPAN: Thermal Triple-Axis Spectrometer, Neutron News, 20 (4), 37 – 39,
(2009)
S.A. Danilkin, M. Yethiraj, T. Saerbeck, F. Klose, C. Ulrich, J. Fujioka, S. Miyasaka, Y. Tokura and B. Keimer,
J. Phys.: Conf. Ser., 340, 012003 (2012)
P.069 Upgrade project of TOF spectrometer NEAT at Helmholtz-Zentrum Berlin
M Russina1, Z Izaola2, K Rolfs1, N Tsapatsaris2, G Guenther1, J Olabarrieta3, L Drescher1, B Urban1, S Alimov1 and H
Kutz1
1
Helmholtz Zentrum Berlin, Germany, 2Helmholtz Zentrum Berlin; ESS-Bilbao, Germany, 3Scientifica International,
Spain
The fast evolution of TOF neutron spectroscopy in the last years resulted in substantial increase of data rate on
several existing instruments and new developments at pulsed spallation sources. To address the user community
needs at HZB full upgrade of NEAT spectrometer is being undertaken with the goal to deliver more than 40 fold data
rate increase. The project started in 2010 and proceeds at full pace with the aimed start of the commissioning in
2014.
The advanced and unique features of the new instrument include novel neutron guide system with modern
supermirrors neutron optics and ballistic guide concept. Variable focusing end-pieces will deliver the neutron beam
with variable divergence and profile: homogeneous for single crystals and “hot spot” for small samples. Depending
on applications the intensity gain ranges between factor 5 and 7 compared to NEAT’95. A new design of the
chopper system is another substantial improvement that allows to double the flux at high resolution conditions.
Using variable slits, the new chopper system is optimized for hard and soft matter studies and enables optimal
balance between resolution and intensity for each experiment. The increase of the detector solid angle coverage by
using novel position sensitive BF3 gas detectors results in another factor 8 higher count rate and high resolution in
the position of neutron detection. Upgraded NEAT will provide an outstanding experimental tool for a large spectrum
of research areas including magnetism, material science and soft matter. In addition, the technical advances
realized in the NEAT upgrade project offer relevant know-how for the instrument development at ESS.
ICNS 2013 International Conference on Neutron Scattering
P.070 Versatile bi-spectral high-resolution direct TOF spectrometer for ESS
M Russina1, K Rolfs1, J Voigt2 and N Violini2
1
Helmholtz Zentrum Berlin, Germany, 2JCNS, Reserach Center Juelich, Germany
We present a concept of a versatile high-resolution direct geometry TOF spectrometer with multispectral capabilities.
The instrument will take full benefit of the high flux delivered by ESS and will at same time couple it with large
flexibility customary for reactor based instruments. The access to the broad time domain of 10 -15 – 10– 10 s and
length scale of 0.5 – 500 Å combined with a new level of performance that surpass IN5 by a factor > 3 in resolution
at the same beam intensity will make the instrument unique in exploration of dynamics processes in a broad variety
of scientific fields. The instrument will operate in Repetition Rate Multiplication mode covering 1.6 Å wavelength
bands that can be freely chosen in the 1-25 Å range and will have variable resolution. In the highest resolution
mode of less than 1% of the incoming neutron energy, it will surpass the resolution of the graphite analyzer
backscattering spectrometers at 6.3Å. The neutron guide will have exchangeable end-sections to adjust best to the
scientific requirements such as sample size, divergence and beam profile. Study of the nanoscale dynamics of large
structures will be enabled by application of a small angle detector positioned at up to 8 m from the sample. The
spectrometer will accommodate extreme and complex sample environment such as high magnetic field, levitation,
high pressure and will be designed for application of polarized TOF spectroscopy. The high luminosity of the
instrument will allow for many applications currently limited due to insufficient intensity.
