V. Santoro, K. Andersen, D. Dijulio, E. Klinkby, T. Miller, D. Milstead, G. Muhrer, M.Stroble, A. Takibayev, L. Zanini, O. Zimmer
The European Spallation Source being constructed in Lund, Sweden will provide the user community with a neutron source of unprecedented brightness. By 2025, a suite of 15 instruments will be served by a high-brightness moderator system placed above the spallation target. The ESS infrastructure, consisting of the proton linac, the target station, and the instrument halls, allows for implementation of a second source below the spallation target. We propose to develop a second neutron source with a high-intensity moderator able to (1) deliver a larger total cold neutron flux, (2) provide high intensities at longer wavelengths in the spectral regions of Cold (4–10 Å), Very Cold (10–40 Å), and Ultra Cold (several 100 Å) neutrons, as opposed to Thermal and Cold neutrons delivered by the top moderator. Offering both unprecedented brilliance, flux, and spectral range in a single facility, this upgrade will make ESS the most versatile neutron source in the world and will further strengthen the leadership of Europe in neutron science. The new source will boost several areas of condensed matter research such as imaging and spin-echo, and will provide outstanding opportunities in fundamental physics investigations of the laws of nature at a precision unattainable anywhere else. At the heart of the proposed system is a volumetric liquid deuterium moderator. Based on proven technology, its performance will be optimized in a detailed engineering study. This moderator will be complemented by secondary sources to provide intense beams of Very- and Ultra-Cold Neutrons.
{"title":"Development of high intensity neutron source at the European Spallation Source","authors":"V. Santoro, K. Andersen, D. Dijulio, E. Klinkby, T. Miller, D. Milstead, G. Muhrer, M.Stroble, A. Takibayev, L. Zanini, O. Zimmer","doi":"10.3233/jnr-200159","DOIUrl":"https://doi.org/10.3233/jnr-200159","url":null,"abstract":"The European Spallation Source being constructed in Lund, Sweden will provide the user community with a neutron source of unprecedented brightness. By 2025, a suite of 15 instruments will be served by a high-brightness moderator system placed above the spallation target. The ESS infrastructure, consisting of the proton linac, the target station, and the instrument halls, allows for implementation of a second source below the spallation target. We propose to develop a second neutron source with a high-intensity moderator able to (1) deliver a larger total cold neutron flux, (2) provide high intensities at longer wavelengths in the spectral regions of Cold (4–10 Å), Very Cold (10–40 Å), and Ultra Cold (several 100 Å) neutrons, as opposed to Thermal and Cold neutrons delivered by the top moderator. Offering both unprecedented brilliance, flux, and spectral range in a single facility, this upgrade will make ESS the most versatile neutron source in the world and will further strengthen the leadership of Europe in neutron science. The new source will boost several areas of condensed matter research such as imaging and spin-echo, and will provide outstanding opportunities in fundamental physics investigations of the laws of nature at a precision unattainable anywhere else. At the heart of the proposed system is a volumetric liquid deuterium moderator. Based on proven technology, its performance will be optimized in a detailed engineering study. This moderator will be complemented by secondary sources to provide intense beams of Very- and Ultra-Cold Neutrons.","PeriodicalId":44708,"journal":{"name":"Journal of Neutron Research","volume":"1 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2020-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3233/jnr-200159","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70093148","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We acknowledge Grant No. PGC-2018-099024-B-I00 from Spanish Ministry of Science Innovation and Universities and funding from the project I-COOP B20319. This work was performed within the world class Science and Innovation with Neutrons in Europe 2020 (“SINE2020”) project, funded by the European Union’s Horizon 2020 research and innovation programme under grant agreement No. 654000.
{"title":"Routines for optimizing neutron scattering instruments with McStas","authors":"V. Laliena, M. V. Alvarez, J. D. Campo","doi":"10.3233/jnr-190117","DOIUrl":"https://doi.org/10.3233/jnr-190117","url":null,"abstract":"We acknowledge Grant No. PGC-2018-099024-B-I00 from Spanish Ministry of Science Innovation and Universities and funding from the project I-COOP B20319. This work was performed within the world class Science and Innovation with Neutrons in Europe 2020 (“SINE2020”) project, funded by the European Union’s Horizon 2020 research and innovation programme under grant agreement No. 654000.","PeriodicalId":44708,"journal":{"name":"Journal of Neutron Research","volume":"21 1","pages":"95-104"},"PeriodicalIF":1.1,"publicationDate":"2020-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3233/jnr-190117","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42039937","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S. Klotz, T. Hansen, E. Lelièvre-Berna, L. Amand, J. Maurice, C. Payre
Paris-Edinburgh (PE) presses are nowadays the dominant high pressure devices for neutron scattering in the 10 GPa range and above. Here, we present developments of gasket-anvil assemblies with 30% improved pressure performance and considerably increased lifetime compared to the currently used “single-toroidal” anvils, and giving nevertheless a similar signal-to-background ratio. We also present an improved Bridgman seal package which makes the low-temperature operation of the PE press significantly more reliable. A systematic investigation of background sources in the “equatorial” scattering geometry is reported.
