R. Assmann, P. Chen, F. Decker, R. Iverson, M. Hogan, S. Rokni, R.H. Siemanu, D. Walz, D. Whittum, P. Catravas, S. Chattopadhyay, E. Esarey, W. Leemans, P. Volfbeyn, C. Clayton, R. Hemker, C. Joshi, K. Marsh, W. Mori, S. Wang, T. Katsouleas, S. Lee, P. Muggli
A plasma based wakefield acceleration (PWFA) experiment, scheduled to run this summer, will accelerate parts of a 28.5 GeV bunch from the SLAC linac by up to 1 GeV over a length of 1 meter. A single 28.5 GeV bunch will both induce the wakefields in the one meter long plasma and witness the resulting acceleration fields. The experiment will explore and further develop the techniques that are needed to apply high-gradient PWFA to large scale accelerators. This paper summarizes the goals of the first round of experiments as well as the status of the individual components: construction and diagnosis of the homogeneous lithium oven plasma source and associated ionization laser, commissioning of the electron beam, simulated performance of the electron beam energy measurement, and first PIC simulations of the full meter long experiment.
{"title":"Progress toward E-157: a 1 GeV plasma wakefield accelerator","authors":"R. Assmann, P. Chen, F. Decker, R. Iverson, M. Hogan, S. Rokni, R.H. Siemanu, D. Walz, D. Whittum, P. Catravas, S. Chattopadhyay, E. Esarey, W. Leemans, P. Volfbeyn, C. Clayton, R. Hemker, C. Joshi, K. Marsh, W. Mori, S. Wang, T. Katsouleas, S. Lee, P. Muggli","doi":"10.1109/PAC.1999.795697","DOIUrl":"https://doi.org/10.1109/PAC.1999.795697","url":null,"abstract":"A plasma based wakefield acceleration (PWFA) experiment, scheduled to run this summer, will accelerate parts of a 28.5 GeV bunch from the SLAC linac by up to 1 GeV over a length of 1 meter. A single 28.5 GeV bunch will both induce the wakefields in the one meter long plasma and witness the resulting acceleration fields. The experiment will explore and further develop the techniques that are needed to apply high-gradient PWFA to large scale accelerators. This paper summarizes the goals of the first round of experiments as well as the status of the individual components: construction and diagnosis of the homogeneous lithium oven plasma source and associated ionization laser, commissioning of the electron beam, simulated performance of the electron beam energy measurement, and first PIC simulations of the full meter long experiment.","PeriodicalId":20453,"journal":{"name":"Proceedings of the 1999 Particle Accelerator Conference (Cat. No.99CH36366)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1999-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88126397","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}
The Main Injector (MI) supports the Tevatron fixed target and proton-antiproton collider modes of operation as well as providing 120 GeV/c resonantly extracted beam for the Main Injector Fixed Target Program. A set of beam transport lines, called A1 and P1, from the Main Injector converge on the injection point of the Tevatron, with the A1 being used to transport 150 GeV/c antiprotons (pbars) to the Tevatron. P1 is used to transport 150 GeV/c protons to the Tevatron, 120 GeV/c protons to the pbar target, and eventually 120 GeV/c resonantly extracted protons to the existing Fixed Target areas.
{"title":"Design of the Main Injector extraction beamlines","authors":"D.E. Johnson","doi":"10.1109/PAC.1999.795509","DOIUrl":"https://doi.org/10.1109/PAC.1999.795509","url":null,"abstract":"The Main Injector (MI) supports the Tevatron fixed target and proton-antiproton collider modes of operation as well as providing 120 GeV/c resonantly extracted beam for the Main Injector Fixed Target Program. A set of beam transport lines, called A1 and P1, from the Main Injector converge on the injection point of the Tevatron, with the A1 being used to transport 150 GeV/c antiprotons (pbars) to the Tevatron. P1 is used to transport 150 GeV/c protons to the Tevatron, 120 GeV/c protons to the pbar target, and eventually 120 GeV/c resonantly extracted protons to the existing Fixed Target areas.","PeriodicalId":20453,"journal":{"name":"Proceedings of the 1999 Particle Accelerator Conference (Cat. No.99CH36366)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1999-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86374266","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 digital fast feedback system for beam energy and position stabilization at the target of the CEBAF accelerator is capable of suppressing beam motion in the frequency band from 0 to 80 Hz and also performs narrow band suppression at the first twelve power line harmonics. The system utilizes two VME computers and runs at a 2.4 kHz sampling rate. The numerical algorithm is based on a recursive digital filter with an additional feedforward loop for suppression of high power line harmonics. The system suppresses beam motion by a factor greater than ten, thus achieving the stabilization of relative beam energy fluctuations to better than 10/sup -5/ and stabilization of beam position on the target to better than 20 /spl mu/m.
