Total thermal neutron cross section measurements serve as the primary means of validation for thermal neutron scattering kernels, an important quantity for neutron transport calculations. In an effort to improve the quality of thermal neutron scattering kernels, researchers at Rensselaer Polytechnic Institute (RPI) designed and constructed a polyethylene based cold moderation system to enhance neutron flux below 10 meV when coupled with the Enhanced Thermal Target (ETT) at the RPI Gaerttner LINAC. The final design yielded an increase in sub-thermal neutron flux (below 10 meV) by a factor of 4.5 for a moderator temperature of 37.5 K relative to the ETT alone. A further increase to a factor of 6 is expected after a minor geometry modification and decrease in polyethylene temperature to 25 K. This novel capability will be used to conduct total thermal neutron cross section measurements from 0.0005–10 eV for different materials including moderator materials.
{"title":"Enhancement of sub-thermal neutron flux through cold polyethylene","authors":"D. Fritz, Y. Danon, E. Liu","doi":"10.3233/jnr-210010","DOIUrl":"https://doi.org/10.3233/jnr-210010","url":null,"abstract":"Total thermal neutron cross section measurements serve as the primary means of validation for thermal neutron scattering kernels, an important quantity for neutron transport calculations. In an effort to improve the quality of thermal neutron scattering kernels, researchers at Rensselaer Polytechnic Institute (RPI) designed and constructed a polyethylene based cold moderation system to enhance neutron flux below 10 meV when coupled with the Enhanced Thermal Target (ETT) at the RPI Gaerttner LINAC. The final design yielded an increase in sub-thermal neutron flux (below 10 meV) by a factor of 4.5 for a moderator temperature of 37.5 K relative to the ETT alone. A further increase to a factor of 6 is expected after a minor geometry modification and decrease in polyethylene temperature to 25 K. This novel capability will be used to conduct total thermal neutron cross section measurements from 0.0005–10 eV for different materials including moderator materials.","PeriodicalId":44708,"journal":{"name":"Journal of Neutron Research","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3233/jnr-210010","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70093941","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. Rimmler, O. Felden, U. Rücker, H. Soltner, P. Zakalek, R. Gebel, T. Gutberlet, T. Brückel
The High-Brilliance Neutron Source project (HBS) aims at developing a medium-flux accelerator-driven neutron source based on a 70 MeV, 100 mA proton accelerator. The concept optimizes the facility such that it provides high-brilliance neutron beams for instruments operating at different time structures. This can be realized by generating an interlaced proton pulse structure, which is unraveled and sent to three different target stations by a multiplexer system. In the following we present the developments of a multiplexer system at the JULIC accelerator at Forschungszentrum Jülich GmbH (FZJ), which serves as test facility for HBS. The main components of the JULIC multiplexer system are designed to be scalable to the HBS parameters.
{"title":"Developments of a multiplexer system for the High-Brilliance Neutron Source HBS","authors":"M. Rimmler, O. Felden, U. Rücker, H. Soltner, P. Zakalek, R. Gebel, T. Gutberlet, T. Brückel","doi":"10.3233/jnr-210009","DOIUrl":"https://doi.org/10.3233/jnr-210009","url":null,"abstract":"The High-Brilliance Neutron Source project (HBS) aims at developing a medium-flux accelerator-driven neutron source based on a 70 MeV, 100 mA proton accelerator. The concept optimizes the facility such that it provides high-brilliance neutron beams for instruments operating at different time structures. This can be realized by generating an interlaced proton pulse structure, which is unraveled and sent to three different target stations by a multiplexer system. In the following we present the developments of a multiplexer system at the JULIC accelerator at Forschungszentrum Jülich GmbH (FZJ), which serves as test facility for HBS. The main components of the JULIC multiplexer system are designed to be scalable to the HBS parameters.","PeriodicalId":44708,"journal":{"name":"Journal of Neutron Research","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3233/jnr-210009","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70093772","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}
V. Kruglov, A. Balagurov, M. Belova, I. Bobrikov, A. Bogdzel’, V. Bodnarchuk, V. V. Bulavina, O. Daulbaev, V. Drozdov, V. Zhuravlev, A. Kirilov, S. Kulikov, A. K. Kurilkin, V. Milkov, S. Murashkevich, M. M. Podlesnyy, V. I. Prikhod’ko, A. Churakov, V. Shvetsov
The high-resolution Fourier diffractometer (HRFD) operates at the IBR-2 pulsed reactor, on which the correlation method of data registering has been implemented using a fast Fourier chopper and specialized electronics. A wide-aperture ring back-scattering detector for HRFD has been developed. The detector consists of six Z n S ( A g ) / 6 L i F-scintillation rings, each one of which is divided into 12 sections. Main parameters of this detector: covered solid angle 2 θ = ( 133 − 175 ) ∘ ; Ω d ≈ 2.0 sr; average absorption efficiency 85 %, geometric contribution to resolution Δ d / d < 0.0005. The concept of a detector and its data acquisition system are presented.
