Pub Date : 2007-06-25DOI: 10.1109/PAC.2007.4441052
S. Reiche, P. Musumeci, K. Goldammer
The time-dependent code GENESIS 1.3 has been modified to address new problems in modeling Free-Electron Lasers. The functionality has been extended to include higher harmonics and to allow for a smoother modeling of cascading FELs. The code has also been exported to a parallel computer architecture for faster execution using the MPI protocol.
{"title":"Recent upgrade to the free-electron laser code GENESIS 1.3","authors":"S. Reiche, P. Musumeci, K. Goldammer","doi":"10.1109/PAC.2007.4441052","DOIUrl":"https://doi.org/10.1109/PAC.2007.4441052","url":null,"abstract":"The time-dependent code GENESIS 1.3 has been modified to address new problems in modeling Free-Electron Lasers. The functionality has been extended to include higher harmonics and to allow for a smoother modeling of cascading FELs. The code has also been exported to a parallel computer architecture for faster execution using the MPI protocol.","PeriodicalId":446026,"journal":{"name":"2007 IEEE Particle Accelerator Conference (PAC)","volume":"17 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":"127660806","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.2007.4440123
W. Flavell
Recent advances in accelerator science make feasible the provision of XUV and harder X-ray FELs that will generate short (fs regime) pulses of light that is broadly tuneable and >106 times more intense than spontaneous undulator radiation. Energy recovery technology offers the promise of short pulse, high peak flux spontaneous radiation, with particular advantages in the IR and THz parts of the spectrum. The new science enabled by these 4th generation sources is reviewed. A key feature is dynamic measurements. Pump-probe experiments will allow real-time measurements of reaction pathways and short-lived intermediates. The high intensity of FEL radiation will allow very high resolution in imaging applications. The very high field intensity of the XUV radiation will lead to the creation of new states of matter, while at the highest X-ray energies, the goal is to achieve single molecule diffraction. Illustrations are provided of some of the experiments proposed in the Science Cases for the major world 4th generation projects. Some of the science already undertaken using IR and UV FELs, and results obtained from new XUV sources (such as FLASH at DESY) are discussed.
{"title":"Next generation advanced light source science","authors":"W. Flavell","doi":"10.1109/PAC.2007.4440123","DOIUrl":"https://doi.org/10.1109/PAC.2007.4440123","url":null,"abstract":"Recent advances in accelerator science make feasible the provision of XUV and harder X-ray FELs that will generate short (fs regime) pulses of light that is broadly tuneable and >106 times more intense than spontaneous undulator radiation. Energy recovery technology offers the promise of short pulse, high peak flux spontaneous radiation, with particular advantages in the IR and THz parts of the spectrum. The new science enabled by these 4th generation sources is reviewed. A key feature is dynamic measurements. Pump-probe experiments will allow real-time measurements of reaction pathways and short-lived intermediates. The high intensity of FEL radiation will allow very high resolution in imaging applications. The very high field intensity of the XUV radiation will lead to the creation of new states of matter, while at the highest X-ray energies, the goal is to achieve single molecule diffraction. Illustrations are provided of some of the experiments proposed in the Science Cases for the major world 4th generation projects. Some of the science already undertaken using IR and UV FELs, and results obtained from new XUV sources (such as FLASH at DESY) are discussed.","PeriodicalId":446026,"journal":{"name":"2007 IEEE Particle Accelerator Conference (PAC)","volume":"38 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":"126415508","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.2007.4440617
S. Antipov, L. Spentzouris, W. Gai, W. Liu
For an International Linear Collider (ILC) undulator-based positron source target configuration, a strong optical matching device (OMD) field is needed inside the target to increase the positron yield (by more than 40%). It is also required that the positron target is constantly rotated to reduce thermal and radiation damage. We report on a simulation of the rotating metal target wheel under a strong magnetic field. By rearranging Maxwell's equations for a rotating frame and using Comsol, we have solved the detailed magnetic field distribution and eddy current of a rotating metal disk in magnetic field, and so the required power to drive the target wheel. In order to validate the simulation process, we have compared our results with previous experimental data and found they are in very good agreement. Here we give detailed results on the proposed ILC target system, such as induced magnetic field (dipole and higher orders), eddy current distribution and the driving force requirements. The effect of these higher order fields on the positron beam dynamics is also considered.
