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}
R. SharankovaFermi National Accelerator Laboratory, A. ShemyakinFermi National Accelerator Laboratory, S. RegoFermi National Accelerator LaboratoryEcole Polytechnique Palaiseau, France
The Fermi National Accelerator Laboratory (Fermilab) Linac accepts 750 keV H- ions from the front end and accelerates them to 400 MeV for injection into the Booster rapid cycling synchrotron. Day-to-day drifts in the beam longitudinal trajectory during regular operation are of the order of several degrees. They are believed to cause additional losses in both the Linac and the Booster and are addressed by empirically adjusting cavity phases of front end and Linac RF cavities. This work explores a scheme for expressing these drifts in terms of phase shifts in the low-energy part of the Linac. Such a description allows for a simplified visual representation of the drifts, suggests a clear algorithm for their compensation, and provides a tool for estimating efficiency of such compensation.
{"title":"Quantitative description and correction of longitudinal drifts in the Fermilab linac","authors":"R. SharankovaFermi National Accelerator Laboratory, A. ShemyakinFermi National Accelerator Laboratory, S. RegoFermi National Accelerator LaboratoryEcole Polytechnique Palaiseau, France","doi":"arxiv-2407.17456","DOIUrl":"https://doi.org/arxiv-2407.17456","url":null,"abstract":"The Fermi National Accelerator Laboratory (Fermilab) Linac accepts 750 keV H-\u0000ions from the front end and accelerates them to 400 MeV for injection into the\u0000Booster rapid cycling synchrotron. Day-to-day drifts in the beam longitudinal\u0000trajectory during regular operation are of the order of several degrees. They\u0000are believed to cause additional losses in both the Linac and the Booster and\u0000are addressed by empirically adjusting cavity phases of front end and Linac RF\u0000cavities. This work explores a scheme for expressing these drifts in terms of\u0000phase shifts in the low-energy part of the Linac. Such a description allows for\u0000a simplified visual representation of the drifts, suggests a clear algorithm\u0000for their compensation, and provides a tool for estimating efficiency of such\u0000compensation.","PeriodicalId":501318,"journal":{"name":"arXiv - PHYS - Accelerator Physics","volume":"63 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141771407","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. UesugiInstitute for Integrated Radiation and Nuclear Science, Kyoto University, Y. IshiInstitute for Integrated Radiation and Nuclear Science, Kyoto University, Y. KuriyamaInstitute for Integrated Radiation and Nuclear Science, Kyoto University, Y. MoriInstitute for Integrated Radiation and Nuclear Science, Kyoto University, C. JollySTFC ISIS Department, D. J. KelliherSTFC ISIS Department, J. -B. LagrangeSTFC ISIS Department, A. P. LetchfordSTFC ISIS Department, S. MachidaSTFC ISIS Department, D. W. Poshuma de BoerSTFC ISIS Department, C. T. RogersSTFC ISIS Department, E. YamakawaSTFC ISIS Department, M. Topp-MugglestoneJohn Adams Institute, University of Oxford
A key challenge in particle accelerators is to achieve high peak intensity. Space charge is particularly strong at lower energy such as during injection and typically limits achievable peak intensity. The beam stacking technique can overcome this limitation by accumulating a beam at high energy where space charge is weaker. In beam stacking, a bunch of particles is injected and accelerated to high energy. This bunch continues to circulate, while a second and subsequent bunches are accelerated to merge into the first. It also allows the user cycle and acceleration cycles to be separated which is often valuable. Beam stacking is not possible in a time varying magnetic field, but a fixed field machine such as an Fixed Field Alternating Gradient Accelerator (FFA) does not sweep the magnetic field. In this paper, we describe experimental demonstration of beam stacking of two beams at KURNS FFA in Kyoto University. The momentum spread and intensity of the beam was analysed by study of the Schottky signal, demonstrating stacking with only a slight increase of momentum spread of the combined beams. The intensity of the first beam was, however, significantly reduced. RF knock-out is the suspected source of the beam loss.
