The European Spallation Source (ESS) in Lund, Sweden, is going to be the most powerful spallation neutron source in the world. As one subsystem of the Target Station, which was develop and built at Central Institute of Engineering, Electronics and Analytics – Engineering and Technology (ZEA-1) of Forschungszentrum Juelich, the cold Moderator slows down high energy neutrons from the spallation process. To gain maximum neutron flux intensities along with high system availability for condensed and soft matter research, an optimized liquid hydrogen Moderator circuit has been developed. Hydrogen with a pressure around 1 MPa, a temperature around 20 K, and a para-hydrogen fraction of at least 0.995 will be utilized to interact with neutrons in a unique cold Moderator vessel arrangement. Hydrogen conversion from ortho- to para-hydrogen will be controlled using a catalyst. Two turbo pumps are arranged in series and circulate the cryogen. A helium refrigerator, the Target Moderator Cryoplant (TMCP), continuously recools the hydrogen mass flow. The pressure stabilization is achieved by a pressure control buffer. The individual ESS Cryogenic Moderator System (CMS) components, the first and second generation of hydrogen Moderators (BF1 and BF2) and a first draft of a deuterium Moderator upgrade are described in detail.
{"title":"Cryogenic hydrogen Moderator infrastructure at ESS","authors":"Y. Bessler, G. Natour","doi":"10.3233/jnr-220033","DOIUrl":"https://doi.org/10.3233/jnr-220033","url":null,"abstract":"The European Spallation Source (ESS) in Lund, Sweden, is going to be the most powerful spallation neutron source in the world. As one subsystem of the Target Station, which was develop and built at Central Institute of Engineering, Electronics and Analytics – Engineering and Technology (ZEA-1) of Forschungszentrum Juelich, the cold Moderator slows down high energy neutrons from the spallation process. To gain maximum neutron flux intensities along with high system availability for condensed and soft matter research, an optimized liquid hydrogen Moderator circuit has been developed. Hydrogen with a pressure around 1 MPa, a temperature around 20 K, and a para-hydrogen fraction of at least 0.995 will be utilized to interact with neutrons in a unique cold Moderator vessel arrangement. Hydrogen conversion from ortho- to para-hydrogen will be controlled using a catalyst. Two turbo pumps are arranged in series and circulate the cryogen. A helium refrigerator, the Target Moderator Cryoplant (TMCP), continuously recools the hydrogen mass flow. The pressure stabilization is achieved by a pressure control buffer. The individual ESS Cryogenic Moderator System (CMS) components, the first and second generation of hydrogen Moderators (BF1 and BF2) and a first draft of a deuterium Moderator upgrade are described in detail.","PeriodicalId":44708,"journal":{"name":"Journal of Neutron Research","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2022-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43668799","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. Frost, M. Elfman, K. Fissum, Markus Kristensson, P. Kristiansson, N. Mauritzson, J. Pallon, H. Perrey, G. Pédehontaa-Hiaa, A. Sjöland, K. Stenström
The Applied Nuclear Physics Group at Lund University is constructing a prototype CANS (Compact Accelerator-driven Neutron Source). The CANS is based around a 3 MV, single-ended, Pelletron accelerator, which is used to impinge a 2.8 MeV deuterium beam into a beryllium target. The anticipated neutron production will be on the order of 1010 n/s in 4π sr. A further upgrade to the ion source of the Pelletron is expected to increase neutron production to 1011 n/s. Neutron energies will be up to 9 MeV with peak emission at ∼5 MeV. Shielding and moderation will be provided by a large water tank surrounding the target, with three exit ports to allow neutrons of different energies to be directed to experiments. The design is supported by simulation results which predict fast-neutron fluxes of 9×104 to 5×106 n/cm2/s, and thermal-neutron fluxes of 1×104 to 5×104 n/cm2/s to be readily obtainable with a 10 µA deuteron beam.
