W. AsztalosIllinois Institute of Technology, Y. TorunIllinois Institute of Technology, S. BidharFermi National Accelerator Laboratory, F. PellemoineFermi National Accelerator Laboratory, P. RathIndian Institute of Technology Bhubaneswar
Increase of primary beam power for neutrino beam-lines leads to a reduced lifespan for production targets. New concepts for robust targets are emerging from the field of High Power Targetry (HPT); one idea being investigated by the HPT R&D Group at Fermilab is an electrospun nanofiber target. As part of their evaluation, samples with different densities were sent to the HiRadMat facility at CERN for thermal shock tests. The samples with the higher density, irradiated under a high intensity beam pulse, exhibit major damage at the impact site whereas those with the lower density show no apparent damage. The exact cause of this failure was unclear at the time. In this paper, we present the results of multiphysics simulations of the thermal shock experienced by the nanofiber targets that suggest the failure originates from the reduced permeability of the high density sample to air flow. The air present in the porous target expands due to heating from the beam, but is unable to flow freely in the high density sample, resulting in a larger back pressure that blows apart the nanofiber mat. We close with a discussion on how to further validate this hypothesis.
{"title":"Multiphysics Simulations of Thermal Shock Testing of Nanofibrous High Power Targets","authors":"W. AsztalosIllinois Institute of Technology, Y. TorunIllinois Institute of Technology, S. BidharFermi National Accelerator Laboratory, F. PellemoineFermi National Accelerator Laboratory, P. RathIndian Institute of Technology Bhubaneswar","doi":"arxiv-2405.19496","DOIUrl":"https://doi.org/arxiv-2405.19496","url":null,"abstract":"Increase of primary beam power for neutrino beam-lines leads to a reduced\u0000lifespan for production targets. New concepts for robust targets are emerging\u0000from the field of High Power Targetry (HPT); one idea being investigated by the\u0000HPT R&D Group at Fermilab is an electrospun nanofiber target. As part of their\u0000evaluation, samples with different densities were sent to the HiRadMat facility\u0000at CERN for thermal shock tests. The samples with the higher density,\u0000irradiated under a high intensity beam pulse, exhibit major damage at the\u0000impact site whereas those with the lower density show no apparent damage. The\u0000exact cause of this failure was unclear at the time. In this paper, we present\u0000the results of multiphysics simulations of the thermal shock experienced by the\u0000nanofiber targets that suggest the failure originates from the reduced\u0000permeability of the high density sample to air flow. The air present in the\u0000porous target expands due to heating from the beam, but is unable to flow\u0000freely in the high density sample, resulting in a larger back pressure that\u0000blows apart the nanofiber mat. We close with a discussion on how to further\u0000validate this hypothesis.","PeriodicalId":501318,"journal":{"name":"arXiv - PHYS - Accelerator Physics","volume":"47 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141189878","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}
K. E. AndersonFermi National Accelerator Laboratory, Batavia, IL, USA, A. DeshpandeFermi National Accelerator Laboratory, Batavia, IL, USA, V. I. SidorovFermi National Accelerator Laboratory, Batavia, IL, USA, J. ZahuronesFermi National Accelerator Laboratory, Batavia, IL, USA
The LBNF Absorber consists of thirteen 6061-T6 aluminum core blocks. The core blocks are water cooled with de-ionized (DI) water which becomes radioactive during beam operations. The cooling water flows through gun-drilled channels in the core blocks. A weld quality optimization was performed to produce National Aeronautical Standard 1514 Class I quality welds on the aluminum core blocks. This was not successful in all cases. An existing Gas Tungsten Arc Welding Procedure Specification was fine tuned to minimize, in most cases, and eliminate detect-able tungsten inclusions in the welds. All the weld coupons, however passed welding inspection as per the piping code: ASME B31.3 Normal Fluid Service. Tungsten electrode diameter, type, and manufacturer were varied. Some of the samples were pre-heated and others were not. It was observed that larger diameter electrodes, 5/32 in., with pre-heated joints resulted in welds with the least number of tungsten inclusions. It is hypothesized that thinner electrodes breakdown easily and get lodged into the weld pool during the welding process. This breakdown is further enhanced by the large temperature differential between the un-preheated sample and the hot electrode.
