Pub Date : 2007-06-25DOI: 10.1109/PAC.2007.4440193
K. Artoos, S. Bartolome-Jimenez, O. Capatina, J. M. Chevalley, K. Foraz, M. Guinchard, C. Hauviller, K. Kershaw, S. Prodon, I. Ruehl, G. Trinquart, S. Weisz, P. Ponsot
Eleven years have passed between the beginning of transport and handling studies in 1996 and the completion of the LHC cryo-magnets installation in 2007. More than 1700 heavy, long and fragile cryo-magnets had to be transported and installed in the 27 km long LHC tunnel with very restricted available space. The size and complexity of the project involved challenges in the field of equipment design and manufacturing, maintenance, training and follow-up of operators and logistics. The paper presents the milestones, problems to be overcome and lessons learned during this project.
{"title":"Transport and installation of the LHC cryo-magnets","authors":"K. Artoos, S. Bartolome-Jimenez, O. Capatina, J. M. Chevalley, K. Foraz, M. Guinchard, C. Hauviller, K. Kershaw, S. Prodon, I. Ruehl, G. Trinquart, S. Weisz, P. Ponsot","doi":"10.1109/PAC.2007.4440193","DOIUrl":"https://doi.org/10.1109/PAC.2007.4440193","url":null,"abstract":"Eleven years have passed between the beginning of transport and handling studies in 1996 and the completion of the LHC cryo-magnets installation in 2007. More than 1700 heavy, long and fragile cryo-magnets had to be transported and installed in the 27 km long LHC tunnel with very restricted available space. The size and complexity of the project involved challenges in the field of equipment design and manufacturing, maintenance, training and follow-up of operators and logistics. The paper presents the milestones, problems to be overcome and lessons learned during this project.","PeriodicalId":446026,"journal":{"name":"2007 IEEE Particle Accelerator Conference (PAC)","volume":"115 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":"115154062","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.2007.4440811
P. Saha, F. Noda, H. Hotchi, Y. Irie, S. Machida
We have updated our simulation for a more realistic beam loss estimation at the RCS(rapid cycling synchrotron) injection area of J-PARC (Japan proton accelerator research complex). At the injection area, the beam loss caused by the nuclear scattering together with the multiple Coulomb scattering in the charge-exchange foil is the dominant one. A precise estimation of the beam loss can give direct feedback for a smooth operation strategy of RCS towards its goal of a 1MW class machine. The simulation code GEANT3 to take into account the scattering part and the realistic space charge simulation code SIMPSONS were used together for the present purpose. A precise loss together with the loss point identification can thus be obtained from the present method. We are in a stage of making the model more intelligent mainly concerning the CPU time when handling with relatively large number of macro particles for very precise calculation and will present here the interim report.
{"title":"Updated simulation for the nuclear scattering loss estimation at the RCS injection area","authors":"P. Saha, F. Noda, H. Hotchi, Y. Irie, S. Machida","doi":"10.1109/PAC.2007.4440811","DOIUrl":"https://doi.org/10.1109/PAC.2007.4440811","url":null,"abstract":"We have updated our simulation for a more realistic beam loss estimation at the RCS(rapid cycling synchrotron) injection area of J-PARC (Japan proton accelerator research complex). At the injection area, the beam loss caused by the nuclear scattering together with the multiple Coulomb scattering in the charge-exchange foil is the dominant one. A precise estimation of the beam loss can give direct feedback for a smooth operation strategy of RCS towards its goal of a 1MW class machine. The simulation code GEANT3 to take into account the scattering part and the realistic space charge simulation code SIMPSONS were used together for the present purpose. A precise loss together with the loss point identification can thus be obtained from the present method. We are in a stage of making the model more intelligent mainly concerning the CPU time when handling with relatively large number of macro particles for very precise calculation and will present here the interim report.","PeriodicalId":446026,"journal":{"name":"2007 IEEE Particle Accelerator Conference (PAC)","volume":"91 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":"124397977","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.2007.4440977
Chuanxiang Tang, Wenhui Huang, Huaibi Chen, Yingchao Du, Lixin Yan, Renkai Li, D. Xiang, P. Yu, J. Hua, Jiaru Shi, Yuzheng Lin
In this paper we report the preliminary design and considerations on a multi-discipline ultra-fast source, which is capable of providing the user community with femtosecond electron bunch and light pulses with the wavelength ranging from IR to X-ray. The facility is based on photocathode RF gun driven by a Ti:Sapphire laser system. The low emittance subpicosecond electron bunch at the gun exit can be used in femtosecond electron diffraction setup to visualize the ultrafast structural dynamics. After acceleration and compression, the electron beam with the energy of 50 MeV is further used to provide high peak brightness X-ray by inverse Compton scattering with TW laser. We also consider the possibility and reliability of storing the electron beam in a compact storage ring and the laser pulse in a super-cavity Operating in this scheme may increase the average flux of the X-ray photons by orders of magnitude.
