In this paper, we use one-dimensional measurements to infer the four-dimensional phase space density of an accumulated 1 GeV proton beam in the Spallation Neutron Source (SNS) accelerator. The reconstruction was performed using MENT, an exact maximum-entropy tomography algorithm, and thus represents the most reasonable inference from the data. The reconstructed distribution reproduces the measured profiles with the same dynamic range as the measurement devices, and simulations indicate that the problem is well-constrained. Similar measurements could serve as benchmarks for simulations of intense, coupled beam dynamics in the SNS or other hadron rings.
{"title":"Four-dimensional phase space tomography from one-dimensional measurements in a high-power hadron ring","authors":"Austin Hoover","doi":"arxiv-2409.02862","DOIUrl":"https://doi.org/arxiv-2409.02862","url":null,"abstract":"In this paper, we use one-dimensional measurements to infer the\u0000four-dimensional phase space density of an accumulated 1 GeV proton beam in the\u0000Spallation Neutron Source (SNS) accelerator. The reconstruction was performed\u0000using MENT, an exact maximum-entropy tomography algorithm, and thus represents\u0000the most reasonable inference from the data. The reconstructed distribution\u0000reproduces the measured profiles with the same dynamic range as the measurement\u0000devices, and simulations indicate that the problem is well-constrained. Similar\u0000measurements could serve as benchmarks for simulations of intense, coupled beam\u0000dynamics in the SNS or other hadron rings.","PeriodicalId":501318,"journal":{"name":"arXiv - PHYS - Accelerator Physics","volume":"36 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142216460","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}
Sadiq Setiniyaz, R. Apsimon, P. H. Williams, C. Barbagallo, S. A. Bogacz, R. M. Bodenstei, K. Deitrick
The maximum achievable beam current in an Energy Recovery Linac (ERL) is often constrained by Beam Breakup (BBU) instability. Our previous research highlighted that filling patterns have a substantial impact on BBU instabilities in multi-pass ERLs. In this study, we extend our investigation to the 8-cavity model of the Powerful ERL for Experiment (PERLE). We evaluate its requirements for damping cavity Higher Order Modes (HOMs) and propose optimal filling patterns and bunch timing strategies. Our findings reveal a significant new insight: while filling patterns are crucial, the timing of bunches also plays a critical role in mitigating HOM beam loading and BBU instability. This previously underestimated factor is essential for effective BBU control. We estimated the PERLE threshold current using both analytical and numerical models, incorporating the designed PERLE HOM dampers. During manufacturing, HOM frequencies are expected to vary slightly, with an assumed RMS frequency jitter of 0.001 between cavities for the same HOM. Introducing this jitter into our models, we found that the dampers effectively suppressed BBU instability, achieving a threshold current an order of magnitude higher than the design requirement. Our results offer new insights into ERL BBU beam dynamics and have important implications for the design of future ERLs.
能量回收直列加速器（ERL）中可达到的最大光束电流往往受到光束破裂（BBU）不稳定性的限制。我们之前的研究强调，填充模式对多通道ERL中的BBU不稳定性有很大影响。在本研究中，我们将研究扩展到了用于实验的强力 ERL（PERLE）的 8 腔模型。我们评估了它对阻尼腔高阶模（HOMs）的要求，并提出了优化填充模式和波束定时策略。我们的研究结果揭示了一个重要的新观点：虽然填充模式至关重要，但束的时间选择在减轻 HOM 梁负载和 BBU 不稳定性方面也起着关键作用。这个之前被低估的因素对于有效控制 BBU 至关重要。我们使用分析和数值模型估算了 PERLE 的阈值电流，并结合设计的 PERLE HOM 阻尼器。在制造过程中，HOM 频率预计会略有不同，假定同一 HOM 的腔体之间的有效值频率抖动为 0.001。将这种抖动引入我们的模型后，我们发现阻尼器有效地抑制了 BBU 的不稳定性，使阈值电流比设计要求高出一个数量级。我们的研究结果为ERL BBU波束动力学提供了新的见解，对未来ERL的设计具有重要意义。
{"title":"Beam Breakup Instability Studies of Powerful Energy Recovery Linac for Experiments","authors":"Sadiq Setiniyaz, R. Apsimon, P. H. Williams, C. Barbagallo, S. A. Bogacz, R. M. Bodenstei, K. Deitrick","doi":"arxiv-2409.02798","DOIUrl":"https://doi.org/arxiv-2409.02798","url":null,"abstract":"The maximum achievable beam current in an Energy Recovery Linac (ERL) is\u0000often constrained by Beam Breakup (BBU) instability. Our previous research\u0000highlighted that filling patterns have a substantial impact on BBU\u0000instabilities in multi-pass ERLs. In this study, we extend our investigation to\u0000the 8-cavity model of the Powerful ERL for Experiment (PERLE). We evaluate its\u0000requirements for damping cavity Higher Order Modes (HOMs) and propose optimal\u0000filling patterns and bunch timing strategies. Our findings reveal a significant\u0000new insight: while filling patterns are crucial, the timing of bunches also\u0000plays a critical role in