Pub Date : 2024-10-23DOI: 10.1016/j.nima.2024.169966
D. Bosnar , L. Abbene , C. Amsler , F. Artibani , M. Bazzi , M. Bragadireanu , A. Buttacavoli , M. Cargnelli , M. Carminati , A. Clozza , F. Clozza , G. Deda , L. De Paolis , R. Del Grande , K. Dulski , L. Fabbietti , C. Fiorini , I. Friščić , C. Guaraldo , M. Iliescu , C. Curceanu
An HPGe detector equipped with a transistor reset preamplifier and readout with a CAEN DT5781 fast pulse digitizer was employed in the measurement of X-rays from kaonic lead at the DANE collider at the Laboratori Nazionali di Frascati of INFN. A thin scintillator in front of a lead target was used to select kaons impinging on it and to form the trigger for the HPGe detector. We present the results of the kaonic lead feasibility measurement, where we show that the resolution of the HPGe detector in regular beam conditions remains the same as that without the beam and that a satisfactory background reduction can be achieved. This measurement serves as a test bed for future dedicated kaonic X-rays measurements for the more precise determination of the charged kaon mass.
在 INFN 弗拉斯卡蒂国家实验室的 DAΦNE e+e- 对撞机上，使用了配备晶体管复位前置放大器和 CAEN DT5781 快速脉冲数字转换器读出的 HPGe 探测器来测量来自高子铅的 X 射线。铅靶前面的薄闪烁器被用来选择撞击它的高子，并形成 HPGe 探测器的触发器。我们展示了高子铅可行性测量的结果，结果表明，在正常光束条件下，HPGe 探测器的分辨率与无光束条件下的分辨率相同，并且可以实现令人满意的背景降低。这次测量为今后进行专门的高子 X 射线测量提供了试验平台，以便更精确地确定带电高子的质量。
{"title":"A feasibility study of the measurement of kaonic lead X-rays at DAΦNE for the precise determination of the charged kaon mass","authors":"D. Bosnar , L. Abbene , C. Amsler , F. Artibani , M. Bazzi , M. Bragadireanu , A. Buttacavoli , M. Cargnelli , M. Carminati , A. Clozza , F. Clozza , G. Deda , L. De Paolis , R. Del Grande , K. Dulski , L. Fabbietti , C. Fiorini , I. Friščić , C. Guaraldo , M. Iliescu , C. Curceanu","doi":"10.1016/j.nima.2024.169966","DOIUrl":"10.1016/j.nima.2024.169966","url":null,"abstract":"<div><div>An HPGe detector equipped with a transistor reset preamplifier and readout with a CAEN DT5781 fast pulse digitizer was employed in the measurement of X-rays from kaonic lead at the DA<span><math><mi>Φ</mi></math></span>NE <span><math><mrow><msup><mrow><mi>e</mi></mrow><mrow><mo>+</mo></mrow></msup><msup><mrow><mi>e</mi></mrow><mrow><mo>−</mo></mrow></msup></mrow></math></span> collider at the Laboratori Nazionali di Frascati of INFN. A thin scintillator in front of a lead target was used to select kaons impinging on it and to form the trigger for the HPGe detector. We present the results of the kaonic lead feasibility measurement, where we show that the resolution of the HPGe detector in regular beam conditions remains the same as that without the beam and that a satisfactory background reduction can be achieved. This measurement serves as a test bed for future dedicated kaonic X-rays measurements for the more precise determination of the charged kaon mass.</div></div>","PeriodicalId":19359,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment","volume":"1069 ","pages":"Article 169966"},"PeriodicalIF":1.5,"publicationDate":"2024-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142538859","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-23DOI: 10.1016/j.nima.2024.169992
R. Kino , S. Nagao , T. Akiyama , H. Fujioka , T. Fujiwara , T. Ishige , K. Itabashi , S. Kajikawa , M. Kaneta , M. Mizuno , S.N. Nakamura , K. Nishi , K. Nishida , K. Okuyama , F. Oura , K. Tachibana , Y. Toyama , D. Watanabe
A real-time beam profile monitoring system is proposed for GeV photon beams at the BM4 beamline of the Mikamine site, Research Center for Accelerator and Radioisotope Science (RARiS; previously known as ELPH) at Tohoku University. This monitoring system enhances the capability to monitor the entire beamline by incorporating newly developed beam profile monitors (BPMs) for upstream and midstream sections, in addition to the existing high-speed BPM used for downstream monitoring. This paper reports on the detection mechanisms of the newly developed BPMs and the actual measurement results obtained using the integrated beam monitoring system. The new BPMs are composed of plastic scintillation fibers and silicon photomultipliers, enabling high-precision, real-time measurements. Data acquisition utilizes streaming TDC, a firmware commonly employed in the J-PARC Hadron-hall, allowing real-time detection of high-intensity photon beams with count rates reaching several tens of MHz. With sufficient statistical data, the BPM achieved a 1-s beam-profiling accuracy of 10 . The proposed BPM system serves as a valuable resource for future physics experiments at the BM4 photon beamline and will significantly contribute to ongoing accelerator research endeavors.
