Wednesday 10 July 2013, Strathblane & Cromdale Halls, 16:30-18:30
Poster session B - Instruments - diffraction and imaging
P.112 NyRTex: Spatially resolved texture analysis on a TOF neutron strain scanner
J J Blostein1, F Malamud1, J R Santisteban1, M A Vicente Alvarez1 and Winfried Kockelmann2
1
Centro Atómico Bariloche - CONICET, Argentina, 2STFC, Rutherford Appleton Laboratory, ISIS Facility, UK
Most industrial metallic products are produced by processes such as rolling, extrusion or drawing, involving large
plastic deformation, unevenly distributed across the thickness of the piece. As a result, the crystallographic texture
of the finished piece changes from point to point, presenting clear differences between the core, and inner and
outer surfaces of the piece. Here, we describe a methodology to quantitatively characterize such texture distribution
by performing neutron diffraction experiments in a TOF neutron strain scanner, where the gauge volume is accurately
defined by the use of radial collimators. The description of a material texture is expressed in terms of the orientation
distribution function (ODF) of the crystallites composing the sample, which can be defined from a number of
experimental incomplete pole figures. To perform such task with a neutron strains scanner, we have developed
NyRTex, a freely available Matlab library based on the texture toolbox MTEX [J Appl Crystall 41 (2008) 1024].
Essentially, the code performs the following tasks: (i) it splits the relatively large solid angle of detection banks in
neutron strain scanners into smaller groups, (ii) it performs robust multi-peak least squares fitting of the diffraction
data, (iii) it creates experimental pole figures from the Euler angles of the explored sample orientations and refined
peak areas, (iv) it computes the ODF from the experimental pole figures. We present demonstration experiments on
an archaeological bronze and a rolled aluminum plate performed on the ENGIN-X beamline at ISIS, UK; together
with a spatially resolved texture analysis of Zr2.5%Nb pressure tubes from CANDU nuclear power plants.
P.113 A general Monte Carlo simulation sample module for neutron scattering and imaging experiments
M Boin1, R C Wimpory1 and R Woracek2
1
Helmholtz Centre Berlin, Germany, 2University of Tennessee, USA
Simulations of neutron instruments using the Monte Carlo method have been presented to be a successful tool
towards design specifications for the development of new and the upgrade of existing beamlines at steady-state
reactors as well as (pulsed) spallation sources. The existing tools to perform Monte Carlo simulations feature the
sampling of parameters ranging from source and moderator characteristics to neutron optics devices, such as
guides, choppers, monochromators and collimators. Furthermore, virtual samples exist to also evaluate the
performance of an instrument design based on the scattering signal at the detector, for example. Thus, the
development of new measurement methods can be supported. However, a growing demand for realistic sample
simulations including physical processes in engineering materials, for example, was shown just recently in [1]. Here,
we report about the development of a general polycrystalline sample simulation module to allow for both imaging
and scattering neutron experiments, and include effects such as stress distributions and preferred crystallographic
orientations. It is further shown, that the module, integrated in an instrument simulation, is able to account for
aberrations of the expected measurement signal caused by multiple scattering and surface effects, for example. The
presented simulation module has been made available for the Monte Carlo simulation packages McStas and
VITESS and, thus, for a broad community of neutron users as well as instrument scientists.
[1]
ESS Science Symposium 2012, Physical simulations of processes in engineering materials with in-situ
neutron diffraction/imaging. Nov 15-16, 2012, Prague, Czech Republic
ICNS 2013 International Conference on Neutron Scattering
P.114 Instrument concept for probing multiple length scales
M Christensen1, S Holm2, M Bertelsen2, N Aliouane3, J Schefer3, K Lefmann2 and P Henry4
1
Aarhus University, Denmark, 2University of Copenhagen, Denmark, ESS Design Update Programme, Denmark, 3Paul
Scherrer Institut, Switzerland, 4ESS-AB, Science Division, Sweden
The properties of advanced functional materials are determined by the structural characteristics on multiple length
scales. It is the combined atomic-, nano-, meso-, and microstructure, which govern the resulting properties. A
classical example is heterogeneous catalysts, here the atomic structure of catalytic nanoparticles placed in a
microporous matrix, both are relevant for the efficiency of the catalytic process. Understanding of advanced
functional materials often involves external stimuli e.g. gas flow and temperature in the case of a catalyst.
Commonly information on different length scales on advanced functional materials is collected separately and quite
often post mortem i.e. after the process have taken place.
We suggest the construction of an instrument for the ESS, which combines - powder diffraction (NPD), small angle
scattering (SANS) and neutron imaging (NI) in a single instrumental setup. The designed allows quasi simultaneous
coverage of multiple lengths scales and with a time resolution sufficient to follow chemical and physical processes
in real time.
The different techniques have highly different requirements to the incoming neutron beam. Therefore we suggest a
new concept, where two guides are viewing the cold and thermal part of a bispectral moderator. The two beams are
extracted from the same beamport and transport to the sample. The thermal guide will be optimized for NPD, while
the cold guide will be optimized for SANS and NI. By having two guides it is possible to individually optimize the
beam condition.
P.115 PONTO II - an instrument for imaging with polarized neutrons
O Ebrahimi1, N Karakas2, C Schramm2, A Ebrahimi2, I Dhiman1 and W Treimer2
1
Helmholtz Zentrum Berlin Wannsee, Joint Research Group,Germany, 2University of Applied Sciences - Beuth
Hochschule für Technik Berlin, Germany
PONTO II is an instrument situated at BER II and dedicated to radiography and tomography studies, using polarized
neutrons. Neutron beam is monochromatized using graphite crystal (002), which covers a range of wavelength from
0.31 nm < λ < 0.52 nm and thus relevant Bragg edges of elements such as Cu, Fe, Ni. The horizontal and vertical
collimation of 0.1° corresponds to Δλ/λ of 2.8×10-3 < Δλ/λ < 1.7×10-3 and yields a L/D ratio of 570, which can
be further increased up to > 1000. The neutron beam is polarized and spin-analyzed with benders, yielding a total
beam polarization P > 96%, which facilitates high contrast images. Spin flippers can rotate the neutron spin in any
direction in front of the sample. The intensity for unpolarized at the sample position (approx. 2.5m away from the
monochromator) is about 5 × 106 n [cm-2.s-1] for wavelength 0.32 nm < λ < 0.42 nm and decrease to 2×106 n
[cm-2.s-1] for λ = 0.46 nm. The detector has 2k × 2k pixels (each 13.6 µm × 13.6 µm, Andor camera) with a LiF
scintillator (thickness variable between 50µm – 200µm), which yields a field of view (FOV) of 70 mm × 70 mm and
a spatial resolution ΔxΔy of 60µm for un-polarized neutrons. In comparison, the field of view for polarized neutrons
is 40 mm × 40 mm with spatial resolution in the range of 150 µm. The sample can be placed in any environment
(e.g. cryostat, external magnetic field up to 200 G), with a flexibility of moving it parallel and perpendicular to the
incident beam. High resolution radiographies and tomographies are presented.
2
ICNS 2013 International Conference on Neutron Scattering
P.116 New abilities and performance of neutron powder diffraction at FIREPOD
A Franz, D Többens and M Tovar
Helmholtz-Zentrum Berlin für Materialien und Energie, Germany
The fine-resolution powder diffractometer FIREPOD (E9) has undergone major alterations, which improved both the
performance and the flexibility [1]. A new detector system was mounted consisting of eight individual 2D-detectors
and a radial collimator to reduce background noise.
The instrument is dedicated to collect diffractograms suited for crystal structure determinations and Rietveld
refinements and can be operated in different modes: the stationary and the mobile detector mode with high
resolution/high intensity option. The first mode enables fast scans concentrating on a specific 2θ-region, useful for
e.g. temperature or field strength dependency of magnetic structures or phase compositions. In the mobile mode
the complete 2θ-range is covered by a small number of detector bench steps. The high intensity conformation is
suitable for atomic and magnetic structures with small unit cells and high symmetry, and also for particularly small
samples. This is especially interesting when combined with the new option to equip more than 10 different gasadsorption modules, covering a wide pressure and temperature range from 4 K to 1500 K and up to 10000 bar.