{"title":"Optimization of a Welding Procedure for Making Critical Aluminum Welds on the LBNF Absorber Core Block","authors":"K. E. AndersonFermi National Accelerator Laboratory, Batavia, IL, USA, A. DeshpandeFermi National Accelerator Laboratory, Batavia, IL, USA, V. I. SidorovFermi National Accelerator Laboratory, Batavia, IL, USA, J. ZahuronesFermi National Accelerator Laboratory, Batavia, IL, USA","doi":"arxiv-2406.12883","DOIUrl":"https://doi.org/arxiv-2406.12883","url":null,"abstract":"The LBNF Absorber consists of thirteen 6061-T6 aluminum core blocks. The core\u0000blocks are water cooled with de-ionized (DI) water which becomes radioactive\u0000during beam operations. The cooling water flows through gun-drilled channels in\u0000the core blocks. A weld quality optimization was performed to produce National\u0000Aeronautical Standard 1514 Class I quality welds on the aluminum core blocks.\u0000This was not successful in all cases. An existing Gas Tungsten Arc Welding\u0000Procedure Specification was fine tuned to minimize, in most cases, and\u0000eliminate detect-able tungsten inclusions in the welds. All the weld coupons,\u0000however passed welding inspection as per the piping code: ASME B31.3 Normal\u0000Fluid Service. Tungsten electrode diameter, type, and manufacturer were varied.\u0000Some of the samples were pre-heated and others were not. It was observed that\u0000larger diameter electrodes, 5/32 in., with pre-heated joints resulted in welds\u0000with the least number of tungsten inclusions. It is hypothesized that thinner\u0000electrodes breakdown easily and get lodged into the weld pool during the\u0000welding process. This breakdown is further enhanced by the large temperature\u0000differential between the un-preheated sample and the hot electrode.","PeriodicalId":501318,"journal":{"name":"arXiv - PHYS - Accelerator Physics","volume":"142 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141526859","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}
Sara Dastan, Demin Zhou, Takuya Ishibashi, Emanuel Karantzoulis, Simone Di Mitri, Ryan Lindberg
Longitudinal impedances at high frequencies, which extend far beyond the width of the beam spectrum, can pose a threat to the performance of modern low-emittance electron storage rings, as they can establish a relatively low threshold for microwave instability. In such rings, coherent synchrotron radiation (CSR) emerges as a prominent contributor to these high-frequency impedances. This paper undertakes a systematic investigation into the effects of CSR on electron rings, utilizing Elettra 2.0, a ring of fourth-generation light sources, and the SuperKEKB low-energy ring, a ring of $e^+e^-$ circular colliders, as illustrative examples. Our work revisits theories of microwave instability driven by CSR impedance, extending the analysis to encompass other high-frequency impedances such as resistive wall and coherent wiggler radiation. Through instability analysis and numerical simulations conducted on the two aforementioned rings, the study explored the impact of high-frequency impedances and their interactions with broadband impedances from discontinuities in vacuum chambers.
{"title":"Coherent synchrotron radiation instability in low-emittance electron storage rings","authors":"Sara Dastan, Demin Zhou, Takuya Ishibashi, Emanuel Karantzoulis, Simone Di Mitri, Ryan Lindberg","doi":"arxiv-2405.18738","DOIUrl":"https://doi.org/arxiv-2405.18738","url":null,"abstract":"Longitudinal impedances at high frequencies, which extend far beyond the\u0000width of the beam spectrum, can pose a threat to the performance of modern\u0000low-emittance electron storage rings, as they can establish a relatively low\u0000threshold for microwave instability. In such rings, coherent synchrotron\u0000radiation (CSR) emerges as a prominent contributor to these high-frequency\u0000impedances. This paper undertakes a systematic investigation into the effects\u0000of CSR on electron rings, utilizing Elettra 2.0, a ring of fourth-generation\u0000light sources, and the SuperKEKB low-energy ring, a ring of $e^+e^-$ circular\u0000colliders, as illustrative examples. Our work revisits theories of microwave\u0000instability driven by CSR impedance, extending the analysis to encompass other\u0000high-frequency impedances such as resistive wall and coherent wiggler\u0000radiation. Through instability analysis and numerical simulations conducted on\u0000the two aforementioned rings, the study explored the impact of high-frequency\u0000impedances and their interactions with broadband impedances from\u0000discontinuities in vacuum chambers.","PeriodicalId":501318,"journal":{"name":"arXiv - PHYS - Accelerator Physics","volume":"61 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141189757","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. DeshpandeFNAL, Batavia, IL, USA, P. HurhFNAL, Batavia, IL, USA, J. HylenFNAL, Batavia, IL, USA, A. LeeFNAL, Batavia, IL, USA, J. LewisFNAL, Batavia, IL, USA, I. RakhnoFNAL, Batavia, IL, USA, V. I. SidorovFNAL, Batavia, IL, USA, Z. TangFNAL, Batavia, IL, USA, S. Tariq I. TropinFNAL, Batavia, IL, USA
The LBNF Absorber consists of thirteen 6061-T6 aluminum core blocks. The core blocks are water cooled with de-ionized (DI) water which becomes radioactive during beam operations. The cooling water flows through gun-drilled channels in the core blocks. The cooling water is supplied by the LBNF Absorber Radioactive Water (RAW) cooling system which is designed as per ASME B31.3 Normal Fluid Service [1]. An uninhibited beam accident pulse striking the water channels was identified as a credible accident scenario. In this study, it is assumed that the beam pulse hits the Absorber directly without interacting with any of the other upstream beamline components. The beam parameters used for the LBNF beam are 120 GeV, 2.4 MW with a 1.2 s cycle time. The accident pulse lasts for 10 {mu}s. The maximum energy is deposited in the 3rd aluminum core block. For the sake of simplicity, it is assumed that the accident pulse strikes the 1 in. ID water channel directly. The analysis here simulates the pressure rise in the water during and after the beam pulse and its effects on the aluminum piping components that deliver water to the core blocks. The weld strengths as determined by the Load and Resistance Factor Design (LRDF) and the Allowable Strength Design (ASD) are compared to the forces generated in the weld owing to the pressure spike. A transient structural analysis was used to determine the equivalent membrane, peak, and bending stresses and they were com-pared to allowable limits.
