Aligning beamlines at synchrotron light sources is a high-dimensional, expensive-to-sample optimization problem, as beams are focused using a series of dynamic optical components. Bayesian Optimization is an efficient machine learning approach to finding global optima of beam quality, but the model can easily be impaired by faulty data points caused by the beam going off the edge of the sensor or by background noise. This study, conducted at the National Synchrotron Light Source II (NSLS-II) facility at Brookhaven National Laboratory (BNL), is an investigation of methods to identify untrustworthy readings of beam quality and discourage the optimization model from seeking out points likely to yield low-fidelity beams. The approaches explored include dynamic pruning using loss analysis of size and position models and a lengthscale-based genetic algorithm to determine which points to include in the model for optimal fit. Each method successfully classified high and low fidelity points. This research advances BNL's mission to tackle our nation's energy challenges by providing scientists at all beamlines with access to higher quality beams, and faster convergence to these optima for their experiments.
{"title":"Dynamic Exclusion of Low-Fidelity Data in Bayesian Optimization for Autonomous Beamline Alignment","authors":"Megha R. Narayanan, Thomas W. Morris","doi":"arxiv-2408.06540","DOIUrl":"https://doi.org/arxiv-2408.06540","url":null,"abstract":"Aligning beamlines at synchrotron light sources is a high-dimensional,\u0000expensive-to-sample optimization problem, as beams are focused using a series\u0000of dynamic optical components. Bayesian Optimization is an efficient machine\u0000learning approach to finding global optima of beam quality, but the model can\u0000easily be impaired by faulty data points caused by the beam going off the edge\u0000of the sensor or by background noise. This study, conducted at the National\u0000Synchrotron Light Source II (NSLS-II) facility at Brookhaven National\u0000Laboratory (BNL), is an investigation of methods to identify untrustworthy\u0000readings of beam quality and discourage the optimization model from seeking out\u0000points likely to yield low-fidelity beams. The approaches explored include\u0000dynamic pruning using loss analysis of size and position models and a\u0000lengthscale-based genetic algorithm to determine which points to include in the\u0000model for optimal fit. Each method successfully classified high and low\u0000fidelity points. This research advances BNL's mission to tackle our nation's\u0000energy challenges by providing scientists at all beamlines with access to\u0000higher quality beams, and faster convergence to these optima for their\u0000experiments.","PeriodicalId":501318,"journal":{"name":"arXiv - PHYS - Accelerator Physics","volume":"64 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142216296","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. Vieira, B. Cros, P. Muggli, I. A. Andriyash, O. Apsimon, M. Backhouse, C. Benedetti, S. S. Bulanov, A. Caldwell, Min Chen, V. Cilento, S. Corde, R. D'Arcy, S. Diederichs, E. Ericson, E. Esarey, J. Farmer, L. Fedeli, A. Formenti, B. Foster, M. Garten, C. G. R. Geddes, T. Grismayer, M. J. Hogan, S. Hooker, A. Huebl, S. Jalas, M. Kirchen, R. Lehe, W. Leemans, Boyuan Li, C. A. Lindström, R. Losito, C. E. Mitchell, W. B. Mori, P. Muggli, D. Terzani, M. Thévenet, M. Turner, J. -L. Vay, J. Vieira, D. Völker, Jie Zhang, W. Zhang
The workshop focused on the application of ANAs to particle physics keeping in mind the ultimate goal of a collider at the energy frontier (10,TeV, e$^+$/e$^-$, e$^-$/e$^-$, or $gammagamma$). The development of ANAs is conducted at universities and national laboratories worldwide. The community is thematically broad and diverse, in particular since lasers suitable for ANA research (multi-hundred-terawatt peak power, a few tens of femtosecond-long pulses) and acceleration of electrons to hundreds of mega electron volts to multi giga electron volts became commercially available. The community spans several continents (Europe, America, Asia), including more than 62 laboratories in more than 20 countries. It is among the missions of the ICFA-ANA panel to feature the amazing progress made with ANAs, to provide international coordination and to foster international collaborations towards a future HEP collider. The scope of this edition of the workshop was to discuss the recent progress and necessary steps towards realizing a linear collider for particle physics based on novel-accelerator technologies (laser or beam driven in plasma or structures). Updates on the relevant aspects of the European Strategy for Particle Physics (ESPP) Roadmap Process as well as of the P5 (in the US) were presented, and ample time was dedicated to discussions. The major outcome of the workshop is the decision for ALEGRO to coordinate efforts in Europe, in the US, and in Asia towards a pre-CDR for an ANA-based, 10,TeV CM collider. This goal of this coordination is to lead to a funding proposal to be submitted to both EU and EU/US funding agencies. This document presents a summary of the workshop, as seen by the co-chairs, as well as short 'one-pagers' written by the presenters at the workshop.