{"title":"Beam Stacking Experiment at a Fixed Field Alternating Gradient Accelerator","authors":"T. UesugiInstitute for Integrated Radiation and Nuclear Science, Kyoto University, Y. IshiInstitute for Integrated Radiation and Nuclear Science, Kyoto University, Y. KuriyamaInstitute for Integrated Radiation and Nuclear Science, Kyoto University, Y. MoriInstitute for Integrated Radiation and Nuclear Science, Kyoto University, C. JollySTFC ISIS Department, D. J. KelliherSTFC ISIS Department, J. -B. LagrangeSTFC ISIS Department, A. P. LetchfordSTFC ISIS Department, S. MachidaSTFC ISIS Department, D. W. Poshuma de BoerSTFC ISIS Department, C. T. RogersSTFC ISIS Department, E. YamakawaSTFC ISIS Department, M. Topp-MugglestoneJohn Adams Institute, University of Oxford","doi":"arxiv-2407.13962","DOIUrl":"https://doi.org/arxiv-2407.13962","url":null,"abstract":"A key challenge in particle accelerators is to achieve high peak intensity.\u0000Space charge is particularly strong at lower energy such as during injection\u0000and typically limits achievable peak intensity. The beam stacking technique can\u0000overcome this limitation by accumulating a beam at high energy where space\u0000charge is weaker. In beam stacking, a bunch of particles is injected and\u0000accelerated to high energy. This bunch continues to circulate, while a second\u0000and subsequent bunches are accelerated to merge into the first. It also allows\u0000the user cycle and acceleration cycles to be separated which is often valuable.\u0000Beam stacking is not possible in a time varying magnetic field, but a fixed\u0000field machine such as an Fixed Field Alternating Gradient Accelerator (FFA)\u0000does not sweep the magnetic field. In this paper, we describe experimental\u0000demonstration of beam stacking of two beams at KURNS FFA in Kyoto University.\u0000The momentum spread and intensity of the beam was analysed by study of the\u0000Schottky signal, demonstrating stacking with only a slight increase of momentum\u0000spread of the combined beams. The intensity of the first beam was, however,\u0000significantly reduced. RF knock-out is the suspected source of the beam loss.","PeriodicalId":501318,"journal":{"name":"arXiv - PHYS - Accelerator Physics","volume":"64 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141744635","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. Accettura, S. Adrian, R. Agarwal, C. Ahdida, C. Aimé, A. Aksoy, G. L. Alberghi, S. Alden, N. Amapane, D. Amorim, P. Andreetto, F. Anulli, R. Appleby, A. Apresyan, P. Asadi, M. Attia Mahmoud, B. Auchmann, J. Back, A. Badea, K. J. Bae, E. J. Bahng, L. Balconi, F. Balli, L. Bandiera, C. Barbagallo, R. Barlow, C. Bartoli, N. Bartosik, E. Barzi, F. Batsch, M. Bauce, M. Begel, J. S. Berg, A. Bersani, A. Bertarelli, F. Bertinelli, A. Bertolin, P. Bhat, C. Bianchi, M. Bianco, W. Bishop, K. Black, F. Boattini, A. Bogacz, M. Bonesini, B. Bordini, P. Borges de Sousa, S. Bottaro, L. Bottura, S. Boyd, M. Breschi, F. Broggi, M. Brunoldi, X. Buffat, L. Buonincontri, P. N. Burrows, G. C. Burt, D. Buttazzo, B. Caiffi, S. Calatroni, M. Calviani, S. Calzaferri, D. Calzolari, C. Cantone, R. Capdevilla, C. Carli, C. Carrelli, F. Casaburo, M. Casarsa, L. Castelli, M. G. Catanesi, L. Cavallucci, G. Cavoto, F. G. Celiberto, L. Celona, A. Cemmi, S. Ceravolo, A. Cerri, F. Cerutti, G. Cesarini, C. Cesarotti, A. Chancé, N. Charitonidis, M. Chiesa, P. Chiggiato, V. L. Ciccarella, P. Cioli Puviani, A. Colaleo, F. Colao, F. Collamati, M. Costa, N. Craig, D. Curtin, L. D'Angelo, G. Da Molin, H. Damerau, S. Dasu, J. de Blas, S. De Curtis, H. De Gersem, T. Del Moro, J. -P. Delahaye, D. Denisov, H. Denizli, R. Dermisek, P. Desiré Valdor, C. Desponds, L. Di Luzio, E. Di Meco, K. F. Di Petrillo, I. Di Sarcina, E. Diociaiuti, T. Dorigo, K. Dreimanis, T. du Pree, T. Edgecock, S. Fabbri, M. Fabbrichesi, S. Farinon, G. Ferrand, J. A. Ferreira Somoza, M. Fieg, F. Filthaut, P. Fox, R. Franceschini, R. Franqueira Ximenes, M. Gallinaro, M. Garcia-Sciveres, L. Garcia-Tabares, R. Gargiulo, C. Garion, M. V. Garzelli, M. Gast, C. E. Gerber, L. Giambastiani, A. Gianelle, E. Gianfelice-Wendt, S. Gibson, S. Gilardoni, D. A. Giove, V. Giovinco, C. Giraldin, A. Glioti, A. Gorzawski, M. Greco, C. Grojean, A. Grudiev, E. Gschwendtner, E. Gueli, N. Guilhaudin, C. Han, T. Han, J. M. Hauptman, M. Herndon, A. D. Hillier, M. Hillman, T. R. Holmes, S. Homiller, S. Jana, S. Jindariani, S. Johannesson, B. Johnson, O. R. Jones, P. -B. Jurj, Y. Kahn, R. Kamath, A. Kario, I. Karpov, D. Kelliher, W. Kilian, R. Kitano, F. Kling, A. Kolehmainen, K. C. Kong, J. Kosse, G. Krintiras, K. Krizka, N. Kumar, E. Kvikne, R. Kyle, E. Laface, K. Lane, A. Latina, A. Lechner, J. Lee, L. Lee, S. W. Lee, T. Lefevre, E. Leonardi, G. Lerner, P. Li, Q. Li, T. Li, W. Li, R. Li Voti, M. Lindroos, R. Lipton, D. Liu, M. Liu, Z. Liu, A. Lombardi, S. Lomte, K. Long, L. Longo, J. Lorenzo, R. Losito, I. Low, X. Lu, D. Lucchesi, T. Luo, A. Lupato, E. Métral, K. Mękała, Y. Ma, J. M. Mańczak, S. Machida, T. Madlener, L. Magaletti, M. Maggi, H. Mainaud