高分辨率傅立叶衍射仪(HRFD)工作在IBR-2脉冲反应堆上，利用快速傅立叶斩波器和专用电子器件实现了数据记录的相关方法。研制了一种用于HRFD的大孔径环形后向散射探测器。探测器由6个Z n S (A g) / 6 L i f闪烁环组成，每个闪烁环分为12个部分。本探测器主要参数:覆盖立体角2 θ =(133−175)°;Ω d≈2.0 sr;平均吸收效率85%，对分辨率的几何贡献Δ d / d < 0.0005。提出了探测器及其数据采集系统的概念。
{"title":"Wide-aperture back-scattering detector (BSD) for the High-Resolution Fourier Diffractometer (HRFD) at the IBR-2 reactor","authors":"V. Kruglov, A. Balagurov, M. Belova, I. Bobrikov, A. Bogdzel’, V. Bodnarchuk, V. V. Bulavina, O. Daulbaev, V. Drozdov, V. Zhuravlev, A. Kirilov, S. Kulikov, A. K. Kurilkin, V. Milkov, S. Murashkevich, M. M. Podlesnyy, V. I. Prikhod’ko, A. Churakov, V. Shvetsov","doi":"10.3233/jnr-210001","DOIUrl":"https://doi.org/10.3233/jnr-210001","url":null,"abstract":"The high-resolution Fourier diffractometer (HRFD) operates at the IBR-2 pulsed reactor, on which the correlation method of data registering has been implemented using a fast Fourier chopper and specialized electronics. A wide-aperture ring back-scattering detector for HRFD has been developed. The detector consists of six Z n S ( A g ) / 6 L i F-scintillation rings, each one of which is divided into 12 sections. Main parameters of this detector: covered solid angle 2 θ = ( 133 − 175 ) ∘ ; Ω d ≈ 2.0 sr; average absorption efficiency 85 %, geometric contribution to resolution Δ d / d < 0.0005. The concept of a detector and its data acquisition system are presented.","PeriodicalId":44708,"journal":{"name":"Journal of Neutron Research","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3233/jnr-210001","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70093697","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}
T. Robillard, P. Lavie, A. Dael, G. Aubert, P. Brédy, A. Madur, C. Berriaud, J. Rifflet, D. Nguyen-Ba, S. Klimko, G. Exil, X. Fabrèges, S. Petit, A. Bataille
The LLB is part of a large project aiming at the development of experimental tools available for the spintronics community. This includes the design and construction of vector magnets for neutron and X-ray scattering (deployed on the Léon Brillouin-Orphée and Synchrotron SOLEIL TGIRs: neutron diffractometer 6T2 and XMRS Sextants). For neutron scattering, a very innovative design has been developed, relying solely on the use of vertical axis coils. This magnet called WAVE (for Wide Aperture VEctor) is now available at the LLB-Orphée for the user community.