mitigating HOM beam loading and BBU instability. This\u0000previously underestimated factor is essential for effective BBU control. We\u0000estimated the PERLE threshold current using both analytical and numerical\u0000models, incorporating the designed PERLE HOM dampers. During manufacturing, HOM\u0000frequencies are expected to vary slightly, with an assumed RMS frequency jitter\u0000of 0.001 between cavities for the same HOM. Introducing this jitter into our\u0000models, we found that the dampers effectively suppressed BBU instability,\u0000achieving a threshold current an order of magnitude higher than the design\u0000requirement. Our results offer new insights into ERL BBU beam dynamics and have\u0000important implications for the design of future ERLs.","PeriodicalId":501318,"journal":{"name":"arXiv - PHYS - Accelerator Physics","volume":"26 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142216467","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. OzelisFermilab, M. BarbaFermilab, J. BernardiniFermilab, C. Contreras-MartinezFermilab, D. CrawfordFermilab, J. DongFermilab, V. GrzelakFermilab, P. HanletFermilab, J. HolzbauerFermilab, Y. JiaFermilab, S. KazakovFermilab, T. KhabiboullineFermilab, J. MakaraFermilab, N. PatelFermilab, V. PatelFermilab, L. PeiFermilab, D. PetersonFermilab, Y. PischalnikovFermilab, D. PorwisiakFermilab, S. RanpariyaFermilab, J. SteimelFermilab, N. SolyakFermilab, J. SubediFermilab, A. SukhanovFermilab, P. VargheseFermilab, T. WallaceFermilab, M. WhiteFermilab, S. WijethungaFermilab, Y. XieFermilab, S. YoonFermilab
After shipment to the Daresbury Lab and return to Fermilab, the prototype HB650 cryomodule underwent another phase of 2K RF testing to ascertain any performance issues that may have arisen from the transport of the cryomodule. While measurements taken at room temperature after the conclusion of shipment indicated that there were no negative impacts on cavity alignment, beamline vacuum, or cavity frequency, testing at 2K was required to validate other aspects such as tuner operation, cavity coupling, cryogenic system integrity, and cavity performance. Results of this latest round of limited 2K testing will be presented.
{"title":"Performance of PIP-II High-beta 650 Cryomodule After Transatlantic Shipping","authors":"J. OzelisFermilab, M. BarbaFermilab, J. BernardiniFermilab, C. Contreras-MartinezFermilab, D. CrawfordFermilab, J. DongFermilab, V. GrzelakFermilab, P. HanletFermilab, J. HolzbauerFermilab, Y. JiaFermilab, S. KazakovFermilab, T. KhabiboullineFermilab, J. MakaraFermilab, N. PatelFermilab, V. PatelFermilab, L. PeiFermilab, D. PetersonFermilab, Y. PischalnikovFermilab, D. PorwisiakFermilab, S. RanpariyaFermilab, J. SteimelFermilab, N. SolyakFermilab, J. SubediFermilab, A. SukhanovFermilab, P. VargheseFermilab, T. WallaceFermilab, M. WhiteFermilab, S. WijethungaFermilab, Y. XieFermilab, S. YoonFermilab","doi":"arxiv-2409.02264","DOIUrl":"https://doi.org/arxiv-2409.02264","url":null,"abstract":"After shipment to the Daresbury Lab and return to Fermilab, the prototype\u0000HB650 cryomodule underwent another phase of 2K RF testing to ascertain any\u0000performance issues that may have arisen from the transport of the cryomodule.\u0000While measurements taken at room temperature after the conclusion of shipment\u0000indicated that there were no negative impacts on cavity alignment, beamline\u0000vacuum, or cavity frequency, testing at 2K was required to validate other\u0000aspects such as tuner operation, cavity coupling, cryogenic system integrity,\u0000and cavity performance. Results of this latest round of limited 2K testing will\u0000be presented.","PeriodicalId":501318,"journal":{"name":"arXiv - PHYS - Accelerator Physics","volume":"159 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142216464","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
E. ChenFermi National Accelerator Laboratory, R. SharankovaFermi National Accelerator Laboratory, A. ShemyakinFermi National Accelerator Laboratory, J. StantonFermi National Accelerator Laboratory
The Fermilab Side-Coupled Linac accelerates H-beam from 116 MeV to 400 MeV through seven 805 MHz modules. Twelve wire scanners are present in the Side Coupled Linac and four are present in the transfer line between the Linac and the Booster synchrotron ring. These wire scanners act as important diagnostic instruments to directly collect information on the beam's transverse distribution. The manipulation of the conditions of wire scanner data collection enables further characterization of the beamline, such as calculating emittance and the Twiss parameters of the beam at select regions, which we present here.