{"title":"Development of a Pelletron-based compact neutron source","authors":"R. Frost, M. Elfman, K. Fissum, Markus Kristensson, P. Kristiansson, N. Mauritzson, J. Pallon, H. Perrey, G. Pédehontaa-Hiaa, A. Sjöland, K. Stenström","doi":"10.3233/jnr-220026","DOIUrl":"https://doi.org/10.3233/jnr-220026","url":null,"abstract":"The Applied Nuclear Physics Group at Lund University is constructing a prototype CANS (Compact Accelerator-driven Neutron Source). The CANS is based around a 3 MV, single-ended, Pelletron accelerator, which is used to impinge a 2.8 MeV deuterium beam into a beryllium target. The anticipated neutron production will be on the order of 1010 n/s in 4π sr. A further upgrade to the ion source of the Pelletron is expected to increase neutron production to 1011 n/s. Neutron energies will be up to 9 MeV with peak emission at ∼5 MeV. Shielding and moderation will be provided by a large water tank surrounding the target, with three exit ports to allow neutrons of different energies to be directed to experiments. The design is supported by simulation results which predict fast-neutron fluxes of 9×104 to 5×106 n/cm2/s, and thermal-neutron fluxes of 1×104 to 5×104 n/cm2/s to be readily obtainable with a 10 µA deuteron beam.","PeriodicalId":44708,"journal":{"name":"Journal of Neutron Research","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2022-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43119832","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}
This note is based on a talk given at the “Workshop on Very Cold and Ultra Cold Neutron Sources for ESS”. It presents several arguments in favor of using very cold neutrons (VCN) for neutron – antineutron ( n − n ‾) searches. It also proposes a scheme for the implementation of a solid-deuterium VCN converter with a fluorinated detonation nanodiamond (F-DND) reflector that is optimized for an ( n − n ‾) experiment with VCN. An analysis of the feasibility of such a source, as well as its effect on the ( n − n ‾) experiment are beyond the scope of this short note. They will, however, be pursued in the near future in a collaborative manner.
{"title":"Why very cold neutrons could be useful for neutron antineutron oscillation searches","authors":"V. Nesvizhevsky","doi":"10.3233/jnr-220003","DOIUrl":"https://doi.org/10.3233/jnr-220003","url":null,"abstract":"This note is based on a talk given at the “Workshop on Very Cold and Ultra Cold Neutron Sources for ESS”. It presents several arguments in favor of using very cold neutrons (VCN) for neutron – antineutron ( n − n ‾) searches. It also proposes a scheme for the implementation of a solid-deuterium VCN converter with a fluorinated detonation nanodiamond (F-DND) reflector that is optimized for an ( n − n ‾) experiment with VCN. An analysis of the feasibility of such a source, as well as its effect on the ( n − n ‾) experiment are beyond the scope of this short note. They will, however, be pursued in the near future in a collaborative manner.","PeriodicalId":44708,"journal":{"name":"Journal of Neutron Research","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2022-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47569826","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}
The improvement of the neutron intensity of mesitylene cold moderator in KUANS has been conducted in two ways. One is the change of the mesitylene phase by annealing and the other is the optimization of the configuration. The change of the phase of the mesitylene was conducted by keeping the temperature of mesitylene just below its melting point for several hours. It made the cold neutron intensity about 20% larger than that of normally cooled mesitylene. For the configurational optimization, an arrangement giving highest cold neutron intensity was chosen using a Monte Carlo code. The cold neutron intensity measured with this arrangement revealed that its intensity is 3.4 times higher than that for a polyethylene moderator with room temperature.
{"title":"Improvement of the mesitylene cold moderator at KUANS","authors":"S. Tasaki, Hiroaki Yamakawa, Yutaka Abe","doi":"10.3233/jnr-220023","DOIUrl":"https://doi.org/10.3233/jnr-220023","url":null,"abstract":"The improvement of the neutron intensity of mesitylene cold moderator in KUANS has been conducted in two ways. One is the change of the mesitylene phase by annealing and the other is the optimization of the configuration. The change of the phase of the mesitylene was conducted by keeping the temperature of mesitylene just below its melting point for several hours. It made the cold neutron intensity about 20% larger than that of normally cooled mesitylene. For the configurational optimization, an arrangement giving highest cold neutron intensity was chosen using a Monte Carlo code. The cold neutron intensity measured with this arrangement revealed that its intensity is 3.4 times higher than that for a polyethylene moderator with room temperature.","PeriodicalId":44708,"journal":{"name":"Journal of Neutron Research","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2022-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45846211","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}
E. Chanel, Simon Baudoin, Marie-Hélène Baurand, Nadir Belkhier, Eric Bourgeat-Lami, S. Degenkolb, M. Jentschel, Victorien Joyet, M. Kreuz, E. Lelièvre-Berna, J. Lucas, X. Tonon, O. Zimmer
A new source of ultracold neutrons (UCNs), developed at the Institut Laue-Langevin (ILL) and named SuperSUN, is currently being commissioned. Its operational principle is the conversion of cold neutrons, delivered by ILL’s existing beam H523, to UCNs in a vessel filled with superfluid helium-4, wherein the neutron’s energy and momentum are transferred by inelastic scattering to phonons in the superfluid. The inverse Boltzmann-suppressed process is negligible at temperatures below 0.6 K, enabling long storage times and high in-situ UCN densities as demonstrated at the ILL for two prototype sources. These two prototypes are installed at secondary beams behind crystal monochromators, whereas a primary beam with a white cold spectrum illuminates the SuperSUN conversion volume. This provides not only higher intensity around the wavelength 0.89 nm where the dominant single-phonon process for UCN production takes place, but also a contribution to UCN production by multi-phonon processes. In the first phase of the project, material walls will trap the UCNs, while in the second phase an octupole magnet will generate a 2.1 T magnetic field at the edge of the conversion volume. For low-field-seeking UCNs, this field increases the trapping potential and reduces wall losses so that the accumulated UCNs are spin-polarized as a result. SuperSUN aims to deliver the highest possible UCN densities to external storage experiments, the first of which will be the PanEDM experiment measuring the neutron’s permanent electric dipole moment.