{"title":"WAVE – An innovative magnet devoted to spintronics","authors":"T. Robillard, P. Lavie, A. Dael, G. Aubert, P. Brédy, A. Madur, C. Berriaud, J. Rifflet, D. Nguyen-Ba, S. Klimko, G. Exil, X. Fabrèges, S. Petit, A. Bataille","doi":"10.3233/JNR-200167","DOIUrl":"https://doi.org/10.3233/JNR-200167","url":null,"abstract":"The LLB is part of a large project aiming at the development of experimental tools available for the spintronics community. This includes the design and construction of vector magnets for neutron and X-ray scattering (deployed on the Léon Brillouin-Orphée and Synchrotron SOLEIL TGIRs: neutron diffractometer 6T2 and XMRS Sextants). For neutron scattering, a very innovative design has been developed, relying solely on the use of vertical axis coils. This magnet called WAVE (for Wide Aperture VEctor) is now available at the LLB-Orphée for the user community.","PeriodicalId":44708,"journal":{"name":"Journal of Neutron Research","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2020-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3233/JNR-200167","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47576215","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 Italian Neutron Experimental Station, or INES for short, instrument beamline at the ISIS Neutron and Muon Spallation Source recently underwent an upgrade to its sample positioning area to improve the sample handling capability and capacity of the instrument. INES is a powder diffractometer instrument devoted to materials characterization and cultural heritage studies. Due to the types of samples received for cultural heritage studies the instrument scientists wanted to maximize the height of samples that could be scanned with the instrument. This paper covers the in-house design and delivery of a new, two axis, linear positioning stage for INES that due to the addition of a new linear height stage, needed to be as low profile as possible to give the instrument scientists the sample capacity they required.
{"title":"Design of low profile sample stage","authors":"S. Cooper","doi":"10.3233/jnr-200169","DOIUrl":"https://doi.org/10.3233/jnr-200169","url":null,"abstract":"The Italian Neutron Experimental Station, or INES for short, instrument beamline at the ISIS Neutron and Muon Spallation Source recently underwent an upgrade to its sample positioning area to improve the sample handling capability and capacity of the instrument. INES is a powder diffractometer instrument devoted to materials characterization and cultural heritage studies. Due to the types of samples received for cultural heritage studies the instrument scientists wanted to maximize the height of samples that could be scanned with the instrument. This paper covers the in-house design and delivery of a new, two axis, linear positioning stage for INES that due to the addition of a new linear height stage, needed to be as low profile as possible to give the instrument scientists the sample capacity they required.","PeriodicalId":44708,"journal":{"name":"Journal of Neutron Research","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2020-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3233/jnr-200169","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41543170","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}
{"title":"23rd Meeting of the International Collaboration on Advanced Neutron Sources Organized by the Neutron Sciences Directorate at the Oak Ridge National Laboratory (ORNL) Chattanooga Convention Center, Chattanooga, TN (USA) 13–18 October 2019","authors":"K. Herwig, E. Iverson","doi":"10.3233/jnr-200183","DOIUrl":"https://doi.org/10.3233/jnr-200183","url":null,"abstract":"","PeriodicalId":44708,"journal":{"name":"Journal of Neutron Research","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2020-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3233/jnr-200183","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41433879","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. Reggiani, B. Blau, R. Dölling, P. Duperrex, D. Kiselev, V. Talanov, J. Welte, M. Wohlmuther
With a nominal beam power of nearly 1.4 MW, the PSI High Intensity Proton Accelerator (HIPA) is currently at the forefront of the high intensity frontier of particle accelerators. Key issues of this facility are minimization of beam losses as well as safe operation of the SINQ spallation source. Particular attention is being recently paid towards an improved understanding of the properties of the SINQ beam line by both enhancing the beam transport simulations and developing new diagnostic elements which can also, in some cases, preserve the target integrity by preventing too large beam current density, inaccurate beam steering or improper beam delivery. Moreover, part of the SINQ beam diagnostic concept is being rethought in order to include important missing devices like BPMs. On the simulation side, newly developed composite calculations involving general purpose particle transport programs like MCNPX and BDSIM will deliver insights about beam losses and transmission through collimators. All recent and planned developments of the SINQ beam line will be discussed in this contribution.