研讨会重点讨论了ANA在粒子物理学中的应用，并牢记在能量前沿（10,TeV,e$^+$/e$^-$, e$^-$/e$^-$, 或$gammagamma$）建造对撞机的最终目标。全世界的大学和国家实验室都在开发 ANA。特别是自从适合 ANA 研究的激光器（数百兆瓦峰值功率、几十飞秒长脉冲）和将电子加速到数百兆电子伏特到数千兆电子伏特后，这一研究领域变得广泛而多样。该社区横跨几大洲（欧洲、美洲和亚洲），包括 20 多个国家的 62 个实验室。ICFA-ANA 小组的使命之一就是展示 ANA 取得的惊人进展，提供国际协调，并促进国际合作，以实现未来的高能电子对撞机。本期讲习班的范围是讨论在新型加速器技术（等离子体或结构中的激光或光束驱动）基础上实现粒子物理学直线对撞机的最新进展和必要步骤。会议介绍了欧洲粒子物理战略（ESPP）路线图进程和五常（美国）相关方面的最新情况，并专门安排了大量时间进行讨论。研讨会的主要成果是决定由ALEGRO协调欧洲、美国和亚洲的努力，为基于ANA的10,TeV CM对撞机制定预CDR。这项协调工作的目标是向欧盟和欧盟/美国资助机构提交一份资助提案。本文件介绍了联合主席对研讨会的总结，以及研讨会发言人撰写的简短 "单页"。
{"title":"Report on the Advanced Linear Collider Study Group (ALEGRO) Workshop 2024","authors":"J. Vieira, B. Cros, P. Muggli, I. A. Andriyash, O. Apsimon, M. Backhouse, C. Benedetti, S. S. Bulanov, A. Caldwell, Min Chen, V. Cilento, S. Corde, R. D'Arcy, S. Diederichs, E. Ericson, E. Esarey, J. Farmer, L. Fedeli, A. Formenti, B. Foster, M. Garten, C. G. R. Geddes, T. Grismayer, M. J. Hogan, S. Hooker, A. Huebl, S. Jalas, M. Kirchen, R. Lehe, W. Leemans, Boyuan Li, C. A. Lindström, R. Losito, C. E. Mitchell, W. B. Mori, P. Muggli, D. Terzani, M. Thévenet, M. Turner, J. -L. Vay, J. Vieira, D. Völker, Jie Zhang, W. Zhang","doi":"arxiv-2408.03968","DOIUrl":"https://doi.org/arxiv-2408.03968","url":null,"abstract":"The workshop focused on the application of ANAs to particle physics keeping\u0000in mind the ultimate goal of a collider at the energy frontier (10,TeV,\u0000e$^+$/e$^-$, e$^-$/e$^-$, or $gammagamma$). The development of ANAs is\u0000conducted at universities and national laboratories worldwide. The community is\u0000thematically broad and diverse, in particular since lasers suitable for ANA\u0000research (multi-hundred-terawatt peak power, a few tens of femtosecond-long\u0000pulses) and acceleration of electrons to hundreds of mega electron volts to\u0000multi giga electron volts became commercially available. The community spans\u0000several continents (Europe, America, Asia), including more than 62 laboratories\u0000in more than 20 countries. It is among the missions of the ICFA-ANA panel to\u0000feature the amazing progress made with ANAs, to provide international\u0000coordination and to foster international collaborations towards a future HEP\u0000collider. The scope of this edition of the workshop was to discuss the recent\u0000progress and necessary steps towards realizing a linear collider for particle\u0000physics based on novel-accelerator technologies (laser or beam driven in plasma\u0000or structures). Updates on the relevant aspects of the European Strategy for\u0000Particle Physics (ESPP) Roadmap Process as well as of the P5 (in the US) were\u0000presented, and ample time was dedicated to discussions. The major outcome of\u0000the workshop is the decision for ALEGRO to coordinate efforts in Europe, in the\u0000US, and in Asia towards a pre-CDR for an ANA-based, 10,TeV CM collider. This\u0000goal of this coordination is to lead to a funding proposal to be submitted to\u0000both EU and EU/US funding agencies. This document presents a summary of the\u0000workshop, as seen by the co-chairs, as well as short 'one-pagers' written by\u0000the presenters at the workshop.","PeriodicalId":501318,"journal":{"name":"arXiv - PHYS - Accelerator Physics","volume":"41 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141934510","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}
Space-charge-induced resonance crossing is one notable limitation of beam intensity in high-intensity synchrotrons. This paper proposes a modification to the Resonance Driving Terms (RDTs) to compensate for the combined effects of space charge and magnetic field imperfections under resonance crossing. The new RDTs are named modified RDTs. The effectiveness of the modified RDTs is demonstrated through simulations of half-integer and 3rd-order resonance crossings using the lattice of the High Intensity Heavy-Ion Accelerator Facility Booster Ring (HIAF-BRing). The simulations illustrate that the compensation provided by the modified RDTs significantly suppresses emittance growth and reduces distortion in the phase space.