{"title":"Design of a source to supply ultra-fast electron and X-ray pulses","authors":"Chuanxiang Tang, Wenhui Huang, Huaibi Chen, Yingchao Du, Lixin Yan, Renkai Li, D. Xiang, P. Yu, J. Hua, Jiaru Shi, Yuzheng Lin","doi":"10.1109/PAC.2007.4440977","DOIUrl":"https://doi.org/10.1109/PAC.2007.4440977","url":null,"abstract":"In this paper we report the preliminary design and considerations on a multi-discipline ultra-fast source, which is capable of providing the user community with femtosecond electron bunch and light pulses with the wavelength ranging from IR to X-ray. The facility is based on photocathode RF gun driven by a Ti:Sapphire laser system. The low emittance subpicosecond electron bunch at the gun exit can be used in femtosecond electron diffraction setup to visualize the ultrafast structural dynamics. After acceleration and compression, the electron beam with the energy of 50 MeV is further used to provide high peak brightness X-ray by inverse Compton scattering with TW laser. We also consider the possibility and reliability of storing the electron beam in a compact storage ring and the laser pulse in a super-cavity Operating in this scheme may increase the average flux of the X-ray photons by orders of magnitude.","PeriodicalId":446026,"journal":{"name":"2007 IEEE Particle Accelerator Conference (PAC)","volume":"809 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":"116847233","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.2007.4440416
Y. Shobuda, Y. Chin, K. Takata
The Napoly integral for the wake potential calculations in the axisymmetric structure is a very useful method because the integration of Ez field can be confined in a finite length instead of the infinite length by deforming the integration path, which reduces CPU time for the accurate calculations. However, his original method could not be applied to the transverse wake potentials in a structure where the two beam tubes on both sides have unequal radii. In this case, the integration path needs to be a straight line and the integration stretches out to an infinite in principle. We generalize the Napoly integrals so that integrals are always confined in a finite length even when the two beam tubes have unequal radii, for both longitudinal and transverse wake potential calculations. The extended method has been successfully implemented to ABCI code.
{"title":"Extension of napoly integral for transverse wake potentials to general axisymmetric structure","authors":"Y. Shobuda, Y. Chin, K. Takata","doi":"10.1109/PAC.2007.4440416","DOIUrl":"https://doi.org/10.1109/PAC.2007.4440416","url":null,"abstract":"The Napoly integral for the wake potential calculations in the axisymmetric structure is a very useful method because the integration of Ez field can be confined in a finite length instead of the infinite length by deforming the integration path, which reduces CPU time for the accurate calculations. However, his original method could not be applied to the transverse wake potentials in a structure where the two beam tubes on both sides have unequal radii. In this case, the integration path needs to be a straight line and the integration stretches out to an infinite in principle. We generalize the Napoly integrals so that integrals are always confined in a finite length even when the two beam tubes have unequal radii, for both longitudinal and transverse wake potential calculations. The extended method has been successfully implemented to ABCI code.","PeriodicalId":446026,"journal":{"name":"2007 IEEE Particle Accelerator Conference (PAC)","volume":"39 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":"116928312","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.2007.4440180
S. Varnasseri, G. Vignola, M. Shehab
In this paper the SESAME storage ring injection pulsed magnet system is described. The injection process in the SESAME storage ring requires septum and kicker magnets. In this paper we discuss the geometrical and magnetic field requirements for septum and kicker magnets and present the results obtained from magnetic field analysis and also the optimization of titanium coating for the injection kicker chambers. The final specification for thin septum and injection kickers are also presented.
{"title":"Design of injection pulsed magnets for SESAME ring","authors":"S. Varnasseri, G. Vignola, M. Shehab","doi":"10.1109/PAC.2007.4440180","DOIUrl":"https://doi.org/10.1109/PAC.2007.4440180","url":null,"abstract":"In this paper the SESAME storage ring injection pulsed magnet system is described. The injection process in the SESAME storage ring requires septum and kicker magnets. In this paper we discuss the geometrical and magnetic field requirements for septum and kicker magnets and present the results obtained from magnetic field analysis and also the optimization of titanium coating for the injection kicker chambers. The final specification for thin septum and injection kickers are also presented.","PeriodicalId":446026,"journal":{"name":"2007 IEEE Particle Accelerator Conference (PAC)","volume":"116 2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120882550","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.2007.4440542
D. Kayran, V. Litvinenko
A super-conducting RF R&D energy recovery linac (ERL) is under construction at Brookhaven National Laboratory (BNL). This ERL will be used as a test facility to study issues relevant to high-current, high-brightness beams. One of the goals is to demonstrate an electron beam with high charge per bunch (˜ 5 nC) and extremely low normalized emittance (˜ 5 mm-mrad) at an energy of 20 MeV. In contrast with operational high-brightness linear electron accelerators, all presently operating ERLs have order of magnitude larger emittances for the same charge per bunch. One reason for this emittance growth is that the merger system mixes transverse and longitudinal degrees of freedom, and consequently violates emittance compensation conditions. A merger system based on zigzag scheme resolves this problem. In this paper we discuss performance of the present design of the BNL R&D ERL injector with a zigzag merger.