{"title":"Pressure Spike in The LBNF Absorber Core s Gun Drilled Cooling Channel from an Accident Beam Pulse","authors":"A. DeshpandeFNAL, Batavia, IL, USA, P. HurhFNAL, Batavia, IL, USA, J. HylenFNAL, Batavia, IL, USA, A. LeeFNAL, Batavia, IL, USA, J. LewisFNAL, Batavia, IL, USA, I. RakhnoFNAL, Batavia, IL, USA, V. I. SidorovFNAL, Batavia, IL, USA, Z. TangFNAL, Batavia, IL, USA, S. Tariq I. TropinFNAL, Batavia, IL, USA","doi":"arxiv-2405.19448","DOIUrl":"https://doi.org/arxiv-2405.19448","url":null,"abstract":"The LBNF Absorber consists of thirteen 6061-T6 aluminum core blocks. The core\u0000blocks are water cooled with de-ionized (DI) water which becomes radioactive\u0000during beam operations. The cooling water flows through gun-drilled channels in\u0000the core blocks. The cooling water is supplied by the LBNF Absorber Radioactive\u0000Water (RAW) cooling system which is designed as per ASME B31.3 Normal Fluid\u0000Service [1]. An uninhibited beam accident pulse striking the water channels was\u0000identified as a credible accident scenario. In this study, it is assumed that\u0000the beam pulse hits the Absorber directly without interacting with any of the\u0000other upstream beamline components. The beam parameters used for the LBNF beam\u0000are 120 GeV, 2.4 MW with a 1.2 s cycle time. The accident pulse lasts for 10\u0000{mu}s. The maximum energy is deposited in the 3rd aluminum core block. For the\u0000sake of simplicity, it is assumed that the accident pulse strikes the 1 in. ID\u0000water channel directly. The analysis here simulates the pressure rise in the\u0000water during and after the beam pulse and its effects on the aluminum piping\u0000components that deliver water to the core blocks. The weld strengths as\u0000determined by the Load and Resistance Factor Design (LRDF) and the Allowable\u0000Strength Design (ASD) are compared to the forces generated in the weld owing to\u0000the pressure spike. A transient structural analysis was used to determine the\u0000equivalent membrane, peak, and bending stresses and they were com-pared to\u0000allowable limits.","PeriodicalId":501318,"journal":{"name":"arXiv - PHYS - Accelerator Physics","volume":"68 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141189756","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. Krasilnikov, Z. Aboulbanine, G. Adhikari, N. Aftab, A. Asoyan, P. Boonpornprasert, H. Davtyan, G. Georgiev, J. Good, A. Grebinyk, M. Gross, A. Hoffmann, E. Kongmon, X. -K. Li, A. Lueangaramwong, D. Melkumyan, S. Mohanty, R. Niemczyk, A. Oppelt, H. Qian, C. Richard, F. Stephan, G. Vashchenko, T. Weilbach, X. Zhang, M. Tischer, E. Schneidmiller, P. Vagin, M. Yurkov, E. Zapolnova, W. Hillert, J. Rossbach A. Brachmann, N. Holtkamp, H. -D. Nuhn
Advanced experiments using THz pump and X-ray probe pulses at modern free-electron lasers (FELs) like the European X-ray FEL require a frequency-tunable, high-power, narrow-band THz source maintaining the repetition rate and pulse structure of the X-ray pulses. This paper reports the first results from a THz source, that is based on a single-pass high-gain THz FEL operating with a central wavelength of 100 micrometers. The THz FEL prototype is currently in operation at the Photo Injector Test facility at DESY in Zeuthen (PITZ) and uses the same type of electron source as the European XFEL photo injector. A self-amplified spontaneous emission (SASE) FEL was envisioned as the main mechanism for generating the THz pulses. Although the THz FEL at PITZ is supposed to use the same mechanism as at X-ray facilities, it cannot be considered as a simple scaling of the radiation wavelength because there is a large difference in the number of electrons per radiation wavelength, which is five orders of magnitude higher for the THz case. The bunching factor arising from the electron beam current profile contributes strongly to the initial spontaneous emission starting the FEL process. Proof-of-principle experiments were done at PITZ using an LCLS-I undulator to generate the first high-power, high-repetition-rate single-pass THz FEL radiation. Electron bunches with a beam energy of ~17 MeV and a bunch charge of up to several nC are used to generate THz pulses with a pulse energy of several tens of microjoules. For example, for an electron beam with a charge of ~2.4 nC, more than 100 microjoules were generated at a central wavelength of 100 micrometers. The narrowband spectrum was also demonstrated by spectral measurements. These proof-of-principle experiments pave the way for a tunable, high-repetition-rate THz source providing pulses with energies in the millijoule range.