Durand, F. Maltoni, M. Mandurrino, C. Marchand, F. Mariani, S. Marin, S. Mariotto, S. Martin-Haugh, M. R. Masullo, G. S. Mauro, A. Mazzolari, B. Mele, F. Meloni, X. Meng, M. Mentink, R. Miceli, N. Milas, A. Mohammadi, D. Moll, A. Montella, M. Morandin, M. Morrone, T. Mulder, R. Musenich, M. Nardecchia, F. Nardi, D. Neuffer, D. Newbold, D. Novelli, M. Olvegård, Y. Onel, D. Orestano, J. Osborne, S. Otten, Y. M. Oviedo Torres, D. Paesani, S. Pagan Griso, D. Pagani, K. Pal, M. Palmer, A. Pampaloni, P. Panci, P. Pani, Y. Papaphilippou, R. Paparella, P. Paradisi, A. Passeri, N. Pastrone, A. Pellecchia, F. Piccinini, H. Piekarz, T. Pieloni, J. Plouin, A. Portone, K. Potamianos, J. Potdevin, S. Prestemon, T. Puig, J. Qiang, L. Quettier, T. R. Rabemananjara, E. Radicioni, R. Radogna, I. C. Rago, A. Ratkus, E. Resseguie, J. Reuter, P. L. Ribani, C. Riccardi, S. Ricciardi, T. Robens, Y. Robert, C. Roger, J. Rojo, M. Romagnoni, K. Ronald, B. Rosser, C. Rossi, L. Rossi, L. Rozanov, M. Ruhdorfer, R. Ruiz, F. S. Queiroz, S. Saini, F. Sala, C. Salierno, T. Salmi, P. Salvini, E. Salvioni, N. Sammut, C. Santini, A. Saputi, I. Sarra, G. Scarantino, H. Schneider-Muntau, D. Schulte, J. Scifo, T. Sen, C. Senatore, A. Senol, D. Sertore, L. Sestini, R. C. Silva Rêgo, F. M. Simone, K. Skoufaris, G. Sorbello, M. Sorbi, S. Sorti, L. Soubirou, D. Spataro, A. Stamerra, S. Stapnes, G. Stark, M. Statera, B. M. Stechauner, S. Su, W. Su, X. Sun, A. Sytov, J. Tang, J. Tang, R. Taylor, H. Ten Kate, P. Testoni, L. S. Thiele, R. Tomas Garcia, M. Topp- Mugglestone, T. Torims, R. Torre, L. T. Tortora, S. Trifinopoulos, S. -A. Udongwo, I. Vai, R. U. Valente, U. van Rienen, R. van Weelderen, M. Vanwelde, G. Velev, R. Venditti, A. Vendrasco, A. Verna, A. Verweij, P. Verwilligen, Y. Villamzar, L. Vittorio, P. Vitulo, I. Vojskovic, D. Wang, L. -T. Wang, X. Wang, M. Wendt, M. Widorski, M. Wozniak, Y. Wu, A. Wulzer, K. Xie, Y. Yang, Y. C. Yap, K. Yonehara, H. D. Yoo, Z. You, M. Zanetti, A. Zaza, L. Zhang, R. Zhu, A. Zlobin, D. Zuliani, J. F. Zurita
The International Muon Collider Collaboration (IMCC) [1] was established in 2020 following the recommendations of the European Strategy for Particle Physics (ESPP) and the implementation of the European Strategy for Particle Physics-Accelerator R&D Roadmap by the Laboratory Directors Group [2], hereinafter referred to as the the European LDG roadmap. The Muon Collider Study (MuC) covers the accelerator complex, detectors and physics for a future muon collider. In 2023, European Commission support was obtained for a design study of a muon collider (MuCol) [3]. This project started on 1st March 2023, with work-packages aligned with the overall muon collider studies. In preparation of and during the 2021-22 U.S. Snowmass process, the muon collider project parameters, technical studies and physics performance studies were performed and presented in great detail. Recently, the P5 panel [4] in the U.S. recommended a muon collider R&D, proposed to join the IMCC and envisages that the U.S. should prepare to host a muon collider, calling this their "muon shot". In the past, the U.S. Muon Accelerator Programme (MAP) [5] has been instrumental in studies of concepts and technologies for a muon collider.
{"title":"Interim report for the International Muon Collider Collaboration (IMCC)","authors":"C. Accettura, S. Adrian, R. Agarwal, C. Ahdida, C. Aimé, A. Aksoy, G. L. Alberghi, S. Alden, N. Amapane, D. Amorim, P. Andreetto, F. Anulli, R. Appleby, A. Apresyan, P. Asadi, M. Attia Mahmoud, B. Auchmann, J. Back, A. Badea, K. J. Bae, E. J. Bahng, L. Balconi, F. Balli, L. Bandiera, C. Barbagallo, R. Barlow, C. Bartoli, N. Bartosik, E. Barzi, F. Batsch, M. Bauce, M. Begel, J. S. Berg, A. Bersani, A. Bertarelli, F. Bertinelli, A. Bertolin, P. Bhat, C. Bianchi, M. Bianco, W. Bishop, K. Black, F. Boattini, A. Bogacz, M. Bonesini, B. Bordini, P. Borges de Sousa, S. Bottaro, L. Bottura, S. Boyd, M. Breschi, F. Broggi, M. Brunoldi, X. Buffat, L. Buonincontri, P. N. Burrows, G. C. Burt, D. Buttazzo, B. Caiffi, S. Calatroni, M. Calviani, S. Calzaferri, D. Calzolari, C. Cantone, R. Capdevilla, C. Carli, C. Carrelli, F. Casaburo, M. Casarsa, L. Castelli, M. G. Catanesi, L. Cavallucci, G. Cavoto, F. G. Celiberto, L. Celona, A. Cemmi, S. Ceravolo, A. Cerri, F. Cerutti, G. Cesarini, C. Cesarotti, A. Chancé, N. Charitonidis, M. Chiesa, P. Chiggiato, V. L. Ciccarella, P. Cioli Puviani, A. Colaleo, F. Colao, F. Collamati, M. Costa, N. Craig, D. Curtin, L. D'Angelo, G. Da Molin, H. Damerau, S. Dasu, J. de Blas, S. De Curtis, H. De Gersem, T. Del Moro, J. -P. Delahaye, D. Denisov, H. Denizli, R. Dermisek, P. Desiré Valdor, C. Desponds, L. Di Luzio, E. Di Meco, K. F. Di Petrillo, I. Di Sarcina, E. Diociaiuti, T. Dorigo, K. Dreimanis, T. du Pree, T. Edgecock, S. Fabbri, M. Fabbrichesi, S. Farinon, G. Ferrand, J. A. Ferreira Somoza, M. Fieg, F. Filthaut, P. Fox, R. Franceschini, R. Franqueira