P.071 IN12: the newly upgraded cold neutron three-axis spectrometer at the ILL
K Schmalzl1, W Schmidt1, S Raymond2 and T Brueckel3
1
JCNS, Forschungszentrum Juelich, Outstation at ILL, Germany, 2CEA-Grenoble, INAC SPSMS MDN, France, 3JCNS
and Peter Gruenberg Institut PGI, JARA-FIT, Forschungszentrum Juelich, Germany
IN12 is a cold neutron three-axis spectrometer at the Institut Laue-Langevin in Grenoble, France. It is operated by
the Juelich center for neutron science (JCNS) in collaboration with the CEA Grenoble. The recent relocation of IN12
has been used to rebuild and upgrade the whole primary spectrometer.
IN12 is situated now at an end position at a long and newly installed m=2 guide. The adapted coating at the
outside guide walls leads to a broad wavelength range transmitted to the sample (lambda=1.3-6.3 A). On the last
8m the guide is vertically splayed and horizontally focused to use the virtual source concept. A new double focusing
PG monochromator leads to a substantial increase in flux compared to the old IN12.
A velocity selector in the guide eliminates higher order contributions and guarantees a low background. Polarised
neutrons in the incident beam are provided by an interchangeable transmission polariser (cavity).
Flux measurements at the sample position show an extended wavelength range far into the warmish region and a
considerable gain in flux by more than an order of magnitude. User operation started in December 2012. A
polarized neutron set-up is possible as well as the cryopad set-up, high magnetic fields, low temperatures, high
pressures.
With the high gain in flux, the large accessible wavelength range, the intrinsic low background and the high
resolution IN12 belongs presently to the best cold three-axis spectrometers.
ICNS 2013 International Conference on Neutron Scattering
P.072 Advanced neutron optics for the new IN12 - Simulations and first results
W Schmidt1, K Schmalzl1, S Raymond2 and T Brückel3
1
Forschungszentrum Jülich, JCNS @ ILL, Germany, 2CEA Grenoble, INAC SPSMS MDN, France, 3Forschungszentrum
Jülich, JCNS, Germany
IN12, a three-axis spectrometer for cold neutrons, is operated as a CRG-instrument from the Jülich Centre for
Neutron Science (JCNS) at the Institute Laue Langevin in Grenoble. In the framework of the Millenium Program of
the ILL IN12 has been relocated to a new position at the end of a new guide. Along with this relocation the whole
primary spectrometer has been upgraded with new state-of-the-art components. The main improvements concern a
new optimized focusing neutron guide together with a new double focusing monochromator. For the use of polarized
neutrons a new transmission polarizer (cavity) will be placed in the neutron guide, mounted on a guide changer
together with a standard guide element. This guarantees high intensities and an easy change from non-polarized to
polarized mode.
In this presentation we will show details of the design and optimization of the various neutron optical components.
This includes the results of various model calculations that had been performed to match a curved focusing guide
end with a double focusing monochromator. in order to combine high flux, good energy resolution and a smooth
homogenous beam profile at the sample. Further, also the results for the design of the polarizing cavity will be
presented.
Since IN12 has been commissioned recently we are now able to show first neutron measurements concerning flux,
energy resolution and polarization and compare them to the calculations.
P.073 A Si crystal analyzer near backscattering TOF spectrometer at the spallation neutron source of J-PARC, DNA design and current performance
K Shibata1, N Takahashi2, T Yamada3, K Kamasawa3, Y Kawakita2, W Kambara2, K Nakajima2, Y Inamura2, T
Nakatani2, K Aizawa2, M Arai2 and K Soyama2
1
JAEA, MLF, J-PARC, Japan, 2J-PARC, Japan, 3Cross, Japan
We report the design and current performance of the Si crystal analyzer near backscattering spectrometer (DNA), a
TOF near backscattering spectrometer built at the spallation neutron source of the Japan Proton Accelerator
Research Complex (J-PARC). DNA is the first Si crystal analyzer backscattering spectrometer with pulse shaping
chopper installed at a spallation neutron source. In addition to high S/N ratio, it offers a high-energy resolution of
about 3.0 micro eV at currently, about 1.5 micro eV at final design goal.