{"title":"Emittance Measurements with Wire Scanners in the Fermilab Side-coupled Linac","authors":"E. ChenFermi National Accelerator Laboratory, R. SharankovaFermi National Accelerator Laboratory, A. ShemyakinFermi National Accelerator Laboratory, J. StantonFermi National Accelerator Laboratory","doi":"arxiv-2409.02229","DOIUrl":"https://doi.org/arxiv-2409.02229","url":null,"abstract":"The Fermilab Side-Coupled Linac accelerates H-beam from 116 MeV to 400 MeV\u0000through seven 805 MHz modules. Twelve wire scanners are present in the Side\u0000Coupled Linac and four are present in the transfer line between the Linac and\u0000the Booster synchrotron ring. These wire scanners act as important diagnostic\u0000instruments to directly collect information on the beam's transverse\u0000distribution. The manipulation of the conditions of wire scanner data\u0000collection enables further characterization of the beamline, such as\u0000calculating emittance and the Twiss parameters of the beam at select regions,\u0000which we present here.","PeriodicalId":501318,"journal":{"name":"arXiv - PHYS - Accelerator Physics","volume":"79 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142216465","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}
A. Frazzitta, M. Yadav, J. Mann, A. R. Rossi, J. B. Rosenzweig
A fundamental comparison between undulator and ion channel radiation is presented. Conventional theory for both devices fails to describe high $k$ and $K/gamma$ regimes accurately, providing an underestimation of particle trajectory amplitude and period. This may lead to incorrect estimation of radiation emission in many setups of practical interest, such as the ion column. A redefinition of plasma density and undulator strength expressions leads to a more reliable prediction of particle behaviour, reproducing the closest possible conditions in the two devices and correctly matching expected betatron oscillation amplitude and wavelength for a wide range of $K/gamma$ values. Differences in spectral features of the two devices can then be addressed via numerical simulations of single particle and beam dynamics. In this paper we outline a theoretical framework and compare its results with numerical simulation applied to setups eligible for possible radiation sources.
{"title":"Extreme radiation emission regime for electron beams in strong focusing ion channels and undulators","authors":"A. Frazzitta, M. Yadav, J. Mann, A. R. Rossi, J. B. Rosenzweig","doi":"arxiv-2409.00186","DOIUrl":"https://doi.org/arxiv-2409.00186","url":null,"abstract":"A fundamental comparison between undulator and ion channel radiation is\u0000presented. Conventional theory for both devices fails to describe high $k$ and\u0000$K/gamma$ regimes accurately, providing an underestimation of particle\u0000trajectory amplitude and period. This may lead to incorrect estimation of\u0000radiation emission in many setups of practical interest, such as the ion\u0000column. A redefinition of plasma density and undulator strength expressions\u0000leads to a more reliable prediction of particle behaviour, reproducing the\u0000closest possible conditions in the two devices and correctly matching expected\u0000betatron oscillation amplitude and wavelength for a wide range of $K/gamma$\u0000values. Differences in spectral features of the two devices can then be\u0000addressed via numerical simulations of single particle and beam dynamics. In\u0000this paper we outline a theoretical framework and compare its results with\u0000numerical simulation applied to setups eligible for possible radiation sources.","PeriodicalId":501318,"journal":{"name":"arXiv - PHYS - Accelerator Physics","volume":"59 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142216466","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. A. Adderley, S. Ahmed, T. Allison, R. Bachimanchi, K. Baggett, M. BastaniNejad, B. Bevins, M. Bevins, M. Bickley, R. M. Bodenstein, S. A. Bogacz, M. Bruker, A. Burrill, L. Cardman, J. Creel, Y. -C. Chao, G. Cheng, G. Ciovati, S. Chattopadhyay, J. Clark, W. A. Clemens, G. Croke, E. Daly, G. K. Davis, J. Delayen, S. U. De