Pub Date : 2007-06-25DOI: 10.1109/PAC.2007.4440164
C. K. Allen, M. Ikegami, H. Sako, G. Shen, H. Ikeda, T. Ohkawa, A. Ueno
The XAL application development environment has been installed as a part of the control system for the Japan Proton Accelerator Research Center (J-PARC) in Tokai, Japan. XAL was initially developed at the spallation neutron source (SNS) and has been described at length in previous conference proceedings. Included in XAL is an online model for doing quick physics simulations. We outline the upgrades and enhancements to the XAL online model necessary for accurate simulation of the J- PARC linac and transport system.
{"title":"XAL online model enhancements for J-PARC commissioning and operation","authors":"C. K. Allen, M. Ikegami, H. Sako, G. Shen, H. Ikeda, T. Ohkawa, A. Ueno","doi":"10.1109/PAC.2007.4440164","DOIUrl":"https://doi.org/10.1109/PAC.2007.4440164","url":null,"abstract":"The XAL application development environment has been installed as a part of the control system for the Japan Proton Accelerator Research Center (J-PARC) in Tokai, Japan. XAL was initially developed at the spallation neutron source (SNS) and has been described at length in previous conference proceedings. Included in XAL is an online model for doing quick physics simulations. We outline the upgrades and enhancements to the XAL online model necessary for accurate simulation of the J- PARC linac and transport system.","PeriodicalId":446026,"journal":{"name":"2007 IEEE Particle Accelerator Conference (PAC)","volume":"247 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122155360","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}
Pub Date : 2007-06-25DOI: 10.1109/PAC.2007.4440514
A. Kabel, W. Fischer, T. Sen
While conventional tracking codes can readily provide higher-order optical quantities and give an estimate of dynamic apertures, they are unable to provide directly measurable quantites such as lifetimes and loss rates. The particle tracking framework Plibb aims at modelling a storage ring with sufficient accuracy and a sufficiently high number of turns and in the presence of beam-beam interactions to allow for an estimate of these quantities. We provide a description of new features of the codes; we also describe a novel method of treating chromaticity in ring sections in a symplectic fashion.
{"title":"Recent progress in a beam-beam simulation code for circular hadron machines","authors":"A. Kabel, W. Fischer, T. Sen","doi":"10.1109/PAC.2007.4440514","DOIUrl":"https://doi.org/10.1109/PAC.2007.4440514","url":null,"abstract":"While conventional tracking codes can readily provide higher-order optical quantities and give an estimate of dynamic apertures, they are unable to provide directly measurable quantites such as lifetimes and loss rates. The particle tracking framework Plibb aims at modelling a storage ring with sufficient accuracy and a sufficiently high number of turns and in the presence of beam-beam interactions to allow for an estimate of these quantities. We provide a description of new features of the codes; we also describe a novel method of treating chromaticity in ring sections in a symplectic fashion.","PeriodicalId":446026,"journal":{"name":"2007 IEEE Particle Accelerator Conference (PAC)","volume":"80 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122183107","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}
Pub Date : 2007-06-25DOI: 10.1109/PAC.2007.4440085
L. Wang, Y. Cai, T. Raubenheimer
Ion induced beam instability is one critical issue for the electron damping ring of the International Linear Collider (ILC) due to its ultra small emittance of 2 pm. Bunch train filling pattern is proposed to mitigate the instability and bunch-by-bunch feedback is applied to suppress it. Multi-bunch train fill pattern is introduced in the electron beam to reduce the number of trapped ions. Our study shows that the ion effects can be significantly mitigated by using multiple gaps. However, the beam can still suffer from the beam-ion instability driven by the accumulated ions that cannot escape from the beam during the gaps. The effects of beam fill pattern, emittance, vacuum and various damping mechanism are studied using self-consistent program, which includes the optics of the ring.