P.074 Development of a cold neutron chopper spectrometer
L Silvi1, W Lohstroh2, J Neuhaus3 and W Petry2
1
Technische Universitaet Muenchen - FRM II, Germany, 2Technische Universitaet Muenchen - FRM 2, Germany, 3FRM
2, Germany
The European Spallation Source (ESS) to be built in Lund, Sweden, will provide a high neutron flux combined with a
unique long pulse time structure. The main task for any instrument design concept is how to take full advantage of
the high brilliance and the time structure of the long pulse. We will present a conceptual design for a direct
geometry cold chopper spectrometer for the ESS with medium to high energy resolution. The instrument will face the
cold moderator and with a total instruments length of 120.4 m a natural wavelength band of 2.6 AA is obtained at
the sample position. The chopper cascade consists of a pulse shaping chopper pair, 2 frame overlap choppers and
a monochromating chopper pair and enables to tune the energy resolution from 112 meV @ 5 Å to 7 meV @ 9 Å
ICNS 2013 International Conference on Neutron Scattering
The source time frame is efficiently used in multi-energy mode and large parts of the scattering function S(q,w) is
explored simultaneously. The guide system foresees a s- shaped bender section thus avoiding direct line of sight
while the beam profile at the sample position can be chosen between 2 x 4 cm2 and 1 x 1 cm2 in focussing mode.
P.075 The new thermal triple-axis-spectrometer EIGER at PSI
U Stuhr1, BRoessli2, S Gvasaliya3, H Ronnow4, U Filges2, D Graf2, P Keller2, R Bürge2, C Kägi2, A Bollhalder2 and T
Mühlebach2
1
Laboratory for Neutron Scattering, Paul Scherrer Institute, Switzerland, 2Neutron Scattering and Magnetism Group,
Laboratorium für Festkörperphysik, ETH Zürich, Switzerland, 3Institute of Condensed Matter Physics (ICMP), École
Polytechnique Fédérale de Lausanne (EPFL), Switzerland, 4Laboratory for Developments and Methods, Paul Scherrer
Institute, Switzerland
In 2012 the new thermal triple-axis spectrometer EIGER was completed and went into operation. EIGER is the first
thermal spectrometer at the continuous spallation source SINQ and extends the available energy range for neutron
spectroscopy at PSI. The main components of the primary spectrometer of EIGER are an adjustable virtual source, a
double focusing PG-monochromator, a horizontal focusing PG-analyzer, and a non-magnetic shielding. The
performance of the instrument will be demonstrated with a few examples of first experiments.
P.076 A new crystal analyser component for high resolution spectroscopy simulations in McStas
N Tsapatsaris1, R Lechner1, H Bordallo2, H Jacobsen3 and P K Willendrup4
1
European Spallation Source, Sweden, 2Niels Bohr Institute, University of Copenhagen, Denmark, 3University of
Copenhagen, Denmark, 4Technical Universitets Danmarks, DTU, Denmark
We present our efforts in continuation to earlier work on building the first bent analyser component for high
resolution studies in McStas. For the purpose of minimising the computation time the new module considers the
generally observed Gaussian like energy distribution of the final wavevector representative of a typical bent single
crystal analyser arranged on an infinitesimally thin spherical surface. The analyser module includes the treatment of
neutrons propagating on the backscattering geometry (i.e. normal to the scattering surface) and considers the
analyser d-spacing, incident wavelength, uncertainty in the d-spacing the full width half maximum of the required
observed energy distribution, the reflectivity factor, and an effective cumulative mosaic caused by the angular
uncertainty of the spherical surface. Through example simulations we present the functionality of the new bent
analyzer McStas component.
P.077 Thermal Spectrometers at the ESS – a comparison example based on virtual experiments
A Vickery1, P Deen2 and K Lefmann3
1
University of Copenhagen, ESS Design Update Denmark, Denmark, 2ESS AB, Sweden, 3University of Copenhagen,
Denmark
The Monte Carlo simulation results presented here have been assembled in the hope that they enable a fair
comparison between two different realizations of a thermal spectrometer at the ESS. There is no global figure of
merit as simple as the bare intensity at the sample for the various types of experiments. Therefore, this work aims to
go beyond the ‘intensity at the sample’ and suggest that the time spent on measuring a gapped magnon sample
may be taken as a criterion to decide whether the one or the other instrument is best suited for this kind of
experiments.