Ximenes, M. Gallinaro, M. Garcia-Sciveres, L. Garcia-Tabares, R. Gargiulo, C. Garion, M. V. Garzelli, M. Gast, C. E. Gerber, L. Giambastiani, A. Gianelle, E. Gianfelice-Wendt, S. Gibson, S. Gilardoni, D. A. Giove, V. Giovinco, C. Giraldin, A. Glioti, A. Gorzawski, M. Greco, C. Grojean, A. Grudiev, E. Gschwendtner, E. Gueli, N. Guilhaudin, C. Han, T. Han, J. M. Hauptman, M. Herndon, A. D. Hillier, M. Hillman, T. R. Holmes, S. Homiller, S. Jana, S. Jindariani, S. Johannesson, B. Johnson, O. R. Jones, P. -B. Jurj, Y. Kahn, R. Kamath, A. Kario, I. Karpov, D. Kelliher, W. Kilian, R. Kitano, F. Kling, A. Kolehmainen, K. C. Kong, J. Kosse, G. Krintiras, K. Krizka, N. Kumar, E. Kvikne, R. Kyle, E. Laface, K. Lane, A. Latina, A. Lechner, J. Lee, L. Lee, S. W. Lee, T. Lefevre, E. Leonardi, G. Lerner, P. Li, Q. Li, T. Li, W. Li, R. Li Voti, M. Lindroos, R. Lipton, D. Liu, M. Liu, Z. Liu, A. Lombardi, S. Lomte, K. Long, L. Longo, J. Lorenzo, R. Losito, I. Low, X. Lu, D. Lucchesi, T. Luo, A. Lupato, E. Métral, K. Mękała, Y. Ma, J. M. Mańczak, S. Machida, T. Madlener, L. Magaletti, M. Maggi, H. Mainaud Durand, F. Maltoni, M. Mandurrino, C. Marchand, F. Mariani, S. Marin, S. Mariotto, S. Martin-Haugh, M. R. Masullo, G. S. Mauro, A. Mazzolari, B. Mele, F. Meloni, X. Meng, M. Mentink, R. Miceli, N. Milas, A. Mohammadi, D. Moll, A. Montella, M. Morandin, M. Morrone, T. Mulder, R. Musenich, M. Nardecchia, F. Nardi, D. Neuffer, D. Newbold, D. Novelli, M. Olvegård, Y. Onel, D. Orestano, J. Osborne, S. Otten, Y. M. Oviedo Torres, D. Paesani, S. Pagan Griso, D. Pagani, K. Pal, M. Palmer, A. Pampaloni, P. Panci, P. Pani, Y. Papaphilippou, R. Paparella, P. Paradisi, A. Passeri, N. Pastrone, A. Pellecchia, F. Piccinini, H. Piekarz, T. Pieloni, J. Plouin, A. Portone, K. Potamianos, J. Potdevin, S. Prestemon, T. Puig, J. Qiang, L. Quettier, T. R. Rabemananjara, E. Radicioni, R. Radogna, I. C. Rago, A. Ratkus, E. Resseguie, J. Reuter, P. L. Ribani, C. Riccardi, S. Ricciardi, T. Robens, Y. Robert, C. Roger, J. Rojo, M. Romagnoni, K. Ronald, B. Rosser, C. Rossi, L. Rossi, L. Rozanov, M. Ruhdorfer, R. Ruiz, F. S. Queiroz, S. Saini, F. Sala, C. Salierno, T. Salmi, P. Salvini, E. Salvioni, N. Sammut, C. Santini, A. Saputi, I. Sarra, G. Scarantino, H. Schneider-Muntau, D. Schulte, J. Scifo, T. Sen, C. Senatore, A. Senol, D. Sertore, L. Sestini, R. C. Silva Rêgo, F. M. Simone, K. Skoufaris, G. Sorbello, M. Sorbi, S. Sorti, L. Soubirou, D. Spataro, A. Stamerra, S. Stapnes, G. Stark, M. Statera, B. M. Stechauner, S. Su, W. Su, X. Sun, A. Sytov, J. Tang, J. Tang, R. Taylor, H. Ten Kate, P. Testoni, L. S. Thiele, R. Tomas Garcia, M. Topp- Mugglestone, T. Torims, R. Torre, L. T. Tortora, S. Trifinopoulos, S. -A. Udongwo, I. Vai, R. U. Valente, U. van Rienen, R. van Weelderen, M. Vanwelde, G. Velev, R. Venditti, A. Vendrasco, A. Verna, A. Verweij, P. Verwilligen, Y. Villamzar, L. Vittorio, P. Vitulo, I. Vojskovic, D. Wang, L. -T. Wang, X. Wang, M. Wendt, M. Widorski, M. Wozniak, Y. Wu, A. Wulzer, K. Xie, Y. Yang, Y. C. Yap, K. Yonehara, H. D. Yoo, Z. You, M. Zanetti, A. Zaza, L. Zhang, R. Zhu, A. Zlobin, D. Zuliani, J. F. Zurita","doi":"arxiv-2407.12450","DOIUrl":"https://doi.org/arxiv-2407.12450","url":null,"abstract":"The International Muon Collider Collaboration (IMCC) [1] was established in\u00002020 following the recommendations of the European Strategy for Particle\u0000Physics (ESPP) and the implementation of the European Strategy for Particle\u0000Physics-Accelerator R&D Roadmap by the Laboratory Directors Group [2],\u0000hereinafter referred to as the the European LDG roadmap. The Muon Collider\u0000Study (MuC) covers the accelerator complex, detectors and physics for a future\u0000muon collider. In 2023, European Commission support was obtained for a design\u0000study of a muon collider (MuCol) [3]. This project started on 1st March 2023,\u0000with work-packages aligned with the overall muon collider studies. In\u0000preparation of and during the 2021-22 U.S. Snowmass process, the muon collider\u0000project parameters, technical studies and physics performance studies were\u0000performed and presented in great detail. Recently, the P5 panel [4] in the U.S.\u0000recommended a muon collider R&D, proposed to join the IMCC and envisages that\u0000the U.S. should prepare to host a muon collider, calling this their \"muon\u0000shot\". In the past, the U.S. Muon Accelerator Programme (MAP) [5] has been\u0000instrumental in studies of concepts and technologies for a muon collider.","PeriodicalId":501318,"journal":{"name":"arXiv - PHYS - Accelerator Physics","volume":"50 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141744636","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}
L. Steder, C. Bate, K. Kasprzak, D. Reschke, L. Trelle, H. Weise, M. Wiencek
