G. Citver, S. Feher, P. Limon, D. Orris, T. Peterson, C. Sylvester, M. Tartaglia, J. Tompkins
R&D high temperature superconductor (HTS) power leads were developed and built for Fermilab by American Superconductor Corporation and Intermagnetics General Corporation. Each company provided one pair of 5 kA HTS current leads, and these have been successfully tested at Fermilab. This paper summarizes the test results.
{"title":"HTS power lead test results","authors":"G. Citver, S. Feher, P. Limon, D. Orris, T. Peterson, C. Sylvester, M. Tartaglia, J. Tompkins","doi":"10.1109/PAC.1999.795568","DOIUrl":"https://doi.org/10.1109/PAC.1999.795568","url":null,"abstract":"R&D high temperature superconductor (HTS) power leads were developed and built for Fermilab by American Superconductor Corporation and Intermagnetics General Corporation. Each company provided one pair of 5 kA HTS current leads, and these have been successfully tested at Fermilab. This paper summarizes the test results.","PeriodicalId":20453,"journal":{"name":"Proceedings of the 1999 Particle Accelerator Conference (Cat. No.99CH36366)","volume":"1 1","pages":"1420-1422 vol.2"},"PeriodicalIF":0.0,"publicationDate":"1999-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74772053","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}
J. Carneiro, R. Carrigan, M. Champion, P. Colestock, H. Edwards, J. Fuerst, W. Hartung, K. Koepke, M. Kuchnir, J. Santucci, L. Spentzouris, M. J. Fitch, A. Melissinos, P. Michelato, C. Pagani, D. Sertore, N. Barov, J. Rosenzweig
A collaboration has been formed between FNAL, UCLA, LNFN Milano, the University of Rochester, and DESY to develop the technology of an RF photoinjector, followed by a superconducting cavity, to produce high bunch charge (8 nC) with low normalized emittance (<20 mm mrad) in bunch spacing trains of 800 bunches separated by /spl mu/s. The activities of bunch charge the collaboration fall into two categories: 1. the development of Injector II for the TeSLA/TTF accelerator. This photoinjector (TTF RF Gun) was tested at Fermilab in September and October 1998 and installed at DESY in November 1998. 2. the installation at the A0 Hall of Fermilab of a modified version of the TTF photoinjector, for photoinjector R&D and to study novel applications of high-brightness, pulsed electron beams. This photoinjector (A0 RF Gun) produced its first beam in March 1999. This paper presents a summary of the tests done at Fermilab on the TITF Injector II and the first results obtained on the new Fermilab photoinjector.
{"title":"First results of the Fermilab high-brightness RF photoinjector","authors":"J. Carneiro, R. Carrigan, M. Champion, P. Colestock, H. Edwards, J. Fuerst, W. Hartung, K. Koepke, M. Kuchnir, J. Santucci, L. Spentzouris, M. J. Fitch, A. Melissinos, P. Michelato, C. Pagani, D. Sertore, N. Barov, J. Rosenzweig","doi":"10.1109/PAC.1999.794361","DOIUrl":"https://doi.org/10.1109/PAC.1999.794361","url":null,"abstract":"A collaboration has been formed between FNAL, UCLA, LNFN Milano, the University of Rochester, and DESY to develop the technology of an RF photoinjector, followed by a superconducting cavity, to produce high bunch charge (8 nC) with low normalized emittance (<20 mm mrad) in bunch spacing trains of 800 bunches separated by /spl mu/s. The activities of bunch charge the collaboration fall into two categories: 1. the development of Injector II for the TeSLA/TTF accelerator. This photoinjector (TTF RF Gun) was tested at Fermilab in September and October 1998 and installed at DESY in November 1998. 2. the installation at the A0 Hall of Fermilab of a modified version of the TTF photoinjector, for photoinjector R&D and to study novel applications of high-brightness, pulsed electron beams. This photoinjector (A0 RF Gun) produced its first beam in March 1999. This paper presents a summary of the tests done at Fermilab on the TITF Injector II and the first results obtained on the new Fermilab photoinjector.","PeriodicalId":20453,"journal":{"name":"Proceedings of the 1999 Particle Accelerator Conference (Cat. No.99CH36366)","volume":"45 1","pages":"2027-2029 vol.3"},"PeriodicalIF":0.0,"publicationDate":"1999-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87045702","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}
These kickers will be used to make fast dipoles and quadrupoles which are driven by sharp risetime pulsers to provide precision beam manipulation for high current kA electron beams. This technology will be used on the 2/sup nd/ axis of the DARHT linac at LANL. It will be used to provide 4 micropulses of pulse width up to 120 nsec. Selected from a 2 /spl mu/sec., 2 kA, 20 MeV macropulse. The fast pulsers will have amplitude modulation capability to compensate for beam-induced steering effects and other slow beam centroid motion to within the bandwidth of the kicker system. Scaling laws derived from theory will be presented along with extensive experimental data obtained on the test bed ETA-II.