Load gasses include nitrogen, hydrogen, heavy hydrogen, argon, helium, vapour and chemisorption. Of course, the
upgraded instrument still allows the use of the usual suite of sample environments: temperatures from 1.5 – 2000
K, pressure up to 2.5 kbar, variable magnetic fields up to 5 T.
FIREPOD is now once again open to applications from external users [2].
[1]
[2]
D. M. Többens et al., Mat. Sci. Forum. 378-381, 288 (2001)
http://www.helmholtz-berlin.de
P.117 Quantifcation of the neutron dark-field signal
C Gruenzweig1, B Betz1, A Kaestner1, E Lehmann1, J Kohlbrecher1, U Gasser1 and J Kopecek2
1
Paul Scherrer Institut, Switzerland, 2Institut of Physics Prague, Czech Republic
Abstract unavailable
P.118 Simulations of diffractometers for the ESS using McStas
B R Hansen1, E Oksanen2, P Henry2 and P Willendrup1
1
Technical University of Denmark, Denmark, 2ESS, Sweden
Presented are monte-carlo simulations of two concepts for neutron diffractometers, which are proposed for the
European Spallation Source (ESS) in Lund, Sweden. The instruments were simulated using the netron ray-trace
simulation package McStas.
One instrument is a t-o-f quasi-Laue diffractometer for structure determination of biological macromolecules, thus
small samples and large unit cells. The instrument has two choppers for bandwave selection, slits to control the
beam size and movable, flat detectors. The detector setup makes it possible to resolve larger unit cells at the
expense of having to perform more measurements.
The other instrument is a thermal t-o-f powder diffractometer. Similarly to the quasi-Laue diffractometer, the thermal
diffractometer also has a pulse-shaping chopper, which allows for a variable wavelength resolution.
Monte-carlo simulations make it possible to optimize the instruments proposed for the ESS, so that the unique longpulsed source can be utilized in the best possible way
ICNS 2013 International Conference on Neutron Scattering
P.119 Powder diffraction at the European Spallation Source
P Henry1, W Schweika2, M Christensen3, J Schefer4 and O Prokhnenko5
1
European Spallation Source (ESS) AB, Sweden, 2Jülich Centre for Neutron Science, Germany, 3Aarhus University,
Denmark, 4Paul Scherrer Institut, Switzerland, 5Helmholtz-Zentrum Berlin, Germany
The European Spallation Source (ESS) will be a 5MW long-pulse spallation source, the first of its kind. The longpulse offers unparalleled source brilliance, while at the same time a time-averaged flux commensurate with the
most powerful research reactors available today. This means that instrument concepts based on either the t-o-f
technique or crystal monochromators are possible. Within the reference suite for the facility costing, there are 4
powder diffractometers: thermal powder diffractometer, bispectral powder diffractometer, pulsed monochromatic
diffractometer and extreme conditions instrument. Other concepts are also under active development, which
combine powder diffraction with other neutron scattering techniques such as SANS, imaging and/or inelastic
scattering. The motivation behind each instrument concept will be presented, highlighting the potential for new
science.
The ESS is a European large-scale facility project with 17 international partners based in Lund, Sweden. It is
scheduled to deliver its first neutrons to target in 2019 and have its full design complement of 22 public
instruments by 2025. The ESS will offer new opportunities to all areas of scientific research, as well as
complementing the existing neutron sources, both reactor and spallation-based, in Europe. The instrument suite is
currently under development and provides an opportunity to investigate and evaluate novel instrument concepts
that fully utilise the possibilities presented by a long-pulse source.
P.120 The pulsed monochromatic powder diffractometer concept for the ESS
P Henry
European Spallation Source (ESS) AB, Sweden
Powder diffraction is the cornerstone of materials characterisation, determining where atoms are in space, without
which it would be impossible to relate structure to physical properties. Neutron powder diffraction is highly
complementary with X-ray powder diffraction for structure determination and refinement. Reflecting on neutron
powder diffraction instrumentation over the last 40 years, a clear trend emerges in instrument types built at large
scale facilities. Reactor-based neutron instruments are predominantly based on crystal monochromators and at
spallation sources on the wide wavelength band time-of-flight (t-o-f) technique. Is this the only way to build
instruments or has it just become the accepted way? Here, I discuss the pros and cons of building a crystal
monochromator-based neutron powder diffractometer at a long-pulse spallation source and the new experiment
types that would become possible compared with existing instruments.
The ESS is a European large-scale facility project with 17 international partners based in Lund, Sweden. It is
scheduled to deliver its first neutrons to target in 2019 and have its full design complement of 22 public
instruments by 2025. The ESS will offer new opportunities to all areas of scientific research, as well as
complementing the existing neutron sources, both reactor and spallation-based, in Europe. The instrument suite is
currently under development and provides an opportunity to investigate and evaluate novel instrument concepts
that fully utilise the possibilities presented by a long-pulse source.
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ICNS 2013 International Conference on Neutron Scattering
P.121 A thermal neutron t-o-f powder diffractometer concept for the ESS
P Henry1, B Hansen2, S Holm3 and K Lefmann3
1
European Spallation Source (ESS) AB, Sweden, 2Technical University of Denmark (DTU), Denmark, 3University of
Copenhagen, Denmark
The thermal neutron instrument concept is a t-o-f diffractometer with variable wavelength resolution (Δλ/λ from
0.02 % to 5 % for a λmean of 1.45 Å), provided by a pulse shaping chopper. It will have a useful Qmax of
approximately 25 Å-1 for medium and high-resolution powder crystallography. The usable wavelength band in the
time-frame is 1.9 Å (normal operational mode λ = 0.5 - 2.4 Å) and the instrument beam transport system is
optimised for shorter wavelengths for structural characterisation and in situ processing. The ability to tune the
instrument resolution to the experiment requirements is a major advantage of ESS instruments. The combination of
the very flexible instrument set-up, event-mode data acquisition and optimised sample environments are key to the
impact of this instrument across a broad range of science. While the instrument will be optimised for thermal
neutron powder diffraction, it will also be possible to perform single crystal diffraction measurements in a quasiLaue mode or to use longer wavelength bands.
The ESS is a European large-scale facility project with 17 international partners based in Lund, Sweden. It is
scheduled to deliver its first neutrons to target in 2019 and have its full design complement of 22 public
instruments by 2025. The ESS will offer new opportunities to all areas of scientific research, as well as
complementing the existing neutron sources, both reactor and spallation-based, in Europe. The instrument suite is
currently under development and provides an opportunity to investigate and evaluate novel instrument concepts
that fully utilise the possibilities presented by a long-pulse source.
P.122 Design of compact polarized neutron imaging system designed for accelerator based small neutron source
K Hironaka, S Tasaki and Y Abe
Kyoto University, Japan
Recently, small neutron sources have been developed consisting of a small proton accelerator, a Be-target and a
moderator within 10 m in length. These sources have a possibility of various industrial applications because of their
compactness. One of the applications is the polarized neutron imaging system. The system consists of neutron
bender, polarizer, spin flipper, sample table, second spin flipper, spin analyzer and 2D-position sensitive detector.
Since the neutron source is small and the imaging system should be installed near by the moderator, the bender
and polarizer have to be properly designed to have relatively wide acceptance angle for the incident beam. In the
present study, the design and estimated results of such imaging system for will be presented.