{"title":"Concept and strategy of SuperSUN: A new ultracold neutron converter","authors":"E. Chanel, Simon Baudoin, Marie-Hélène Baurand, Nadir Belkhier, Eric Bourgeat-Lami, S. Degenkolb, M. Jentschel, Victorien Joyet, M. Kreuz, E. Lelièvre-Berna, J. Lucas, X. Tonon, O. Zimmer","doi":"10.3233/jnr-220013","DOIUrl":"https://doi.org/10.3233/jnr-220013","url":null,"abstract":"A new source of ultracold neutrons (UCNs), developed at the Institut Laue-Langevin (ILL) and named SuperSUN, is currently being commissioned. Its operational principle is the conversion of cold neutrons, delivered by ILL’s existing beam H523, to UCNs in a vessel filled with superfluid helium-4, wherein the neutron’s energy and momentum are transferred by inelastic scattering to phonons in the superfluid. The inverse Boltzmann-suppressed process is negligible at temperatures below 0.6 K, enabling long storage times and high in-situ UCN densities as demonstrated at the ILL for two prototype sources. These two prototypes are installed at secondary beams behind crystal monochromators, whereas a primary beam with a white cold spectrum illuminates the SuperSUN conversion volume. This provides not only higher intensity around the wavelength 0.89 nm where the dominant single-phonon process for UCN production takes place, but also a contribution to UCN production by multi-phonon processes. In the first phase of the project, material walls will trap the UCNs, while in the second phase an octupole magnet will generate a 2.1 T magnetic field at the edge of the conversion volume. For low-field-seeking UCNs, this field increases the trapping potential and reduces wall losses so that the accumulated UCNs are spin-polarized as a result. SuperSUN aims to deliver the highest possible UCN densities to external storage experiments, the first of which will be the PanEDM experiment measuring the neutron’s permanent electric dipole moment.","PeriodicalId":44708,"journal":{"name":"Journal of Neutron Research","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2022-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48613317","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}
This note proposes a new concept for the production of ultracold neutrons (UCNs) in a decelerating trap. UCNs are widely used in the physics of elementary particles and fundamental interactions, and can potentially be used in studies of condensed matter. However, most of these studies are limited by the available UCN densities and fluxes. One of the ways to increase them is to use peak fluxes in pulsed neutron sources, orders of magnitude larger than the mean values. Here, a concept of UCN sources is proposed, which allows to implement this idea. We propose to produce very cold neutrons (VCNs) in converters located in a neutron source, extract and slow them down to UCNs by a decelerating magnetic or material trap. As shown in this paper, for both pulsed and continuous neutron sources, this method could provide a high conversion efficiency of VCNs to UCNs with low losses of density in the phase space. More detailed calculations and the proposals for concrete technical designs are going to be developed in future publications.