{"title":"Improving beam simulations as well as machine and target protection in the SINQ beam line at PSI-HIPA","authors":"D. Reggiani, B. Blau, R. Dölling, P. Duperrex, D. Kiselev, V. Talanov, J. Welte, M. Wohlmuther","doi":"10.3233/jnr-200162","DOIUrl":"https://doi.org/10.3233/jnr-200162","url":null,"abstract":"With a nominal beam power of nearly 1.4 MW, the PSI High Intensity Proton Accelerator (HIPA) is currently at the forefront of the high intensity frontier of particle accelerators. Key issues of this facility are minimization of beam losses as well as safe operation of the SINQ spallation source. Particular attention is being recently paid towards an improved understanding of the properties of the SINQ beam line by both enhancing the beam transport simulations and developing new diagnostic elements which can also, in some cases, preserve the target integrity by preventing too large beam current density, inaccurate beam steering or improper beam delivery. Moreover, part of the SINQ beam diagnostic concept is being rethought in order to include important missing devices like BPMs. On the simulation side, newly developed composite calculations involving general purpose particle transport programs like MCNPX and BDSIM will deliver insights about beam losses and transmission through collimators. All recent and planned developments of the SINQ beam line will be discussed in this contribution.","PeriodicalId":44708,"journal":{"name":"Journal of Neutron Research","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2020-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3233/jnr-200162","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46576818","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. Capogni, M. Capone, A. Pietropaolo, A. Fazio, G. Dellepiane, R. Falconi, A. Colangeli, S. Palomba, G. Valentini, M. Fantuzi, R. Faccini, A. Pizzuto
64Cu is an emerging radionuclide of great interest in personalized nuclear medicine. It is produced by a cyclotron via the reaction 64Ni(p,n)64Cu. This production method increased during the last decades, because small biomedical cyclotrons can be easily installed close to the nuclear medicine department of a hospital. As a matter of fact, 64Ni is a very expensive target material. For this reason, an alternative 64Cu production method was investigated at ENEA by using the quasi-monochromatic 14 MeV fusion neutron beam made available at the Frascati Neutron Generator (FNG) located at the ENEA – Frascati Research Center. In particular, two nuclear reactions were studied: 65Cu(n,2n)64Cu and 64Zn(n,p)64Cu. The radiochemical analysis of the activated samples was performed at the ENEA-NMLNWM laboratory located in ENEA-Casaccia Research Center. The activity measurements were carried out at the ENEA-INMRI, located in the ENEA-Casaccia Research Center, with high metrological level conditions and by assuring their traceability to the 64Cu primary activity standard here developed and maintained. A prediction of the 64Cu production by means of the high-brilliance 14 MeV neutron source named Sorgentina is also discussed.
{"title":"64Cu production by 14 MeV neutron beam","authors":"M. Capogni, M. Capone, A. Pietropaolo, A. Fazio, G. Dellepiane, R. Falconi, A. Colangeli, S. Palomba, G. Valentini, M. Fantuzi, R. Faccini, A. Pizzuto","doi":"10.3233/jnr-190140","DOIUrl":"https://doi.org/10.3233/jnr-190140","url":null,"abstract":"64Cu is an emerging radionuclide of great interest in personalized nuclear medicine. It is produced by a cyclotron via the reaction 64Ni(p,n)64Cu. This production method increased during the last decades, because small biomedical cyclotrons can be easily installed close to the nuclear medicine department of a hospital. As a matter of fact, 64Ni is a very expensive target material. For this reason, an alternative 64Cu production method was investigated at ENEA by using the quasi-monochromatic 14 MeV fusion neutron beam made available at the Frascati Neutron Generator (FNG) located at the ENEA – Frascati Research Center. In particular, two nuclear reactions were studied: 65Cu(n,2n)64Cu and 64Zn(n,p)64Cu. The radiochemical analysis of the activated samples was performed at the ENEA-NMLNWM laboratory located in ENEA-Casaccia Research Center. The activity measurements were carried out at the ENEA-INMRI, located in the ENEA-Casaccia Research Center, with high metrological level conditions and by assuring their traceability to the 64Cu primary activity standard here developed and maintained. A prediction of the 64Cu production by means of the high-brilliance 14 MeV neutron source named Sorgentina is also discussed.","PeriodicalId":44708,"journal":{"name":"Journal of Neutron Research","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2020-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3233/jnr-190140","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41432310","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}