{"title":"Simulation studies on compensation for space-charge-induced half-integer and 3rd-order resonance crossing in HIAF-BRing","authors":"Cheng Guo, Jie Liu, Jiancheng Yang, Ruihu Zhu","doi":"arxiv-2408.01954","DOIUrl":"https://doi.org/arxiv-2408.01954","url":null,"abstract":"Space-charge-induced resonance crossing is one notable limitation of beam\u0000intensity in high-intensity synchrotrons. This paper proposes a modification to\u0000the Resonance Driving Terms (RDTs) to compensate for the combined effects of\u0000space charge and magnetic field imperfections under resonance crossing. The new\u0000RDTs are named modified RDTs. The effectiveness of the modified RDTs is\u0000demonstrated through simulations of half-integer and 3rd-order resonance\u0000crossings using the lattice of the High Intensity Heavy-Ion Accelerator\u0000Facility Booster Ring (HIAF-BRing). The simulations illustrate that the\u0000compensation provided by the modified RDTs significantly suppresses emittance\u0000growth and reduces distortion in the phase space.","PeriodicalId":501318,"journal":{"name":"arXiv - PHYS - Accelerator Physics","volume":"40 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141934514","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}
Magnetic compressors offer an attractive path toward jitter-free bunch compression in MeV-UED. Compared with RF bunchers, magnetic compressors do not introduce additional timing jitter and can be configured to minimize timing jitter due to upstream energy fluctuation. In this work we discuss the principles of designing magnetic compressors for MeV-UED. Start-to-end simulation of a dogleg compressor is presented. Results show a bunch length of 11~fs can be achieved at 100 fC charge with small emittance growth.
磁压缩器为在 MeV-UED 中实现无抖动束压缩提供了一条极具吸引力的途径。与射频束流器相比，磁性压缩器不会带来额外的定时抖动，而且可以通过配置将上游能量波动引起的定时抖动降至最低。在这项工作中，我们讨论了为 MeV-UED 设计磁压缩器的原理。介绍了狗腿式压缩机从开始到结束的模拟。结果表明，在 100 fC 电荷下可以实现 11~fs 的束长，且发射率增长很小。
{"title":"Magnetic Compressors for MeV-UED","authors":"Tianzhe Xu, Robert Joel England","doi":"arxiv-2408.00936","DOIUrl":"https://doi.org/arxiv-2408.00936","url":null,"abstract":"Magnetic compressors offer an attractive path toward jitter-free bunch\u0000compression in MeV-UED. Compared with RF bunchers, magnetic compressors do not\u0000introduce additional timing jitter and can be configured to minimize timing\u0000jitter due to upstream energy fluctuation. In this work we discuss the\u0000principles of designing magnetic compressors for MeV-UED. Start-to-end\u0000simulation of a dogleg compressor is presented. Results show a bunch length of\u000011~fs can be achieved at 100 fC charge with small emittance growth.","PeriodicalId":501318,"journal":{"name":"arXiv - PHYS - Accelerator Physics","volume":"21 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141934511","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}
Tianzhe Xu, Fuhao Ji, Stephen Weathersby, Robert Joel England
A significant contribution to the temporal resolution of an ultrafast electron diffraction (UED) instrument is arrival time jitter caused by amplitude and phase variation of radio frequency (RF) cavities. In this paper, we present a semi-analytical approach for calculating RF-induced temporal jitter from klystron and RF cavity parameters. Our approach allows fast estimation of temporal jitter for MeV-UED beamlines and can serve as a virtual timing tool when shot-to-shot measurements of RF amplitude and phase jitters are available. A simulation study for the SLAC MeV-UED instrument is presented and the temporal resolution for several beamline configurations are compared.