{"title":"Simulations of the rotating positron target in the presence of omd field","authors":"S. Antipov, L. Spentzouris, W. Gai, W. Liu","doi":"10.1109/PAC.2007.4440617","DOIUrl":"https://doi.org/10.1109/PAC.2007.4440617","url":null,"abstract":"For an International Linear Collider (ILC) undulator-based positron source target configuration, a strong optical matching device (OMD) field is needed inside the target to increase the positron yield (by more than 40%). It is also required that the positron target is constantly rotated to reduce thermal and radiation damage. We report on a simulation of the rotating metal target wheel under a strong magnetic field. By rearranging Maxwell's equations for a rotating frame and using Comsol, we have solved the detailed magnetic field distribution and eddy current of a rotating metal disk in magnetic field, and so the required power to drive the target wheel. In order to validate the simulation process, we have compared our results with previous experimental data and found they are in very good agreement. Here we give detailed results on the proposed ILC target system, such as induced magnetic field (dipole and higher orders), eddy current distribution and the driving force requirements. The effect of these higher order fields on the positron beam dynamics is also considered.","PeriodicalId":446026,"journal":{"name":"2007 IEEE Particle Accelerator Conference (PAC)","volume":"17 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":"126429557","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.2007.4441227
L. Ristori, G. Apollinari, I. Gonin, T. Khabiboulline, G. Romanov
The proposed high intensity neutrino source (HINS) at Fermilab is based on an 8 GeV linear proton accelerator that consists of a normal-conducting (warm) and a superconducting section. The warm section is composed of an ion source, a radio frequency quadrupole, a medium energy beam transport (MEBT) and 16 warm Crossbar H-type (CH) cavities that accelerate the beam from 2.5 MeV to 10 MeV (from beta=0.0744 to beta=0.1422). These warm cavities are separated by superconducting solenoids enclosed in individual cryostats. Beyond 10 MeV, the design uses superconducting spoke resonators to accelerate the beam up to 8 GeV. In this paper, we illustrate the completion of the first warm CH cavity (beta=0.0744) explaining in detail the mechanical engineering aspects related to the machining and brazing processes. The radio-frequency (RF) measurements and tuning performed at Fermilab on the resonator and comparisons with simulations are also discussed.
{"title":"Fabrication and test of the first normal-conducting crossbar H-type accelerating cavity at Fermilab for HINS","authors":"L. Ristori, G. Apollinari, I. Gonin, T. Khabiboulline, G. Romanov","doi":"10.1109/PAC.2007.4441227","DOIUrl":"https://doi.org/10.1109/PAC.2007.4441227","url":null,"abstract":"The proposed high intensity neutrino source (HINS) at Fermilab is based on an 8 GeV linear proton accelerator that consists of a normal-conducting (warm) and a superconducting section. The warm section is composed of an ion source, a radio frequency quadrupole, a medium energy beam transport (MEBT) and 16 warm Crossbar H-type (CH) cavities that accelerate the beam from 2.5 MeV to 10 MeV (from beta=0.0744 to beta=0.1422). These warm cavities are separated by superconducting solenoids enclosed in individual cryostats. Beyond 10 MeV, the design uses superconducting spoke resonators to accelerate the beam up to 8 GeV. In this paper, we illustrate the completion of the first warm CH cavity (beta=0.0744) explaining in detail the mechanical engineering aspects related to the machining and brazing processes. The radio-frequency (RF) measurements and tuning performed at Fermilab on the resonator and comparisons with simulations are also discussed.","PeriodicalId":446026,"journal":{"name":"2007 IEEE Particle Accelerator Conference (PAC)","volume":"26 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":"126474245","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.2007.4440282
C. Rivetta, R. Akre, P. Cutino, J. Frisch, K. Kotturi
The LCLC RF gun requires a water based thermal system to tune the resonance frequency of the cavity to 2856.03 MHz. The RF system operates in pulsed mode with bursts of 2 - 3 musec. duration at a repetition rate of 30 - 120 Hz. The thermal system operates in combination with the low-level RF system (LLRF) to set the operation point of the cavity. The LLRF system controls the amplitude and phase of the cavity voltage and defines the necessary slow signals to the thermal system. The thermal system operates by pre-heating / pre-cooling the water and mixing both channels to achieve the temperature to control the cavity resonant frequency. The tune control of the RF gun includes two systems with different dynamics. The dynamics of the thermal system is slow while the RF system is fast. Additionally, different actuators in the system present limits that introduce non-linearities to be taking into account during the start up process. Combining these characteristics, a controller is designed for the resulting hybrid system that allows convergence in large for all the operation conditions and achieve the performance in the magnitude and phase of the cavity voltage required around the operation point.