{"title":"Advances in the use of Paris-Edinburgh presses for high pressure neutron scattering","authors":"S. Klotz, T. Hansen, E. Lelièvre-Berna, L. Amand, J. Maurice, C. Payre","doi":"10.3233/jnr-190120","DOIUrl":"https://doi.org/10.3233/jnr-190120","url":null,"abstract":"Paris-Edinburgh (PE) presses are nowadays the dominant high pressure devices for neutron scattering in the 10 GPa range and above. Here, we present developments of gasket-anvil assemblies with 30% improved pressure performance and considerably increased lifetime compared to the currently used “single-toroidal” anvils, and giving nevertheless a similar signal-to-background ratio. We also present an improved Bridgman seal package which makes the low-temperature operation of the PE press significantly more reliable. A systematic investigation of background sources in the “equatorial” scattering geometry is reported.","PeriodicalId":44708,"journal":{"name":"Journal of Neutron Research","volume":"21 1","pages":"117-124"},"PeriodicalIF":1.1,"publicationDate":"2020-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3233/jnr-190120","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47154425","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
K. Kiefer, L. Rossa, Frank Wutzler, Niklas Ektröm, Anders Pettersson, E. Faulhaber, Markus Zolliker
. The Sample Environment Communication Protocol (SECoP) serves as an international standard for the communication between sample environment equipment and the experiment control software at neutron and photon sources. It eases the integration of sample environment equipment supplied by external research groups and by industrial manufacturers. SECoP is designed to be simple, inclusive and self-describing. SECoP facilitates and structures the provision of metadata which is associated with sample environment equipment. Several existing implementations of SECoP support the development of SECoP-compatible sample environment control software. This article intro- duces SECoP Version 1.0, the first official version of SECoP published in September 2019. It was developed during the SINE2020 project in close cooperation with the International Society for Sample Environment. The complete specifications of SECoP Version 1.0 are available on GitHub.
{"title":"An introduction to SECoP – the sample environment communication protocol","authors":"K. Kiefer, L. Rossa, Frank Wutzler, Niklas Ektröm, Anders Pettersson, E. Faulhaber, Markus Zolliker","doi":"10.3233/jnr-190143","DOIUrl":"https://doi.org/10.3233/jnr-190143","url":null,"abstract":". The Sample Environment Communication Protocol (SECoP) serves as an international standard for the communication between sample environment equipment and the experiment control software at neutron and photon sources. It eases the integration of sample environment equipment supplied by external research groups and by industrial manufacturers. SECoP is designed to be simple, inclusive and self-describing. SECoP facilitates and structures the provision of metadata which is associated with sample environment equipment. Several existing implementations of SECoP support the development of SECoP-compatible sample environment control software. This article intro- duces SECoP Version 1.0, the first official version of SECoP published in September 2019. It was developed during the SINE2020 project in close cooperation with the International Society for Sample Environment. The complete specifications of SECoP Version 1.0 are available on GitHub.","PeriodicalId":44708,"journal":{"name":"Journal of Neutron Research","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2020-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3233/jnr-190143","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41549633","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
C. Goodway, P. Mcintyre, A. Sears, Nadir Belkhier, G. Burgess, O. Kirichek, E. Lelièvre-Berna, F. Marchal, Sébastien Turc, S. Wakefield
Blue series top-loading furnaces are regularly used at neutron facilities to carry out experiments at up to 1700◦C. The sample temperature is controlled using the indirect resistance heating method which consists in placing the sample inside a radiating cylindrical heater made from vanadium or niobium into which a current of up to 180 A circulates. To prevent the oxydation and deterioration of the heated elements, the sample, the heater and the heat shields are in a secondary vacuum which limits very much the cooling rate. We present an automated fast-cooling technique which reduces the cool-down time by a factor of 4 to 5 without impacting the lifetime of the heated elements. This method is now routinely used at the ILL and ISIS facilities and reduces very much beam time losses.