{"title":"Development of a real-time beam profile monitor for GeV photons and its application in accelerator facilities","authors":"R. Kino , S. Nagao , T. Akiyama , H. Fujioka , T. Fujiwara , T. Ishige , K. Itabashi , S. Kajikawa , M. Kaneta , M. Mizuno , S.N. Nakamura , K. Nishi , K. Nishida , K. Okuyama , F. Oura , K. Tachibana , Y. Toyama , D. Watanabe","doi":"10.1016/j.nima.2024.169992","DOIUrl":"10.1016/j.nima.2024.169992","url":null,"abstract":"<div><div>A real-time beam profile monitoring system is proposed for GeV photon beams at the BM4 beamline of the Mikamine site, Research Center for Accelerator and Radioisotope Science (RARiS; previously known as ELPH) at Tohoku University. This monitoring system enhances the capability to monitor the entire beamline by incorporating newly developed beam profile monitors (BPMs) for upstream and midstream sections, in addition to the existing high-speed BPM used for downstream monitoring. This paper reports on the detection mechanisms of the newly developed BPMs and the actual measurement results obtained using the integrated beam monitoring system. The new BPMs are composed of plastic scintillation fibers and silicon photomultipliers, enabling high-precision, real-time measurements. Data acquisition utilizes streaming TDC, a firmware commonly employed in the J-PARC Hadron-hall, allowing real-time detection of high-intensity photon beams with count rates reaching several tens of MHz. With sufficient statistical data, the BPM achieved a 1-s beam-profiling accuracy of 10 <span><math><mrow><mi>μ</mi><mi>m</mi></mrow></math></span>. The proposed BPM system serves as a valuable resource for future physics experiments at the BM4 photon beamline and will significantly contribute to ongoing accelerator research endeavors.</div></div>","PeriodicalId":19359,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment","volume":"1070 ","pages":"Article 169992"},"PeriodicalIF":1.5,"publicationDate":"2024-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142573553","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-22DOI: 10.1016/j.nima.2024.169991
Shouyan Xu, Xiaohan Lu, Jianliang Chen, Yuwen An, Yong Li, Sheng Wang
At a Rapid Cycling Synchrotron (RCS), dynamic magnetic field errors, such as magnetic field tracking errors and dynamic fringe field effects, can cause time-dependent tune shift during beam acceleration. If the tune shift is significant enough to pass through resonance lines, it can lead to emittance growth and beam losses. Correcting time-dependent tune shift during acceleration is crucial for a RCS. Modulating the exciting current and magnetic field of quadrupole magnets at a RCS, which are powered by resonant circuits, is challenging during the ramping process. Correcting time-dependent tune shift at a RCS poses a significant technical challenge. We have proposed a method for correcting time-dependent tune shift at the rapid cycling synchrotron of China Spallation Neutron Source (CSNS), based on waveform compensation at the quadrupole magnets. This approach involves modulating the magnetic field variation process by injecting time harmonic exciting current into the quadrupole magnets. This method has been validated during the CSNS beam commissioning and has been applied at the RCS of CSNS to correct various dynamic magnetic field errors.