P.123 Significant upgrades of 2-dimension scintillator detector system for J-PARC/MLF iBIX diffractometer
T Hosoya1, T Nakamura2, M Katagiri1, M Ebine2, A Birumachi2, K Kusaka1 and K Soyama2
1
Ibaraki University, 2Japan Atomic Energy Agency, Japan
iBIX is a most powerful single-crystal neutron diffractometer using time-of-flight technique for both biological and
chemical crystallography, and is now working at BL03 in J-PARC/MLF. This diffractometer is designed to cover the
sample crystals from organic small molecules to biological macromolecules with maximum 150Å of cell dimension.
The detectors of iBIX have high spatial/time resolutions to resolve the Bragg peaks observed in high density, and
large detective region to cover the solid angle as large as possible. Its composition is two ceramic ZnS/10B2O3
scintillator sheets, 256×256 wavelength-shifting fiber grid (0.5-mm pitch), 64-ch multi-anode photomultipliers, a
high-speed 512-channel amplifier and discriminator, and a 512-channel encoder module with three FPGAs for time
ICNS 2013 International Conference on Neutron Scattering
and position analysis. Since 2012, iBIX had 14 detectors. However, there are considerable individual specificity in
the detector efficiency (20–50%), the variation of sensitivity across the channel (10–30%), and the rate of multicounting (1–10%). In order to overcome these problems, we had newly developed bright but short-lifetime and low
afterglow scintillator, high efficient light-guide system, a new encoder module with a new position-analysis algorithm
on FPGAs, and DAQ electronics with a giga-bit Ethernet port. Last year we have installed the new detector system
into iBIX, and made sure that the performance of all 30 detectors had high detector efficiency (>50%), low variation
of sensitivity (<10%), and low multi-counting rate (<1%). Finally iBIX became 6 times more efficient for diffraction
measurments than it had been before.
P.124 First measurements with the neutron laue diffractometer in Berlin
G Iles and S Schorr
Helmholtz-Zentrum Berlin, Germany
The Fast Acquistion Laue Camera for Neutrons, FALCON, has been constructed in the experimental hall of the BER-II
reactor at HZB in Berlin. The thermal guide, D1S, delivers a stream of neutrons direct to FALCON without passing
through any other objects upstream. Two scintillator plates are coupled to eight iCCD cameras capable of obtaining
20-bit digitization Laue images in under ten seconds. We present here some first images of kesterite and sanidine
samples taken in ambient conditions with associated structural parameters ascertained using the Orient Express
software.
P.125 A new method for obtaining accurate sample orientation and lattice parameters on a time-of-flight singlecrystal instrument with 2D detectors
M Johnson1, C Bul1, R Nelmes1, M Gutmann2, H Hamidov1, K Komatsu3, M Guthrie4 and J Loveday1
1
Edinburgh University, UK, 2ISIS Facility, Rutherford Appleton Laboratory, UK, 3University of Tokyo, Japan, 4Carnegie
Institution of Washington, USA
We will describe a new method for determining the orientation and lattice parameters of a single-crystal sample
using the neutron Laue time-of-flight (TOF) technique and 2D detectors. The new method has resulted in very
significant improvements in the determination of both the crystal lattice parameters and the positions of calculated
reflections on the ISIS SXD instrument.
The reason for developing this new method on the ISIS single crystal diffractometer SXD stems from its use in highpressure studies. In such studies it is often important to know accurately both the location of weak reflections
among often strong background features and also the pressure of the sample under study.
The method uses a mathematical model of the relative positions of all the detector pixels of the instrument, together
with a methodology which establishes a reproducible reference frame. The mathematical model is embedded in a
new computer program SXDCALIB. This uses a least squares method to determine the parameters of the instrument
detectors, or the unknown lattice parameters and crystal orientation once the instrument has been calibrated using
a standard sample. An important feature of SXDCALIB is its full propagation of errors throughout the entire
calibration and measurement process.
The method enables the determination of lattice parameters to within 0.015% for high symmetry systems, and the
location of calculated reflection positions to within 0.5 mm or 0.1º. It is very likely that the method described
here will be of use for studies on other time-of-flight instruments where accurate lattice parameters and reflection
coordinates are required.
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ICNS 2013 International Conference on Neutron Scattering
P.126 Experimental study of broad band time-of-flight diffraction by wavelength frame multiplication
G Káli1, M Russina2 and F Mezei3
1
Wigner Center for Physics Research, Hungary, 2Helmholtz Zentrum Berlin, Germany, 3European Spallation Source
AB, Sweden
WFM has been proposed in 2002 for providing a universal pulse shaping method for pulsed neutron sources with
unlimited wavelength band capability. It opened up a series of novel experimental opportunities in elastic and
inverted geometry inelastic neutron scattering, primarily at long pulse spallation sources (LPSS) and also in
providing for enhanced resolution performance at short pulse spallation sources (SPSS). This technique is
fundamental for the efficient use of LPSS with medium and high wavelength resolution and offers a new potential for
SPSS. In WFM the fine and flexible pulse shaping without any perturbation to accessing and utilizing unlimited
bandwidth is achieved by the multiplexing principle, which consists of cutting out from each source pulse a series of
shorter pulses. The method was experimentally first implemented at the time-of-flight (TOF) diffractometer at the
continuous reactor source of Budapest Neutron Center in 2009, by using the chopper system in a fashion to
emulate LPSS operation. A suite of experiments provided full proof of principle of the WFM approach, including both
synchronized and asynchronous modes of operation with respect to the source and use of beam monitor for
normalization to the incoming neutron spectra. We report here about the extension of these studies to vanadium
normalization. The results prove that the WMF mode of operation can fully emulate the conventional single pulse
data collection and evaluation approaches well-established at SPSS diffractometers. In combination with event
recording detection, already the raw spectra were proved to be indistinguishable from those obtained customarily
and are adequate for data evaluation by the use of established existing software.
P.127 Perspectives for materials investigations at the structured pulse engineering diffractometer (speed)
R Kampmann1, M Rouijaa1, P Staron1, H G Brokmeier2, M Strobl3, M Mueller1 and A Schreyer1
1
Helmholtz-Zentrum Geesthacht, Germany, 2 Clausthal University of Technology, Germany, 3European Spallation
Source ESS AB
One important goal of modern engineering investigations is to improve our understanding of materials behaviour
and failure on a microstructural basis. Various experimental investigations are performed to achieve this goal
comprising measurements of stresses and textures. Those characterizations need neutron measurements if well
defined gauge volumes located deep in the bulk of materials are to be analyzed which should allow for threedimensional maps of stresses and textures within engineering components or in-situ studies of fatigue behaviour or
stresses in rotating machinery. Those measurements are, however, extremely time consuming and can thus not be
performed to the required extent at existing beamlines.
Against this background the Helmholtz-Zentrum Geesthacht proposes to build a novel structured pulse engineering
diffractometer (SPEED) at the European Spallation Source (ESS) in Lund/Sweden. The instrument will be based on
a novel ToF-design distinguished by a modulation chopper positioned at a distance of ~ 25 m from the source. The
design of SPEED is introduced and its performance based on numerical simulations for texture and stress
measurements is outlined. The development of SPEED is performed as an in-kind contribution to the ESS
instrumentation, it is part of the German support to the ESS Pre-Construction Phase and Design Update. A close cooperation with Czech colleagues has been started with the main goal to merge the Czech CEED and the German
SPEED concepts.
ICNS 2013 International Conference on Neutron Scattering
P.128 Development of low temperature 2-axes goniometer system for single crystal ToF Laue diffractometer SENJU
K Kaneko1, K Munakata2, Y Dohi3, Y Noda3, T Hanashima2, K Sato2, T Kawasaki1, R Kiyanagi1, A Nakao2, T Ohhara2, K
Oikawa1 and I Tamura1
1
Japan Atomic Energy Agency, 2Comprehensive Research Organization for Science and Society, 3Tohoku University,
Japan
Single crystal diffraction experiments require rotation of a crystal in order to access to an arbitrary point in reciprocal
lattice space. A typical instrument to fulfil this demand is a four-circle goniometer equipped with χ, φ and ω. For
low temperature measurement, sample rotation is usually realised by rotating a whole cryostat, which requires a
large goniometer in size. In addition, this could cause background originating from radiation shield and vacuum
chamber, since an incident beam spot on the cryostat depends on angles, so that one cannot make a beam hall for
incoming/outgoing beam. In this respect, it is ideal if one can rotate only the crystal inside the cryostat at low
temperature.