在现代自由电子激光器（FEL）（如欧洲 X 射线 FEL）上使用太赫兹泵浦脉冲和 X 射线探针脉冲进行高级实验，需要频率可调、高功率、窄带太赫兹源，以保持 X 射线脉冲的脉冲频率和脉冲结构。本文报告了基于中心波长为 100 微米的单通道高增益 THzFEL 的 THz 源的首批结果。太赫兹 FEL 原型目前正在宙申（PITZ）DESY 的光注入器测试设备上运行，使用与欧洲 XFEL 光注入器相同类型的电子源。自放大自发辐射（SASE）FEL 是产生太赫兹脉冲的主要机制。尽管 PITZ 的太赫兹 FEL 应该使用与 X 射线设施相同的机制，但不能将其视为辐射波长的简单缩放，因为每个辐射波长的电子数量差异很大，太赫兹情况下要高出五个数量级。PITZ使用LCLS-I型减压器进行了原理验证实验，产生了首个高功率、高重复率的单通道太赫兹FEL辐射。束流能量约为 17 MeV、束流电荷高达几 nC 的电子束被用来产生脉冲能量为几十微焦耳的太赫兹脉冲。例如，对于电荷量约为 2.4nC 的电子束，在中心波长为 100 厘米时可产生超过 100 微焦的脉冲能量。窄带光谱也通过光谱测量得到了证明。这些原理验证实验为可调谐、高重复率太赫兹源提供毫焦耳范围内的脉冲能量铺平了道路。
{"title":"First high peak and average power single-pass THz FEL based on high brightness photoinjector","authors":"M. Krasilnikov, Z. Aboulbanine, G. Adhikari, N. Aftab, A. Asoyan, P. Boonpornprasert, H. Davtyan, G. Georgiev, J. Good, A. Grebinyk, M. Gross, A. Hoffmann, E. Kongmon, X. -K. Li, A. Lueangaramwong, D. Melkumyan, S. Mohanty, R. Niemczyk, A. Oppelt, H. Qian, C. Richard, F. Stephan, G. Vashchenko, T. Weilbach, X. Zhang, M. Tischer, E. Schneidmiller, P. Vagin, M. Yurkov, E. Zapolnova, W. Hillert, J. Rossbach A. Brachmann, N. Holtkamp, H. -D. Nuhn","doi":"arxiv-2405.19152","DOIUrl":"https://doi.org/arxiv-2405.19152","url":null,"abstract":"Advanced experiments using THz pump and X-ray probe pulses at modern\u0000free-electron lasers (FELs) like the European X-ray FEL require a\u0000frequency-tunable, high-power, narrow-band THz source maintaining the\u0000repetition rate and pulse structure of the X-ray pulses. This paper reports the\u0000first results from a THz source, that is based on a single-pass high-gain THz\u0000FEL operating with a central wavelength of 100 micrometers. The THz FEL\u0000prototype is currently in operation at the Photo Injector Test facility at DESY\u0000in Zeuthen (PITZ) and uses the same type of electron source as the European\u0000XFEL photo injector. A self-amplified spontaneous emission (SASE) FEL was\u0000envisioned as the main mechanism for generating the THz pulses. Although the\u0000THz FEL at PITZ is supposed to use the same mechanism as at X-ray facilities,\u0000it cannot be considered as a simple scaling of the radiation wavelength because\u0000there is a large difference in the number of electrons per radiation\u0000wavelength, which is five orders of magnitude higher for the THz case. The\u0000bunching factor arising from the electron beam current profile contributes\u0000strongly to the initial spontaneous emission starting the FEL process.\u0000Proof-of-principle experiments were done at PITZ using an LCLS-I undulator to\u0000generate the first high-power, high-repetition-rate single-pass THz FEL\u0000radiation. Electron bunches with a beam energy of ~17 MeV and a bunch charge of\u0000up to several nC are used to generate THz pulses with a pulse energy of several\u0000tens of microjoules. For example, for an electron beam with a charge of ~2.4\u0000nC, more than 100 microjoules were generated at a central wavelength of 100\u0000micrometers. The narrowband spectrum was also demonstrated by spectral\u0000measurements. These proof-of-principle experiments pave the way for a tunable,\u0000high-repetition-rate THz source providing pulses with energies in the\u0000millijoule range.","PeriodicalId":501318,"journal":{"name":"arXiv - PHYS - Accelerator Physics","volume":"41 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141189668","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}
W. AsztalosIllinois Institute of Technology, Y. TorunIllinois Institute of Technology, S. BidharFermi National Accelerator Laboratory, F. PellemoineFermi National Accelerator Laboratory, P. RathIndian Institute of Technology Bhubaneswar
High Power Targetry (HPT) R&D is critical in the context of increasing beam intensity and energy for next generation accelerators. Many target concepts and novel materials are being developed and tested for their ability to withstand extreme beam environments; the HPT R&D Group at Fermilab is developing an electrospun nanofiber material for this purpose. The performance of these nanofiber targets is sensitive to their construction parameters, such as the packing density of the fibers. Lowering the density improves the survival of the target, but reduces the secondary particle yield. Optimizing the lifetime and production efficiency of the target poses an interesting design problem, and in this paper we study the applicability of Bayesian optimization to its solution. We first describe how to encode the nanofiber target design problem as the optimization of an objective function, and how to evaluate that function with computer simulations. We then explain the optimization loop setup. Thereafter, we present the optimal design parameters suggested by the algorithm, and close with discussions of limitations and future refinements.