The application of heat treatments on 1.3 GHz TESLA type cavities in ultra-high vacuum at 250{deg}C to 350{deg}C is called medium temperature or mid-T heat treatment. In various laboratories such treatments on superconducting radio frequency (SRF) cavities result reproducible in three main characteristic features for the quality factor $Q_0$ in dependency of the accelerating electric field strength $E_{acc}$. First, comparing mid-T heat treatment with a baseline treatment, a significant increase of $Q_0$ up to $5cdot10^{10}$ at 2K can be observed. Second, with increasing accelerating gradient $E_{acc}$ the $Q_0$ increases up to a maximum around 16 to 20 MV/m. This effect is known as anti-Q-slope. The third observation for a mid-T heat treatment compared to a baseline treatment is an often reduced maximum gradient $E_{acc}$. The appearance of a high-field-Q-slope (HFQS) was reported after mid-T heat treatments of 3 hours at 350{deg}C or of 20 hours at 300{deg}C at DESY. Using the heating temperature and the heating time taken from the temperature profile of the furnace effective oxygen diffusion lengths $l$ were calculated. In the follow-up study presented here, a set of three single-cell cavities with diffusion lengths $l$ above 1700 nm, showing HFQS, were treated with an additional so-called low-T bake of 24-48 hours at 120{deg}C to 130{deg}C. The subsequent reproducible Q(E) -performances results indicate that the low-T bake procedure cures the HFQS like for cavities treated with the EuXFEL recipe of EP and following low-T treatments. As presented in the following, Q values of more than $3cdot10^{10}$ at 16 MV/m and accelerating gradients of 32 to 40 MV/m are achieved.
{"title":"Further improvement of medium temperature heat treated SRF cavities for high gradients","authors":"L. Steder, C. Bate, K. Kasprzak, D. Reschke, L. Trelle, H. Weise, M. Wiencek","doi":"arxiv-2407.12570","DOIUrl":"https://doi.org/arxiv-2407.12570","url":null,"abstract":"The application of heat treatments on 1.3 GHz TESLA type cavities in\u0000ultra-high vacuum at 250{deg}C to 350{deg}C is called medium temperature or\u0000mid-T heat treatment. In various laboratories such treatments on\u0000superconducting radio frequency (SRF) cavities result reproducible in three\u0000main characteristic features for the quality factor $Q_0$ in dependency of the\u0000accelerating electric field strength $E_{acc}$. First, comparing mid-T heat\u0000treatment with a baseline treatment, a significant increase of $Q_0$ up to\u0000$5cdot10^{10}$ at 2K can be observed. Second, with increasing accelerating\u0000gradient $E_{acc}$ the $Q_0$ increases up to a maximum around 16 to 20 MV/m.\u0000This effect is known as anti-Q-slope. The third observation for a mid-T heat\u0000treatment compared to a baseline treatment is an often reduced maximum gradient\u0000$E_{acc}$. The appearance of a high-field-Q-slope (HFQS) was reported after mid-T heat\u0000treatments of 3 hours at 350{deg}C or of 20 hours at 300{deg}C at DESY. Using\u0000the heating temperature and the heating time taken from the temperature profile\u0000of the furnace effective oxygen diffusion lengths $l$ were calculated. In the\u0000follow-up study presented here, a set of three single-cell cavities with\u0000diffusion lengths $l$ above 1700 nm, showing HFQS, were treated with an\u0000additional so-called low-T bake of 24-48 hours at 120{deg}C to 130{deg}C. The\u0000subsequent reproducible Q(E) -performances results indicate that the low-T bake\u0000procedure cures the HFQS like for cavities treated with the EuXFEL recipe of EP\u0000and following low-T treatments. As presented in the following, Q values of more\u0000than $3cdot10^{10}$ at 16 MV/m and accelerating gradients of 32 to 40 MV/m are\u0000achieved.","PeriodicalId":501318,"journal":{"name":"arXiv - PHYS - Accelerator Physics","volume":"64 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141744680","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. Pennington, M. Gaowei, E. M. Echeverria, K. Evans-Lutterodt, A. Galdi, T. Juffmann, S. Karkare, J. Maxson, S. J. van der Molen, P. Saha, J. Smedley, W. G. Stam, R. M. Tromp
Alkali antimonides are well established as high efficiency, low intrinsic emittance photocathodes for accelerators and photon detectors. However, conventionally grown alkali antimonide films are polycrystalline with surface disorder and roughness that can limit achievable beam brightness. Ordering the crystalline structure of alkali antimonides has the potential to deliver higher brightness electron beams by reducing surface disorder and enabling the engineering of material properties at the level of atomic layers. In this report, we demonstrate the growth of ordered Cs$_{3}$Sb films on single crystal substrates 3C-SiC and graphene-coated 4H-SiC using pulsed laser deposition and conventional thermal evaporation growth techniques. The crystalline structures of the Cs$_{3}$Sb films were examined using reflection high energy electron diffraction (RHEED) and X-ray diffraction (XRD) diagnostics, while film thickness and roughness estimates were made using x-ray reflectivity (XRR). With these tools, we observed ordered domains in less than 10 nm thick films with quantum efficiencies greater than one percent at 530 nm. Moreover, we identify structural features such as Laue oscillations indicative of highly ordered films. We found that Cs$_{3}$Sb films grew with flat, fiber-textured surfaces on 3C-SiC and with multiple ordered domains and sub-nanometer surface roughness on graphene-coated 4H-SiC under our growth conditions. We identify the crystallographic orientations of Cs$_{3}$Sb grown on graphene-coated 4H-SiC substrates and discuss the significance of examining the crystal structure of these films for growing epitaxial heterostructures in future experiments.