{"title":"Correction of dynamic magnetic field errors at the rapid cycling synchrotron of China Spallation Neutron Source","authors":"Shouyan Xu, Xiaohan Lu, Jianliang Chen, Yuwen An, Yong Li, Sheng Wang","doi":"10.1016/j.nima.2024.169991","DOIUrl":"10.1016/j.nima.2024.169991","url":null,"abstract":"<div><div>At a Rapid Cycling Synchrotron (RCS), dynamic magnetic field errors, such as magnetic field tracking errors and dynamic fringe field effects, can cause time-dependent tune shift during beam acceleration. If the tune shift is significant enough to pass through resonance lines, it can lead to emittance growth and beam losses. Correcting time-dependent tune shift during acceleration is crucial for a RCS. Modulating the exciting current and magnetic field of quadrupole magnets at a RCS, which are powered by resonant circuits, is challenging during the ramping process. Correcting time-dependent tune shift at a RCS poses a significant technical challenge. We have proposed a method for correcting time-dependent tune shift at the rapid cycling synchrotron of China Spallation Neutron Source (CSNS), based on waveform compensation at the quadrupole magnets. This approach involves modulating the magnetic field variation process by injecting time harmonic exciting current into the quadrupole magnets. This method has been validated during the CSNS beam commissioning and has been applied at the RCS of CSNS to correct various dynamic magnetic field errors.</div></div>","PeriodicalId":19359,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment","volume":"1069 ","pages":"Article 169991"},"PeriodicalIF":1.5,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142538751","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-21DOI: 10.1016/j.nima.2024.169988
Benjamin Folsom, Emanuele Laface
An algorithm is demonstrated that performs first-principles tracking of relativistic charged-particles. A covariant approach is used which relies on retarded vector potentials for trajectory integration instead of performing electromagnetic field calculations. When accounting for retardation effects, the peak vector potential and corresponding Lorentz force in the direction of travel increase asymptotically for high- particles. This produces a very strong field distribution at small angles from the particle’s direction of travel, which can result in considerable change in momentum when approaching a conducting or charged object. We study these dynamics using protons and electrons at relativistic energies passing through apertures in conducting surfaces, where substantial energy shifts are observed for particles passing within roughly of the aperture boundary.
We also simulate breaking a test particle’s line of sight with a conductor or other charged body. After this instant, the test particle continues to accelerate due to residual fields, but no longer produces an opposing force on any charged or conducting object; thus any recoil on the enclosing structure is effectively reduced. In this test, a 1% energy gain is observed for an 85 MeV electron traversing its reflected wake after having conducting plate in its path screened by a dielectric object.
We then incorporate a micro-scale dielectric laser acceleration (DLA) device into our simulations. Compared with a 2 mm DLA on its own, we find a factor of two increase in energy gain when adding a series of conducting-surface choppers.
演示了一种对相对论带电粒子进行第一原理跟踪的算法。该算法采用了一种协变方法，依靠迟滞矢量势进行轨迹积分，而不是进行电磁场计算。当考虑到迟滞效应时，对于高β粒子，行进方向上的峰值矢量势和相应的洛伦兹力会近似增加。这就在与粒子运动方向成很小角度时产生了很强的场分布，在接近导电或带电物体时会导致相当大的动量变化。我们利用质子和电子在相对论能量下穿过导电表面的孔洞来研究这些动力学。我们还模拟了测试粒子与导体或其他带电体的视线断裂。在这一瞬间之后，测试粒子由于残留场的作用而继续加速，但不再对任何带电体或导电体产生反作用力；因此，包围结构上的任何反冲力都会有效减弱。在这个测试中，我们观察到一个 85 MeV 的电子在其路径上的导电板被电介质物体屏蔽后，其反射尾迹的能量增益为 1%。与单独的 2 毫米 DLA 相比，我们发现在添加一系列导电表面斩波器后，能量增益提高了两倍。
{"title":"Relativistic beam loading, recoil-reduction, and residual-wake acceleration with a covariant retarded-potential integrator","authors":"Benjamin Folsom, Emanuele Laface","doi":"10.1016/j.nima.2024.169988","DOIUrl":"10.1016/j.nima.2024.169988","url":null,"abstract":"<div><div>An algorithm is demonstrated that performs first-principles tracking of relativistic charged-particles. A covariant approach is used which relies on retarded vector potentials for trajectory integration instead of performing electromagnetic field calculations. When accounting for retardation effects, the peak vector potential and corresponding Lorentz force in the direction of travel increase asymptotically for high-<span><math><mi>β</mi></math></span> particles. This produces a very strong field distribution at small angles from the particle’s direction of travel, which can result in considerable change in momentum when approaching a conducting or charged object. We study these dynamics using protons and electrons at relativistic energies passing through apertures in conducting surfaces, where substantial energy shifts are observed for particles passing within roughly <span><math><mrow><mn>10</mn><mspace></mspace><mi>μ</mi><mi>m</mi></mrow></math></span> of the aperture boundary.