{"title":"Simulation of the beam-ion instability in the electron damping ring of the international linear collider","authors":"L. Wang, Y. Cai, T. Raubenheimer","doi":"10.1109/PAC.2007.4440085","DOIUrl":"https://doi.org/10.1109/PAC.2007.4440085","url":null,"abstract":"Ion induced beam instability is one critical issue for the electron damping ring of the International Linear Collider (ILC) due to its ultra small emittance of 2 pm. Bunch train filling pattern is proposed to mitigate the instability and bunch-by-bunch feedback is applied to suppress it. Multi-bunch train fill pattern is introduced in the electron beam to reduce the number of trapped ions. Our study shows that the ion effects can be significantly mitigated by using multiple gaps. However, the beam can still suffer from the beam-ion instability driven by the accumulated ions that cannot escape from the beam during the gaps. The effects of beam fill pattern, emittance, vacuum and various damping mechanism are studied using self-consistent program, which includes the optics of the ring.","PeriodicalId":446026,"journal":{"name":"2007 IEEE Particle Accelerator Conference (PAC)","volume":"528 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116706786","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}
Pub Date : 2007-06-25DOI: 10.1109/PAC.2007.4441208
J. Norem, D. Huang, P. Stoltz, S. Veitzer
Recent experimental work done to develop high gradient, low frequency cavities for muon cooling has led to a model of rf breakdown and high gradient limits in warm structures. We have recently been extending this model to try to explain some superconducting rf quench mechanisms, as well as DC and dielectric breakdown. The model assumes that the dominant mechanisms in warm metal systems are fractures caused by the electric tensile stress, and surface micro-topography that is strongly determined by the cavity design and history. We describe how these processes can determine all measurable parameters in warm systems. With superconducting systems, these mechanisms also apply, however field emission, impurities and temperature produce a somewhat different picture of quenching and pulsed power processing. We describe the model and some recent extensions and improvements.
{"title":"A general model of high gradient limits","authors":"J. Norem, D. Huang, P. Stoltz, S. Veitzer","doi":"10.1109/PAC.2007.4441208","DOIUrl":"https://doi.org/10.1109/PAC.2007.4441208","url":null,"abstract":"Recent experimental work done to develop high gradient, low frequency cavities for muon cooling has led to a model of rf breakdown and high gradient limits in warm structures. We have recently been extending this model to try to explain some superconducting rf quench mechanisms, as well as DC and dielectric breakdown. The model assumes that the dominant mechanisms in warm metal systems are fractures caused by the electric tensile stress, and surface micro-topography that is strongly determined by the cavity design and history. We describe how these processes can determine all measurable parameters in warm systems. With superconducting systems, these mechanisms also apply, however field emission, impurities and temperature produce a somewhat different picture of quenching and pulsed power processing. We describe the model and some recent extensions and improvements.","PeriodicalId":446026,"journal":{"name":"2007 IEEE Particle Accelerator Conference (PAC)","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116828052","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}
Pub Date : 2007-06-25DOI: 10.1109/PAC.2007.4440451
N. Sereno, M. Borland
In recent years, we have explored various upgrade options for the Advanced Photon Source (APS) storage ring that would provide the user community with higher brightness. Increased brightness would be accomplished by reducing the emittance of the storage ring as well as increasing the stored beam current from 100 mA to 200 mA. Two upgrade lattices were developed that reduce the effective beam emittance to 1 nm from the present 2.7 nm. These lattices have reduced dynamic aperture compared to the present ring lattice, which may require a reduced emittance booster to minimize injection losses. This paper describes injection tracking simulations that explore how high the booster emittance can be and still have no losses at injection for the 1-nm ring upgrade lattices. An alternative booster lattice is presented with reduced emittance compared to the present booster lattice (65 nm).
{"title":"Booster requirements for Advanced Photon Source I-nm emittance upgrade lattices","authors":"N. Sereno, M. Borland","doi":"10.1109/PAC.2007.4440451","DOIUrl":"https://doi.org/10.1109/PAC.2007.4440451","url":null,"abstract":"In recent years, we have explored various upgrade options for the Advanced Photon Source (APS) storage ring that would provide the user community with higher brightness. Increased brightness would be accomplished by reducing the emittance of the storage ring as well as increasing the stored beam current from 100 mA to 200 mA. Two upgrade lattices were developed that reduce the effective beam emittance to 1 nm from the present 2.7 nm. These lattices have reduced dynamic aperture compared to the present ring lattice, which may require a reduced emittance booster to minimize injection losses. This paper describes injection tracking simulations that explore how high the booster emittance can be and still have no losses at injection for the 1-nm ring upgrade lattices. An alternative booster lattice is presented with reduced emittance compared to the present booster lattice (65 nm).","PeriodicalId":446026,"journal":{"name":"2007 IEEE Particle Accelerator Conference (PAC)","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116986702","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}
Pub Date : 2007-06-25DOI: 10.1109/PAC.2007.4440107
E. Pozdeyev, I. Ben-Zvi, P. Cameron, A. Drees, D. Gassner, D. Kayran, V. Litvinenko, G. Mahler, T. Rao
The ERL Prototype project is currently under development at the Brookhaven National Laboratory. The ERL is expected to demonstrate energy recovery of high- intensity beams with a current of up to a few hundred milliamps, while preserving the emittance of bunches with a charge of a few nanocoulombs produced by a high- current SRF gun. To successfully accomplish this task the machine will include beam diagnostics that will be used for accurate characterization of the three dimensional beam phase space at the injection and recirculation energies, transverse and longitudinal beam matching, orbit alignment, beam current measurement, and machine protection. This paper outlines requirements on the ERL diagnostics and describes its setup and modes of operation.