{"title":"A structural analysis of ordered Cs$_{3}$Sb films grown on single crystal graphene and silicon carbide substrates","authors":"C. Pennington, M. Gaowei, E. M. Echeverria, K. Evans-Lutterodt, A. Galdi, T. Juffmann, S. Karkare, J. Maxson, S. J. van der Molen, P. Saha, J. Smedley, W. G. Stam, R. M. Tromp","doi":"arxiv-2407.12224","DOIUrl":"https://doi.org/arxiv-2407.12224","url":null,"abstract":"Alkali antimonides are well established as high efficiency, low intrinsic\u0000emittance photocathodes for accelerators and photon detectors. However,\u0000conventionally grown alkali antimonide films are polycrystalline with surface\u0000disorder and roughness that can limit achievable beam brightness. Ordering the\u0000crystalline structure of alkali antimonides has the potential to deliver higher\u0000brightness electron beams by reducing surface disorder and enabling the\u0000engineering of material properties at the level of atomic layers. In this\u0000report, we demonstrate the growth of ordered Cs$_{3}$Sb films on single crystal\u0000substrates 3C-SiC and graphene-coated 4H-SiC using pulsed laser deposition and\u0000conventional thermal evaporation growth techniques. The crystalline structures\u0000of the Cs$_{3}$Sb films were examined using reflection high energy electron\u0000diffraction (RHEED) and X-ray diffraction (XRD) diagnostics, while film\u0000thickness and roughness estimates were made using x-ray reflectivity (XRR).\u0000With these tools, we observed ordered domains in less than 10 nm thick films\u0000with quantum efficiencies greater than one percent at 530 nm. Moreover, we\u0000identify structural features such as Laue oscillations indicative of highly\u0000ordered films. We found that Cs$_{3}$Sb films grew with flat, fiber-textured\u0000surfaces on 3C-SiC and with multiple ordered domains and sub-nanometer surface\u0000roughness on graphene-coated 4H-SiC under our growth conditions. We identify\u0000the crystallographic orientations of Cs$_{3}$Sb grown on graphene-coated 4H-SiC\u0000substrates and discuss the significance of examining the crystal structure of\u0000these films for growing epitaxial heterostructures in future experiments.","PeriodicalId":501318,"journal":{"name":"arXiv - PHYS - Accelerator Physics","volume":"15 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141744678","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}
Advanced accelerator-based light sources such as free electron lasers (FEL) accelerate highly relativistic electron beams to generate incredibly short (10s of femtoseconds) coherent flashes of light for dynamic imaging, whose brightness exceeds that of traditional synchrotron-based light sources by orders of magnitude. FEL operation requires precise control of the shape and energy of the extremely short electron bunches whose characteristics directly translate into the properties of the produced light. Control of short intense beams is difficult due to beam characteristics drifting with time and complex collective effects such as space charge and coherent synchrotron radiation. Detailed diagnostics of beam properties are therefore essential for precise beam control. Such measurements typically rely on a destructive approach based on a combination of a transverse deflecting resonant cavity followed by a dipole magnet in order to measure a beam's 2D time vs energy longitudinal phase-space distribution. In this paper, we develop a non-invasive virtual diagnostic of an electron beam's longitudinal phase space at megapixel resolution (1024 x 1024) based on a generative conditional diffusion model. We demonstrate the model's generative ability on experimental data from the European X-ray FEL.