Recent technical development in piezo devices offers a possibility to move a crystal even at dilution temperature.
We tried to develop a piezo-based goniometer in time with the construction of single crystal time-of-flight neutron
Laue diffractometer SENJU at BL18 of J-PARC. The goniometer consists of two rotatable axes ω and φ with fixed-χ
(45˚) to cover entire reciprocal space. A goniometers is directly mounted onto the cold finger of the standard
closed-circle refrigerator. So far, sample rotation can be realised at base temperature of 4.4 K with reasonable
cooling time of roughly 5 hours. In fact, several low temperature experiments using this goniometer have been
worked out. Further efforts to improve base temperature, cooling time and accuracy of movements are in progress.
P.129 Upgrading of IBARAKI biological crystal diffractometer iBIX at J-PARC
K Kusaka1, T Hosoya1, T Yamada1, K Tomoyori1, T Ohhara2, K Kurihara3, M Katagiri1, I Tanaka1 and N Niimura1
1
Ibaraki University, 2CROSS, 3 Japan Atomic Energy Agency, Japan
IBARAKI biological crystal diffractometer iBIX is a high performance time of flight neutron single crystal
diffractometer to elucidate the hydrogen, protonation and hydration structures of organic compound and biological
macromolecules in various life processes.
Since the end of 2008, iBIX has been available to user experiments supported by Ibaraki University. Since August
2012, we have started to upgrade the 14 existing detectors and install the 16 new detectors for diffractometer of
iBIX. The total solid angle of detectors subtended by a sample and the average of detector efficiency become 2 and
3 times, respectively. The total measurement efficiency of the present diffractometer was on one order of magnitude
from the previous one coupled with the increasing of accelerator power.
In December 2012, the commissioning of the detectors could be succeeded, we have tried to collect the diffraction
dataset of Riboncrease A as a standard protein in order to estimate the performance of the new diffractometer in
comparison with the results by the previous one. The resolution of diffraction data, equivalence among intensities of
symmetry related reflections and reliability of the structure have been improved dramatically. iBIX is expected as
one of the highest performance of a neutron single crystal diffractometer in the world.
In future, the data reduction and acquisition software should be upgraded to improve the accuracy of the integrated
intensity of Bragg reflections, measurement efficiency and users’ usability of the experiment.
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ICNS 2013 International Conference on Neutron Scattering
P.130 Initial commissioning report of the Neutron Image Plate Diffractometer (Bio-C) at HANARO
S A Kim1, S J Cho1, K H Lee1, E Magay1, S Y Ryu1, and T S Yoon2
1
Korea Atomic Energy Research Institute, 2Korea Research Institute of Biotechnology, Korea
Bio-C is a single crystal diffractometer with a neutron image plate detector (nIPD) for determining biological
macromolecule structures such as proteins and nucleic acids. The diffractometer was developed as a joint project of
KAERI (Korea Atomic Energy Research Institute) and KRIBB (Korea Research Institute of Bioscience and
Biotechnology), and installed at the ST3 beam port of the Korean research reactor, HANARO. The nIPD of Bio-C was
manufactured by the French company, MAATEL. Bio-C is equipped with a Si(111) Bent-Perfect-Crystal as a
monochromator, two super mirror guides (M=2) as vacuum beam flight paths before and after the monochromator
and a vacuum slit-box with two slits and a quick shutter. Commissioning of Bio-C has commenced and the first
beam tests were carried out with large-size Hen Egg-White Lysozyme single crystal as a bench-marking crystal. The
commissioning will be performed continuously to optimize the Bio-C for neutron protein crystallography. In addition,
we are trying to grow large-size single crystal samples of biological macromolecules suitable for neutron diffraction
experiments.After the commissioning we expect that Bio-C can provide a research opportunity to apply neutron
crystallography to the life sciences.
This work has been supported by "SEED" program (Seed-11-7) of the Korea Research Council of Fundamental
Science and Technology (KRCF).
P.131 Wavelength frame multiplication - motivation, principle and applications
K Lieutenant1, M Bulat1, F Mezei2, M Russina1, M Sales1, P Schmakat3, M Schulz3, W Schweika4, M Seifert3, M
Strobl2, L Udby5 and C Zendler1
1
Helmholtz Zentrum Berlin, Germany, 2European Spallation Source, 3TU München, Germany, 4Forschungszentrum
Jülich, Germany 5University of Copenhagen, Denmark
On a long pulse neutron source, the instrument resolution is limited by the pulse length, if the whole pulse is used. If
pulse shaping choppers are used to improve resolution, the usable wavelength band is reduced. This problem is
overcome by the concept of wavelength frame multiplication, where the pulse shaping choppers open the beam
several times per source pulse delivering adjacent wavelength bands.
We show here the principle of wavelength frame multiplication and compare different approaches for its realization.
We present several examples of simulations of instruments for the ESS (diffractometers, a reflectometer, an imaging
instrument) and of the ESS test Beamline at HZB, as well as first experimental results from the TOF diffractometer at
BNC in Budapest.
P.132 Initial results of uniaxial polarisation analysis on the WISH diffractometer
P Mills1, S Boag2, J Taylor2, R Stewart2 and P Manuel2
1
ISIS, STFC, UK, 2STFC, UK
We report initial results using the polarization analysis insert, Zoolander [1], on the WISH time-of-flight
diffractometer at ISIS. This insert enables uniaxial polarisation analysis, utilizing a neutron spin filter(NSF)
polariser/flipper [2] and NSF analyser, held within a single magnetic field provided by a optimised four coil Barker
set.
ICNS 2013 International Conference on Neutron Scattering
The arrangement was used to extract flipping ratios from measurements of powdered Si establishing the polarisation
of the beam as a function of time. Initial flipping ratios of up to 20 were achieved. The data collected were corrected
to account for the finite polarisation of both the polariser and analyser NSF allowing a separation of coherent and
incoherent scattering to be achieved.
A discussion of current and future optimisations and development of the system will be presented here. There will
further be discussion on the latest development of wide angle analyser cells for use in large area detector
instruments such as WISH and LET.
[1]
[2]
C.J. Beecham et al, Physica B 406 (2011) 2429-2432. 3He polarization for ISIS TS2 phase I instruments.
T.J. McKetterick et al, Physica B 406 (2011) 2436-2438. Optimised adiabatic fast passage spin flipping
for 3He neutron spin filters.
P.133 DNS – a versatile diffuse neutron scattering spectrometer with polarization analysis at FRM II: towards
enhanced count rate and extended Q-range
K Nemkovskiy, Y Su, W Schweika, A Loffe and T Brückel
1
Forchungszentrum Jülich GmbH, Germany
DNS is a versatile diffuse scattering instrument with polarization analysis operated by the JCNS at the research
reactor FRM II. Compact design, a large double-focusing monochromator and a highly efficient supermirror-based
polarizer provide an impressive polarized neutron flux in the range of 107 n/cm2s. DNS is effectively used for the
studies of highly frustrated spin systems [1], strongly correlated electrons [2], emergent functional materials [3]
and soft condensed matter [4]. We present the current status of the instrument and recent scientific highlights at
DNS as well as ongoing instrument developments. Within the upgrade project the coating of the neutron guide will
be increased to m=2, which will extend the accessible Q-range towards higher values. In the combination with a
large array of 1d position-sensitive detectors covering the solid angle of about 1.9sr and a high-frequency disc
chopper system, both under development, DNS is expected to become a high count-rate cold time-of-flight
spectrometer with medium resolution.