{"title":"Diagnostics of BNL ERL","authors":"E. Pozdeyev, I. Ben-Zvi, P. Cameron, A. Drees, D. Gassner, D. Kayran, V. Litvinenko, G. Mahler, T. Rao","doi":"10.1109/PAC.2007.4440107","DOIUrl":"https://doi.org/10.1109/PAC.2007.4440107","url":null,"abstract":"The ERL Prototype project is currently under development at the Brookhaven National Laboratory. The ERL is expected to demonstrate energy recovery of high- intensity beams with a current of up to a few hundred milliamps, while preserving the emittance of bunches with a charge of a few nanocoulombs produced by a high- current SRF gun. To successfully accomplish this task the machine will include beam diagnostics that will be used for accurate characterization of the three dimensional beam phase space at the injection and recirculation energies, transverse and longitudinal beam matching, orbit alignment, beam current measurement, and machine protection. This paper outlines requirements on the ERL diagnostics and describes its setup and modes of operation.","PeriodicalId":446026,"journal":{"name":"2007 IEEE Particle Accelerator Conference (PAC)","volume":"59 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129468054","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}
Pub Date : 2007-06-25DOI: 10.1109/PAC.2007.4440459
B. Sayyar-Rodsari, C. Schweiger, E. Hartman, J. Schmerge, M. Lee, P. Lui, E. Paterson
High brightness electron beam sources such as rf photo- injectors as proposed for SASE FELs must consistently produce the desired beam quality. We report the results of a study in which a combined neural network (NN) and first- principles (FP) model is used to model the transverse phase space of the beam as a function of quadrupole strength, while beam charge, solenoid field, accelerator gradient, and linac voltage and phase are kept constant. The parametric transport matrix between the exit of the linac section and the spectrometer screen constitutes the FP component of the combined model. The NN block provides the parameters of the transport matrix as functions of quad current. Using real data from SLAC Gun Test Facility, we will highlight the significance of the constrained training of the NN block and show that the phase space of the beam is accurately modeled by the combined NN and FP model, while variations of beam matrix parameters with the quad current are correctly captured. We plan to extend the combined model in the future to capture the effects of variations in beam charge, solenoid field, and accelerator voltage and phase.
{"title":"Parametric modeling of transverse phase space of an rf photoinjector","authors":"B. Sayyar-Rodsari, C. Schweiger, E. Hartman, J. Schmerge, M. Lee, P. Lui, E. Paterson","doi":"10.1109/PAC.2007.4440459","DOIUrl":"https://doi.org/10.1109/PAC.2007.4440459","url":null,"abstract":"High brightness electron beam sources such as rf photo- injectors as proposed for SASE FELs must consistently produce the desired beam quality. We report the results of a study in which a combined neural network (NN) and first- principles (FP) model is used to model the transverse phase space of the beam as a function of quadrupole strength, while beam charge, solenoid field, accelerator gradient, and linac voltage and phase are kept constant. The parametric transport matrix between the exit of the linac section and the spectrometer screen constitutes the FP component of the combined model. The NN block provides the parameters of the transport matrix as functions of quad current. Using real data from SLAC Gun Test Facility, we will highlight the significance of the constrained training of the NN block and show that the phase space of the beam is accurately modeled by the combined NN and FP model, while variations of beam matrix parameters with the quad current are correctly captured. We plan to extend the combined model in the future to capture the effects of variations in beam charge, solenoid field, and accelerator voltage and phase.","PeriodicalId":446026,"journal":{"name":"2007 IEEE Particle Accelerator Conference (PAC)","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129609829","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}
Pub Date : 2007-06-25DOI: 10.1109/PAC.2007.4440079
S. Molloy, Sergei Seletskiy, Mike Woods, Jonathan David, Andrew Smith, Carl David Beard, J. Fernández-Hernando, Nigel Watson, A. Bungau, A. Sopczak
We report on measurements of the transverse wakefields induced by collimators of differing characteristics. An apparatus allowing the insertion of different collimator jaws into the path of a beam was installed in End Station A (ESA) in SLAC. Eight comparable collimator geometries were designed, including one that would allow easy comparison with previous results, and were installed in this apparatus. Measurements of the beam kick due to the collimator wakefields were made with a beam energy of 28.5 GeV, and beam dimensions of 100 microns vertically and a range of 0.5 to 1.5 mm longitudinally. The trajectory of the beam upstream and downstream of the collimator test apparatus was determined from the outputs of ten BPMs (four upstream and six downstream), thus allowing a measurement of the angular kick imparted to the beam by the collimator under test. The transverse wakefield was inferred from the measured kick. The different aperture designs, data collection and analysis, and initial comparison to theoretical and analytic predictions are presented here.