{"title":"Calculation of RF-induced Temporal Jitter in Ultrafast Electron Diffraction","authors":"Tianzhe Xu, Fuhao Ji, Stephen Weathersby, Robert Joel England","doi":"arxiv-2408.00937","DOIUrl":"https://doi.org/arxiv-2408.00937","url":null,"abstract":"A significant contribution to the temporal resolution of an ultrafast\u0000electron diffraction (UED) instrument is arrival time jitter caused by\u0000amplitude and phase variation of radio frequency (RF) cavities. In this paper,\u0000we present a semi-analytical approach for calculating RF-induced temporal\u0000jitter from klystron and RF cavity parameters. Our approach allows fast\u0000estimation of temporal jitter for MeV-UED beamlines and can serve as a virtual\u0000timing tool when shot-to-shot measurements of RF amplitude and phase jitters\u0000are available. A simulation study for the SLAC MeV-UED instrument is presented\u0000and the temporal resolution for several beamline configurations are compared.","PeriodicalId":501318,"journal":{"name":"arXiv - PHYS - Accelerator Physics","volume":"47 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141934471","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. HanletFermi National Accelerator Laboratory, M. GonzalezFermi National Accelerator Laboratory, J. DiamondFermi National Accelerator Laboratory, K. S. MartinFermi National Accelerator Laboratory
Fermilab has traditionally not been an EPICS house; as such expertise in EPICS is limited and scattered. PIP-II will be using EPICS for its control system. When in operation, it will need to interface with the existing, modernized (see ACORN) legacy control system. Treating EPICS controls at Fermilab as a green field, we have developed and deployed a software pipeline which addresses these needs and presents to developers a tested and robust software framework, including template IOCs from which new developers can quickly deploy new front ends, aka IOCs. In this presentation, motivation for this work, implementation of a continuous integration/continuous deployment pipeline, testing, template IOCs, and the deployment of user services/applications will be discussed. This new infrastructure of IOCs and services is being developed and used in the PIP-II cryomodule teststand; our experiences and lessons learned will be also be discussed.
费米实验室历来不是 EPICS 研究机构；因此，EPICS 方面的专业知识有限而且分散。PIP-II 的控制系统将使用 EPICS。在运行时，它将需要与现有的、现代化的（见 ACORN）传统控制系统对接。我们将费米实验室的 EPICS 控制系统视为一块绿地，开发并部署了一个软件管道，以满足这些需求，并为开发人员提供了一个经过测试的强大软件框架，包括模板 IOC，新开发人员可以在此基础上快速部署新的前端（又称 IOC）。本讲座将讨论这项工作的动机、持续集成/持续部署管道的实施、测试、模板 IOC 以及用户服务/应用程序的部署。这种新的 IOC 和服务基础设施正在 PIP-II Cryomodule 测试台中开发和使用；我们的经验和教训也将得到讨论。
{"title":"Epics Deployment at Fermilab","authors":"P. HanletFermi National Accelerator Laboratory, M. GonzalezFermi National Accelerator Laboratory, J. DiamondFermi National Accelerator Laboratory, K. S. MartinFermi National Accelerator Laboratory","doi":"arxiv-2408.00174","DOIUrl":"https://doi.org/arxiv-2408.00174","url":null,"abstract":"Fermilab has traditionally not been an EPICS house; as such expertise in\u0000EPICS is limited and scattered. PIP-II will be using EPICS for its control\u0000system. When in operation, it will need to interface with the existing,\u0000modernized (see ACORN) legacy control system. Treating EPICS controls at\u0000Fermilab as a green field, we have developed and deployed a software pipeline\u0000which addresses these needs and presents to developers a tested and robust\u0000software framework, including template IOCs from which new developers can\u0000quickly deploy new front ends, aka IOCs. In this presentation, motivation for\u0000this work, implementation of a continuous integration/continuous deployment\u0000pipeline, testing, template IOCs, and the deployment of user\u0000services/applications will be discussed. This new infrastructure of IOCs and\u0000services is being developed and used in the PIP-II cryomodule teststand; our\u0000experiences and lessons learned will be also be discussed.","PeriodicalId":501318,"journal":{"name":"arXiv - PHYS - Accelerator Physics","volume":"235 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141884718","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. WallbankFermi National Accelerator Laboratory, Batavia, IL, USA, J. JarvisFermi National Accelerator Laboratory, Batavia, IL, USA