J. Lacy, A. Athanasiades, Christopher S. Martin, Richard Nguyen, Stephen Davenport, T. Lyons, Yangwei Liu
Modified boron-coated straw (BCS) detector configurations are introduced, in order to improve detection efficiency, and reduce the number of layers required to match the response of high-pressure 3He tubes, in large-scale neutron science instruments. A new 7-straw design employing thin-walled aluminum tubes facilitates operation in vacuum, and substantially reduces the scattering material by a factor of 5 compared with the flow-through design of the Multi-Grid detector. Another design introduces 18 radial walls inside each straw, coated on both sides with enriched boron carbide, to increase the coated wall perimeter 4.3 times. The so-called Pie straw offers a significant benefit in detection efficiency compared with round straws used in LoKI. An example of such a straw having 18 septa is explored in modeling and experimental studies, that can potentially reduce the number of layers needed in large-scale instruments like LoKI by a factor of 2.8. In a parallel development, a totally new configuration of boron-coated detectors is introduced, aimed to address the need for high spatial resolution, and high-rate capability in single crystal diffractometers, like MaNDi and TOPAZ at the SNS, and in neutron reflectometers. The proposed structure is a close-packed array of rectangular cells, each fabricated by wrapping copper foil having a coating of 10B4C on one side and electroplated tin on the other side, around precisely machined rectangular bars. The array is pressed together and then vacuum brazed together. The resulting structure is quite strong and precise in geometry. This so-called Microcell Straw Array can be configured with channel dimensions as small as 0.5 mm × 2.5 mm. Due to its ultra thin walls (25 μm) secondary scattering of neutrons is minimized. It is sealed inside a fully welded thin aluminum containment vessel that allows convenient operation in vacuum. A mature low power readout system capable of an estimated count rate of 22 MHz in a 15 × 15 cm2 detector is also proposed. The improvements are the result of recent advances in BCS design, spurred by the development of compact, high-sensitivity monitors for homeland security and military applications.
为了在大型中子科学仪器中提高检测效率，减少与高压3He管响应相匹配所需的层数，介绍了改进的硼包覆吸管(BCS)探测器配置。采用薄壁铝管的新型7吸管设计便于在真空中操作，与Multi-Grid检测器的流动设计相比，散射材料大大减少了5倍。另一种设计在每根稻草内部引入18个径向壁，两面涂有富集的碳化硼，使涂覆壁周长增加4.3倍。与LoKI中使用的圆形吸管相比，所谓的Pie吸管在检测效率方面具有显著的优势。在建模和实验研究中探索了这种具有18个隔层的吸管的例子，这可能会将LoKI等大型仪器所需的层数减少2.8倍。在平行发展中，介绍了一种全新的硼涂层探测器配置，旨在满足单晶衍射仪(如SNS的MaNDi和TOPAZ)和中子反射仪对高空间分辨率和高速率能力的需求。所提出的结构是一个紧密排列的矩形电池阵列，每个电池都是通过包裹铜箔制造的，铜箔的一面是10B4C涂层，另一面是电镀锡，周围是精密加工的矩形棒。阵列被压在一起，然后真空钎焊在一起。由此产生的结构在几何上相当坚固和精确。这种所谓的微细胞吸管阵列可以配置小至0.5 mm × 2.5 mm的通道尺寸。由于它的超薄壁(25 μm)，中子的二次散射最小。它被密封在一个完全焊接的薄铝容器内，可以方便地在真空中操作。提出了一种成熟的低功耗读出系统，在15 × 15 cm2的探测器中估计计数率为22 MHz。这些改进是BCS设计最近取得进展的结果，这是由用于国土安全和军事应用的紧凑型高灵敏度监视器的发展所推动的。
{"title":"Recent improvements in straw neutron detectors for large-scale neutron science instruments","authors":"J. Lacy, A. Athanasiades, Christopher S. Martin, Richard Nguyen, Stephen Davenport, T. Lyons, Yangwei Liu","doi":"10.3233/JNR-190138","DOIUrl":"https://doi.org/10.3233/JNR-190138","url":null,"abstract":"Modified boron-coated straw (BCS) detector configurations are introduced, in order to improve detection efficiency, and reduce the number of layers required to match the response of high-pressure 3He tubes, in large-scale neutron science instruments. A new 7-straw design employing thin-walled aluminum tubes facilitates operation in vacuum, and substantially reduces the scattering material by a factor of 5 compared with the flow-through design of the Multi-Grid detector. Another design introduces 18 radial walls inside each straw, coated on both sides with enriched boron carbide, to increase the coated wall perimeter 4.3 times. The so-called Pie straw offers a significant benefit in detection efficiency compared with round straws used in LoKI. An example of such a straw having 18 septa is explored in modeling and experimental studies, that can potentially reduce the number of layers needed in large-scale instruments like LoKI by a factor of 2.8. In a parallel development, a totally new configuration of boron-coated detectors is introduced, aimed to address the need for high