{"title":"LCLS RF gun feedback control","authors":"C. Rivetta, R. Akre, P. Cutino, J. Frisch, K. Kotturi","doi":"10.1109/PAC.2007.4440282","DOIUrl":"https://doi.org/10.1109/PAC.2007.4440282","url":null,"abstract":"The LCLC RF gun requires a water based thermal system to tune the resonance frequency of the cavity to 2856.03 MHz. The RF system operates in pulsed mode with bursts of 2 - 3 musec. duration at a repetition rate of 30 - 120 Hz. The thermal system operates in combination with the low-level RF system (LLRF) to set the operation point of the cavity. The LLRF system controls the amplitude and phase of the cavity voltage and defines the necessary slow signals to the thermal system. The thermal system operates by pre-heating / pre-cooling the water and mixing both channels to achieve the temperature to control the cavity resonant frequency. The tune control of the RF gun includes two systems with different dynamics. The dynamics of the thermal system is slow while the RF system is fast. Additionally, different actuators in the system present limits that introduce non-linearities to be taking into account during the start up process. Combining these characteristics, a controller is designed for the resulting hybrid system that allows convergence in large for all the operation conditions and achieve the performance in the magnitude and phase of the cavity voltage required around the operation point.","PeriodicalId":446026,"journal":{"name":"2007 IEEE Particle Accelerator Conference (PAC)","volume":"29 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":"127969189","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.2007.4441174
Y. Iwashita, H. Fujisawa, M. Ichikawa, Y. Tajima
Reduction of RF power loss caused by skin effect has been studied. Some measurement results on a coaxial cavity with thin foils are described.
对降低集肤效应引起的射频功率损耗进行了研究。介绍了薄箔同轴腔的一些测量结果。
{"title":"Reduction of RF skin loss with thin foils","authors":"Y. Iwashita, H. Fujisawa, M. Ichikawa, Y. Tajima","doi":"10.1109/PAC.2007.4441174","DOIUrl":"https://doi.org/10.1109/PAC.2007.4441174","url":null,"abstract":"Reduction of RF power loss caused by skin effect has been studied. Some measurement results on a coaxial cavity with thin foils are described.","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":"127986569","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.2007.4441332
R. Kephart
This talk will focus on ILC Main Linac issues and how they can be addressed via various existing test facilities or by those planned or under construction. The talk will focus on ILC main linac component test facilities in the U. S. Facilities described will include Vertical test setups to test bare SCRF cavities to demonstrate maximum achievable accelerating gradient. Horizontal testing of cavities equipped with tuners and couplers and the ILC RF unit test facility at Fermilab. Test facilities existing or under construction at DESY and KEK will also be described for context.
{"title":"Main Linac issues and evolving test facilities","authors":"R. Kephart","doi":"10.1109/PAC.2007.4441332","DOIUrl":"https://doi.org/10.1109/PAC.2007.4441332","url":null,"abstract":"This talk will focus on ILC Main Linac issues and how they can be addressed via various existing test facilities or by those planned or under construction. The talk will focus on ILC main linac component test facilities in the U. S. Facilities described will include Vertical test setups to test bare SCRF cavities to demonstrate maximum achievable accelerating gradient. Horizontal testing of cavities equipped with tuners and couplers and the ILC RF unit test facility at Fermilab. Test facilities existing or under construction at DESY and KEK will also be described for context.","PeriodicalId":446026,"journal":{"name":"2007 IEEE Particle Accelerator Conference (PAC)","volume":"14 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":"128005557","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.2007.4439959
M. Sawamura
The offset beam from the axis induces the HOMs in the cavities. These HOMs in superconducting cavities are usually damped by HOM couplers to suppress the beam instability. The induced HOM field of dipole mode is proportional to the beam offset and can be used to measure the beam position inside the cavity. Measuring the HOM power by scanning the beam permits to estimate the beam position using a known function of the HOM power. The steering magnet was installed to the JAEA superconducting ERL-FEL to vary the beam position. The beam position in the cavity was estimated with the measured HOM power from the HOM coupler.