先进的加速器光源，如自由电子激光器（FEL），可加速高度相对论电子束，产生用于动态成像的超短（10飞秒）相干闪光，其亮度超过传统同步加速器光源的数量级。FEL 的运行需要精确控制极短电子束的形状和能量，而电子束的特性会直接转化为所产生光的特性。由于光束特性随时间漂移以及空间电荷和相干同步辐射等综合反射效应，很难控制短强光束。此类测量通常依赖于一种破坏性方法，该方法基于横向偏转谐振腔与偶极子磁体的组合，以测量光束的二维时间与能量纵向相空间分布。在本文中，我们基于条件扩散生成模型，开发了一种百万像素分辨率（1024 x 1024）的电子束纵向相空间非侵入式虚拟诊断技术。我们在欧洲 X 射线 FEL 的实验数据上演示了该模型的生成能力。
{"title":"Conditional Guided Generative Diffusion for Particle Accelerator Beam Diagnostics","authors":"Alexander Scheinker","doi":"arxiv-2407.10693","DOIUrl":"https://doi.org/arxiv-2407.10693","url":null,"abstract":"Advanced accelerator-based light sources such as free electron lasers (FEL)\u0000accelerate highly relativistic electron beams to generate incredibly short (10s\u0000of femtoseconds) coherent flashes of light for dynamic imaging, whose\u0000brightness exceeds that of traditional synchrotron-based light sources by\u0000orders of magnitude. FEL operation requires precise control of the shape and\u0000energy of the extremely short electron bunches whose characteristics directly\u0000translate into the properties of the produced light. Control of short intense\u0000beams is difficult due to beam characteristics drifting with time and complex\u0000collective effects such as space charge and coherent synchrotron radiation.\u0000Detailed diagnostics of beam properties are therefore essential for precise\u0000beam control. Such measurements typically rely on a destructive approach based\u0000on a combination of a transverse deflecting resonant cavity followed by a\u0000dipole magnet in order to measure a beam's 2D time vs energy longitudinal\u0000phase-space distribution. In this paper, we develop a non-invasive virtual\u0000diagnostic of an electron beam's longitudinal phase space at megapixel\u0000resolution (1024 x 1024) based on a generative conditional diffusion model. We\u0000demonstrate the model's generative ability on experimental data from the\u0000European X-ray FEL.","PeriodicalId":501318,"journal":{"name":"arXiv - PHYS - Accelerator Physics","volume":"9 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141717740","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In an injector system of an X-ray free electron laser (XFEL), solenoid lenses are typically used to confine low-emittance electron beams to low-energy region below a few MeV. Because non-thermionic emittance at such a low-energy region is easily deteriorated by nonlinear electromagnetic fields, it is important to determine the properties of a solenoid lens on electron beam emittance in the design of XFEL injectors. We derived an approximate solution to emittance growth due to lens aberration by a paraxial approximation. It was found that the derivative of the longitudinal magnetic field strongly affects beam emittance, and its growth is proportional to the fourth power of the beam radius. Various properties of the beam can be analyzed as long as the longitudinal magnetic field distribution is prepared using a simulation or measurement. In this study, a theoretical procedure to obtain the emittance growth in the solenoid lens is introduced and the design considerations of the solenoid lens of the SACLA injector are described.
在 X 射线自由电子激光器（XFEL）的注入器系统中，螺线管透镜通常用于将低惰性电子束限制在几 MeV 以下的低能区。由于这种低能区的非热释电态势很容易受到非线性电磁场的影响而恶化，因此在设计 XFEL 注入器时，确定电磁透镜对电子束态势的影响是非常重要的。我们通过准轴近似法推导出了透镜像差引起的发射率增长的近似解。研究发现，纵向磁场的导数对光束辐照度有很大影响，其增长与光束半径的四次方成正比。只要利用模拟或测量方法准备好纵向磁场分布，就可以分析光束的各种特性。本研究介绍了获得电磁透镜中幅射增长的理论过程，并描述了 SACLA 注入器电磁透镜的设计考虑因素。
{"title":"Effect of solenoid lens field on electron beam emittance","authors":"Kazuaki Togawa","doi":"arxiv-2407.09081","DOIUrl":"https://doi.org/arxiv-2407.09081","url":null,"abstract":"In an injector system of an X-ray free electron laser (XFEL), solenoid lenses\u0000are typically used to confine low-emittance electron beams to low-energy region\u0000below a few MeV. Because non-thermionic emittance at such a low-energy region\u0000is easily deteriorated by nonlinear electromagnetic fields, it is important to\u0000determine the properties of a solenoid lens on electron beam emittance in the\u0000design of XFEL injectors. We derived an approximate solution to emittance\u0000growth due to lens aberration by a paraxial approximation. It was found that\u0000the derivative of the longitudinal magnetic field strongly affects beam\u0000emittance, and its growth is proportional to the fourth power of the beam\u0000radius. Various properties of the beam can be analyzed as long as the\u0000longitudinal magnetic field distribution is prepared using a simulation or\u0000measurement. In this study, a theoretical procedure to obtain the emittance\u0000growth in the solenoid lens is introduced and the design considerations of the\u0000solenoid lens of the SACLA injector are described.","PeriodicalId":501318,"journal":{"name":"arXiv - PHYS - Accelerator Physics","volume":"2012 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141717741","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}
NanoTerasu, a new 3 GeV synchrotron light source in Japan, began user operation in April 2024. It provides high-brilliance soft to tender X-rays and covers a wide spectral range from ultraviolet to tender X-rays. Its compact storage ring with a circumference of 349 m is based on a four-bend achromat lattice to provide two straight sections in each cell for insertion devices with a natural horizontal emittance of 1.14 nm rad, which is small enough for soft X-rays users. The NanoTerasu accelerator incorporates several innovative technologies, including a full-energy injector C-band linear accelerator with a length of 110 m, an in-vacuum off-axis injection system, a four-bend achromat with B-Q combined bending magnets, and a TM020 mode accelerating cavity with built-in higher-order-mode dampers in the storage ring. This paper presents the accelerator machine commissioning over a half-year period and our model-consistent ring optics correction. The first user operation with a stored beam current of 160 mA is also reported. We summarize the storage ring parameters obtained from the commissioning. This is helpful for estimating the effective optical properties of synchrotron radiation at NanoTerasu.