[1]
[2]
[3]
[4]
L.J. Chang et al., Nature Communications 3, 922 (2012)
M. Tegel et al., EPL 89, 37006 (2010)
J. de Groot et al., PRL 108, 037206 (2012)
C.Gerstl et al., Macromolecules 45, 7293 (2012)
P.134 Macromolecular diffractometer at ESS
E Oksanen1, B R Hansen2, P K Willendrup2, P Bentley1, R Hall-Wilton1, I Sutton1 and K H Andersen1
1
European Spallation Source, Sweden, 2Technical University of Denmark, Denmark
We present a conceptual design an instrument dedicated to the structure determination of biological
macromolecules by crystallography. The scientific driver is to locate the hydrogen atoms relevant for the function of
the macromolecule. The proposed instrument is a time-of-flight (TOF) quasi-Laue diffractometer optimised for small
samples and large unit cells.
The ESS long pulse source is well suited for a quasi-Laue macromolecular diffractometer that can spread the
background in the TOF dimension, while the Bragg peaks are observed at a defined TOF. Therefore a
macromolecular diffractometer at the ESS could be used either to study systems with smaller crystals or larger unit
cell volumes. The main limiting factor today is the difficulty in growing well-ordered crystals of cubic millimetre
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volume, so the instrument is optimised for submillimeter crystal sizes. As the background from incoherent scattering
increases dramatically if all 1H cannot be replaced by 2H, the instrument proposed here has a dramatic advantage
with systems where perdeuteration cannot be achieved. Many challenging and interesting proteins fall into this
category, as they cannot be expressed in prokaryotic systems with high enough yield.
One of the limiting factors with current instruments is that the fixed detector geometry only allows a maximal unit
cell edge of 150 Å to be resolved without a compromise in the diffraction resolution (dmin). The instrument
proposed here allows larger unit cells to be resolved by increasing the crystal-to-detector distance, albeit which
incurs an increase in the data collection time, but reflections to the same dmin can still be observed by swinging the
detector in 2θ angle.
P.135 Macromolecular crystallography at the FRM II - The new neutron single crystal diffractometer BIODIFF
A Ostermann1, T E Schrader2, M Monkenbusch2, B Laatsch2, P Jüttner1, W Petry1 and Dieter Richter2
1
Forschungs-Neutronenquelle Heinz Maier-Leibnitz FRM II, 2Forschungszentrum Jülich GmbH, 4Forschungszentrum
Jülich GmbH, Germany
The newly build neutron single crystal diffractometer BIODIFF is especially designed to collect data from crystals
with large unit cells. The main field of application is the structure analysis of proteins, especially the determination
of hydrogen atom positions. BIODIFF is a joint project of the Forschungszentrum Jülich (FZJ/JCNS) and the
Forschungs-Neutronenquelle Heinz Maier-Leibnitz (FRM II). Typical scientific questions addressed are the
determination of protonation states of amino acid side chains and the characterization of the hydrogen bonding
network between the protein and an inhibitor or substrate.
BIODIFF is designed as a monochromatic instrument. By using a highly orientated pyrolytic graphite monochromator
(PG002) the diffractometer is able to operate in the wavelength range of 2.4 Å to about 5.6 Å. Contaminations of
higher order wavelengths are removed by a neutron velocity selector. To cover a large solid angle and thus to
minimize the data collection time the main detector of BIODIFF consists of a neutron imaging plate system in a
cylindrical geometry. A Li/ZnS scintillator CCD camera is available for additional detection abilities. The main
advantage of BIODIFF is the possibility to adapt the wavelength to the size of the unit cell of the sample crystal while
operating with a clean monochromatic beam that keeps the background level low. BIODFF is equipped with a
standard Oxford Cryosystem “Cryostream 700+” which allows measurements in the temperature regime from 90K
up to 500K.
P.136 Estimating the information content in small-angle neutron scattering
M C Pedersen, S L Hansen, L Arleth and K Mortensen
University of Copenhagen, Denmark
It is well-known that the information content in small-angle neutron scattering is fairly low compared to other
scattering techniques. Using a Bayesian approach, one can quantify the information content of a given small-angle
scattering dataset and represent this by a single parameter - the number of extractable parameters from a dataset as described in [1] and [2].
Thus, using virtual experiments (e.g. with [3]) and experimental data, the behaviour of this quantity can be
investigated in order to optimally plan and carry out small-angle scattering experiments.
Furthermore, in cross-disciplinary science, one often utilises several techniques on the same sample to achieve a
more complete description of the sample in question. Using the statistical method of profile likelihood, the increase
ICNS 2013 International Conference on Neutron Scattering
in information content - should one consider several datasets - can be estimated, leading to a situation where
improved conditions for i.e. contrast variation experiments.
Quantification of the total amount of information in such a situation is highly beneficial to the choice of future
techniques and/or potential use of this data.
[1]
[2]
[3]
Vestergaard, B., & Hansen, S. (2006). Journal of Applied Crystallography, 39(6), 797–804.
Hansen, S. (2012). Journal of Applied Crystallography, 45(3), 35–36.
McStas - A neutron ray-trace simulation package, www.mcstas.org.
P.137 Monte Carlo simulation assisted correction of through surface neutron stress scanning – application to deep
rolled steel sample
J Rebelo-Kornmeier1, J Gibmeier2, J Saroun3 and M Hofmann1
1
Technical University Munich, Germany 2Karslruhe Institute of Technology, Germany, 3Nuclear Physics Institute,
Czech Republic
Neutron stress/strain analysis is critical at the surface when the gauge volume (GV) is not completely immersed in
the sample, since for scans close to a sample surface, aberration peak shifts in the same order of magnitude as the
peak shifts related to residual strains may arise. Using horizontally focusing single crystal monochromators offers
the possibility to tune the resolution at a required range of scattering angles by varying the monochromator
curvature. Further, the appropriate choice of the monochromator radius allows for the minimisation of spurious
strains even for large GVs, thus reducing measurement times and dispensing complicated and more error prone
alignment of small GVs.
For the STRESS-SPEC instrument at FRM-II series of Monte Carlo (MC) simulations using the software package
RESTRAX were carried out to determine the peak shift as a function of GV depth, monochromator curvature and
further instrumental parameters. The results showed that the MC simulation of set-ups for spurious strain
minimisation can be used to quickly optimize the experimental set-up for measuring residual strains near the
sample surface and allow direct measurements i.e. by avoiding redundant reference measurements.
The optimum monochromator radius can be at extreme values of the bending device and is thus unfavourable. For
these cases, corrections of the spurious strains for measurement data gained using a high resolution set-up can be
applied using the results of MC simulations.
Our approach was applied to a steel sample with a deep rolling residual stress (RS) distribution. The RS depth
distribution of neutron stress analysis is compared and discussed with data determined by means of X ray stress
analyses.
P.138 Monte Carlo simulations of a narrow band ToF powder diffractometer at a long pulse spallation source
V Ryukhtin, J Saroun, P Beran, P Lukas, J Navratil, J Pilch, P Strunz and P Sittner
ASCR, Czech Republic
The time structure of the future European Spallation Source (ESS) is not in general favourable for time-of-flight (ToF)
powder diffraction. However, very high integrated power of the 2.86 ms pulse together with long flight paths open
the way for a powder diffractometer with very good characteristics. A Complex-Environment Engineering
Diffractometer (CEED) has been proposed at ESS as an instrument dedicated to in-situ physical simulation of
material processing. It combines high flexibility of a single frame ToF instrument allowing for easy choice of
resolution and wavelength with an open sample area suitable to accommodate large high-power sample
environment. The latter includes particularly equipment for thermo-mechanical testing of engineering materials
exposed to complex loading/heating/cooling conditions designed for simulations of physical processes taking place
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during material production and use. We present a detailed study of such an instrument using Monte Carlo
simulations for optimization of neutron guides and chopper systems and assessment of performance characteristics
like neutron flux, brilliance transfer ratio, resolution etc. Virtual experiments with single phase high-symmetry
materials as well as more complex multi-phase materials were carried out with the aim to assess the quality of
expected experimental data and to test data analysis techniques. The simulations predict resolution below < 0.1%
in high resolution mode. In the low resolution mode, more than 20% of the huge integrated flux of the ESS pulse
can be employed, which should allow for diffraction measurements in a single pulse. New experimental possibilities
would thus be open for studying fast structural changes during materials processing.