这些加速器将被用于制造快速偶极子和四极子，它们由急剧上升时间脉冲驱动，为高电流kA电子束提供精确的光束操纵。该技术将用于LANL的DARHT直线加速器的2/sup和/ axis。它将用于提供4个脉冲宽度高达120秒的微脉冲。从2 /spl mu/sec中选择。， 2 kA, 20 MeV巨脉冲。快速脉冲将具有调幅能力，以补偿波束诱导的转向效应和其他缓慢的波束质心运动，使其在踢脚器系统的带宽范围内。从理论推导出的比例定律将与在试验台ETA-II上获得的大量实验数据一起提出。
{"title":"Precision fast kickers for kiloampere electron beams","authors":"Y. Chen, G. Caporaso, J. Weir","doi":"10.1109/PAC.1999.795777","DOIUrl":"https://doi.org/10.1109/PAC.1999.795777","url":null,"abstract":"These kickers will be used to make fast dipoles and quadrupoles which are driven by sharp risetime pulsers to provide precision beam manipulation for high current kA electron beams. This technology will be used on the 2/sup nd/ axis of the DARHT linac at LANL. It will be used to provide 4 micropulses of pulse width up to 120 nsec. Selected from a 2 /spl mu/sec., 2 kA, 20 MeV macropulse. The fast pulsers will have amplitude modulation capability to compensate for beam-induced steering effects and other slow beam centroid motion to within the bandwidth of the kicker system. Scaling laws derived from theory will be presented along with extensive experimental data obtained on the test bed ETA-II.","PeriodicalId":20453,"journal":{"name":"Proceedings of the 1999 Particle Accelerator Conference (Cat. No.99CH36366)","volume":"5 1","pages":"622-624 vol.1"},"PeriodicalIF":0.0,"publicationDate":"1999-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75135255","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}
C. Adolphsen, K. Bane, R. Jones, N. Kroll, D. McCormick, R. Miller, M. Ross, T. Slaton, J.W. Wang, T. Higo
We present wakefield measurements of a prototype Next Linear Collider (NLC) accelerator structure that was built with dipole mode damping and detuning to suppress the long-range transverse wakefield induced by a beam. In addition, we describe beam centering tests that use as a guide the dipole power coupled out of the structure for damping purposes.
{"title":"Wakefield and beam centering measurements of a damped and detuned X-band accelerator structure","authors":"C. Adolphsen, K. Bane, R. Jones, N. Kroll, D. McCormick, R. Miller, M. Ross, T. Slaton, J.W. Wang, T. Higo","doi":"10.1109/PAC.1999.792342","DOIUrl":"https://doi.org/10.1109/PAC.1999.792342","url":null,"abstract":"We present wakefield measurements of a prototype Next Linear Collider (NLC) accelerator structure that was built with dipole mode damping and detuning to suppress the long-range transverse wakefield induced by a beam. In addition, we describe beam centering tests that use as a guide the dipole power coupled out of the structure for damping purposes.","PeriodicalId":20453,"journal":{"name":"Proceedings of the 1999 Particle Accelerator Conference (Cat. No.99CH36366)","volume":"44 1","pages":"3477-3479 vol.5"},"PeriodicalIF":0.0,"publicationDate":"1999-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74276820","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
W. Chou, Y. Mori, M. Muto, Y. Shirakabe, A. Takagi
This paper introduces a new type of chopper, which is similar to a beam transformer first discussed by R. Wideroe (1928). It is based on the fact that the RFQ has a rather small energy window. A pulsed beam transformer that provides 10% energy modulation to the beam in front of an RFQ can effectively chop the beam. It has fast rise- and fall-time and a short physical length. A prototype, which consists of a cavity and a high voltage pulsed power supply, has been constructed and tested. Two types of magnetic materials were tried for making the core of the cavity-the Finemet and the ferrite Philips 4M2. While the former gave good performance, the latter failed the test. Results from the bench measurements and a plan for beam tests are briefly described.