{"title":"Bayesian optimization scheme for the design of a nanofibrous high power target","authors":"W. AsztalosIllinois Institute of Technology, Y. TorunIllinois Institute of Technology, S. BidharFermi National Accelerator Laboratory, F. PellemoineFermi National Accelerator Laboratory, P. RathIndian Institute of Technology Bhubaneswar","doi":"arxiv-2405.19490","DOIUrl":"https://doi.org/arxiv-2405.19490","url":null,"abstract":"High Power Targetry (HPT) R&D is critical in the context of increasing beam\u0000intensity and energy for next generation accelerators. Many target concepts and\u0000novel materials are being developed and tested for their ability to withstand\u0000extreme beam environments; the HPT R&D Group at Fermilab is developing an\u0000electrospun nanofiber material for this purpose. The performance of these\u0000nanofiber targets is sensitive to their construction parameters, such as the\u0000packing density of the fibers. Lowering the density improves the survival of\u0000the target, but reduces the secondary particle yield. Optimizing the lifetime\u0000and production efficiency of the target poses an interesting design problem,\u0000and in this paper we study the applicability of Bayesian optimization to its\u0000solution. We first describe how to encode the nanofiber target design problem\u0000as the optimization of an objective function, and how to evaluate that function\u0000with computer simulations. We then explain the optimization loop setup.\u0000Thereafter, we present the optimal design parameters suggested by the\u0000algorithm, and close with discussions of limitations and future refinements.","PeriodicalId":501318,"journal":{"name":"arXiv - PHYS - Accelerator Physics","volume":"80 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141189990","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}
N. BanerjeeFermilab, Batavia, Illinois, USA, A. RomanovFermilab, Batavia, Illinois, USA, M. WallbankFermilab, Batavia, Illinois, USA
We are commissioning a 2.5-MeV proton beam for the Integrable Optics Test Accelerator at Fermilab, allowing experiments in the strong space-charge regime with incoherent betatron tune shifts nearing 0.5. Accurate modelling of space-charge dynamics is vital for understanding planned experiments. We compare anticipated emittance growth and beam loss in the bare IOTA configuration using transverse space-charge models in Xsuite, PyORBIT, and MADX simulation codes. Our findings reveal agreement within a factor of 2 in core phase-space density predictions up to 100 synchrotron periods at moderate beam currents, while tail distributions and beam loss show significant differences.
{"title":"Proton beam dynamics in bare IOTA with intense space-charge","authors":"N. BanerjeeFermilab, Batavia, Illinois, USA, A. RomanovFermilab, Batavia, Illinois, USA, M. WallbankFermilab, Batavia, Illinois, USA","doi":"arxiv-2405.19163","DOIUrl":"https://doi.org/arxiv-2405.19163","url":null,"abstract":"We are commissioning a 2.5-MeV proton beam for the Integrable Optics Test\u0000Accelerator at Fermilab, allowing experiments in the strong space-charge regime\u0000with incoherent betatron tune shifts nearing 0.5. Accurate modelling of\u0000space-charge dynamics is vital for understanding planned experiments. We\u0000compare anticipated emittance growth and beam loss in the bare IOTA\u0000configuration using transverse space-charge models in Xsuite, PyORBIT, and MADX\u0000simulation codes. Our findings reveal agreement within a factor of 2 in core\u0000phase-space density predictions up to 100 synchrotron periods at moderate beam\u0000currents, while tail distributions and beam loss show significant differences.","PeriodicalId":501318,"journal":{"name":"arXiv - PHYS - Accelerator Physics","volume":"77 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141189740","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. PathakFermi National Accelerator Laboratory, Batavia, USA, O. NapolyFermi National Accelerator Laboratory, Batavia, USA, J. -F. OstiguyFermi National Accelerator Laboratory, Batavia, USA
The upcoming Proton Improvement Plan-II (PIP-II), designated for enhancements to the Fermilab accelerator complex, features a new 800 MeV superconducting linac and a Beam Transfer Line (BTL) to transport the beam to the existing Booster synchrotron. To mitigate the space charge tune shift associated with a high intensity accumulated beam, the low emittance linac beam is used to paint the ring phase space both transversely and longitudinally. To prevent losses caused by particles injected outside the rf separatrix while painting longitudinal phase space, the momentum spread of the incoming beam should not exceed 2.1 x 10^-4. Detailed simulations showed that due to space charge, the rms momentum spread increases to 4 x 10^-4 while it is transported in the BTL --about twice the allowable limit. In this paper, we outline a mitigation strategy involving a debuncher cavity. We discuss location, operating frequency, and gap voltage under both nominal and perturbed beam conditions, specifically accounting for momentum jitter. The impact of cavity misalignments is also assessed. The paper concludes by recommending an optimized configuration.