P.139 Versatile strain tomography by Bragg-Edge neutron transmission with the Tensor CT method
H Sato1, Y Shiota1, H Hasemi1, S Uno2, T Shinohara3, T Kamiyama1, M Furusaka1 and Y Kiyanagi1
1
Hokkaido University, 2KEK, 3J-PARC, Japan
Quantitative CT image reconstruction of crystalline structural information in a bulk material by using the Bragg-edge
neutron transmission spectroscopy is one of the final goals of technical developments on the energy-resolved
neutron imaging. The development is indispensable for the application to materials science and engineering, and
means that a useful new tool for “three-dimensional” crystalline structure analysis may be available. Some studies
on the reconstruction of tomographic strain distribution based on the Bragg-edge transmission spectroscopy are in
progress, but present methods are limited more or less; these are applicable to only a cylindrical material consisting
of an axisymmetric strain distribution. Strain tomography is quite difficult in principle because the traditional CT
reconstruction techniques can deal with only the “scalar” quantity although crystal lattice strain is the “tensor” one.
For this reason, we developed the new CT reconstruction method, the tensor CT method, for an unlimited versatile
strain tomography by the Bragg-edge transmission spectroscopy. This new method is based on the modified
principle of the ML-EM method that is one of the iterative approximation type CT reconstruction methods. We
performed some simulation calculation studies on this new technique in terms of accuracy and precision.
Furthermore, we carried out a verification experiment using the VAMAS neutron strain standard sample with the
boron-coated GEM type neutron imaging detector at the BL10 “NOBORU” beamline at MLF in J-PARC. The highprecision projection data of the crystal lattice strain for the ML-EM tensor CT were analyzed by the RITS code.
P.140 Upgrated neutron optics and upgrated high resolution TOF-diffraktometer Epsilon at pulsed reactor IBR-2
C Scheffzük1, K Walther1, F Schilling1, V Sikolenko1, A Bulkin2 and A Frischbutter
1
Karlsruhe Institute for Technology, Germany, 2Petersburg Nuclear Physics Institute, Russia
The pulsed neutron source IBR-2M was shut down for a complete renewal of the core and has become critically
recently. During this time the neutron guides of the strain diffractometer Epsilon, the texture diffractometer SKAT and
the spectrometer NERA have been renewed too after nearly 20 years of work.
At a distance of 5.50 m from the surface of the moderator a background disc-chopper reduces the background of
delayed neutrons from the source. Then a 14 m long guide splitter produces the three subbeams. After the splitter
the guides for the diffractometers are bent with a radius of 13400 m. The cross section is 95 × 50 mm2 (height ×
width). The length of the bent part of the guide is 85 m followed by a straight part for homogenization of the beam.
The total flight path at Epsilon is about 107 m. The guides are covered with Ni of natural abundance (m=1).
The diffractometer Epsilon is equipped with 9 large radial collimators (length: 500 mm) with 48 foils covert with
Gd2O3. The divergence angle between two foils is one third of degree. Due to the frame overlapping the wavelength
band is limited to 7.4 Å. An additional drum-chopper (at a distance of 18 m from the surface of the moderator)
enlarges the upper limit to 12 Å.
ICNS 2013 International Conference on Neutron Scattering
Recently, the sample environment includes a Paris-Edinburg-cell (VX4) for pressures up to 8 GPa. A further smaller
press was upgraded with a mechanism for rotating the sample under (full) load in order to measure orientation
dependent strain (strain pole figure).
A cold source works with solidified mesitylene at a temperature of 20 K and gives a large gain in the incident beam
for neutrons with wavelengths larger than 3 Å.
P.141 A Monte Carlo component for the simulation of refraction based edge effects in neutron imaging
M Schulz1, F Horstbrink2, E Lehmann3 and M Morgano3
1
Technische Universität München, FRM II, Germany, 2Technische Universität München, Germany, 3Paul Scherrer
Institut, Switzerland
Neutron imaging is a method which is being used in many different applications in the context of nondestructive
testing. Current development in this field goes towards the detection of ever smaller features in the sample and the
location of defects in the µm regime. Due to the limited detector resolution, which is in the best cases around
10µm, in standard absorption radiography the contrast for such small features is limited. Contrast agents have been
used to visualize open cracks with extensions smaller than the detector resolution. Another approach is to use
phase contrast techniques which enhance edge effects but reduce the flux due to gratings or pinholes introduced in
the beam.
Experimentally more easily accessible are edge effects based on neutron refraction which are already visible in
standard neutron radiography. To determine and discuss the detectability of such effects we have developed a
Monte Carlo component for the McStas package which allows the simulation of the transmission image of a sample
including refraction and total reflection effects. The sample geometry as well as the sample material can be
specified. Neutron refraction and total reflection is calculated at the interfaces between two materials leading to a
deflection of the beam. The wavelength dependencies of these effects are included in our simulation tool.
A comparison of simulations and experiments will be presented. A very good agreement is achieved making our
simulation technique a helpful tool for data analysis as well as feasibility studies before planning imaging
experiments.
P.142 A wavelength frame multiplication chopper system for an ESS imaging instrument
M Schulz1, P Schmakat1, M Seifert1 and M Strobl2
1
Technische Universität München, FRM II, Germany, 2European Spallation Source ESS, Sweden
The European Spallation Source (ESS) which will be built in Lund, Sweden by 2020 will become the world’s
brightest pulsed neutron source offering a time averaged flux comparable to the ILL, while at the same time
providing high gain factors for many instruments by making use of the time structure of the neutron pulses.
Neutron Imaging is a technique where high time averaged flux is essential while at the same time more advanced
imaging techniques such as polarized imaging, stress & strain imaging or neutron grating interferometry, are being
developed with different requirements for the monochromatisation of the beam. By using the entire spectrum
provided by the ESS in one measurement by introducing a chopper system, high gain factors over conventional
imaging facilities can be achieved.
In contrast to all existing spallation sources, the ESS will be a long pulse source, which requires different
approaches for a chopper system. On this poster we present a highly flexible chopper system designed for an
imaging instrument at the ESS based on the principle of wavelength frame multiplication. This chopper system has
been optimized for the proposed guide geometry of the instrument and offers an adjustable wavelength resolution of
Δλ/λ=0.3% - 0.9% which is constant over the source spectrum. Furthermore a coarse resolution mode is available
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ICNS 2013 International Conference on Neutron Scattering
with Δλ/λ=10%-2% from 1-9Å. The wavelength band covered by the chopper system can be adjusted by changing
the rotation speed or the phase of the choppers and covers a maximum range from 1-9.25Å
We present Monte Carlo simulations with McStas giving detailed insight into the performance of the chopper
system.
P.143 The new neutron imaging beam line ANTARES at FRM II
M Schulz and B Schillinger
Technische Universität München, FRM II, Germany
Neutron imaging is a method which is being used in many different applications in the context of nondestructive
testing. After six years of operation during which excellent experiments have been performed, the neutron imaging
beam line ANTARES at FRM II has been completely rebuilt in the last two years and is now nearing completion.
Together with the rebuild a major upgrade has been performed and the beam line now comes back to operation with
new features, lower background and higher flexibility.
ANTARES now offers three separate chambers along the beam. The first chamber contains the collimators,
instrument shutter as well as all beam formation devices such as filter crystals, double crystal monochromator,
velocity selector, etc.