{"title":"Fast digital feedback system for energy and beam position stabilization","authors":"R. Dickson, V. Lebedev","doi":"10.1109/PAC.1999.795783","DOIUrl":"https://doi.org/10.1109/PAC.1999.795783","url":null,"abstract":"A digital fast feedback system for beam energy and position stabilization at the target of the CEBAF accelerator is capable of suppressing beam motion in the frequency band from 0 to 80 Hz and also performs narrow band suppression at the first twelve power line harmonics. The system utilizes two VME computers and runs at a 2.4 kHz sampling rate. The numerical algorithm is based on a recursive digital filter with an additional feedforward loop for suppression of high power line harmonics. The system suppresses beam motion by a factor greater than ten, thus achieving the stabilization of relative beam energy fluctuations to better than 10/sup -5/ and stabilization of beam position on the target to better than 20 /spl mu/m.","PeriodicalId":20453,"journal":{"name":"Proceedings of the 1999 Particle Accelerator Conference (Cat. No.99CH36366)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1999-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90336010","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 new finite element gun code is under development. In an effort to improve the gun code model, a concept has been proposed recently that treats fields in a typical way, but includes a unique, formal approach to both particle tracking and source allocation. Being a new approach, there are concerns about the speed, accuracy, and appropriateness of this proposal for the electrostatic, steady-state particle-in-cell (PIC) gun model. In order to resolve some of these issues, a variety of particle tracking and charge deposition schemes are being evaluated with respect to accuracy, speed, robustness, and effect on the model. This includes various methods for computing the electric field at the particle locations. For this study, we are using the SAIC 3D gun code AVGUN as a testbed to incorporate and evaluate these methods. Results of a theoretical analysis of the methods will be presented, and a comparison will be made with the empirical results.
{"title":"Comparisons of particle tracking and charge deposition schemes for a finite element gun code","authors":"E. Nelson, K. Eppley, J. Petillo, S. Humphries","doi":"10.1109/PAC.1999.792935","DOIUrl":"https://doi.org/10.1109/PAC.1999.792935","url":null,"abstract":"A new finite element gun code is under development. In an effort to improve the gun code model, a concept has been proposed recently that treats fields in a typical way, but includes a unique, formal approach to both particle tracking and source allocation. Being a new approach, there are concerns about the speed, accuracy, and appropriateness of this proposal for the electrostatic, steady-state particle-in-cell (PIC) gun model. In order to resolve some of these issues, a variety of particle tracking and charge deposition schemes are being evaluated with respect to accuracy, speed, robustness, and effect on the model. This includes various methods for computing the electric field at the particle locations. For this study, we are using the SAIC 3D gun code AVGUN as a testbed to incorporate and evaluate these methods. Results of a theoretical analysis of the methods will be presented, and a comparison will be made with the empirical results.","PeriodicalId":20453,"journal":{"name":"Proceedings of the 1999 Particle Accelerator Conference (Cat. No.99CH36366)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1999-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72574980","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}
The paper describes the project of a compact accelerator (120 kV, 2 kA, 15-25 ns pulse duration, 1 kHz repetition rate). To attract the attention of the accelerator community to the abilities of modern power fast semiconductors, this device is suggested by using modern high-power super-fast semiconductor switches.
{"title":"Project of semiconductor high-power high-repetition rate compact accelerator","authors":"E. Galstjan, L. Kazanskiy","doi":"10.1109/PAC.1999.794139","DOIUrl":"https://doi.org/10.1109/PAC.1999.794139","url":null,"abstract":"The paper describes the project of a compact accelerator (120 kV, 2 kA, 15-25 ns pulse duration, 1 kHz repetition rate). To attract the attention of the accelerator community to the abilities of modern power fast semiconductors, this device is suggested by using modern high-power super-fast semiconductor switches.","PeriodicalId":20453,"journal":{"name":"Proceedings of the 1999 Particle Accelerator Conference (Cat. No.99CH36366)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1999-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80263633","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 class of planar microstructures is proposed which provide high accelerating gradients when excited by an infrared laser pulse. These structures consist of parallel dielectric slabs separated by a vacuum gap; the dielectric or the outer surface coating are spatially modulated at the laser wavelength along the beam direction so as to support a standing wave accelerating field. We have developed numerical and analytic models of the accelerating mode fields in the structure. We show an optimized coupling scheme such that this mode is excited resonantly with a large quality factor. The status of planned experiments on fabricating and measuring these planar structures is described.