即将实施的 "质子改进计划-II"（PIP-II）是为增强费米实验室加速器综合设施而制定的，它包括一个新的 800 兆电子伏超导线性加速器和一条光束传输线（BTL），用于将光束传输到现有的增压同步加速器。为了减轻与高强度累积光束相关的空间电荷调谐偏移，低幅射线性加速器光束被用于横向和纵向涂抹环形相空间。为了防止在绘制纵向相空间时注入射频分离矩阵外的粒子所造成的损耗，入射束的动量扩散不应超过 2.1 x 10^-4。详细的模拟结果表明，由于空间电荷的作用，热动量扩散会增加到 4 x 10^-4，而它是在 BTL 中传输的，大约是允许极限的两倍。在本文中，我们概述了一种涉及去势腔的缓解策略。我们讨论了标称和扰动光束条件下的位置、工作频率和间隙电压，特别是动量抖动。我们还评估了腔体错位的影响。论文最后提出了优化配置建议。
{"title":"Space charge dominated momentum spread and compensation strategies in the post-linac section of Proton Improvement Plan-II at Fermilab","authors":"A. PathakFermi National Accelerator Laboratory, Batavia, USA, O. NapolyFermi National Accelerator Laboratory, Batavia, USA, J. -F. OstiguyFermi National Accelerator Laboratory, Batavia, USA","doi":"arxiv-2405.19515","DOIUrl":"https://doi.org/arxiv-2405.19515","url":null,"abstract":"The upcoming Proton Improvement Plan-II (PIP-II), designated for enhancements\u0000to the Fermilab accelerator complex, features a new 800 MeV superconducting\u0000linac and a Beam Transfer Line (BTL) to transport the beam to the existing\u0000Booster synchrotron. To mitigate the space charge tune shift associated with a\u0000high intensity accumulated beam, the low emittance linac beam is used to paint\u0000the ring phase space both transversely and longitudinally. To prevent losses\u0000caused by particles injected outside the rf separatrix while painting\u0000longitudinal phase space, the momentum spread of the incoming beam should not\u0000exceed 2.1 x 10^-4. Detailed simulations showed that due to space charge, the\u0000rms momentum spread increases to 4 x 10^-4 while it is transported in the BTL\u0000--about twice the allowable limit. In this paper, we outline a mitigation\u0000strategy involving a debuncher cavity. We discuss location, operating\u0000frequency, and gap voltage under both nominal and perturbed beam conditions,\u0000specifically accounting for momentum jitter. The impact of cavity misalignments\u0000is also assessed. The paper concludes by recommending an optimized\u0000configuration.","PeriodicalId":501318,"journal":{"name":"arXiv - PHYS - Accelerator Physics","volume":"130 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141189670","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}
K. AmmiganFermi National Accelerator Laboratory, Batavia, IL, USA, G. AroraFermi National Accelerator Laboratory, Batavia, IL, USA, S. BidharFermi National Accelerator Laboratory, Batavia, IL, USA, A. BurleighFermi National Accelerator Laboratory, Batavia, IL, USA, F. PellemoineFermi National Accelerator Laboratory, Batavia, IL, USA, A. CouetUniversity of Wisconsin-Madison, Madison, WI, USA, N. CrnkovichUniversity of Wisconsin-Madison, Madison, WI, USA, I. SzlufarskaUniversity of Wisconsin-Madison, Madison, WI, USA
As beam power continues to increase in next-generation accelerator facilities, high-power target systems face crucial challenges. Components like beam windows and particle-production targets must endure significantly higher levels of particle fluence. The primary beam's energy deposition causes rapid heating (thermal shock) and induces microstructural changes (radiation damage) within the target material. These effects ultimately deteriorate the components' properties and lifespan. With conventional materials already stretched to their limits, we are exploring novel materials including High-Entropy Alloys and Electrospun Nanofibers that offer a fresh approach to enhancing tolerance against thermal shock and radiation damage. Following an introduction to the challenges facing high-power target systems, we will give an overview of the promising advancements we have made so far in customizing the compositions and microstructures of these pioneering materials. Our focus is on optimizing their in-beam thermomechanical and physics performance. Additionally, we will outline our ongoing plans for in-beam irradiation experiments and advanced material characterizations. The primary goal of this research is to push the frontiers of target materials, thereby enabling future multi-MW facilities that will benefit various programs in high-energy physics and beyond.
{"title":"Novel materials for next-generation accelerator target facilities","authors":"K. AmmiganFermi National Accelerator Laboratory, Batavia, IL, USA, G. AroraFermi National Accelerator Laboratory, Batavia, IL, USA, S. BidharFermi National Accelerator Laboratory, Batavia, IL, USA, A. BurleighFermi National Accelerator Laboratory, Batavia, IL, USA, F. PellemoineFermi National Accelerator Laboratory, Batavia, IL, USA, A. CouetUniversity of Wisconsin-Madison, Madison, WI, USA, N. CrnkovichUniversity of Wisconsin-Madison, Madison, WI, USA, I. SzlufarskaUniversity of Wisconsin-Madison, Madison, WI, USA","doi":"arxiv-2405.18545","DOIUrl":"https://doi.org/arxiv-2405.18545","url":null,"abstract":"As beam power continues to increase in next-generation accelerator\u0000facilities, high-power target systems face crucial challenges. Components like\u0000beam windows and particle-production targets must endure significantly higher\u0000levels of particle fluence. The primary beam's energy deposition causes rapid\u0000heating (thermal shock) and induces microstructural changes (radiation damage)\u0000within the target material. These effects ultimately deteriorate the\u0000components' properties and lifespan. With conventional materials already\u0000stretched to their limits, we are exploring novel materials including\u0000High-Entropy Alloys and Electrospun Nanofibers that offer a fresh approach to\u0000enhancing tolerance against thermal shock and radiation damage. Following an\u0000introduction to the challenges facing high-power target systems, we will give\u0000an overview of the promising advancements we have made so far in customizing\u0000the compositions and microstructures of these pioneering materials. Our focus\u0000is on optimizing their in-beam thermomechanical and physics performance.