</div><div>We also simulate breaking a test particle’s line of sight with a conductor or other charged body. After this instant, the test particle continues to accelerate due to residual fields, but no longer produces an opposing force on any charged or conducting object; thus any recoil on the enclosing structure is effectively reduced. In this test, a 1% energy gain is observed for an 85 MeV electron traversing its reflected wake after having conducting plate in its path screened by a dielectric object.</div><div>We then incorporate a micro-scale dielectric laser acceleration (DLA) device into our simulations. Compared with a 2 mm DLA on its own, we find a factor of two increase in energy gain when adding a series of conducting-surface choppers.</div></div>","PeriodicalId":19359,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment","volume":"1069 ","pages":"Article 169988"},"PeriodicalIF":1.5,"publicationDate":"2024-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142538781","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-20DOI: 10.1016/j.nima.2024.169982
S. Ajimura , K. Akutagawa , T. Batpurev , F. Doukaku , K. Fushimi , R. Hazama , K. Ichimura , T. Iida , H. Kakubata , K. Kanagawa , S. Katagiri , B.T. Khai , T. Kishimoto , X. Li , T. Maeda , A. Masuda , K. Matsuoka , K. Mizukoshi , K. Morishita , K. Nakajima , N. Yotsunaga
The CANDLES-III detector was installed at the Kamioka Observatory in Japan to investigate the double decay of 48Ca. This system combines an undoped calcium fluoride scintillator with a long attenuation length (larger than 100 cm), and a two-phase liquid scintillator, thereby serving as a larger-mass detector of 305 kg (contains 350 g of 48Ca) while maintaining a high energy resolution (% at -value of 48Ca double beta decay). Low-background conditions are achieved in the energy region of interest by improving the light yield and collection efficiency of the detector system, allowing to access a high energy resolution, as well as by installing passive and active radiation shielding, and using pulse-shape analysis. This paper describes the details of the detector including its site and data acquisition system and presents its performance characterization.
{"title":"CANDLES-III detector: Low-background spectrometer for studying neutrino-less double β decay of 48Ca","authors":"S. Ajimura , K. Akutagawa , T. Batpurev , F. Doukaku , K. Fushimi , R. Hazama , K. Ichimura , T. Iida , H. Kakubata , K. Kanagawa , S. Katagiri , B.T. Khai , T. Kishimoto , X. Li , T. Maeda , A. Masuda , K. Matsuoka , K. Mizukoshi , K. Morishita , K. Nakajima , N. Yotsunaga","doi":"10.1016/j.nima.2024.169982","DOIUrl":"10.1016/j.nima.2024.169982","url":null,"abstract":"<div><div>The CANDLES-III detector was installed at the Kamioka Observatory in Japan to investigate the double <span><math><mi>β</mi></math></span> decay of <sup>48</sup>Ca. This system combines an undoped calcium fluoride scintillator with a long attenuation length (larger than 100 cm), and a two-phase liquid scintillator, thereby serving as a larger-mass detector of 305 kg (contains 350 g of <sup>48</sup>Ca) while maintaining a high energy resolution (<span><math><mrow><mi>σ</mi><mo>=</mo><mn>2</mn><mo>.</mo><mn>6</mn></mrow></math></span>% at <span><math><mi>Q</mi></math></span>-value of <sup>48</sup>Ca double beta decay). Low-background conditions are achieved in the energy region of interest by improving the light yield and collection efficiency of the detector system, allowing to access a high energy resolution, as well as by installing passive and active radiation shielding, and using pulse-shape analysis. This paper describes the details of the detector including its site and data acquisition system and presents its performance characterization.</div></div>","PeriodicalId":19359,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment","volume":"1069 ","pages":"Article 169982"},"PeriodicalIF":1.5,"publicationDate":"2024-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142538843","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-20DOI: 10.1016/j.nima.2024.169990
T. Matsumura , Y. Hirayama , G.Y. Lim , H. Nanjo , T. Nomura , K. Shiomi , H. Watanabe
A muon-flux measurement behind the beam dump of the J-PARC Hadron Experimental Facility was performed with a compact muon detector that can be inserted into a vertical observing hole with 81 mm in diameter which was dug underground. The detector consists of 12 plastic scintillation strips with a length of 80 mm each, which are arranged with cylindrical shape and contained inside an aluminum housing with an outer diameter of 75 mm. A silicon photomultiplier is coupled to the end of each strip to collect the scintillating light. The flux of the muons penetrating the beam dump was scanned vertically at intervals of 0.5 m, showing a wide distribution with a maximum at the beam level. The muon flux was consistent with the expectation from a Monte-Carlo simulation at more than 1 m away from the beam axis, which is expected to be used for signal-loss evaluation in the future KOTO II experiment for measuring rare kaon decays. The data can also be used in improving the accuracy of shielding calculations in the radiation protection.