ICNS 2013 International Conference on Neutron Scattering
We present simulated data from a virtual gapped magnon sample. Data from this virtual sample has been simulated
with a TAS and a thermal chopper spectrometer. The thermal chopper spectrometer is a broad mapping instrument
with relaxed resolution (dE/E 5 %). The TAS features a 145m elliptically focusing guide, a virtual source point, a
doubly focusing monochromator and a focusing analyzer. The simulated instruments are characterized in terms of
the (q,E)-resolution function.
P.078 Monte Carlo simulations of 150 m thermal chopper spectrometer for the ESS
A Vickery1, P P Deen2, K Andersen2 and K Lefmann3
1
University of Copenhagen, ESS Design Update Denmark, 2ESS AB, Sweden, 3Niels Bohr Institute, Copenhagen
University, Denmark
The ESS Science Symposia indicated a scientific need for a thermal chopper spectrometer optimised for broad
mapping of thermal excitations with high energy and spatial resolution in hard condensed matter. Such a high
resolution thermal chopper spectrometer is included in the technical design update of the ESS. The 2 Å wavelength
band of this 150 m instrument will provide a large bandwidth of thermal neutron energies so that it is possible to
measure incident wavelengths between 0.6 Å and 2.5 Å in a single measurement thus probing incident energies
between 11 meV and 225 meV simultaneously via repetition rate multiplication (RRM). The long pulse nature of the
ESS source allows a versatile energy resolution that can be varied between 1 % and 6 %. The instrument will be
optimised for 1 % energy resolution.
Position sensitive detectors with a 1 cm spatial resolution in addition to homogenous flux and divergence profiles
across the sample will provide a very high Q resolution as required for studies of single crystals. Polarisation
analysis will be a day one option to enable the measurement of complex magnetic components and to separate
coherent from incoherent scattering contributions. We present Monte Carlo simulations of a 150 m instrument using
an elliptically focussed guide. The instrument is characterised in terms of flux at the sample position and (E,Q)
resolution. The flux at the sample position is compared favourably to analytical results that do not take guide losses
into account. To address the future scientific needs, this high resolution thermal chopper spectrometer design is
optimised for the broad and weak scattering features provided by the complex physics of magnetic correlations.
P.079 Polychromatic chopper spectrometers for long pulse neutron sources
J Voigt, N Violini, E Babcock, Z Salhi and T Brückel
Forschungszentrum Jülich, Germany
Traditionally direct geometry time-of-flight spectrometers employ a single incoming wavelength and analyse the
neutron velocity after scattering to determine the energy transfer between neutron and sample. At a continuous
source the energy region of interest is sampled with a high repetition rate, which can be controlled by the chopper
system, in particular by the frame overlap chopper. At spallation sources, the periodicity of the source is much
longer than the time frame required to record the energy region of interest in a typical experiment. Therefore the
Repetition Rate Multiplication (RRM) or multiple Ei method [1,2] have been developed to increase the duty cycle of
the instrument. Here a chopper spinning at a higher frequency than the source selects subsequently different
wavelengths to explore the inelastic response of a sample in different energy regions.
For the new chopper spectrometers at long pulse sources this will open new possibilities for polychromatic
operation. Due to the long distance between the moderator and the final resolution defining chopper the wavelength
steps become small and hence the dynamic range and also the energy resolution remain similar. Combined with
position sensitive neutron detection one can therefore probe large volumes in reciprocal space without sample
rotation. We explore the opportunities and limitations of such a polychromatic operation with an emphasis on single
crystal studies, considering also the use of polarization analysis.