\u0000Additionally, we will outline our ongoing plans for in-beam irradiation\u0000experiments and advanced material characterizations. The primary goal of this\u0000research is to push the frontiers of target materials, thereby enabling future\u0000multi-MW facilities that will benefit various programs in high-energy physics\u0000and beyond.","PeriodicalId":501318,"journal":{"name":"arXiv - PHYS - Accelerator Physics","volume":"27 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141189739","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. BaldiniFermi National Accelerator Laboratory, Batavia, Illinois, USA, G. AmbrosioFermi National Accelerator Laboratory, Batavia, Illinois, USA, G. ApollinariFermi National Accelerator Laboratory, Batavia, Illinois, USA, J. BlowersFermi National Accelerator Laboratory, Batavia, Illinois, USA, R. BossertFermi National Accelerator Laboratory, Batavia, Illinois, USA, R. CarcagnoFermi National Accelerator Laboratory, Batavia, Illinois, USA, G. ChlachidzeFermi National Accelerator Laboratory, Batavia, Illinois, USA, J. DiMarcoFermi National Accelerator Laboratory, Batavia, Illinois, USA, S. FeherFermi National Accelerator Laboratory, Batavia, Illinois, USA, S. KraveFermi National Accelerator Laboratory, Batavia, Illinois, USA, V. LombardoFermi National Accelerator Laboratory, Batavia, Illinois, USA, L. MartinFermi National Accelerator Laboratory, Batavia, Illinois, USA, C. NarugFermi National Accelerator Laboratory, Batavia, Illinois, USA, T. H. NicolFermi National Accelerator Laboratory, Batavia, Illinois, USA, V. NikolicFermi National Accelerator Laboratory, Batavia, Illinois, USA, A. NobregaFermi National Accelerator Laboratory, Batavia, Illinois, USA, V. MarinozziFermi National Accelerator Laboratory, Batavia, Illinois, USA, C. OrozcoFermi National Accelerator Laboratory, Batavia, Illinois, USA, T. PageFermi National Accelerator Laboratory, Batavia, Illinois, USA, S. StoynevFermi National Accelerator Laboratory, Batavia, Illinois, USA, T. StraussFermi National Accelerator Laboratory, Batavia, Illinois, USA, M. TurenneFermi National Accelerator Laboratory, Batavia, Illinois, USA, D. TurrioniFermi National Accelerator Laboratory, Batavia, Illinois, USA, A. VourisFermi National Accelerator Laboratory, Batavia, Illinois, USA, M. YuFermi National Accelerator Laboratory, Batavia, Illinois, USA, A. BaskysLawrence Berkeley National Laboratory, Berkeley CA, D. ChengLawrence Berkeley National Laboratory, Berkeley CA, J. F. CroteauLawrence Berkeley National Laboratory, Berkeley CA, P. FerracinLawrence Berkeley National Laboratory, Berkeley CA, L. Garcia FajardoLawrence Berkeley National Laboratory, Berkeley CA, E. LeeLawrence Berkeley National Laboratory, Berkeley CA, A. LinLawrence Berkeley National Laboratory, Berkeley CA, M. Marchev-skyLawrence Berkeley National Laboratory, Berkeley CA, M. NausLawrence Berkeley National Laboratory, Berkeley CA, H. PanLawrence Berkeley National Laboratory, Berkeley CA, I. PongLawrence Berkeley National Laboratory, Berkeley CA, S. PrestemonLawrence Berkeley National Laboratory, Berkeley CA, K. RayLawrence Berkeley National Laboratory, Berkeley CA, G. SabbiLawrence Berkeley National Laboratory, Berkeley CA, C. SanabriaLawrence Berkeley National Laboratory, Berkeley CA, G. ValloneLawrence Berkeley National Laboratory, Berkeley CA, X. WangLawrence Berkeley National Laboratory, Berkeley CA, K. AmmBrookhaven National Laboratory, Upton, NY, M. AnerellaBrookhaven National Laboratory, Upton, NY, A. Ben YahiaBrookhaven National Laboratory, Upton, NY, H. HockerBrookhaven National Laboratory, Upton, NY, P. JoshiBrookhaven National Laboratory, Upton, NY, J. MuratoreBrookhaven National Laboratory, Upton, NY, J. SchmalzleBrookhaven National Laboratory, Upton, NY, H. SongBrookhaven National Laboratory, Upton, NY, P. WandererBrookhaven National Laboratory, Upton, NY
The Large Hadron Collider will soon undergo an upgrade to increase its luminosity by a factor of ~10 [1]. A crucial part of this upgrade will be replacement of the NbTi focusing magnets with Nb3Sn magnets that achieve a ~50% increase in the field strength. This will be the first ever large-scale implementation of Nb3Sn magnets in a particle accelerator. The High-Luminosity LHC Upgrade, HL-LHC is a CERN project with a world-wide collaboration. It is under construction and utilizes Nb3Sn Magnets (named MQXF) as key ingredients to increase tenfold the integrated luminosity delivered to the CMS and ATLAS experiments in the next decade. The HL-LHC AUP is the US effort to contribute approximately 50% of the low-beta focusing magnets and crab cavities for the HL-LHC. This paper will present the program to fabricate the Nb3Sn superconducting magnets. We are reporting the status of the HL-LHC AUP project present the results from horizontal tests of the first fully assembled cryo-assembly.