{"title":"Measurement of muon flux behind the beam dump of the J-PARC Hadron Experimental Facility","authors":"T. Matsumura , Y. Hirayama , G.Y. Lim , H. Nanjo , T. Nomura , K. Shiomi , H. Watanabe","doi":"10.1016/j.nima.2024.169990","DOIUrl":"10.1016/j.nima.2024.169990","url":null,"abstract":"<div><div>A muon-flux measurement behind the beam dump of the J-PARC Hadron Experimental Facility was performed with a compact muon detector that can be inserted into a vertical observing hole with 81 mm in diameter which was dug underground. The detector consists of 12 plastic scintillation strips with a length of 80 mm each, which are arranged with cylindrical shape and contained inside an aluminum housing with an outer diameter of 75 mm. A silicon photomultiplier is coupled to the end of each strip to collect the scintillating light. The flux of the muons penetrating the beam dump was scanned vertically at intervals of 0.5 m, showing a wide distribution with a maximum at the beam level. The muon flux was consistent with the expectation from a Monte-Carlo simulation at more than 1 m away from the beam axis, which is expected to be used for signal-loss evaluation in the future KOTO II experiment for measuring rare kaon decays. The data can also be used in improving the accuracy of shielding calculations in the radiation protection.</div></div>","PeriodicalId":19359,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment","volume":"1069 ","pages":"Article 169990"},"PeriodicalIF":1.5,"publicationDate":"2024-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142538749","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-18DOI: 10.1016/j.nima.2024.169975
Kuo Zhao , Xiong-Nan Ma , Rui Meng , Ning Lv , Bin Wu , Hui-Ping Guo , Han Wang , Xiao-Yan Cao
Access to a gas tritium source with controlled concentrations is the key to calibrating tritium measurement instruments. In this study, a method of generating multi-concentration tritiated water vapor based on a closed circulation loop is outlined. The method produces tritiated water vapor by a bubbling process, the operational parameters for achieving the saturated bubbling process were determined through simulation. The temperature dependence of the isotope fractionation coefficient has been established through experimental tests. In order to avoid leakage of tritium and contamination of laboratory environment, tritiated water vapor generator was plugged into a closed loop and tested. Two tritiated water standard samples with known concentrations were used to produce 20 tritiated water vapor samples at 10 different temperatures, where the experimental results were in good agreement with the empirical formula. Based on the experimental results, the model for a non-closed loop tritiated water vapor generation has been modified, and the formula for multi-concentration tritiated water vapor generation based on a closed loop is established.