{"title":"Merger system optimization in BNL's high current R&D ERL","authors":"D. Kayran, V. Litvinenko","doi":"10.1109/PAC.2007.4440542","DOIUrl":"https://doi.org/10.1109/PAC.2007.4440542","url":null,"abstract":"A super-conducting RF R&D energy recovery linac (ERL) is under construction at Brookhaven National Laboratory (BNL). This ERL will be used as a test facility to study issues relevant to high-current, high-brightness beams. One of the goals is to demonstrate an electron beam with high charge per bunch (˜ 5 nC) and extremely low normalized emittance (˜ 5 mm-mrad) at an energy of 20 MeV. In contrast with operational high-brightness linear electron accelerators, all presently operating ERLs have order of magnitude larger emittances for the same charge per bunch. One reason for this emittance growth is that the merger system mixes transverse and longitudinal degrees of freedom, and consequently violates emittance compensation conditions. A merger system based on zigzag scheme resolves this problem. In this paper we discuss performance of the present design of the BNL R&D ERL injector with a zigzag merger.","PeriodicalId":446026,"journal":{"name":"2007 IEEE Particle Accelerator Conference (PAC)","volume":"46 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":"120885624","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.2007.4441243
R. Geng, P. Barnes, B. Clasby, J. Kaminski, M. Liepe, V. Medjidzade, D. Meidlinger, H. Padamsee, J. Sears, V. Shemelin, N. Sherwood, M. Tigner
Six 1300 MHz superconducting niobium 2-cell cavities are manufactured in-house for the prototype of the Cornell ERL injector to boost the energy of a high current, low emittance beam produced by a DC gun. Designed for high current beam acceleration, these cavities have new characteristics as compared to previously developed low-current cavities such as those for TTF Precision manufacture is emphasized for a better straightness of the cavity axis so as to avoid unwanted emittance dilution. We present the manufacturing, processing and vertical test performance of these cavities. We also present the impact of new cavity characteristics to the cavity performance as learnt from vertical tests.
{"title":"Fabrication and performance of superconducting RF cavities for the cornell ERL injector","authors":"R. Geng, P. Barnes, B. Clasby, J. Kaminski, M. Liepe, V. Medjidzade, D. Meidlinger, H. Padamsee, J. Sears, V. Shemelin, N. Sherwood, M. Tigner","doi":"10.1109/PAC.2007.4441243","DOIUrl":"https://doi.org/10.1109/PAC.2007.4441243","url":null,"abstract":"Six 1300 MHz superconducting niobium 2-cell cavities are manufactured in-house for the prototype of the Cornell ERL injector to boost the energy of a high current, low emittance beam produced by a DC gun. Designed for high current beam acceleration, these cavities have new characteristics as compared to previously developed low-current cavities such as those for TTF Precision manufacture is emphasized for a better straightness of the cavity axis so as to avoid unwanted emittance dilution. We present the manufacturing, processing and vertical test performance of these cavities. We also present the impact of new cavity characteristics to the cavity performance as learnt from vertical tests.","PeriodicalId":446026,"journal":{"name":"2007 IEEE Particle Accelerator Conference (PAC)","volume":"34 2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120917608","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.2007.4440781
B. Hofmann, A. Schempp, O. Kester
The HITRAP linac at GSI will decelerate ions from 5 MeV/u to 6 keV/u for experiments with the large GSI Penning trap. The ions are decelerated at first in the existing experimental storage ring (ESR) down to an energy of 5 MeV/u and will be injected into a new 'Decelerator- Linca of a IH-structure, which decelerates down to 500 keV/u and a 4-Rod RFQ, decelerating to 6 keV/u. The properties of the RFQ decelerator and the status of the project will be discussed.