Operation with ultra-low momentum-compaction factor (alpha) is a desirable capability for many storage rings and synchrotron radiation sources. For example, low-alpha lattices are commonly used to produce picosecond bunches for the generation of coherent THz radiation and are the basis of a number of conceptual designs for EUV generation via steady-state microbunching (SSMB). Achieving ultra-low alpha requires not only a high-level of stability in the linear optics but also flexible control of higher-order compaction terms. Operation with lower momentum-compaction lattices has recently been investigated at the IOTA storage ring at Fermilab. A procedure for lowering the ring compaction using the linear optics along with compensations from the higher-order magnets was developed with the aid of a model, and an experimental technique for measuring the momentum compaction was developed. The lowest momentum compaction achieved during the available run-time was $3.4times10^{-4}$, around 15 times lower than previously operated. These feasibility studies ensure an improved experimental understanding of the IOTA optics and potentially will enable new research programs at the facility.
{"title":"Low-alpha Operation of the Iota Storage Ring","authors":"M. WallbankFermi National Accelerator Laboratory, Batavia, IL, USA, J. JarvisFermi National Accelerator Laboratory, Batavia, IL, USA","doi":"arxiv-2407.20358","DOIUrl":"https://doi.org/arxiv-2407.20358","url":null,"abstract":"Operation with ultra-low momentum-compaction factor (alpha) is a desirable\u0000capability for many storage rings and synchrotron radiation sources. For\u0000example, low-alpha lattices are commonly used to produce picosecond bunches for\u0000the generation of coherent THz radiation and are the basis of a number of\u0000conceptual designs for EUV generation via steady-state microbunching (SSMB).\u0000Achieving ultra-low alpha requires not only a high-level of stability in the\u0000linear optics but also flexible control of higher-order compaction terms.\u0000Operation with lower momentum-compaction lattices has recently been\u0000investigated at the IOTA storage ring at Fermilab. A procedure for lowering the\u0000ring compaction using the linear optics along with compensations from the\u0000higher-order magnets was developed with the aid of a model, and an experimental\u0000technique for measuring the momentum compaction was developed. The lowest\u0000momentum compaction achieved during the available run-time was\u0000$3.4times10^{-4}$, around 15 times lower than previously operated. These\u0000feasibility studies ensure an improved experimental understanding of the IOTA\u0000optics and potentially will enable new research programs at the facility.","PeriodicalId":501318,"journal":{"name":"arXiv - PHYS - Accelerator Physics","volume":"87 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141865241","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}
Quench heaters are often an essential part of protecting a superconducting accelerator magnet during a quench. Their purpose is to spread the quench throughout the coil as quickly as possible. They are located in areas of high magnetic fields and are thus prone to magnetoresistive phenomena and the Hall effect. Such influences can cause currents to distribute unevenly in the heaters, which results in uneven heating. This can reduce the effectiveness of the heaters and even endanger them due to excessive local heating. Also, the heater geometry itself can be the cause of uneven current density. In this paper we investigate by numerical simulations the importance of the magnetic effects on quench heater performance and whether they should be taken into account in the design. The main interest is in the Hall effect, which was perceived as the most likely source of trouble for the design of quench heaters. We use a simple phenomenological approach for modeling the Hall effect, utilizing values from the literature for the Hall coefficients. Magnetoresistance is also considered and the impact of heater geometry on current distributions is briefly visited. The conclusion of this research is that magnetoresistance plays an insignificant role in the functioning of quench heaters. The Hall effect can clearly be more influential, but nevertheless should not pose any problems in most cases. Current distributions due to heater geometry should be take into consideration in the design phase and, if needed, take measures to equalize the current density by using, for example, copper cladding in appropriate locations.