{"title":"Measurement of beam position monitor using HOM couplers of superconducting cavities","authors":"M. Sawamura","doi":"10.1109/PAC.2007.4439959","DOIUrl":"https://doi.org/10.1109/PAC.2007.4439959","url":null,"abstract":"The offset beam from the axis induces the HOMs in the cavities. These HOMs in superconducting cavities are usually damped by HOM couplers to suppress the beam instability. The induced HOM field of dipole mode is proportional to the beam offset and can be used to measure the beam position inside the cavity. Measuring the HOM power by scanning the beam permits to estimate the beam position using a known function of the HOM power. The steering magnet was installed to the JAEA superconducting ERL-FEL to vary the beam position. The beam position in the cavity was estimated with the measured HOM power from the HOM coupler.","PeriodicalId":446026,"journal":{"name":"2007 IEEE Particle Accelerator Conference (PAC)","volume":"7 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":"128108310","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.2007.4440271
M. Borden, C. Chapman, C. Kelsey, J. O'Hara, J. Sturrock
Dose rate modeling and post irradiation measurements of the Isotope Production Facility (IPF) beamline, at the Los Alamos Neutron Science Center (LANSCE) accelerator have determined that a radiation shielding shutter is required to protect personnel from shine from irradiated targets for routine beam tunnel entries. This paper will describe radiation dose modeling, shielding calculations, and the fail-safe mechanical shutter design.
{"title":"Lansce fail-safe radiation shutter design for isotope production facility","authors":"M. Borden, C. Chapman, C. Kelsey, J. O'Hara, J. Sturrock","doi":"10.1109/PAC.2007.4440271","DOIUrl":"https://doi.org/10.1109/PAC.2007.4440271","url":null,"abstract":"Dose rate modeling and post irradiation measurements of the Isotope Production Facility (IPF) beamline, at the Los Alamos Neutron Science Center (LANSCE) accelerator have determined that a radiation shielding shutter is required to protect personnel from shine from irradiated targets for routine beam tunnel entries. This paper will describe radiation dose modeling, shielding calculations, and the fail-safe mechanical shutter design.","PeriodicalId":446026,"journal":{"name":"2007 IEEE Particle Accelerator Conference (PAC)","volume":"37 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":"125436679","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.2007.4441215
V. Kamerdzhiev, H. Pfeffer, G. Saewert, V. Shiltsev, D. Wolff
The solid-state Marx generator modulates the anode of the electron gun to produce the electron beam pulses in the second Tevatron Electron Lens (TEL2). It is capable of driving the 60 pF terminal with 600 ns pulses of up to 6 kV with a p.r.r. of 50 kHz. The rise and fall times are 150 ns. Stangenes industries developed the unit and is working on a second version which will go to higher voltage and have the ability to vary its output in 396 ns intervals over a 5 mus pulse.
{"title":"A solid state Marx generator for TEL2","authors":"V. Kamerdzhiev, H. Pfeffer, G. Saewert, V. Shiltsev, D. Wolff","doi":"10.1109/PAC.2007.4441215","DOIUrl":"https://doi.org/10.1109/PAC.2007.4441215","url":null,"abstract":"The solid-state Marx generator modulates the anode of the electron gun to produce the electron beam pulses in the second Tevatron Electron Lens (TEL2). It is capable of driving the 60 pF terminal with 600 ns pulses of up to 6 kV with a p.r.r. of 50 kHz. The rise and fall times are 150 ns. Stangenes industries developed the unit and is working on a second version which will go to higher voltage and have the ability to vary its output in 396 ns intervals over a 5 mus pulse.","PeriodicalId":446026,"journal":{"name":"2007 IEEE Particle Accelerator Conference (PAC)","volume":"9 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":"125588442","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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