Following this chamber the user can choose between two experimental chambers. The first one offers a smaller
beam for high resolution / high flux and low background experiments with an adjustable L/D ratio of 100 - 3600. A
maximum flux of 1.9•109n/cm2/s can be achieved for time resolved imaging. The second chamber has a larger
beam size and ample space for even large sample environment. Here the L/D ratio can be varied between 200 and
7100.
In this presentation the new ANTARES beam line and its performance and features will be shown.
P.144 The design of the bispectral powder diffractometer at the ESS
W Schweika1, N Violini2, K Lieutenant3, A Houben4, P Jacobs4 and P F Henry5
1
ESS, FZ-Jülich, Germany, 2Forschungszentrum-Jülich, Germany, 3Helmholtz Centre Berlin, Germany, 4RWTH Aachen
University, Germany, 5European Spallation Source ESS AB, Sweden
Within the ESS Design Update Programme funded by the German Federal Ministry of Education and Research, we
investigate the performance of an instrument concept for powder diffraction at the ESS.
Regarding typical resolution properties of powder diffractometers, there is a clear preference for short-pulses and it
is necessary to tailor the long pulse of the ESS. However, the superior brightness of the ESS still ensures an
outstanding performance for powder diffraction. The benefit of pulse shaping is highly flexible resolution, which will
broaden the scope of potential scientific applications.
The simultaneous view of thermal and cold moderators results in an intense and broad wavelength band and leads
to a dedicated bispectral powder diffractometer. The instrument is attractive for the determination of complex unit
cells and magnetic ordered structures.
The conceptual design utilizes a 1 cm2 eye-of-the-needle[1] at 6 m from the source to reduce background and
shielding issues, and to fit in the beat chopper system, which provides flexible pulse shaping from 10 µs to 1 ms.
The desired brilliance for an initial divergence of +/- 0.25° on a 1 cm2 sample focus is transported by elliptic
guides with only small losses.
We shall discuss detector options and alternatives to 3He for covering a large solid angle and new concepts for data
acquisition and analysis.
[1]
A. Houben et al., NIMA, 2012,680, 124.
ICNS 2013 International Conference on Neutron Scattering
P.145 The design of the ESS single crystal magnetism diffractometer
W Schweika1 and A Gukasov2
1
ESS, Sweden / FZ-Jülich, Germany, 2Laboratoire Léon Brillouin, France
Neutron time-of-flight (TOF) Laue technique is best adapted to single crystal diffraction at a pulsed source. We
present an instrument for the ESS that takes full advantage of the long pulse structure and hence, the gain factors
to existing instruments will be very large. In addition to the gain in flux, a large volume of reciprocal space can be
measured by a 2D detector in a single sample setting.
The instrument will be dedicated to magnetism to collect high-precision data on magnetic Bragg and diffuse
scattering on possibly very small samples. Research topics are magnetic structure determination, magnetic disorder
and highly frustrated magnetism, site susceptibilities, spin density distributions, hydrogen bonding, parametric realtime exploration of reciprocal space and monitoring the order parameters of weak signals.
The use of polarized neutrons includes wide-angle xyz polarization analysis and spherical polarimetry, methods that
rigorously disentangle the various scattering contributions of magnetic, nuclear coherent, spin-incoherent scattering
and interference terms. A spin-echo method enables efficiently polarimetry for the white beam and for a wide range
of scattering angles. The user may benefit from the versatility of the instrument by adjusting wavelength band and
extracting efficiently neutrons from either the thermal or cold moderator spectrum.
P.146 Towards an engineering beamline at ESS
M Strobl1, R Kampmann2, J Saroun3, P Strunz3, J Pilch3, M Rouijaa2, P Staron2, H G Brokmeier2, P Sittner5, A
Steuwer6, M Mueller2, P Lukas3 and A Schreyer2
1
ESS-AB, Sweden, 2 Helmholtz Centre Berlin, Germany, 3ASCR, Czech Republic, 4FZU, Germany, 6Lund University,
Sweden
The Czech and the German neutron and engineering communities have created two different approaches for
engineering beamlines at the ESS: The ToF-design of a Czech approach is based on an upstream pulse shaping
chopper and a vertically focusing guide as an option for high neutron intensity, and the German one on a
modulation chopper. In collaboration with the ESS the approaches have been refined to on the one hand a medium
bandwidth instrument at what is referred to the “natural length” including a double disc pulse shaping chopper for
resolution tuning. This concept provides extended flexibility, allowing for various intensity and resolution modes as
well as wavelength bands. On the other hand a potential integration of the two concepts is investigated with the
perspective to offer optimized performance for various areas of applications in one instrument and taking advantage
of the German approach for multiplication of diffraction lines when a specific application allows to. It permits to
achieve very high count rates while preserving high resolution in the case of high symmetry materials.
Both concepts target scientific, engineering and industrial areas comprising especially in-situ testing and
characterization of engineering materials exposed to complex thermal, mechanical and electric or magnetic field
loading. Under particular consideration are (i) physical simulations of processing of engineering materials, (ii) longlasting creep and fatigue experiments, (iii) investigation of magnetic materials in pulsed magnetic field and (iv)
combination of in-situ diffraction and micro-imaging. The instrument will also be used for texture and residual stress
measurements serving industry.
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P.147 Polarised neutrons, to study the structure of liquid water: new developements at the ILL D3 diffractometer
A Stunault1, G Cuello1, T Laszlo2, P Laszlo2 and V Sebastien1
1
Institut Laue Langevin, France, 2Wigner Research Center for Physics, Hungary
Hydrogen containing liquids are very difficult to study by scattering methods, due to the specificity of hydrogen: Xrays are not really sensitive to hydrogen, and the exceptionally high level of spin incoherence of hydrogen atoms
renders the neutron diffraction data very difficult to analyse. A striking case is that of liquid water, for which over 90
% of the scattered neutron intensity is actually incoherent background. One way out is to separate the coherent and
incoherent parts of the neutron diffraction signal by using polarized neutrons: two thirds of the spin incoherent
scattering reverse the neutron polarisation, which is not affected by coherent scattering. By analysing the
polarisation of the scattered beam, one can expect to separate both contributions experimentally.
The short wavelength of hot neutron beams is well suited to structural studies of liquids, but polarisation analysis
used to be difficult at such short. Now, thanks to the huge progress on polarised 3He neutron spin filters from the
last decade, one can routinely analyse the neutron beam polarisation at short wavelengths.
The hot neutron diffractometer D3 at ILL, initially optimised for single crystal diffraction, can also serve structural
studies of liquids, after a number of minor modifications: implementation of Helmholtz coils, to maintain the neutron
polarisation along the beam path, modification of the pathways, for a larger beam cross section, and improved
shielding.
We will present the current status of the instrument upgrade, and the results of preliminary test measurements on
different H2O – D2O mixtures. As expected, most of the background is eliminated experimentally.
P.148 Application of neutron holography to polycrystalline samples
A Szakál1, G Krexner2, M Markó3 and L Cser1
1
WIGNER Research Centre for Physics, Hungary, 2University of Vienna, Austria, 3Paul Scherrer Institut, Switzerland
Neutron holography is considered to be an efficient tool to investigate the real-space structure of crystalline
materials. Previously it was proven that the interatomic positions of the neighbouring source or detector nuclei are
observable with high (picometry) accuracy [1]. This type of measurements require orientational order which
practically limits the possible candidates for samples to single crystals. However, restricting the aimed information
only to the value of the distances between the source/detector and surrounding nuclei the holographic observation
in principle can be applied to polycrystalline samples as well. In order to prove this statement we calculated the
expected holographic signal from a polycrystalline sample which is isotropic but depends on the wavelength of the
neutron. This wavelength dependce of the scattered signal can be obtained by the use of time-of-flight technique
and a proper mathematical procedure the values of internuclei distances can be get out. The model calculation
verifies this expectation. The experimental verification can be done at the existing pulsed sources being able to
provide conditions for succesful carrying out experimental proof of our predictions. This new method opens the way
towards the widening the field of applications to gain information about the local structure of many industrially
important materials.