{"title":"Hall Effect, Magnetoresistance, and Current Distribution in Quench Heaters","authors":"J. Rysti","doi":"arxiv-2407.19830","DOIUrl":"https://doi.org/arxiv-2407.19830","url":null,"abstract":"Quench heaters are often an essential part of protecting a superconducting\u0000accelerator magnet during a quench. Their purpose is to spread the quench\u0000throughout the coil as quickly as possible. They are located in areas of high\u0000magnetic fields and are thus prone to magnetoresistive phenomena and the Hall\u0000effect. Such influences can cause currents to distribute unevenly in the\u0000heaters, which results in uneven heating. This can reduce the effectiveness of\u0000the heaters and even endanger them due to excessive local heating. Also, the\u0000heater geometry itself can be the cause of uneven current density. In this paper we investigate by numerical simulations the importance of the\u0000magnetic effects on quench heater performance and whether they should be taken\u0000into account in the design. The main interest is in the Hall effect, which was\u0000perceived as the most likely source of trouble for the design of quench\u0000heaters. We use a simple phenomenological approach for modeling the Hall\u0000effect, utilizing values from the literature for the Hall coefficients.\u0000Magnetoresistance is also considered and the impact of heater geometry on\u0000current distributions is briefly visited. The conclusion of this research is that magnetoresistance plays an\u0000insignificant role in the functioning of quench heaters. The Hall effect can\u0000clearly be more influential, but nevertheless should not pose any problems in\u0000most cases. Current distributions due to heater geometry should be take into\u0000consideration in the design phase and, if needed, take measures to equalize the\u0000current density by using, for example, copper cladding in appropriate\u0000locations.","PeriodicalId":501318,"journal":{"name":"arXiv - PHYS - Accelerator Physics","volume":"78 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141872895","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
C. Mohs, C. Müller-Gatermann, M. Gott, J. Nolen, R. Gampa, J. Greene
One of the primary goals of the Center for Accelerator Target Science (CATS) is to provide targets and foils in support of the ATLAS User Facility and the Low-Energy community at large. While a wide array of target production techniques are available at CATS, new methods that must be explored invariably arise. One such technique, the High-Intensity Vibrational Powder Plating (HIVIPP), was first reported in 1997 by Isao Sugai. It was developed to produce targets and stripper foils that were difficult to make by standard methods. At Argonne National Laboratory (ANL), we have successfully constructed and tested a simple system for this purpose. We have produced targets of carbon and titanium on various metal backings using the HIVIPP method. We are currently in the exciting phase of exploring the production of other elements, including isotopically enriched and radioactive material. This work is in progress and will be further detailed with specific examples.
{"title":"Target Development Using the Method of High-Intensity Vibrational Powder Plating (HIVIPP) at the Center for Accelerator Target Science (CATS) at Argonne National Laboratory (ANL)","authors":"C. Mohs, C. Müller-Gatermann, M. Gott, J. Nolen, R. Gampa, J. Greene","doi":"arxiv-2407.19052","DOIUrl":"https://doi.org/arxiv-2407.19052","url":null,"abstract":"One of the primary goals of the Center for Accelerator Target Science (CATS)\u0000is to provide targets and foils in support of the ATLAS User Facility and the\u0000Low-Energy community at large. While a wide array of target production\u0000techniques are available at CATS, new methods that must be explored invariably\u0000arise. One such technique, the High-Intensity Vibrational Powder Plating\u0000(HIVIPP), was first reported in 1997 by Isao Sugai. It was developed to produce\u0000targets and stripper foils that were difficult to make by standard methods. At\u0000Argonne National Laboratory (ANL), we have successfully constructed and tested\u0000a simple system for this purpose. We have produced targets of carbon and\u0000titanium on various metal backings using the HIVIPP method. We are currently in\u0000the exciting phase of exploring the production of other elements, including\u0000isotopically enriched and radioactive material. This work is in progress and\u0000will be further detailed with specific examples.","PeriodicalId":501318,"journal":{"name":"arXiv - PHYS - Accelerator Physics","volume":"42 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141865242","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}