{"title":"Production of ultracold neutrons in a decelerating trap","authors":"V. Nesvizhevsky, A. Sidorin","doi":"10.3233/jnr-220006","DOIUrl":"https://doi.org/10.3233/jnr-220006","url":null,"abstract":"This note proposes a new concept for the production of ultracold neutrons (UCNs) in a decelerating trap. UCNs are widely used in the physics of elementary particles and fundamental interactions, and can potentially be used in studies of condensed matter. However, most of these studies are limited by the available UCN densities and fluxes. One of the ways to increase them is to use peak fluxes in pulsed neutron sources, orders of magnitude larger than the mean values. Here, a concept of UCN sources is proposed, which allows to implement this idea. We propose to produce very cold neutrons (VCNs) in converters located in a neutron source, extract and slow them down to UCNs by a decelerating magnetic or material trap. As shown in this paper, for both pulsed and continuous neutron sources, this method could provide a high conversion efficiency of VCNs to UCNs with low losses of density in the phase space. More detailed calculations and the proposals for concrete technical designs are going to be developed in future publications.","PeriodicalId":44708,"journal":{"name":"Journal of Neutron Research","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2022-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46162732","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}
Y. Wakabayashi, M. Yan, M. Takamura, Ryuutarou Ooishi, Hiroshi Watase, Yujiro Ikeda, Y. Otake
We have started the development of a transportable neutron salt-meter, we call it RANS-μ, combining a 252Cf neutron source and a prompt gamma neutron activation analysis. Trials of chloride detection measurement with RANS-μ were performed outdoor using removed bridges damaged by chloride attack at an outdoor yard in Public Works Research Institute (PWRI) and a test bridge in Fukushima Robot Test Field. For the measurement at PWRI, the results obtained by RANS-μ were compared with those of the automatic potentiometric titration by drilled powder, and then consistent results were obtained.
{"title":"Development of the neutron salt-meter RANS-μ for non-destructive inspection of concrete structure at on-site use","authors":"Y. Wakabayashi, M. Yan, M. Takamura, Ryuutarou Ooishi, Hiroshi Watase, Yujiro Ikeda, Y. Otake","doi":"10.3233/jnr-220031","DOIUrl":"https://doi.org/10.3233/jnr-220031","url":null,"abstract":"We have started the development of a transportable neutron salt-meter, we call it RANS-μ, combining a 252Cf neutron source and a prompt gamma neutron activation analysis. Trials of chloride detection measurement with RANS-μ were performed outdoor using removed bridges damaged by chloride attack at an outdoor yard in Public Works Research Institute (PWRI) and a test bridge in Fukushima Robot Test Field. For the measurement at PWRI, the results obtained by RANS-μ were compared with those of the automatic potentiometric titration by drilled powder, and then consistent results were obtained.","PeriodicalId":44708,"journal":{"name":"Journal of Neutron Research","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2022-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42870424","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}
The IPHI–Neutrons facility is a low energy neutron CANS ( E p = 3 MeV) used to test various technologies for the construction of high current CANS (HiCANS). Part of the research program includes the investigation of the possibility to perform neutron scattering and radiography experiments around CANS. For this purpose, the DIoGENE instrument has recently been installed around the IPHI source. The instrument is aimed as a general-purpose neutron scattering instrument featuring 256 high-pressure 3 He tubes covering a solid angle of 0.74 sr. The instrument is especially suited for diffraction experiments but may be upgraded as a SANS or reflectometry instrument. We are using the DIoGENE instrument to investigate the performances of the neutron TMR, the issues related to background noise due to fast neutrons and gamma rays productions and more generally the ToF data acquisition protocols and processing in event mode. We present in this communication the recent diffraction results obtained on DIoGENE during the tests of the new high power Be target on IPHI–Neutrons.
iphi -中子设备是一个低能中子can (E p = 3 MeV)，用于测试用于构建大电流can (HiCANS)的各种技术。研究计划的一部分包括研究在can周围进行中子散射和射线照相实验的可能性。为此，最近在IPHI源周围安装了DIoGENE仪器。该仪器的目的是作为一个通用的中子散射仪器，具有256个高压3氦管，覆盖0.74 sr的立体角。该仪器特别适合于衍射实验，但可以升级为SANS或反射仪。我们正在使用DIoGENE仪器研究中子TMR的性能，快中子和伽马射线产生的背景噪声相关问题，以及更普遍的ToF数据采集协议和事件模式下的处理。本文介绍了新型高功率Be靶在ihi中子上的最新衍射结果。
{"title":"Neutron scattering on DIoGENE at IPHI–neutrons","authors":"J. Darpentigny, F. Ott","doi":"10.3233/jnr-220018","DOIUrl":"https://doi.org/10.3233/jnr-220018","url":null,"abstract":"The IPHI–Neutrons facility is a low energy neutron CANS ( E p = 3 MeV) used to test various technologies for the construction of high current CANS (HiCANS). Part of the research program includes the investigation of the possibility to perform neutron scattering and radiography experiments around CANS. For this purpose, the DIoGENE instrument has recently been installed around the IPHI source. The instrument is aimed as a general-purpose neutron scattering instrument featuring 256 high-pressure 3 He tubes covering a solid angle of 0.74 sr. The instrument is especially suited for diffraction experiments but may be upgraded as a SANS or reflectometry instrument. We are using the DIoGENE instrument to investigate the performances of the neutron TMR, the issues related to background noise due to fast neutrons and gamma rays productions and more generally the ToF data acquisition protocols and processing in event mode. We present in this communication the recent diffraction results obtained on DIoGENE during the tests of the new high power Be target on IPHI–Neutrons.","PeriodicalId":44708,"journal":{"name":"Journal of Neutron Research","volume":"1 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2022-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41336675","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. Ikeda, Tomohiro Kobayashi, Y. Otake, Ryuji Matsui, M. Okamura, N. Hayashizaki