{"title":"Slab symmetric dielectric micron scale structures for high gradient electron acceleration","authors":"P. Schoessow, J. Rosenzweig","doi":"10.1109/PAC.1999.792391","DOIUrl":"https://doi.org/10.1109/PAC.1999.792391","url":null,"abstract":"A class of planar microstructures is proposed which provide high accelerating gradients when excited by an infrared laser pulse. These structures consist of parallel dielectric slabs separated by a vacuum gap; the dielectric or the outer surface coating are spatially modulated at the laser wavelength along the beam direction so as to support a standing wave accelerating field. We have developed numerical and analytic models of the accelerating mode fields in the structure. We show an optimized coupling scheme such that this mode is excited resonantly with a large quality factor. The status of planned experiments on fabricating and measuring these planar structures is described.","PeriodicalId":20453,"journal":{"name":"Proceedings of the 1999 Particle Accelerator Conference (Cat. No.99CH36366)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1999-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90126809","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}
Fermilab is in the midst of a program to raise the luminosity in the Tevatron proton-antiproton collider by at least a factor of five above the currently achieved level of 1.6/spl times/10/sup 31/ cm/sup -2/ sec/sup -1/. Components of this program include the construction of a new synchrotron, the Main Injector, a new antiproton storage ring, the recycler, and a variety of improvements to the existing antiproton source and Tevatron. Commissioning of these components will be underway in early 1999 with the next Tevatron collider run scheduled to start in April 2000. Initial commissioning experience with these systems will be described, along with developments underway to support further Tevatron luminosity enhancements over the coming decade.
{"title":"Tevatron performance goals for the coming decade","authors":"S. Holmes","doi":"10.1109/PAC.1999.795620","DOIUrl":"https://doi.org/10.1109/PAC.1999.795620","url":null,"abstract":"Fermilab is in the midst of a program to raise the luminosity in the Tevatron proton-antiproton collider by at least a factor of five above the currently achieved level of 1.6/spl times/10/sup 31/ cm/sup -2/ sec/sup -1/. Components of this program include the construction of a new synchrotron, the Main Injector, a new antiproton storage ring, the recycler, and a variety of improvements to the existing antiproton source and Tevatron. Commissioning of these components will be underway in early 1999 with the next Tevatron collider run scheduled to start in April 2000. Initial commissioning experience with these systems will be described, along with developments underway to support further Tevatron luminosity enhancements over the coming decade.","PeriodicalId":20453,"journal":{"name":"Proceedings of the 1999 Particle Accelerator Conference (Cat. No.99CH36366)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1999-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84918578","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}
The recent development of miniature inductive adders has made it feasible to design programmable high-repetition-rate pulsers with a substantially higher voltage than is possible using a conventional field-effect transistor architecture. Prototype pulsers using the new technology are being developed as part of a series experiments at Lawrence Livermore National Laboratory (LLNL) to test the concept of a recirculating induction accelerator. Preliminary numerical work is reported here to determine what effects the higher-voltage pulsers would have on the beam quality of the LLNL small recirculator.
{"title":"Acceleration schedules for a recirculating heavy-ion accelerator","authors":"W. Sharp, D. Grote","doi":"10.1109/PAC.1999.794275","DOIUrl":"https://doi.org/10.1109/PAC.1999.794275","url":null,"abstract":"The recent development of miniature inductive adders has made it feasible to design programmable high-repetition-rate pulsers with a substantially higher voltage than is possible using a conventional field-effect transistor architecture. Prototype pulsers using the new technology are being developed as part of a series experiments at Lawrence Livermore National Laboratory (LLNL) to test the concept of a recirculating induction accelerator. Preliminary numerical work is reported here to determine what effects the higher-voltage pulsers would have on the beam quality of the LLNL small recirculator.","PeriodicalId":20453,"journal":{"name":"Proceedings of the 1999 Particle Accelerator Conference (Cat. No.99CH36366)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1999-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75450611","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. Raimondi, M. Breidenbach, J. Clendenin, F. Decker, M. Minty, N. Phinney, K. Skarpass, T. Usher, M. Woodley
Recent performance improvements at the SLAC Linear Collider (SLC) have led to a proposal to further increase the luminosity up to a factor of four through a series of modest hardware upgrades. New final focus optics introduced in 1997 combined with permanent magnet octupoles have reduced the contribution to the final beam size due to higher order aberrations. The minimum betas achievable at the IP are presently limited by the increase in detector backgrounds as the beam is focused more strongly. By moving the final quadrupoles closer to the interaction point (IP), one can reduce the synchrotron radiation background while decreasing the IP betas. Other upgrades include increasing the bending radius in the final focus to minimize emittance dilutions due to synchrotron radiation, a fast feedforward from the linac to the final focus to cancel trajectory jitter, and a change in the horizontal damping ring partition number to reduce the emittance of the extracted beam. With these upgrades, the expected disruption enhancement should be 2.4.