spatial resolution, and high-rate capability in single crystal diffractometers, like MaNDi and TOPAZ at the SNS, and in neutron reflectometers. The proposed structure is a close-packed array of rectangular cells, each fabricated by wrapping copper foil having a coating of 10B4C on one side and electroplated tin on the other side, around precisely machined rectangular bars. The array is pressed together and then vacuum brazed together. The resulting structure is quite strong and precise in geometry. This so-called Microcell Straw Array can be configured with channel dimensions as small as 0.5 mm × 2.5 mm. Due to its ultra thin walls (25 μm) secondary scattering of neutrons is minimized. It is sealed inside a fully welded thin aluminum containment vessel that allows convenient operation in vacuum. A mature low power readout system capable of an estimated count rate of 22 MHz in a 15 × 15 cm2 detector is also proposed. The improvements are the result of recent advances in BCS design, spurred by the development of compact, high-sensitivity monitors for homeland security and military applications.","PeriodicalId":44708,"journal":{"name":"Journal of Neutron Research","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2020-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3233/JNR-190138","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46530146","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}
P. Mastinu, D. Bisello, Rogelio Alfonso Barrera, I. Porras, G. Prete, L. Silvestrin, J. Wyss
In this contribution we describe NEPIR, the fast-neutron irradiation facility under construction at the 70 MeV cyclotron SPES facility of the INFN laboratory of Legnaro (LNL). NEPIR will be constructed in stages, according to the available funds. The initial configuration, based on a thick Be neutron production target, will be operational in 2022; it will be used for shielding studies against fast neutrons for space applications and to investigate neutron-induced Single Event Effects (SEE) in microelectronic devices and systems. In its final configuration NEPIR will have two target systems: one will deliver a Quasi Mono-energetic Neutron (QMN) beam, of general interest, with an adjustable energy peak in the 20–70 MeV range; the second target will deliver a specialized continuous energy neutron beam for studying the effects of fast neutrons produced in cosmic ray air-showers in electronic devices and systems. We review the use of NEPIR to characterize the sensitivity of electronics, describe the neutron production targets and the facility layout. In closing we describe ways, presently under investigation, to use the 15 MV XTU Tandem of LNL to produce nearly monochromatic fast neutrons that would complement the QMN system by allowing one to probe for SEE below 20 MeV.
{"title":"Fast neutrons at LNL Legnaro","authors":"P. Mastinu, D. Bisello, Rogelio Alfonso Barrera, I. Porras, G. Prete, L. Silvestrin, J. Wyss","doi":"10.3233/jnr-200156","DOIUrl":"https://doi.org/10.3233/jnr-200156","url":null,"abstract":"In this contribution we describe NEPIR, the fast-neutron irradiation facility under construction at the 70 MeV cyclotron SPES facility of the INFN laboratory of Legnaro (LNL). NEPIR will be constructed in stages, according to the available funds. The initial configuration, based on a thick Be neutron production target, will be operational in 2022; it will be used for shielding studies against fast neutrons for space applications and to investigate neutron-induced Single Event Effects (SEE) in microelectronic devices and systems. In its final configuration NEPIR will have two target systems: one will deliver a Quasi Mono-energetic Neutron (QMN) beam, of general interest, with an adjustable energy peak in the 20–70 MeV range; the second target will deliver a specialized continuous energy neutron beam for studying the effects of fast neutrons produced in cosmic ray air-showers in electronic devices and systems. We review the use of NEPIR to characterize the sensitivity of electronics, describe the neutron production targets and the facility layout. In closing we describe ways, presently under investigation, to use the 15 MV XTU Tandem of LNL to produce nearly monochromatic fast neutrons that would complement the QMN system by allowing one to probe for SEE below 20 MeV.","PeriodicalId":44708,"journal":{"name":"Journal of Neutron Research","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2020-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3233/jnr-200156","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48696902","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：