Chao Liu, Ryan Herbst, Larry Ruckman, Emilio Nanni
The Low-Level RF (LLRF) control circuits of linear accelerators (LINACs) are conventionally realized with heterodyne based architectures, which have analog RF mixers for up and down conversion with discrete data converters. We have developed a new LLRF platform for C-band linear accelerator based on the Frequency System-on-Chip (RFSoC) device from AMD Xilinx. The integrated data converters in the RFSoC can directly sample the RF signals in C-band and perform the up and down mixing digitally. The programmable logic and processors required for signal processing for the LLRF control system are also included in a single RFSoC chip. With all the essential components integrated in a device, the RFSoC-based LLRF control platform can be implemented more cost-effectively and compactly, which can be applied to a broad range of accelerator applications. In this paper, the structure and configuration of the newly developed LLRF platform will be described. The LLRF prototype has been tested with high power test setup with a Cool Cooper Collider (C(^3)) accelerating structure. The LLRF and the solid state amplifier (SSA) loopback setup demonstrated phase jitter in 1 s as low as 115 fs, which is lower than the requirement of C(^3). The rf signals from the klystron forward and accelerating structure captured with peak power up to 16.45 MW will be presented and discussed.
线性加速器（LINAC）的低电平射频（LLRF）控制电路传统上是通过基于外差的架构实现的，这种架构具有用于上下转换的模拟射频混频器和分立数据转换器。我们基于 AMD Xilinx 公司的频率片上系统 (RFSoC) 设备，为 C 波段线性加速器开发了一种新型 LLRF 平台。RFSoC 中集成的数据转换器可直接对 C 波段射频信号进行采样，并以数字方式执行上下混合。LLRF 控制系统信号处理所需的可编程逻辑和处理器也包含在单个 RFSoC 芯片中。由于所有重要组件都集成在一个器件中，基于 RFSoC 的 LLRF 控制平台可以更经济、更紧凑地实现，可广泛应用于加速器领域。本文将介绍新开发的 LLRF 平台的结构和配置。LLRF原型已经在冷库珀对撞机（Cool Cooper Collider）加速结构的高功率测试装置上进行了测试。LLRF和固态放大器（SSA）环回装置证明，1秒内的相位抖动低至115 fs，低于C（^3）的要求。将介绍和讨论从速调管正向和加速结构捕获的峰值功率高达 16.45 MW 的射频信号。
{"title":"Next Generation LLRF Control Platform for Compact C-band Linear Accelerator","authors":"Chao Liu, Ryan Herbst, Larry Ruckman, Emilio Nanni","doi":"arxiv-2407.18198","DOIUrl":"https://doi.org/arxiv-2407.18198","url":null,"abstract":"The Low-Level RF (LLRF) control circuits of linear accelerators (LINACs) are\u0000conventionally realized with heterodyne based architectures, which have analog\u0000RF mixers for up and down conversion with discrete data converters. We have\u0000developed a new LLRF platform for C-band linear accelerator based on the\u0000Frequency System-on-Chip (RFSoC) device from AMD Xilinx. The integrated data\u0000converters in the RFSoC can directly sample the RF signals in C-band and\u0000perform the up and down mixing digitally. The programmable logic and processors\u0000required for signal processing for the LLRF control system are also included in\u0000a single RFSoC chip. With all the essential components integrated in a device,\u0000the RFSoC-based LLRF control platform can be implemented more cost-effectively\u0000and compactly, which can be applied to a broad range of accelerator\u0000applications. In this paper, the structure and configuration of the newly\u0000developed LLRF platform will be described. The LLRF prototype has been tested\u0000with high power test setup with a Cool Cooper Collider (C(^3)) accelerating\u0000structure. The LLRF and the solid state amplifier (SSA) loopback setup\u0000demonstrated phase jitter in 1 s as low as 115 fs, which is lower than the\u0000requirement of C(^3). The rf signals from the klystron forward and\u0000accelerating structure captured with peak power up to 16.45 MW will be\u0000presented and discussed.","PeriodicalId":501318,"journal":{"name":"arXiv - PHYS - Accelerator Physics","volume":"123 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141771406","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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