Silva, R. Dickson, M. Diaz, M. Drury, L. Doolittle, D. Douglas, E. Feldl, J. Fischer, A. Freyberger, V. Ganni, R. L. Geng, C. Ginsburg, J. Gomez, J. Grames, J. Gubeli, J. Guo, F. Hannon, J. Hansknecht, L. Harwood, J. Henry, C. Hernandez-Garcia, S. Higgins, D. Higinbotham, A. S. Hofler, T. Hiatt, J. Hogan, C. Hovater, A. Hutton, C. Jones, K. Jordan, M. Joyce, R. Kazimi, M. Keesee, M. J. Kelley, C. Keppel, A. Kimber, L. King, P. Kjeldsen, P. Kneisel, J. Koval, G. A. Krafft, G. Lahti, T. Larrieu, R. Lauze, C. Leemann, R. Legg, R. Li, F. Lin, D. Machie, J. Mammosser, K. Macha, K. Mahoney, F. Marhauser, B. Mastracci, J. Matalevich, J. McCarter, M. McCaughan, L. Merminga, R. Michaud, V. Morozov, C. Mounts, J. Musson, R. Nelson, W. Oren, R. B. Overton, G. Palacios-Serrano, H. -K. Park, L. Phillips, S. Philip, F. Pilat, T. Plawski, M. Poelker, P. Powers, T. Powers, J. Preble, T. Reilly, R. Rimmer, C. Reece, H. Robertson, Y. Roblin, C. Rode, T. Satogata, D. J. Seidman, A. Seryi, A. Shabalina, I. Shin, R. Slominski, C. Slominski, M. Spata, D. Spell, J. Spradlin, M. Stirbet, M. L. Stutzman, S. Suhring, K. Surles-Law, R. Suleiman, C. Tennant, H. Tian, D. Turner, M. Tiefenback, O. Trofimova, A. -M. Valente, H. Wang, Y. Wang, K. White, C. Whitlatch, T. Whitlatch, M. Wiseman, M. J. Wissman, G. Wu, S. Yang, B. Yunn, S. Zhang, Y. Zhang
This review paper describes the energy-upgraded CEBAF accelerator. This superconducting linac has achieved 12 GeV beam energy by adding 11 new high-performance cryomodules containing eighty-eight superconducting cavities that have operated CW at an average accelerating gradient of 20 MV/m. After reviewing the attributes and performance of the previous 6 GeV CEBAF accelerator, we discuss the upgraded CEBAF accelerator system in detail with particular attention paid to the new beam acceleration systems. In addition to doubling the acceleration in each linac, the upgrade included improving the beam recirculation magnets, adding more helium cooling capacity to allow the newly installed modules to run cold, adding a new experimental hall, and improving numerous other accelerator components. We review several of the techniques deployed to operate and analyze the accelerator performance, and document system operating experience and performance. In the final portion of the document, we present much of the current planning regarding projects to improve accelerator performance and enhance operating margins, and our plans for ensuring CEBAF operates reliably into the future. For the benefit of potential users of CEBAF, the performance and quality measures for beam delivered to each of the experimental halls is summarized in the appendix.
{"title":"The Continuous Electron Beam Accelerator Facility at 12 GeV","authors":"P. A. Adderley, S. Ahmed, T. Allison, R. Bachimanchi, K. Baggett, M. BastaniNejad, B. Bevins, M. Bevins, M. Bickley, R. M. Bodenstein, S. A. Bogacz, M. Bruker, A. Burrill, L. Cardman, J. Creel, Y. -C. Chao, G. Cheng, G. Ciovati, S. Chattopadhyay, J. Clark, W. A. Clemens, G. Croke, E. Daly, G. K. Davis, J. Delayen, S. U. De Silva, R. Dickson, M. Diaz, M. Drury, L. Doolittle, D. Douglas, E. Feldl, J. Fischer, A. Freyberger, V. Ganni, R. L. Geng, C. Ginsburg, J. Gomez, J. Grames, J. Gubeli, J. Guo, F. Hannon, J. Hansknecht, L. Harwood, J. Henry, C. Hernandez-Garcia, S. Higgins, D. Higinbotham, A. S. Hofler, T. Hiatt, J. Hogan, C. Hovater, A. Hutton, C. Jones, K. Jordan, M. Joyce, R. Kazimi, M. Keesee, M. J. Kelley, C. Keppel, A. Kimber, L. King, P. Kjeldsen, P. Kneisel, J. Koval, G. A. Krafft, G. Lahti, T. Larrieu, R. Lauze, C. Leemann, R. Legg, R. Li, F. Lin, D. Machie, J. Mammosser, K. Macha, K. Mahoney, F. Marhauser, B. Mastracci, J. Matalevich, J. McCarter, M. McCaughan, L. Merminga, R. Michaud, V. Morozov, C. Mounts, J. Musson, R. Nelson, W. Oren, R. B. Overton, G. Palacios-Serrano, H. -K. Park, L. Phillips, S. Philip, F. Pilat, T. Plawski, M. Poelker, P. Powers, T. Powers, J. Preble, T. Reilly, R. Rimmer, C. Reece, H. Robertson, Y. Roblin, C. Rode, T. Satogata, D. J. Seidman, A. Seryi, A. Shabalina, I. Shin, R. Slominski, C. Slominski, M. Spata, D. Spell, J. Spradlin, M. Stirbet, M. L. Stutzman, S. Suhring, K. Surles-Law, R. Suleiman, C. Tennant, H. Tian, D. Turner, M. Tiefenback, O. Trofimova, A. -M. Valente, H. Wang, Y. Wang, K. White, C. Whitlatch, T. Whitlatch, M. Wiseman, M. J. Wissman, G. Wu, S. Yang, B. Yunn, S. Zhang, Y. Zhang","doi":"arxiv-2408.16880","DOIUrl":"https://doi.org/arxiv-2408.16880","url":null,"abstract":"This review paper describes the energy-upgraded CEBAF accelerator. This\u0000superconducting linac has achieved 12 GeV beam energy by adding 11 new\u0000high-performance cryomodules containing eighty-eight superconducting cavities\u0000that have operated CW at an average accelerating gradient of 20 MV/m. After\u0000reviewing the attributes and performance of the previous 6 GeV CEBAF\u0000accelerator, we discuss the upgraded CEBAF accelerator system in detail with\u0000particular attention paid to the new beam acceleration systems. In addition to\u0000doubling the acceleration in each linac, the upgrade included improving the\u0000beam recirculation magnets, adding more helium cooling capacity to allow the\u0000newly installed modules to run cold, adding a new experimental hall, and\u0000improving numerous other accelerator components. We review several of the\u0000techniques deployed to operate and analyze the accelerator performance, and\u0000document system operating experience and performance. In the final portion of\u0000the document, we present much of the current planning regarding projects to\u0000improve accelerator performance and enhance operating margins, and our plans\u0000for ensuring CEBAF operates reliably into the future. For the benefit of\u0000potential users of CEBAF, the performance and quality measures for beam\u0000delivered to each of the experimental halls is summarized in the appendix.","PeriodicalId":501318,"journal":{"name":"arXiv - PHYS - Accelerator Physics","volume":"6 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142216285","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. Yadav, M. H. Oruganti, B. Naranjo, G. Andonian, Ö. Apsimon, C. P. Welsch, J. B. Rosenzweig
Photons emitted from high-energy electron beam interactions with high-field systems, such as the upcoming FACET-II experiments at SLAC National Accelerator Laboratory, may provide deep insight into the electron beam's underlying dynamics at the interaction point. With high-energy photons being utilized to generate electron-positron pairs in a novel spectrometer, there remains a key problem of interpreting the spectrometer's raw data to determine the energy distribution of the incoming photons. This paper uses data from simulations of the primary radiation emitted from electron interactions with a high-field, short-pulse laser to determine optimally reliable methods of reconstructing the measured photon energy distributions. For these measurements, recovering the emitted 10 MeV to 10 GeV photon energy spectra from the pair spectrometer currently being commissioned requires testing multiple methods to finalize a pipeline from the spectrometer data to incident photon and, by extension, electron beam information. In this study, we compare the performance QR decomposition, a matrix deconstruction technique and neural network with and without maximum likelihood estimation (MLE). Although QR decomposition proved to be the most effective theoretically, combining machine learning and MLE proved to be superior in the presence of noise, indicating its promise for analysis pipelines involving high-energy photons.