At RIKEN, a transportable accelerator-driven compact neutron source (RANS-III) is under development for an on-site nondestructive inspection of the degradation of old concrete and reinforcing steel. RANS-III consists of an ion source, a low-energy beam transport, a radio frequency quadrupole linear accelerator (RFQ linac), a radio frequency (RF) system, a high-energy beam transport, a target station and a neutron measurement system. Because the inner diameter of the RFQ linac is inversely proportional to the resonance frequency, the resonance frequency of the RANS-III RFQ linac in this study was chosen to be 500 MHz, which is 2.5 times that of the RANS-II RFQ linac. Therefore, the inner diameter and weight of the RANS-III RFQ linac were reduced to approximately half and one third, respectively, of those of the RANS-II RFQ linac. The RANS-III RFQ linac was designed to accelerate a proton beam with a 10 mA peak current and 100 μA average beam current from 30 keV to 2.49 MeV (Journal of Disaster Research 12(3) (2017) 585–592). Based on the evaluations, an RFQ linac for RANS-III was fabricated, and the RF characteristics of the cavity, such as the resonant frequency and electric-field distribution, were measured using a low-power test and tuned using fixed tuners. In addition, RF couplers and RF systems were constructed to inject RF power into the RANS-III RFQ linac, and RF input tests were performed.
{"title":"Fabrication and RF test of the 500 MHz-RFQ linear accelerator for a transportable neutron source RANS-III","authors":"S. Ikeda, Tomohiro Kobayashi, Y. Otake, Ryuji Matsui, M. Okamura, N. Hayashizaki","doi":"10.3233/jnr-220021","DOIUrl":"https://doi.org/10.3233/jnr-220021","url":null,"abstract":"At RIKEN, a transportable accelerator-driven compact neutron source (RANS-III) is under development for an on-site nondestructive inspection of the degradation of old concrete and reinforcing steel. RANS-III consists of an ion source, a low-energy beam transport, a radio frequency quadrupole linear accelerator (RFQ linac), a radio frequency (RF) system, a high-energy beam transport, a target station and a neutron measurement system. Because the inner diameter of the RFQ linac is inversely proportional to the resonance frequency, the resonance frequency of the RANS-III RFQ linac in this study was chosen to be 500 MHz, which is 2.5 times that of the RANS-II RFQ linac. Therefore, the inner diameter and weight of the RANS-III RFQ linac were reduced to approximately half and one third, respectively, of those of the RANS-II RFQ linac. The RANS-III RFQ linac was designed to accelerate a proton beam with a 10 mA peak current and 100 μA average beam current from 30 keV to 2.49 MeV (Journal of Disaster Research 12(3) (2017) 585–592). Based on the evaluations, an RFQ linac for RANS-III was fabricated, and the RF characteristics of the cavity, such as the resonant frequency and electric-field distribution, were measured using a low-power test and tuned using fixed tuners. In addition, RF couplers and RF systems were constructed to inject RF power into the RANS-III RFQ linac, and RF input tests were performed.","PeriodicalId":44708,"journal":{"name":"Journal of Neutron Research","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2022-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42562382","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}
In high resolution neutron scattering experimental work the use of significantly longer incoming neutron wavelengths compared to the currently widely used cold neutron range can be of significant advantage. Such advantages are to obtain higher data rates at equal resolution conditions, for example in small angle neutron scattering, to obtain far better resolution, e.g. in neutron spin echo and time-of-flight spectroscopy or both.
{"title":"Very cold neutrons in condensed matter research","authors":"F. Mezei","doi":"10.3233/jnr-220012","DOIUrl":"https://doi.org/10.3233/jnr-220012","url":null,"abstract":"In high resolution neutron scattering experimental work the use of significantly longer incoming neutron wavelengths compared to the currently widely used cold neutron range can be of significant advantage. Such advantages are to obtain higher data rates at equal resolution conditions, for example in small angle neutron scattering, to obtain far better resolution, e.g. in neutron spin echo and time-of-flight spectroscopy or both.","PeriodicalId":44708,"journal":{"name":"Journal of Neutron Research","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2022-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45811667","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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