{"title":"A device to generate multi-concentration tritiated water vapor","authors":"Kuo Zhao , Xiong-Nan Ma , Rui Meng , Ning Lv , Bin Wu , Hui-Ping Guo , Han Wang , Xiao-Yan Cao","doi":"10.1016/j.nima.2024.169975","DOIUrl":"10.1016/j.nima.2024.169975","url":null,"abstract":"<div><div>Access to a gas tritium source with controlled concentrations is the key to calibrating tritium measurement instruments. In this study, a method of generating multi-concentration tritiated water vapor based on a closed circulation loop is outlined. The method produces tritiated water vapor by a bubbling process, the operational parameters for achieving the saturated bubbling process were determined through simulation. The temperature dependence of the isotope fractionation coefficient has been established through experimental tests. In order to avoid leakage of tritium and contamination of laboratory environment, tritiated water vapor generator was plugged into a closed loop and tested. Two tritiated water standard samples with known concentrations were used to produce 20 tritiated water vapor samples at 10 different temperatures, where the experimental results were in good agreement with the empirical formula. Based on the experimental results, the model for a non-closed loop tritiated water vapor generation has been modified, and the formula for multi-concentration tritiated water vapor generation based on a closed loop is established.</div></div>","PeriodicalId":19359,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment","volume":"1069 ","pages":"Article 169975"},"PeriodicalIF":1.5,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142538858","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-18DOI: 10.1016/j.nima.2024.169977
G. Kazakevich , R.P. Johnson , T. Khabiboulline , G. Romanov , V. Yakovlev , Ya. Derbenev , Yu. Eidelman
CW magnetrons, initially developed for industrial RF heaters, were suggested to power RF cavities of superconducting accelerators due to their higher efficiency and lower cost than traditionally used klystrons, IOTs or solid-state amplifiers. RF amplifiers driven by a master oscillator serve as coherent RF sources. CW magnetrons are regenerative RF generators with a huge regenerative gain. This causes regenerative instability with a quite large noise when a magnetron operates with the anode voltage above the threshold of self-excitation. Traditionally, an injection locking by a small signal is used for stabilization of magnetrons. In this case CW magnetrons with the injection-locked oscillations generate a high level of noise. This may preclude use of standard CW magnetrons in this operating mode in the Superconducting RF (SRF) accelerators. In this article we described a method developed for forced RF generation of CW magnetrons when the magnetron startup is provided by the injected forcing signal and the regenerative noise is suppressed. The method is most suitable for powering high Q-factor cavities.
{"title":"On forced RF generation of CW magnetrons for accelerators","authors":"G. Kazakevich , R.P. Johnson , T. Khabiboulline , G. Romanov , V. Yakovlev , Ya. Derbenev , Yu. Eidelman","doi":"10.1016/j.nima.2024.169977","DOIUrl":"10.1016/j.nima.2024.169977","url":null,"abstract":"<div><div>CW magnetrons, initially developed for industrial RF heaters, were suggested to power RF cavities of superconducting accelerators due to their higher efficiency and lower cost than traditionally used klystrons, IOTs or solid-state amplifiers. RF amplifiers driven by a master oscillator serve as coherent RF sources. CW magnetrons are regenerative RF generators with a huge regenerative gain. This causes regenerative instability with a quite large noise when a magnetron operates with the anode voltage above the threshold of self-excitation. Traditionally, an injection locking by a small signal is used for stabilization of magnetrons. In this case CW magnetrons with the injection-locked oscillations generate a high level of noise. This may preclude use of standard CW magnetrons in this operating mode in the Superconducting RF (SRF) accelerators. In this article we described a method developed for forced RF generation of CW magnetrons when the magnetron startup is provided by the injected forcing signal and the regenerative noise is suppressed. The method is most suitable for powering high Q-factor cavities.</div></div>","PeriodicalId":19359,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment","volume":"1069 ","pages":"Article 169977"},"PeriodicalIF":1.5,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142571506","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-18DOI: 10.1016/j.nima.2024.169995
Ray Gunnink , Andriy Berlizov
The Plutonium Attribute Test (PAT) is a software program originally developed for determining the category of a plutonium sample. The premise for its development was that, to assign Pu samples to particular categories, it is not necessary to determine the abundance of all its isotopes. Rather, it is sufficient to determine only 239Pu abundance, which is universally used to establish a category assignment, i.e., >90 wt% 239Pu is low burnup (LBPu), <70 wt% is high burnup (HBPu), and the abundances in between could be considered medium burnup (MBPu) plutonium grade. In contrast to previous Pu isotopic analysis programs which analyse spectra taken with HPGe detectors, the algorithms developed in PAT analyses use spectra taken with medium resolution detectors such as LaBr3(Ce) and CZT detectors. As demonstrated by initial tests, PAT was found capable of not only assigning the material category, but also accurately determining 239Pu abundance, with several per cent typical relative combined standard uncertainty. Furthermore, an advanced algorithm (A-PAT) was added to allow full isotopic characterization of samples. This paper presents further enhancements of the PAT/A-PAT algorithms towards analysis of heavily shielded samples, samples with varied size and age, as well as mixed oxide (MOX) materials.