{"title":"Reconstructing Gamma-ray Energy Distributions from PEDRO Pair Spectrometer Data","authors":"M. Yadav, M. H. Oruganti, B. Naranjo, G. Andonian, Ö. Apsimon, C. P. Welsch, J. B. Rosenzweig","doi":"arxiv-2409.02113","DOIUrl":"https://doi.org/arxiv-2409.02113","url":null,"abstract":"Photons emitted from high-energy electron beam interactions with high-field\u0000systems, such as the upcoming FACET-II experiments at SLAC National Accelerator\u0000Laboratory, may provide deep insight into the electron beam's underlying\u0000dynamics at the interaction point. With high-energy photons being utilized to\u0000generate electron-positron pairs in a novel spectrometer, there remains a key\u0000problem of interpreting the spectrometer's raw data to determine the energy\u0000distribution of the incoming photons. This paper uses data from simulations of\u0000the primary radiation emitted from electron interactions with a high-field,\u0000short-pulse laser to determine optimally reliable methods of reconstructing the\u0000measured photon energy distributions. For these measurements, recovering the\u0000emitted 10 MeV to 10 GeV photon energy spectra from the pair spectrometer\u0000currently being commissioned requires testing multiple methods to finalize a\u0000pipeline from the spectrometer data to incident photon and, by extension,\u0000electron beam information. In this study, we compare the performance QR\u0000decomposition, a matrix deconstruction technique and neural network with and\u0000without maximum likelihood estimation (MLE). Although QR decomposition proved\u0000to be the most effective theoretically, combining machine learning and MLE\u0000proved to be superior in the presence of noise, indicating its promise for\u0000analysis pipelines involving high-energy photons.","PeriodicalId":501318,"journal":{"name":"arXiv - PHYS - Accelerator Physics","volume":"53 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142216286","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}
Terawatt x-ray free-electron lasers (XFELs) represent the frontier in further development of x-ray sources and require high current densities with strong transverse focusing. In this paper, we investigate the implications/potentialities of TW XFELs on the generation of harmonics at still shorter wavelengths and higher photon energies with variable polarization. The simulations indicate that significant power levels are possible at high harmonics of the XFEL resonance and that these XFELs can be an important coherent source of hard x-rays through the gamma ray spectrum. For this purpose, we use the MINERVA simulation code which self-consistently includes harmonic generation. Both helical and planar undulators are discussed in which the fundamental is at 1.5 {AA} and study the associated harmonic generation. While tapered undulators are needed to reach TW powers at the fundamental, the taper does not enhance the harmonics because the taper must start before saturation of the fundamental, while the harmonics saturate before this point is reached. Nevertheless, the harmonics reach substantial powers. Simulations indicate that, for the parameters under consideration, peak powers of the order of 180 MW are possible at the fifth harmonic with a photon energy of about 41 keV and still high harmonics may also be generated at substantial powers. Such high harmonic powers are certain to enable a host of enhanced applications
超大瓦 X 射线自由电子激光器（XFEL）是 X 射线源进一步发展的前沿，需要高电流密度和强横向聚焦。在本文中，我们研究了 TW XFEL 在更短波长和更高光子能量以及可变极化条件下产生谐波的影响/潜力。模拟结果表明，在XFEL共振的高次谐波上有可能产生巨大的功率水平，这些XFEL可以成为贯穿伽马射线频谱的硬X射线的重要相干源。为此，我们使用了 MINERVA 仿真代码，该代码自洽地包含了谐波的产生。我们讨论了基频为 1.5 {AA} 的螺旋和平面起爆器，并研究了相关谐波的产生。虽然需要锥形起爆器来达到基频的 TW 功率，但锥形起爆器并不能增强谐波，因为锥形起爆器必须在基频饱和之前开始，而谐波在达到这一点之前就已经饱和了。尽管如此，谐波仍能达到相当大的功率。模拟结果表明，就目前考虑的参数而言，在光子能量约为 41keV 的情况下，五次谐波的峰值功率可能达到 180 兆瓦，而且还可能以相当大的功率产生高次谐波。如此高的谐波功率必将带来一系列增强型应用
{"title":"The Generation of Variable Polarization States in Terawatt X-Ray Free-Electron Lasers","authors":"Henry P. Freund, Patrick G. O'Shea","doi":"arxiv-2408.15363","DOIUrl":"https://doi.org/arxiv-2408.15363","url":null,"abstract":"Terawatt x-ray free-electron lasers (XFELs) represent the frontier in further\u0000development of x-ray sources and require high current densities with strong\u0000transverse focusing. In this paper, we investigate the\u0000implications/potentialities of TW XFELs on the generation of harmonics at still\u0000shorter wavelengths and higher photon energies with variable polarization. The\u0000simulations indicate that significant power levels are possible at high\u0000harmonics of the XFEL resonance and that these XFELs can be an important\u0000coherent source of hard x-rays through the gamma ray spectrum. For this\u0000purpose, we use the MINERVA simulation code which self-consistently includes\u0000harmonic generation. Both helical and planar undulators are discussed in which\u0000the fundamental is at 1.5 {AA} and study the associated harmonic generation.\u0000While tapered undulators are needed to reach TW powers at the fundamental, the\u0000taper does not enhance the harmonics because the taper must start before\u0000saturation of the fundamental, while the harmonics saturate before this point\u0000is reached. Nevertheless, the harmonics reach substantial powers. Simulations\u0000indicate that, for the parameters under consideration, peak powers of the order\u0000of 180 MW are possible at the fifth harmonic with a photon energy of about 41\u0000keV and still high harmonics may also be generated at substantial powers. Such\u0000high harmonic powers are certain to enable a host of enhanced applications","PeriodicalId":501318,"journal":{"name":"arXiv - PHYS - Accelerator Physics","volume":"9 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142216284","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}
Yongjun Li, Kelly Anderson, Derong Xu, Yue Hao, Kiman Ha, Yoshiteru Hidaka, Minghao Song, Robert Rainer, Victor Smaluk, Timur Shaftan
Shannon Entropy is adopted to quantify the chaos of measured Poincar'e maps in the National Synchrotron Light Source-II (NSLS-II) storage ring. The recurrent Poincar'e maps, constructed from beam position monitor's turn-by-turn readings, are commonly used to observe the nonlinearity in ring-based accelerators. However, these observations typically only provide a qualitative observation. With some canonical transformations on Poincar'e maps, not only can the commonly used nonlinear characterizations be extracted, but more importantly, the chaos can be quantitatively measured with entropy. Entropy, therefore as a chaos indicator, is used for online Poincar'e map regularization and dynamic aperture optimization in the NSLS-II ring.