{"title":"Commissioning of a compact multibend achromat lattice: A new 3 GeV synchrotron radiation facility","authors":"Shuhei Obara, Kota Ueshima, Takao Asaka, Yuji Hosaka, Koichi Kan, Nobuyuki Nishimori, Toshitaka Aoki, Hiroyuki Asano, Koichi Haga, Yuto Iba, Akira Ihara, Katsumasa Ito, Taiki Iwashita, Masaya Kadowaki, Rento Kanahama, Hajime Kobayashi, Hideki Kobayashi, Hideo Nishihara, Masaaki Nishikawa, Haruhiko Oikawa, Ryota Saida, Keisuke Sakuraba, Kento Sugimoto, Masahiro Suzuki, Kouki Takahashi, Shunya Takahashi, Tatsuki Tanaka, Tsubasa Tsuchiyama, Risa Yoshioka, Tsuyoshi Aoki, Hideki Dewa, Takahiro Fujita, Morihiro Kawase, Akio Kiyomich, Takashi Hamano, Mitsuhiro Masaki, Takemasa Masuda, Shinichi Matsubara, Kensuke Okada, Choji Saji, Tsutomu Taniuchi, Yukiko Taniuchi, Yosuke Ueda, Hiroshi Yamaguchi, Kenichi Yanagida, Kenji Fukami, Naoyasu Hosoda, Miho Ishii, Toshiro Itoga, Eito Iwai, Tamotsu Magome, Masaya Oishi, Takashi Ohshima, Chikara Kondo, Tatsuyuki Sakurai, Masazumi Shoji, Takashi Sugimoto, Shiro Takano, Kazuhiro Tamura, Takahiro Watanabe, Takato Tomai, Noriyoshi Azumi, Takahiro Inagaki, Hirokazu Maesaka, Sunao Takahashi, Takashi Tanaka, Shinobu Inoue, Hirosuke Kumazawa, Kazuki Moriya, Kohei Sakai, Toshio Seno, Hiroshi Sumitomo, Ryoichi Takesako, Shinichiro Tanaka, Ryo Yamamoto, Kazutoshi Yokomachi, Masamichi Yoshioka, Toru Hara, Sakuo Matsui, Toshihiko Hiraiwa, Hitoshi Tanaka, Hiroyasu Ego","doi":"arxiv-2407.08925","DOIUrl":"https://doi.org/arxiv-2407.08925","url":null,"abstract":"NanoTerasu, a new 3 GeV synchrotron light source in Japan, began user\u0000operation in April 2024. It provides high-brilliance soft to tender X-rays and\u0000covers a wide spectral range from ultraviolet to tender X-rays. Its compact\u0000storage ring with a circumference of 349 m is based on a four-bend achromat\u0000lattice to provide two straight sections in each cell for insertion devices\u0000with a natural horizontal emittance of 1.14 nm rad, which is small enough for\u0000soft X-rays users. The NanoTerasu accelerator incorporates several innovative\u0000technologies, including a full-energy injector C-band linear accelerator with a\u0000length of 110 m, an in-vacuum off-axis injection system, a four-bend achromat\u0000with B-Q combined bending magnets, and a TM020 mode accelerating cavity with\u0000built-in higher-order-mode dampers in the storage ring. This paper presents the\u0000accelerator machine commissioning over a half-year period and our\u0000model-consistent ring optics correction. The first user operation with a stored\u0000beam current of 160 mA is also reported. We summarize the storage ring\u0000parameters obtained from the commissioning. This is helpful for estimating the\u0000effective optical properties of synchrotron radiation at NanoTerasu.","PeriodicalId":501318,"journal":{"name":"arXiv - PHYS - Accelerator Physics","volume":"29 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141717742","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In coherent radiation of an ensemble of electrons, radiation field from electrons resonantly drives the other electrons inside to produce stimulated emission. The radiation reaction force on the electrons accounting for this stimulated radiation loss is classically described by the Lienard-Wiechert potential. Despite its being the foundation of beam physics for decades, we show that using the "acceleration field'' in Lienard-Wiechert potential to describe radiative interactions leads to divergences due to its implicit dependence on instantaneous interactions. Here, we propose an alternative theory for electromagnetic radiation by decomposing the interactions into instantaneous part and retarded part. It is shown that only the retarded part contributes to the irreversible radiation loss and the instantaneous part describes the space charge related effects. We further apply this theory to study the coherent synchrotron radiation wake, which hopefully will reshape our understanding of coherent radiation and collective interactions.
{"title":"Instantaneous and Retarded Interactions in Coherent Radiation","authors":"Zhuoyuan Liu, Xiujie Deng, Tong Li, Lixin Yan","doi":"arxiv-2407.08579","DOIUrl":"https://doi.org/arxiv-2407.08579","url":null,"abstract":"In coherent radiation of an ensemble of electrons, radiation field from\u0000electrons resonantly drives the other electrons inside to produce stimulated\u0000emission. The radiation reaction force on the electrons accounting for this\u0000stimulated radiation loss is classically described by the Lienard-Wiechert\u0000potential. Despite its being the foundation of beam physics for decades, we\u0000show that using the \"acceleration field'' in Lienard-Wiechert potential to\u0000describe radiative interactions leads to divergences due to its implicit\u0000dependence on instantaneous interactions. Here, we propose an alternative\u0000theory for electromagnetic radiation by decomposing the interactions into\u0000instantaneous part and retarded part. It is shown that only the retarded part\u0000contributes to the irreversible radiation loss and the instantaneous part\u0000describes the space charge related effects. We further apply this theory to\u0000study the coherent synchrotron radiation wake, which hopefully will reshape our\u0000understanding of coherent radiation and collective interactions.","PeriodicalId":501318,"journal":{"name":"arXiv - PHYS - Accelerator Physics","volume":"49 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141613842","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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