{"title":"First results of AUP Nb3Sn quadrupole horizontal tests","authors":"M. BaldiniFermi National Accelerator Laboratory, Batavia, Illinois, USA, G. AmbrosioFermi National Accelerator Laboratory, Batavia, Illinois, USA, G. ApollinariFermi National Accelerator Laboratory, Batavia, Illinois, USA, J. BlowersFermi National Accelerator Laboratory, Batavia, Illinois, USA, R. BossertFermi National Accelerator Laboratory, Batavia, Illinois, USA, R. CarcagnoFermi National Accelerator Laboratory, Batavia, Illinois, USA, G. ChlachidzeFermi National Accelerator Laboratory, Batavia, Illinois, USA, J. DiMarcoFermi National Accelerator Laboratory, Batavia, Illinois, USA, S. FeherFermi National Accelerator Laboratory, Batavia, Illinois, USA, S. KraveFermi National Accelerator Laboratory, Batavia, Illinois, USA, V. LombardoFermi National Accelerator Laboratory, Batavia, Illinois, USA, L. MartinFermi National Accelerator Laboratory, Batavia, Illinois, USA, C. NarugFermi National Accelerator Laboratory, Batavia, Illinois, USA, T. H. NicolFermi National Accelerator Laboratory, Batavia, Illinois, USA, V. NikolicFermi National Accelerator Laboratory, Batavia, Illinois, USA, A. NobregaFermi National Accelerator Laboratory, Batavia, Illinois, USA, V. MarinozziFermi National Accelerator Laboratory, Batavia, Illinois, USA, C. OrozcoFermi National Accelerator Laboratory, Batavia, Illinois, USA, T. PageFermi National Accelerator Laboratory, Batavia, Illinois, USA, S. StoynevFermi National Accelerator Laboratory, Batavia, Illinois, USA, T. StraussFermi National Accelerator Laboratory, Batavia, Illinois, USA, M. TurenneFermi National Accelerator Laboratory, Batavia, Illinois, USA, D. TurrioniFermi National Accelerator Laboratory, Batavia, Illinois, USA, A. VourisFermi National Accelerator Laboratory, Batavia, Illinois, USA, M. YuFermi National Accelerator Laboratory, Batavia, Illinois, USA, A. BaskysLawrence Berkeley National Laboratory, Berkeley CA, D. ChengLawrence Berkeley National Laboratory, Berkeley CA, J. F. CroteauLawrence Berkeley National Laboratory, Berkeley CA, P. FerracinLawrence Berkeley National Laboratory, Berkeley CA, L. Garcia FajardoLawrence Berkeley National Laboratory, Berkeley CA, E. LeeLawrence Berkeley National Laboratory, Berkeley CA, A. LinLawrence Berkeley National Laboratory, Berkeley CA, M. Marchev-skyLawrence Berkeley National Laboratory, Berkeley CA, M. NausLawrence Berkeley National Laboratory, Berkeley CA, H. PanLawrence Berkeley National Laboratory, Berkeley CA, I. PongLawrence Berkeley National Laboratory, Berkeley CA, S. PrestemonLawrence Berkeley National Laboratory, Berkeley CA, K. RayLawrence Berkeley National Laboratory, Berkeley CA, G. SabbiLawrence Berkeley National Laboratory, Berkeley CA, C. SanabriaLawrence Berkeley National Laboratory, Berkeley CA, G. ValloneLawrence Berkeley National Laboratory, Berkeley CA, X. WangLawrence Berkeley National Laboratory, Berkeley CA, K. AmmBrookhaven National Laboratory, Upton, NY, M. AnerellaBrookhaven National Laboratory, Upton, NY, A. Ben YahiaBrookhaven National Laboratory, Upton, NY, H. HockerBrookhaven National Laboratory, Upton, NY, P. JoshiBrookhaven National Laboratory, Upton, NY, J. MuratoreBrookhaven National Laboratory, Upton, NY, J. SchmalzleBrookhaven National Laboratory, Upton, NY, H. SongBrookhaven National Laboratory, Upton, NY, P. WandererBrookhaven National Laboratory, Upton, NY","doi":"arxiv-2405.18530","DOIUrl":"https://doi.org/arxiv-2405.18530","url":null,"abstract":"The Large Hadron Collider will soon undergo an upgrade to increase its\u0000luminosity by a factor of ~10 [1]. A crucial part of this upgrade will be\u0000replacement of the NbTi focusing magnets with Nb3Sn magnets that achieve a ~50%\u0000increase in the field strength. This will be the first ever large-scale\u0000implementation of Nb3Sn magnets in a particle accelerator. The High-Luminosity\u0000LHC Upgrade, HL-LHC is a CERN project with a world-wide collaboration. It is\u0000under construction and utilizes Nb3Sn Magnets (named MQXF) as key ingredients\u0000to increase tenfold the integrated luminosity delivered to the CMS and ATLAS\u0000experiments in the next decade. The HL-LHC AUP is the US effort to contribute approximately 50% of the\u0000low-beta focusing magnets and crab cavities for the HL-LHC. This paper will present the program to fabricate the Nb3Sn superconducting\u0000magnets. We are reporting the status of the HL-LHC AUP project present the\u0000results from horizontal tests of the first fully assembled cryo-assembly.","PeriodicalId":501318,"journal":{"name":"arXiv - PHYS - Accelerator Physics","volume":"181 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141189996","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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