{"title":"Online regularization of Poincaré map of storage rings with Shannon entropy","authors":"Yongjun Li, Kelly Anderson, Derong Xu, Yue Hao, Kiman Ha, Yoshiteru Hidaka, Minghao Song, Robert Rainer, Victor Smaluk, Timur Shaftan","doi":"arxiv-2408.14333","DOIUrl":"https://doi.org/arxiv-2408.14333","url":null,"abstract":"Shannon Entropy is adopted to quantify the chaos of measured Poincar'e maps\u0000in the National Synchrotron Light Source-II (NSLS-II) storage ring. The\u0000recurrent Poincar'e maps, constructed from beam position monitor's\u0000turn-by-turn readings, are commonly used to observe the nonlinearity in\u0000ring-based accelerators. However, these observations typically only provide a\u0000qualitative observation. With some canonical transformations on Poincar'e\u0000maps, not only can the commonly used nonlinear characterizations be extracted,\u0000but more importantly, the chaos can be quantitatively measured with entropy.\u0000Entropy, therefore as a chaos indicator, is used for online Poincar'e map\u0000regularization and dynamic aperture optimization in the NSLS-II ring.","PeriodicalId":501318,"journal":{"name":"arXiv - PHYS - Accelerator Physics","volume":"34 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142216287","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}
Hiroshi SakaiHigh Energy Accelerator Research Organization, Dai ArakawaHigh Energy Accelerator Research Organization, Takaaki FuruyaHigh Energy Accelerator Research Organization, Kaiichi HagaHigh Energy Accelerator Research Organization, Masayuki HagiwaraHigh Energy Accelerator Research Organization, Kentaro HaradaHigh Energy Accelerator Research Organization, Yosuke HondaHigh Energy Accelerator Research Organization, Teruya HonmaHigh Energy Accelerator Research Organization, Eiji KakoHigh Energy Accelerator Research Organization, Ryukou KatoHigh Energy Accelerator Research Organization, Yuuji KojimaHigh Energy Accelerator Research Organization, Taro KonomiHigh Energy Accelerator Research Organization, Hiroshi MatsumuraHigh Energy Accelerator Research Organization, Taichi MiuraHigh Energy Accelerator Research Organization, Takako MiuraHigh Energy Accelerator Research Organization, Shinya NagahashiHigh Energy Accelerator Research Organization, Hirotaka NakaiHigh Energy Accelerator Research Organization, Norio NakamuraHigh Energy Accelerator Research Organization, Kota NakanishiHigh Energy Accelerator Research Organization, Kazuyuki NigorikawaHigh Energy Accelerator Research Organization, Takashi NogamiHigh Energy Accelerator Research Organization, Takashi ObinaHigh Energy Accelerator Research Organization, Feng QiuHigh Energy Accelerator Research Organization, Hidenori SagehashiHigh Energy Accelerator Research Organization, Shogo SakanakaHigh Energy Accelerator Research Organization, Miho ShimadaHigh Energy Accelerator Research Organization, Mikito TadanoHigh Energy Accelerator Research Organization, Takeshi TakahashiHigh Energy Accelerator Research Organization, Ryota TakaiHigh Energy Accelerator Research Organization, Olga TanakaHigh Energy Accelerator Research Organization, Yasunori TanimotoHigh Energy Accelerator Research Organization, Akihiro ToyodaHigh Energy Accelerator Research Organization, Takashi UchiyamaHigh Energy Accelerator Research Organization, Kensei UmemoriHigh Energy Accelerator Research Organization, Masahiro YamamotoHigh Energy Accelerator Research Organization, Go YoshidaHigh Energy Accelerator Research Organization, Nobuyuki NishimoriNational Institutes for Quantum and Radiological Science and Technology, Ryoichi HajimaNational Institutes for Quantum and Radiological Science and Technology, Ryoji NagaiNational Institutes for Quantum and Radiological Science and Technology, Masaru SawamuraNational Institutes for Quantum and Radiological Science and Technology
A compact energy-recovery linac (cERL) has been un-der construction at KEK since 2009 to develop key technologies for the energy-recovery linac. The cERL began operating in 2013 to create a high-current beam with a low-emittance beam with stable continuous wave (CW) superconducting cavities. Owing to the development of critical components, such as the DC gun, superconducting cavities, and the design of ideal beam transport optics, we have successfully established approximately 1 mA stable CW operation with a small beam emittance and extremely small beam loss. This study presents the details of our key technologies and experimental results for achieving 100% energy recovery operation with extremely small beam loss during a stable, approximately 1 mA CW beam operation.