{"title":"A fast-cooling mode for blue series furnaces","authors":"C. Goodway, P. Mcintyre, A. Sears, Nadir Belkhier, G. Burgess, O. Kirichek, E. Lelièvre-Berna, F. Marchal, Sébastien Turc, S. Wakefield","doi":"10.3233/jnr-190128","DOIUrl":"https://doi.org/10.3233/jnr-190128","url":null,"abstract":"Blue series top-loading furnaces are regularly used at neutron facilities to carry out experiments at up to 1700◦C. The sample temperature is controlled using the indirect resistance heating method which consists in placing the sample inside a radiating cylindrical heater made from vanadium or niobium into which a current of up to 180 A circulates. To prevent the oxydation and deterioration of the heated elements, the sample, the heater and the heat shields are in a secondary vacuum which limits very much the cooling rate. We present an automated fast-cooling technique which reduces the cool-down time by a factor of 4 to 5 without impacting the lifetime of the heated elements. This method is now routinely used at the ILL and ISIS facilities and reduces very much beam time losses.","PeriodicalId":44708,"journal":{"name":"Journal of Neutron Research","volume":"21 1","pages":"137-142"},"PeriodicalIF":1.1,"publicationDate":"2020-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3233/jnr-190128","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47765983","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Muon spectroscopy offers a uniquely sensitive method for exploring many mechanisms in chemistry and chemical physics through the study of muonium, a probe species formed during muon implantation that is chemically equivalent to hydrogen. Next generation experiments in the field of muonium chemistry will require reliable liquid handling systems, in-situ experimental capabilities and access to advanced methods such as Radio-Frequency (RF) muon spin resonance spectroscopy. This paper discusses the development and commissioning of systems for sample handling, describing details of two liquid panels suitable for deoxygenation and transfer of liquid samples, the development of a centre stick for an existing 4He flow cryostat suitable for RF muon chemistry experiments, a dedicated muon chemistry insert specifically optimized for RF liquid phase chemistry experiments, and a birdcage RF cavity optimized for high frequency measurements and with a geometry wellsuited for beamline experiments that exploit the chemistry insert. Example data is presented, demonstrating the application of these various pieces of equipment.
{"title":"Next generation equipment for muon chemistry research","authors":"M. Aramini, S. Cottrell, J. Peck, K. Yokoyama","doi":"10.3233/jnr-190118","DOIUrl":"https://doi.org/10.3233/jnr-190118","url":null,"abstract":"Muon spectroscopy offers a uniquely sensitive method for exploring many mechanisms in chemistry and chemical physics through the study of muonium, a probe species formed during muon implantation that is chemically equivalent to hydrogen. Next generation experiments in the field of muonium chemistry will require reliable liquid handling systems, in-situ experimental capabilities and access to advanced methods such as Radio-Frequency (RF) muon spin resonance spectroscopy. This paper discusses the development and commissioning of systems for sample handling, describing details of two liquid panels suitable for deoxygenation and transfer of liquid samples, the development of a centre stick for an existing 4He flow cryostat suitable for RF muon chemistry experiments, a dedicated muon chemistry insert specifically optimized for RF liquid phase chemistry experiments, and a birdcage RF cavity optimized for high frequency measurements and with a geometry wellsuited for beamline experiments that exploit the chemistry insert. Example data is presented, demonstrating the application of these various pieces of equipment.","PeriodicalId":44708,"journal":{"name":"Journal of Neutron Research","volume":"103 27","pages":"143-154"},"PeriodicalIF":1.1,"publicationDate":"2020-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3233/jnr-190118","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41250488","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
D. Hajdú, E. Dian, E. Klinkby, C. Cooper-Jensen, J. Osán, P. Zagyvai
The neutron activation properties of the PE-B4C-concrete recently developed for the European Spallation Source (ESS) ERIC (European Spallation Source, https://europeanspallationsource.se/about) were investigated. On the one hand the concrete activation was compared to that of the ordinary concrete from which it was developed by means of irradiating concrete samples in the Budapest Research Reactor (BRR) (Budapest Neutron Centre, https://www.bnc.hu/). On the other hand, the measured activities were used to study the impact of input composition on Monte Carlo activation simulations. For this purpose, the complete course of the irradiation experiments were reproduced with MCNPX and Cinder90 simulations with nominal and measured elemental concrete compositions. Simulations suggest that for realistic activation predictions more detailed elemental compositions are required than the nominal ones. Energy-dispersive X-ray fluorescence (EDXRF) analysis technique was applied for this purpose, providing fair results for short-term activation estimations.