ICNS 2013 International Conference on Neutron Scattering
[1]
[2]
M. Russina and F. Mezei, NIM A 604(3):624–631, 2009
M. Nakamura et al., Journal of the Physical Society of Japan, 78(9):093002, 2009.
P.080 SIKA- the Taiwan contract cold neutron triple-axis spectrometer at OPAL
C-M Wu1, E Imamovic2, J-C Peng1, P Vorderwisch3, G Deng2 and W-H Li3
1
National Synchrotron Radiation Research Center, Taiwan, 2ANSTO, Australia, 3National Central University, Taiwan
Abstract unavailable
P.081 CAMEA – the continuous angle multiple energy analysis, simulations and design
J OBirk1, M Markó2, P G Freeman3, H Ronnow3, K Lefmann1, N B Christensen4, C Niedermayer2, F Juranyi2, M
Bertelsen1, A Hansen1 and J Jacobsen1
1
Niels Bohr Institute, Copenhagen University, Denmark, 2Paul Scherrer Institute, Switzerland, 3Laboratory for
Quantum Magnetism, Ecole Polytechnique Federale de Lausanne (EPFL), Switzerland, 4Department of Physics,
Technical University of Denmark, Denmark
CAMEA is a spectrometer concept designed for optimal coverage of the horizontal scattering plane. The secondary
spectrometer consists of 10 concentric rings of crystal analysers scattering 10 different energies out of the plane.
Each ring provides a quasi-continuous angular coverage within horizontal plane. If mounted as an inverse time of
flight spectrometer at a long pulsed source such as ESS the pseudo-white incoming beam, high angular coverage
and many analysed energies provides an unprecedented high recording factor of possible in plane scattering
events, with resolutions comparable to good triple axis instruments. This makes the instrument ideal for extreme
environment experiments and other parametric studies.
This presentation will discuss Monte Carlo ray-tracing simulations and calculations of instrument performance and
their influence on instrument design choices. During this design process a new mode were found where flat
analysers can be used to focus a monochromatic signal. This is used together with distance collimation and relaxed
mosaicities leads to a new technique where the reflected beam of a single analyser crystal is split into several small
energy bands enabling an even higher efficiency with no cost in resolution. These results have been confirmed by
neutron scattering data.
P.082 CAMEA – The continuous angle multiple energy analysis instrument concept
P Freeman1, H Ronnow1, N Christensen2, K Lefmann3, J Birk3, C Niedermayer4, M Marton4 and F Jurányi4
1
EPFL LQM, Switzerland, 2Technical University Of Denmark, Denmark, 3Niels Bohr Institute, University of
Copenhagen, Denmark
The CAMEA instrument concept is a neutron spectrometer designed for optimal efficiency in the horizontal scattering
plane to enable detailed and/or rapid mapping of excitations. A spectrometer thus optimized is ideally suited to
studies of materials under extreme environments, the complex sample environs of insitu experiments, or where
neutron studies of specific region of reciprocal space are required.
CAMEA is a cold multi-analyser indirect geometry time of flight spectrometer with an extended energy range. This
concept is based on a secondary spectrometer using a series of analyser arrays being placed behind each other to
simultaneously analyse different final energies of scattered neutrons over a wide pseudo-continuous angular range.
The analyser arrays of CAMEA scatter vertically into position sensitive detector arrays, in a geometry similar to the
flatcone concept. By scanning the excitations as a function of the sample rotation CAMEA maps the excitation
spectrum of single crystals.
ICNS 2013 International Conference on Neutron Scattering
In this presentation we present the CAMEA concept, the experimental capabilities of CAMEA, and the science that
can be performed on this instrument.
P.083 Data treatment for the CAMEA prototype
A L R Hansen1, J O Birk1, M Marko2, P G Freeman3, N B Christensen4, J Jacobsen1, C Niedermayer2, F Jurányi2, M
Bertelsen1 and H N Ronnow3
1
Niels Bohr Institute, Copenhagen University, Denmark, 2Paul Scherrer Institute, Switzerland, 3Laboratory for
Quantum Magnetism, Ecole Polytechnique Federale de Lausanne (EPFL), Switzerland, 4Department of Physics,
Technical University of Denmark, Denmark
The CAMEA (Continuous Angle Multiple Energy Analysis) analyser-detector concept proposed for the ESS offers
several advantages compared to conventional spectrometers: Using multiple analyser-detector sets facilitates
simultaneous measurements of several energies of the scattered neutrons, analysers reflecting out of the scattering
plane allows for a quasi-continuous angular coverage, which in combination with the ability to continuously rotate
the sample facilitates rapid, high resolution energy scans.