{"title":"Luminosity upgrades for the SLC","authors":"P. Raimondi, M. Breidenbach, J. Clendenin, F. Decker, M. Minty, N. Phinney, K. Skarpass, T. Usher, M. Woodley","doi":"10.1109/PAC.1999.792311","DOIUrl":"https://doi.org/10.1109/PAC.1999.792311","url":null,"abstract":"Recent performance improvements at the SLAC Linear Collider (SLC) have led to a proposal to further increase the luminosity up to a factor of four through a series of modest hardware upgrades. New final focus optics introduced in 1997 combined with permanent magnet octupoles have reduced the contribution to the final beam size due to higher order aberrations. The minimum betas achievable at the IP are presently limited by the increase in detector backgrounds as the beam is focused more strongly. By moving the final quadrupoles closer to the interaction point (IP), one can reduce the synchrotron radiation background while decreasing the IP betas. Other upgrades include increasing the bending radius in the final focus to minimize emittance dilutions due to synchrotron radiation, a fast feedforward from the linac to the final focus to cancel trajectory jitter, and a change in the horizontal damping ring partition number to reduce the emittance of the extracted beam. With these upgrades, the expected disruption enhancement should be 2.4.","PeriodicalId":20453,"journal":{"name":"Proceedings of the 1999 Particle Accelerator Conference (Cat. No.99CH36366)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1999-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84802773","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. Barklow, G. Bower, F. Decker, C. Field, L. Hendrickson, T. Markiewicz, D. McCormick, M. Minty, N. Phinney, P. Raimondi, M. Ross, K. Thompson, T. Usher, M. Woodley, F. Zimmermann
A significant luminosity enhancement from beam-beam disruption was observed for the first time during the 1997-98 run of the SLAC Linear Collider (SLC). Disruption, or pinch effect, is due to the decrease in effective beam size during collisions as each beam is focused by the field of the other beam. With beam intensities of 4.0 10/sup 10/ per bunch, bunch lengths of 1.1 mm, and horizontal and vertical beam sizes of /spl sigma//sub x/=1.5 /spl mu/m and /spl sigma//sub y/=0.65 /spl mu/m, the luminosity increase from disruption was more than 100%. Measured data rates as recorded by the SLD detector were in agreement with the theoretically calculated disruption enhancement.
{"title":"Experimental evidence for beam-beam disruption at the SLC","authors":"T. Barklow, G. Bower, F. Decker, C. Field, L. Hendrickson, T. Markiewicz, D. McCormick, M. Minty, N. Phinney, P. Raimondi, M. Ross, K. Thompson, T. Usher, M. Woodley, F. Zimmermann","doi":"10.1109/PAC.1999.795691","DOIUrl":"https://doi.org/10.1109/PAC.1999.795691","url":null,"abstract":"A significant luminosity enhancement from beam-beam disruption was observed for the first time during the 1997-98 run of the SLAC Linear Collider (SLC). Disruption, or pinch effect, is due to the decrease in effective beam size during collisions as each beam is focused by the field of the other beam. With beam intensities of 4.0 10/sup 10/ per bunch, bunch lengths of 1.1 mm, and horizontal and vertical beam sizes of /spl sigma//sub x/=1.5 /spl mu/m and /spl sigma//sub y/=0.65 /spl mu/m, the luminosity increase from disruption was more than 100%. Measured data rates as recorded by the SLD detector were in agreement with the theoretically calculated disruption enhancement.","PeriodicalId":20453,"journal":{"name":"Proceedings of the 1999 Particle Accelerator Conference (Cat. No.99CH36366)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1999-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74264633","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：