{"title":"Stable beam operation of approximately 1 mA beam under highly efficient energy recovery conditions at compact energy-recovery linac","authors":"Hiroshi SakaiHigh Energy Accelerator Research Organization, Dai ArakawaHigh Energy Accelerator Research Organization, Takaaki FuruyaHigh Energy Accelerator Research Organization, Kaiichi HagaHigh Energy Accelerator Research Organization, Masayuki HagiwaraHigh Energy Accelerator Research Organization, Kentaro HaradaHigh Energy Accelerator Research Organization, Yosuke HondaHigh Energy Accelerator Research Organization, Teruya HonmaHigh Energy Accelerator Research Organization, Eiji KakoHigh Energy Accelerator Research Organization, Ryukou KatoHigh Energy Accelerator Research Organization, Yuuji KojimaHigh Energy Accelerator Research Organization, Taro KonomiHigh Energy Accelerator Research Organization, Hiroshi MatsumuraHigh Energy Accelerator Research Organization, Taichi MiuraHigh Energy Accelerator Research Organization, Takako MiuraHigh Energy Accelerator Research Organization, Shinya NagahashiHigh Energy Accelerator Research Organization, Hirotaka NakaiHigh Energy Accelerator Research Organization, Norio NakamuraHigh Energy Accelerator Research Organization, Kota NakanishiHigh Energy Accelerator Research Organization, Kazuyuki NigorikawaHigh Energy Accelerator Research Organization, Takashi NogamiHigh Energy Accelerator Research Organization, Takashi ObinaHigh Energy Accelerator Research Organization, Feng QiuHigh Energy Accelerator Research Organization, Hidenori SagehashiHigh Energy Accelerator Research Organization, Shogo SakanakaHigh Energy Accelerator Research Organization, Miho ShimadaHigh Energy Accelerator Research Organization, Mikito TadanoHigh Energy Accelerator Research Organization, Takeshi TakahashiHigh Energy Accelerator Research Organization, Ryota TakaiHigh Energy Accelerator Research Organization, Olga TanakaHigh Energy Accelerator Research Organization, Yasunori TanimotoHigh Energy Accelerator Research Organization, Akihiro ToyodaHigh Energy Accelerator Research Organization, Takashi UchiyamaHigh Energy Accelerator Research Organization, Kensei UmemoriHigh Energy Accelerator Research Organization, Masahiro YamamotoHigh Energy Accelerator Research Organization, Go YoshidaHigh Energy Accelerator Research Organization, Nobuyuki NishimoriNational Institutes for Quantum and Radiological Science and Technology, Ryoichi HajimaNational Institutes for Quantum and Radiological Science and Technology, Ryoji NagaiNational Institutes for Quantum and Radiological Science and Technology, Masaru SawamuraNational Institutes for Quantum and Radiological Science and Technology","doi":"arxiv-2408.13478","DOIUrl":"https://doi.org/arxiv-2408.13478","url":null,"abstract":"A compact energy-recovery linac (cERL) has been un-der construction at KEK\u0000since 2009 to develop key technologies for the energy-recovery linac. The cERL\u0000began operating in 2013 to create a high-current beam with a low-emittance beam\u0000with stable continuous wave (CW) superconducting cavities. Owing to the\u0000development of critical components, such as the DC gun, superconducting\u0000cavities, and the design of ideal beam transport optics, we have successfully\u0000established approximately 1 mA stable CW operation with a small beam emittance\u0000and extremely small beam loss. This study presents the details of our key\u0000technologies and experimental results for achieving 100% energy recovery\u0000operation with extremely small beam loss during a stable, approximately 1 mA CW\u0000beam operation.","PeriodicalId":501318,"journal":{"name":"arXiv - PHYS - Accelerator Physics","volume":"36 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142216288","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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