The detectors, consisting of several position sensitive detector tubes (PSD’s), can be treated as individual detectors
if a high energy resolution is desired, or their data can be combined to obtain high statistics for a broader energy
band.
To test the CAMEA concept an ESS prototype was built as a joint project between DTU and University of
Copenhagen, Denmark, EPFL, and PSI, Switzerland, where it’s also installed. It features three analyser-detector sets,
where each detector consists of three linear PSD’s. The data recorded with the prototype shows good agreement
with analytic calculations and simulations performed using the McStas software package. The complexity of the
datasets calls for the development of a dedicated program to aid the data treatment.
The work presented covers examples of analyzed data obtained from the CAMEA prototype, performed with the data
analysis program. The presented challenges in the data treatment includes combining the the data from the
individual detectors, and visualizing these in terms of qh, qk and energy transfer. Additionally the resolution of the
different PSD’s will vary, and combining these pose and additional challenge.
P.084 CAMEA - The continuous angle multiple energy analysis concept
M Markó1, J Okkels Birk2, P Gregory Freeman3, H Ronnow3, K Lefmann2, C Niedermayer4, N B Christensen5 and F
Jurányi4
1
PSI Laboratory for Neutron Scattering, Switzerland, 2Condensed Matter Physics, Niels Bohr Institute, Denmark,
Laboratory for Quantum Magnetism, Ecole Polythechnique Federale de Lausanne, Switzerland, 4Laboratory for
Neutron Scattering, Paul Scherrer Institute, Switzerland, 5Department of Physics, Technical University of Denmark,
Denmark
3
CAMEA (Continuous Angle Multiple Energy Analyzer) is a concept for a new type of back end of inelastic neutron
scattering instruments which is designed for optimal efficiency for detection of the scattered neutrons. It contains a
series of analyzers, where each analyzer set selects different final energies by scattering the neutrons of the given
energy out of the scattering plane into position sensitive detector arrays, and covers the same (large) angular range.
Applying a simple rotation on the sample at one initial energy one gets a quasi-continuous mapping in the three
dimensional space spanned by the q-vector in thescattering plane and the energy transfer at different energies
defined by the analyser sets. Changing the initial energy causes highly overlapping data sets in the q-ω
ICNS 2013 International Conference on Neutron Scattering
In this presentation we present the CAMEA concept, the science that can be performed using this instrument, the
prototype of CAMEA built at DTU and KU and installed at PSI, and the results of experiments obtained with the
prototype.
P.085 CAMEA – Prototype
M Markó1, J O Birk2, H Ronnow3, P G Freeman3, K Lefmann2, C Niedermayer4, N B Christensen5, F Jurányi4, S Finn6, O
Rasmussen6, K Theodor7, D Graf8, U Greuter8, C Kägi8 and R Bürge8
1
PSI Laboratory for Neutron Scattering, Switzerland, 2Condensed Matter Physics, Niels Bohr Institute,
Denmark, 3Laboratory for Quantum Magnetism, Ecole Polythechnique Federale de Lausanne,
Switzerland, 4Laboratory for Neutron Scattering, Paul Scherrer Institute, Switzerland, 5Department of Physics,
Technical University of Denmark, 6Technical University of Denmark, Denmark,7Niels Bohr Institute, Denmark, 8Paul
Scherrer Institute, Switzerland
The CAMEA (Continuous Angle Multiple Energy Analyser) is a multi-analyzer back end for inelastic instruments. The
CAMEA with time of flight front end enables to perform fast quasi-continuous mapping of the q-ω space i.e. three
dimensional space spanned by the q-vector in the scattering plane and the energy transfer. This concept is well
suited for studies where the sample environment enables to detect the scattered neutrons only in a small vertical
angular range around the horizontal plane (eg. Split-coil magnet or pressure cell). We are developing such an
instrument for the ESS. The prototype of the instrument was planned and built at DTU and KU and installed at MARS
instrument at PSI. In this presentation we present the results of the first measurements on the prototype (resolution
in the q-ω space, and an inelastic measurement on LiHoF4 sample) and compare the results with our analytical
calculations and McStas simulations.
ICNS 2013 International Conference on Neutron Scattering