{"title":"New capabilities of the PAT plutonium analysis program","authors":"Ray Gunnink , Andriy Berlizov","doi":"10.1016/j.nima.2024.169995","DOIUrl":"10.1016/j.nima.2024.169995","url":null,"abstract":"<div><div>The Plutonium Attribute Test (PAT) is a software program originally developed for determining the category of a plutonium sample. The premise for its development was that, to assign Pu samples to particular categories, it is not necessary to determine the abundance of all its isotopes. Rather, it is sufficient to determine only <sup>239</sup>Pu abundance, which is universally used to establish a category assignment, i.e., >90 wt% <sup>239</sup>Pu is low burnup (LBPu), <70 wt% is high burnup (HBPu), and the abundances in between could be considered medium burnup (MBPu) plutonium grade. In contrast to previous Pu isotopic analysis programs which analyse spectra taken with HPGe detectors, the algorithms developed in PAT analyses use spectra taken with medium resolution detectors such as LaBr<sub>3</sub>(Ce) and CZT detectors. As demonstrated by initial tests, PAT was found capable of not only assigning the material category, but also accurately determining <sup>239</sup>Pu abundance, with several per cent typical relative combined standard uncertainty. Furthermore, an advanced algorithm (A-PAT) was added to allow full isotopic characterization of samples. This paper presents further enhancements of the PAT/A-PAT algorithms towards analysis of heavily shielded samples, samples with varied size and age, as well as mixed oxide (MOX) materials.</div></div>","PeriodicalId":19359,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment","volume":"1069 ","pages":"Article 169995"},"PeriodicalIF":1.5,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142571507","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-18DOI: 10.1016/j.nima.2024.169981
Ye Yang , Kota Mizushima
A compact heavy-ion synchrotron is under development for next-generation cancer therapy. A superconducting magnet is designed with a main dipole field of 3.5 T and a field error less than 5 10−4 to maintain compactness. The coil is wound directly with monolithic Nb-Ti wire on a curved elliptical mandrel, comprising 22 laminated layers to achieve the desired magnetic field. Given the critical need for field quality, it is imperative to determine the tolerance of coil fabrication and to devise a method to eliminate field error during the design stage. This paper presents a numerical investigation of possible random geometric errors stemming from fabrication and assembly tolerances in a curved elliptical superconducting magnet. We first provide an analytical formulation derived in a complex plane to estimate the field error of a straight elliptical coil. We then conduct a Monte Carlo simulation to assess cases involving misalignment of individual wires and coil block sectors. Additionally, we compare simulation results with field measurements obtained from a short model magnet tested previously to predict potential random errors in manufacturing. Finally, we calculate the beam dynamic aperture to assess the effects of random geometric errors on beam loss using Monte Carlo simulation results. This method enables the prediction of tolerances for fabricating high-quality high-field magnets and aids in making design decisions concerning the utilization of active shim coils.
{"title":"Impact of random geometric errors in an elliptical superconducting magnet with application to a compact heavy-ion synchrotron","authors":"Ye Yang , Kota Mizushima","doi":"10.1016/j.nima.2024.169981","DOIUrl":"10.1016/j.nima.2024.169981","url":null,"abstract":"<div><div>A compact heavy-ion synchrotron is under development for next-generation cancer therapy. A superconducting magnet is designed with a main dipole field of 3.5 T and a field error less than 5 <span><math><mo>×</mo></math></span> 10<sup>−4</sup> to maintain compactness. The coil is wound directly with monolithic Nb-Ti wire on a curved elliptical mandrel, comprising 22 laminated layers to achieve the desired magnetic field. Given the critical need for field quality, it is imperative to determine the tolerance of coil fabrication and to devise a method to eliminate field error during the design stage. This paper presents a numerical investigation of possible random geometric errors stemming from fabrication and assembly tolerances in a curved elliptical superconducting magnet. We first provide an analytical formulation derived in a complex plane to estimate the field error of a straight elliptical coil. We then conduct a Monte Carlo simulation to assess cases involving misalignment of individual wires and coil block sectors. Additionally, we compare simulation results with field measurements obtained from a short model magnet tested previously to predict potential random errors in manufacturing. Finally, we calculate the beam dynamic aperture to assess the effects of random geometric errors on beam loss using Monte Carlo simulation results. This method enables the prediction of tolerances for fabricating high-quality high-field magnets and aids in making design decisions concerning the utilization of active shim coils.</div></div>","PeriodicalId":19359,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment","volume":"1069 ","pages":"Article 169981"},"PeriodicalIF":1.5,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142538780","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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