{"title":"A RFQ-decelerator for hitrap","authors":"B. Hofmann, A. Schempp, O. Kester","doi":"10.1109/PAC.2007.4440781","DOIUrl":"https://doi.org/10.1109/PAC.2007.4440781","url":null,"abstract":"The HITRAP linac at GSI will decelerate ions from 5 MeV/u to 6 keV/u for experiments with the large GSI Penning trap. The ions are decelerated at first in the existing experimental storage ring (ESR) down to an energy of 5 MeV/u and will be injected into a new 'Decelerator- Linca of a IH-structure, which decelerates down to 500 keV/u and a 4-Rod RFQ, decelerating to 6 keV/u. The properties of the RFQ decelerator and the status of the project will be discussed.","PeriodicalId":446026,"journal":{"name":"2007 IEEE Particle Accelerator Conference (PAC)","volume":"25 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":"121206504","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.2007.4440445
D. Welch, D. Rose, A. Sefkow, E. Gilson, E. Henestroza, P. Seidl, P. Roy, J. Coleman
Longitudinal bunching factors in excess of 70 of a 300- keV, 27-mA K+ ion beam have been demonstrated in the Neutralized Drift Compression Experiment in rough agreement with particle-in-cell end-to-end simulations. These simulations include the ion source temperature, experimental diode voltage and induction bunching module voltage waveforms in order to determine the initial beam longitudinal phase space critical to longitudinal compression. To maximize simultaneous longitudinal and transverse compression, we designed a solenoidal focusing system that compensated for the impact of the applied velocity tilt on the transverse phase space of the beam. Here, pre-formed plasma provides beam neutralization in the last one meter drift region where the beam perveance becomes large. We compare simulation results with the experimental measurements and discuss the contributions to longitudinal and transverse emittance that limit compression.
{"title":"End-to-end simulations of an accelerator for heavy ion beam bunching","authors":"D. Welch, D. Rose, A. Sefkow, E. Gilson, E. Henestroza, P. Seidl, P. Roy, J. Coleman","doi":"10.1109/PAC.2007.4440445","DOIUrl":"https://doi.org/10.1109/PAC.2007.4440445","url":null,"abstract":"Longitudinal bunching factors in excess of 70 of a 300- keV, 27-mA K+ ion beam have been demonstrated in the Neutralized Drift Compression Experiment in rough agreement with particle-in-cell end-to-end simulations. These simulations include the ion source temperature, experimental diode voltage and induction bunching module voltage waveforms in order to determine the initial beam longitudinal phase space critical to longitudinal compression. To maximize simultaneous longitudinal and transverse compression, we designed a solenoidal focusing system that compensated for the impact of the applied velocity tilt on the transverse phase space of the beam. Here, pre-formed plasma provides beam neutralization in the last one meter drift region where the beam perveance becomes large. We compare simulation results with the experimental measurements and discuss the contributions to longitudinal and transverse emittance that limit compression.","PeriodicalId":446026,"journal":{"name":"2007 IEEE Particle Accelerator Conference (PAC)","volume":"8 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":"121317326","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.2007.4440137
A. Bogomyagkov, S. Nikitin, I. Nikolaev, A. Shamov, A. Skrinsky, G. Tumaikin
The series of experiments on mass measurements of J/psi, psi' and psi" mesons have been done on VEPP-4M collider. The accuracy of obtained mass values for J/psi- and psi'- mesons exceeded the world values about 3 times, based on experiments on VEPP-4 [1] and E760[2]. The ongoing experiment on tau lepton mass measurement is expected to achieve accuracy 1.5-2 times better than the present world value. The present paper describes the process and uncertainties of luminosity weighted interaction energy definition. The errors of interaction energy include uncertainties due to beam energy calibration by resonant depolarization technique and errors of interaction energy calculation.
{"title":"Central mass energy determination in high precision experiments on VEPP-4M","authors":"A. Bogomyagkov, S. Nikitin, I. Nikolaev, A. Shamov, A. Skrinsky, G. Tumaikin","doi":"10.1109/PAC.2007.4440137","DOIUrl":"https://doi.org/10.1109/PAC.2007.4440137","url":null,"abstract":"The series of experiments on mass measurements of J/psi, psi' and psi\" mesons have been done on VEPP-4M collider. The accuracy of obtained mass values for J/psi- and psi'- mesons exceeded the world values about 3 times, based on experiments on VEPP-4 [1] and E760[2]. The ongoing experiment on tau lepton mass measurement is expected to achieve accuracy 1.5-2 times better than the present world value. The present paper describes the process and uncertainties of luminosity weighted interaction energy definition. The errors of interaction energy include uncertainties due to beam energy calibration by resonant depolarization technique and errors of interaction energy calculation.","PeriodicalId":446026,"journal":{"name":"2007 IEEE Particle Accelerator Conference (PAC)","volume":"30 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":"127176889","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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