研究了新研制的用于欧洲散裂源(ESS) ERIC (European Spallation Source, https://europeanspallationsource.se/about)的pe - b4c混凝土的中子活化性能。一方面，混凝土活化与普通混凝土的活化进行了比较，普通混凝土是通过布达佩斯研究反应堆(BRR)(布达佩斯中子中心，https://www.bnc.hu/)中的辐照混凝土样品开发的。另一方面，测量的活度用于研究输入成分对蒙特卡罗激活模拟的影响。为此，用MCNPX和Cinder90模拟模拟了名义和实测混凝土元素成分，再现了辐照实验的完整过程。模拟表明，对于实际的活化预测，需要比名义上的更详细的元素组成。为此应用了能量色散x射线荧光(EDXRF)分析技术，为短期激活估计提供了公平的结果。
{"title":"Neutron activation properties of PE-B4C-concrete assessed by measurements and simulations","authors":"D. Hajdú, E. Dian, E. Klinkby, C. Cooper-Jensen, J. Osán, P. Zagyvai","doi":"10.3233/jnr-190126","DOIUrl":"https://doi.org/10.3233/jnr-190126","url":null,"abstract":"The neutron activation properties of the PE-B4C-concrete recently developed for the European Spallation Source (ESS) ERIC (European Spallation Source, https://europeanspallationsource.se/about) were investigated. On the one hand the concrete activation was compared to that of the ordinary concrete from which it was developed by means of irradiating concrete samples in the Budapest Research Reactor (BRR) (Budapest Neutron Centre, https://www.bnc.hu/). On the other hand, the measured activities were used to study the impact of input composition on Monte Carlo activation simulations. For this purpose, the complete course of the irradiation experiments were reproduced with MCNPX and Cinder90 simulations with nominal and measured elemental concrete compositions. Simulations suggest that for realistic activation predictions more detailed elemental compositions are required than the nominal ones. Energy-dispersive X-ray fluorescence (EDXRF) analysis technique was applied for this purpose, providing fair results for short-term activation estimations.","PeriodicalId":44708,"journal":{"name":"Journal of Neutron Research","volume":"21 1","pages":"87-94"},"PeriodicalIF":1.1,"publicationDate":"2020-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3233/jnr-190126","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42650625","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Kibble, V. Laliena, C. Goodway, E. Lelièvre-Berna, K. Kamenev, S. Klotz, O. Kirichek
This work was performed within the world class Science and Innovation with Neutrons in Europe 2020 (“SINE 2020”) project, funded by the European Commission, Grant Agreement n°654000.
{"title":"Low-background materials for high pressure cells used in inelastic neutron scattering experiments","authors":"M. Kibble, V. Laliena, C. Goodway, E. Lelièvre-Berna, K. Kamenev, S. Klotz, O. Kirichek","doi":"10.3233/jnr-190115","DOIUrl":"https://doi.org/10.3233/jnr-190115","url":null,"abstract":"This work was performed within the world class Science and Innovation with Neutrons in Europe 2020 (“SINE 2020”) project, funded by the European Commission, Grant Agreement n°654000.","PeriodicalId":44708,"journal":{"name":"Journal of Neutron Research","volume":"21 1","pages":"105-116"},"PeriodicalIF":1.1,"publicationDate":"2020-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3233/jnr-190115","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42637152","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
R. Oliveira-Silva, Agathe Belime, Clémence Le Coeur, Alexis Chennevière, A. Hélary, F. Cousin, P. Judeinstein, D. Sakellariou, J. Zanotti
. In soft condensed matter, Small Angle Neutron Scattering (SANS) is a central tool to probe structures with characteristic sizes ranging from 1 to 100 nm. However, when used as a standalone technique, the dynamic properties of the sample are not accessible. Nuclear Magnetic Resonance (NMR) is a versatile technique which can easily probe dynamical information. Here, we report on the coupling of a low-field NMR system to a SANS instrument. We show that this original set-up makes it possible to obtain structural information and to simultaneously extract in situ on a same sample, long-range translational diffusion coefficient, T 1 and T 2 nuclear spin relaxation times. Such a feature is of major interest when a sample experiences a transient physical state or evolves rapidly. We illustrate the capabilities of alliancing these experimental methods by following the critical temperature-induced phase separation of a concentrated Poly(Methacrylic Acid) solution at its Lower Critical Solution Temperature. The characteristic size related to the domain growth of the polymer-rich phase of the gel is monitored by the evolution of the SANS spectra, while the dynamics of the sol phase (H 2 O and polymer) is simultaneously characterized by NMR by measuring T 1 , T 2 and the diffusion coefficient. Great care has been taken to design a cell able to optimize the thermalization of the sample and in particular its equilibration time. Details are given on the sample cell specifically designed and manufactured for these experiments. The acquisition time needed to reach good signal-to-noise ratios, for both NMR and SANS, match: it is of the order of one hour. Altogether, we show that in situ low-field NMR/SANS coupling the NMR is meaningful and is a promising experimental approach.