{"title":"Measurements of the transverse wakefields due to varying collimator characteristics","authors":"S. Molloy, Sergei Seletskiy, Mike Woods, Jonathan David, Andrew Smith, Carl David Beard, J. Fernández-Hernando, Nigel Watson, A. Bungau, A. Sopczak","doi":"10.1109/PAC.2007.4440079","DOIUrl":"https://doi.org/10.1109/PAC.2007.4440079","url":null,"abstract":"We report on measurements of the transverse wakefields induced by collimators of differing characteristics. An apparatus allowing the insertion of different collimator jaws into the path of a beam was installed in End Station A (ESA) in SLAC. Eight comparable collimator geometries were designed, including one that would allow easy comparison with previous results, and were installed in this apparatus. Measurements of the beam kick due to the collimator wakefields were made with a beam energy of 28.5 GeV, and beam dimensions of 100 microns vertically and a range of 0.5 to 1.5 mm longitudinally. The trajectory of the beam upstream and downstream of the collimator test apparatus was determined from the outputs of ten BPMs (four upstream and six downstream), thus allowing a measurement of the angular kick imparted to the beam by the collimator under test. The transverse wakefield was inferred from the measured kick. The different aperture designs, data collection and analysis, and initial comparison to theoretical and analytic predictions are presented here.","PeriodicalId":446026,"journal":{"name":"2007 IEEE Particle Accelerator Conference (PAC)","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129709223","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}
Pub Date : 2007-06-25DOI: 10.1109/PAC.2007.4440738
M. Meddahi, K. Cornells, K. Elsener, E. Gschwendtner, W. Herr, V. Kain, M. Lamont, J. Wenninger
The CNGS project (CERN Neutrinos to Gran Sasso) aims at directly detecting vmu - vtau oscillations. An intense vmu beam is generated at CERN and directed towards LNGS (Laboratori Nazionali del Gran Sasso) in Italy where vtau will be detected in large and complex detectors. An overview of the CNGS beam facility is given. Results from the primary and secondary beam line commissioning performed in summer 2006 are presented. Measurements of proton beam parameters are compared with expectations.
{"title":"Cern Neutrinos to Gran Sasso (CNGS): results from commissioning","authors":"M. Meddahi, K. Cornells, K. Elsener, E. Gschwendtner, W. Herr, V. Kain, M. Lamont, J. Wenninger","doi":"10.1109/PAC.2007.4440738","DOIUrl":"https://doi.org/10.1109/PAC.2007.4440738","url":null,"abstract":"The CNGS project (CERN Neutrinos to Gran Sasso) aims at directly detecting vmu - vtau oscillations. An intense vmu beam is generated at CERN and directed towards LNGS (Laboratori Nazionali del Gran Sasso) in Italy where vtau will be detected in large and complex detectors. An overview of the CNGS beam facility is given. Results from the primary and secondary beam line commissioning performed in summer 2006 are presented. Measurements of proton beam parameters are compared with expectations.","PeriodicalId":446026,"journal":{"name":"2007 IEEE Particle Accelerator Conference (PAC)","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129782288","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}
Pub Date : 2007-06-25DOI: 10.1109/PAC.2007.4440022
R. Miyamoto, S. Kopp, A. Jannson, M. Syphers
In many accelerators, cylindrical pick-ups are used to measure transverse beam positions. Theoretically, signals from these pick-ups are related to infinite power series of the beam position but, in practice, only finite number of terms are considered and the position measurements degrade when a beam is far from the center of a pick-up. This paper shows there is actually a simple geometrical relation between a beam position and induced signals. With help of the geometrical relation, the beam position can be written in a compact function of signals. The paper is concluded with numerical simulations and a test to show this geometry based expression can calculate a beam position better than the conventional methods.
{"title":"Geometrical interpretation of nonlinearities from a cylindrical pick-up","authors":"R. Miyamoto, S. Kopp, A. Jannson, M. Syphers","doi":"10.1109/PAC.2007.4440022","DOIUrl":"https://doi.org/10.1109/PAC.2007.4440022","url":null,"abstract":"In many accelerators, cylindrical pick-ups are used to measure transverse beam positions. Theoretically, signals from these pick-ups are related to infinite power series of the beam position but, in practice, only finite number of terms are considered and the position measurements degrade when a beam is far from the center of a pick-up. This paper shows there is actually a simple geometrical relation between a beam position and induced signals. With help of the geometrical relation, the beam position can be written in a compact function of signals. The paper is concluded with numerical simulations and a test to show this geometry based expression can calculate a beam position better than the conventional methods.","PeriodicalId":446026,"journal":{"name":"2007 IEEE Particle Accelerator Conference (PAC)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129948288","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：