[1]
Cser L et al, Direct observation of local distortion of a crystal lattice with picometer accuracy using atomic
resolution neutron holography, Phys. Rev. Lett. 97, 255501 (2006)
ICNS 2013 International Conference on Neutron Scattering
P.149 Development of the fast neutron imaging system for large-scale concrete structures
A Taketani1, Y Seki1, T Hashiguchi1, H Ota1, S Tanaka2, K Kino3, H Baba1, S Wang1, K Hirota4, Y Yamagata1 and Y
Otake1
1
RIKEN, Japan, 2KEK, Japan, 3Hokkaido University, Japan, 4Nagoya University, Japan
One of the urgent social issues in Japan is the aging deterioration of large-scale concrete structures such as bridges.
This concern increases the demand for novel methods of nondestructive inspection inside the concrete. The fast
neutron ( MeV) can penetrate thick concrete and be the promising probe for detecting its inner defect by the
radiography technique. The neutron radiography has more remarkable advantages than X-ray radiography. One is
strong penetration capability for the heavy materials and other is energy discrimination by the time of flight method.
In neutron imaging, water existence inside the measured object is easily detectable, and in addition, scattered
beam, which smears transmission image, can be rejected by energy selective detection. We propose a new fast
neutron imaging system for concrete structures with a compact neutron source available at outdoors. We also
develop the 2D fast neutron detector which consists of scintillators and solid state Multi-Pixel Photon Counters
(MPPC). The neutron radiographies of concrete samples have preliminary been performed, and the Monte Carlo
simulations have been carried out with respect to image visibility on the condition of using Riken Accelerator-driven
compact Neutron Source (RANS). We will report the status of fast neutron imaging development.
P.150 E9 & DEGAS: Neutron powder diffraction for structural studies at non-ambient atmospheres
D Többens1, D Wallacher1, M Russina1, L Smirnov2, I N Flerov3, P F Henry4, J Eggebrecht5 and A Lieb5
1
Helmholtz-Zentrum Berlin, Germany, 2FSBI SSC RF-Institute for Theoretical and Experimental Physics, Russia,
3
Russian Academy of Science, Russia, 4European Spallation Source ESS AB, 5University of Magdeburg, Germany
E9 is the fine-resolution powder diffractometer at the BER II reactor of the Helmholtz-Zentrum Berlin (HZB). In a
recent upgrade it was equipped with eight individual 2D DENEX detectors in a novel setup, at optimized, individually
variable distances from the sample.
Data collection speed for Rietveld quality data sets increased significantly. In a new stationary detector mode
specific 2Θ regions can be measured at a rate only limited by the samples scattering power. Through variable
sample-detector distance, intensity and resolution can be adapted to the specific scientific question. All detector
modes can be set up fully automatic, with very short changing times.
This instrumental characteristic makes E9 perfectly suited to employ the HZB’s suite of modular experimental setups for in-situ gas ad- and desorption measurements, DEGAS. Multiple different modules allow volumetric and
gravimetric sample loading with stepwise and continuous gas dosing. A wide range of temperature (4 – 1500 K)
and pressure (≤ 8 kbar) is accessible for a variety of gases. DEGAS also allows preliminary and completing
measurements "off-beam".
A series of successful recent experiments demonstrate the abilities of the combination of E9 & DEGAS:
The uptake of D2, CO2, and D2O into various metal-organic framework structures (MOFs) was studied, employing offbeam adsorption isotherms, Rietveld analysis of uptake sites at characteristic load factors, and dynamic gas
conditions.
The effect of low temperature and pressure up to 2.2 kbar on a structural free rotator ND4 was studied, employing a
He gas pressure cell inside a cryostat for isobaric temperature scans and Rietveld analysis at selected conditions.
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ICNS 2013 International Conference on Neutron Scattering
P.151 Newly established neutron diffraction facilities at the SAFARI-1 research reactor
A Venter, R van Heerden, C Raaths and D Marais
Necsa Limited, South Africa
The neutron diffraction facilities at the SAFARI-1 research reactor have undergone substantial upgrades. The fields
of application are independent powder diffraction and residual stress facilities respectively extracted from the same
primary beam channel. Facility optimization was done holistically by incorporating the performance needs
underlying both application fields. Improvements included:
• Beam quality optimization: For these facilities located on a radial beam line (Monte Carlo based Ray Trace
and MCNP5 modeling) in input-slit primary beam collimation geometry was identified, with beam flux and
instrumental resolution enhanced through the incorporation of double focused Si monochromators.
• New goniometers: Incorporating micro-step motion mechanical systems, as well as area detectors. The
substantially larger instruments necessitated the establishment of specialized instrumentation floors
(surface flatness better than 40 µm/m).
• Customisation of the instrument control systems: Based on the SICS system [1] in conjunction with the
Bragg Institute from Ansto.
• Sample environments: Temperature range 3.5K to 1900K covered respectively with the use of a closedcycle He adiabatic expansion cell and a vacuum furnace.
These new instruments will substantially enhance the suite of investigative techniques available to researchers from
South Africa and other regional counties.
[1]
H. Heer, M. Könnecke, and D. Maden, Physica B 241-243 (1998) 124-126
P.152 Reducing dead time on neutron residual stress experiments
R C Wimpory1, M Boin1 and C Randau2
1
Helmholtz-Zentrum Berlin, 2Technische Universität Clausthal/ FRMII TUM, Germany
Making faster measurements is one goal of a residual stress instrument. This can be achieved by increasing the
amount of flux impinging on the sample and the efficiency of detection of the neutrons. It can also be achieved by
reducing the time when the instrument is not measuring, which can be a significant fraction of the total beam time.
The amount of dead time between different experimental set-ups can be greatly reduced by thorough experimental
planning and by the use of optical devices such as a compact laser scanning system. A lot can be done before a
neutron cycle begins in terms of alignment and calibration of the instrument itself as well as the sample. The
ultimate goal is the bringing together and automatization of all available concepts, such as neutron simulations of
instrument and sample, optical alignment of instrument and sample, instrument control and real time data analysis.
The possibilities of doing this as well as recent developments and suggestions will be discussed.
ICNS 2013 International Conference on Neutron Scattering
P.153 The CARR high intensity powder diffractometer
W Y Yang1, H L Du1, J B Yang1, R Berliner2 and W B Yelon2
1
Peking University, China, 2Instrumentation Associates, USA
The High Intensity Powder Diffractometer (HIPD) is one of the initial suite of instruments to be installed at the 60
MW CARR reactor.
HIPD is located on BP-4 at CARR, a port that is shared with the High Resolution Powder Diffractometer. It employs a
doubly bent perfect silicon (Popovici) monochromator at a 90⁰ take-off angle and is optimized for the 511 reflection
and 1.478Ǻ. Beams at 2.31Ǻ, 1.76Ǻ, 1.17Ǻ and 1.07Ǻ are also accessible. The detector is a linear position
sensitive detector array composed of 11 LPSDs, each 2.54 cm in diameter and 61 cm active length. The detector
elements are clamped into a plane and mounted in a poly/borated-poly/Cd shield which is built to accommodate
up to 15 LPSD elements and which rotates about the specimen position on air bearings. The detector array spans
20⁰ 2-θ with the detector array at 1.6 m from the specimen position and 30⁰ 2-θ, at the 1.05 m distance. Position
encoding is by charge division. The instrument is expected to have a minimum resolution of δd/d 3*10-3 near
90⁰ 2-θ when the detector-specimen distance is 1.6 m and δd/d 4.5*10-3 at the 1.05 m sample to detector
distance.
Data acquisition times for the full 5⁰ – 105⁰ spectrum at full CARR power are expected to be a few minutes.
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ICNS 2013 International Conference on Neutron Scattering