{"title":"Coupling NMR to SANS: Addressing at once structure and dynamics in soft matter","authors":"R. Oliveira-Silva, Agathe Belime, Clémence Le Coeur, Alexis Chennevière, A. Hélary, F. Cousin, P. Judeinstein, D. Sakellariou, J. Zanotti","doi":"10.3233/jnr-190114","DOIUrl":"https://doi.org/10.3233/jnr-190114","url":null,"abstract":". In soft condensed matter, Small Angle Neutron Scattering (SANS) is a central tool to probe structures with characteristic sizes ranging from 1 to 100 nm. However, when used as a standalone technique, the dynamic properties of the sample are not accessible. Nuclear Magnetic Resonance (NMR) is a versatile technique which can easily probe dynamical information. Here, we report on the coupling of a low-field NMR system to a SANS instrument. We show that this original set-up makes it possible to obtain structural information and to simultaneously extract in situ on a same sample, long-range translational diffusion coefficient, T 1 and T 2 nuclear spin relaxation times. Such a feature is of major interest when a sample experiences a transient physical state or evolves rapidly. We illustrate the capabilities of alliancing these experimental methods by following the critical temperature-induced phase separation of a concentrated Poly(Methacrylic Acid) solution at its Lower Critical Solution Temperature. The characteristic size related to the domain growth of the polymer-rich phase of the gel is monitored by the evolution of the SANS spectra, while the dynamics of the sol phase (H 2 O and polymer) is simultaneously characterized by NMR by measuring T 1 , T 2 and the diffusion coefficient. Great care has been taken to design a cell able to optimize the thermalization of the sample and in particular its equilibration time. Details are given on the sample cell specifically designed and manufactured for these experiments. The acquisition time needed to reach good signal-to-noise ratios, for both NMR and SANS, match: it is of the order of one hour. Altogether, we show that in situ low-field NMR/SANS coupling the NMR is meaningful and is a promising experimental approach.","PeriodicalId":44708,"journal":{"name":"Journal of Neutron Research","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2020-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3233/jnr-190114","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46170939","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Neutron Spin Echo methods (NSE) use Larmor labelling to measure the precession phase of the neutron beam polarization around well-defined magnetic fields. Scattering by a sample can affect the resulting precession phase providing information on the sample's structure and dynamics with high accuracy and resolution. A major limitation for the performance of Neutron Spin Echo instruments is the homogeneity of the precession magnetic fields. Here we investigate the influence of the new 'pancake' moderator, which is being built at the European Spallation Source, on the design of a Neutron Spin Echo spectrometer. The calculations show clear gains when the height to width ratios of the rectangular beam cross-sections mimic those of the ESS 'pancake' moderator beams. In such a case the homogeneity of the magnetic field integrals could improve by at least 30%. However, the calculations show that will not be possible to preserve a high resolution and at the same time reduce the length of the instrument. Consequently, NSE spectrometers will perform better at the ESS but they will not be substantially compacter than at other neutron sources e.g. ILL or FRM2.
{"title":"Semi-analytical calculations of intrinsic field magnetic field inhomogeneities for a Neutron Spin Echo spectrometer at the ESS","authors":"A. Kusmin, C. Pappas","doi":"10.3233/jnr-190121","DOIUrl":"https://doi.org/10.3233/jnr-190121","url":null,"abstract":"Neutron Spin Echo methods (NSE) use Larmor labelling to measure the precession phase of the neutron beam polarization around well-defined magnetic fields. Scattering by a sample can affect the resulting precession phase providing information on the sample's structure and dynamics with high accuracy and resolution. A major limitation for the performance of Neutron Spin Echo instruments is the homogeneity of the precession magnetic fields. Here we investigate the influence of the new 'pancake' moderator, which is being built at the European Spallation Source, on the design of a Neutron Spin Echo spectrometer. The calculations show clear gains when the height to width ratios of the rectangular beam cross-sections mimic those of the ESS 'pancake' moderator beams. In such a case the homogeneity of the magnetic field integrals could improve by at least 30%. However, the calculations show that will not be possible to preserve a high resolution and at the same time reduce the length of the instrument. Consequently, NSE spectrometers will perform better at the ESS but they will not be substantially compacter than at other neutron sources e.g. ILL or FRM2.","PeriodicalId":44708,"journal":{"name":"Journal of Neutron Research","volume":"21 1","pages":"167-180"},"PeriodicalIF":1.1,"publicationDate":"2020-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3233/jnr-190121","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48322713","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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