{"title":"Design and test of a beam transformer as a chopper","authors":"W. Chou, Y. Mori, M. Muto, Y. Shirakabe, A. Takagi","doi":"10.1109/PAC.1999.795761","DOIUrl":"https://doi.org/10.1109/PAC.1999.795761","url":null,"abstract":"This paper introduces a new type of chopper, which is similar to a beam transformer first discussed by R. Wideroe (1928). It is based on the fact that the RFQ has a rather small energy window. A pulsed beam transformer that provides 10% energy modulation to the beam in front of an RFQ can effectively chop the beam. It has fast rise- and fall-time and a short physical length. A prototype, which consists of a cavity and a high voltage pulsed power supply, has been constructed and tested. Two types of magnetic materials were tried for making the core of the cavity-the Finemet and the ferrite Philips 4M2. While the former gave good performance, the latter failed the test. Results from the bench measurements and a plan for beam tests are briefly described.","PeriodicalId":20453,"journal":{"name":"Proceedings of the 1999 Particle Accelerator Conference (Cat. No.99CH36366)","volume":"15 1","pages":"565-567 vol.1"},"PeriodicalIF":0.0,"publicationDate":"1999-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82164739","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 accelerator for the second axis of the Dual Axis Radiographic Hydrodynamic Test (DARHT) facility will produce a 4-kA, 20-MeV, 2-/spl mu/s output electron beam with a design goal of less than 1000 /spl pi/ mm-mrad normalized transverse emittance and less than 0.5-mm beam centroid motion. In order to meet this goal, the beam transport must have excellent optics and the beam breakup instability (BBU) must be limited in growth. Using a number of simulation codes such as AMOS and BREAKUP, we have modeled the transverse impedances of the DARHT-II accelerator cells and the electron beam response to different transverse excitations such as injector RF noise, magnetic dipole fields arising from the 90-degree bend between the cathode stalk and insulator column, and downstream solenoid alignment errors. The very low Q (/spl sim/2) predicted for the most important TM dipole modes has prompted us to extend the BREAKUP code to be able to use the dipole wakefields calculated by AMOS in addition to the most usual discrete frequency BBU mode model. We present results for the predicted BBU growth and the empirical sensitivity to various machine parameters.
{"title":"Beam breakup calculations for the second axis of DARHT","authors":"W. Fawley, Y. Chen, T. Houck","doi":"10.1109/PAC.1999.795498","DOIUrl":"https://doi.org/10.1109/PAC.1999.795498","url":null,"abstract":"The accelerator for the second axis of the Dual Axis Radiographic Hydrodynamic Test (DARHT) facility will produce a 4-kA, 20-MeV, 2-/spl mu/s output electron beam with a design goal of less than 1000 /spl pi/ mm-mrad normalized transverse emittance and less than 0.5-mm beam centroid motion. In order to meet this goal, the beam transport must have excellent optics and the beam breakup instability (BBU) must be limited in growth. Using a number of simulation codes such as AMOS and BREAKUP, we have modeled the transverse impedances of the DARHT-II accelerator cells and the electron beam response to different transverse excitations such as injector RF noise, magnetic dipole fields arising from the 90-degree bend between the cathode stalk and insulator column, and downstream solenoid alignment errors. The very low Q (/spl sim/2) predicted for the most important TM dipole modes has prompted us to extend the BREAKUP code to be able to use the dipole wakefields calculated by AMOS in addition to the most usual discrete frequency BBU mode model. We present results for the predicted BBU growth and the empirical sensitivity to various machine parameters.","PeriodicalId":20453,"journal":{"name":"Proceedings of the 1999 Particle Accelerator Conference (Cat. No.99CH36366)","volume":"44 1","pages":"1210-1212 vol.2"},"PeriodicalIF":0.0,"publicationDate":"1999-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75934149","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 SPEAR 3 upgrade lattice will provide much reduced beam emittance to increase the brightness of synchrotron radiation beams from wigglers and undulators. Seven existing insertion devices will be used in the lattice. In this paper we review the wiggler parameters, outline the wiggler compensation scheme, and evaluate wiggler effect on the optics and dynamic aperture.
{"title":"Effect of insertion devices in SPEAR-3","authors":"J. Corbett, Y. Nosochkov","doi":"10.1109/PAC.1999.792690","DOIUrl":"https://doi.org/10.1109/PAC.1999.792690","url":null,"abstract":"The SPEAR 3 upgrade lattice will provide much reduced beam emittance to increase the brightness of synchrotron radiation beams from wigglers and undulators. Seven existing insertion devices will be used in the lattice. In this paper we review the wiggler parameters, outline the wiggler compensation scheme, and evaluate wiggler effect on the optics and dynamic aperture.","PeriodicalId":20453,"journal":{"name":"Proceedings of the 1999 Particle Accelerator Conference (Cat. No.99CH36366)","volume":"251 1","pages":"2358-2360 vol.4"},"PeriodicalIF":0.0,"publicationDate":"1999-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80718061","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}
At the present time, there are a number of future linear collider designs with a center-of-mass energy of 500 GeV or more that have luminosities in excess of 10/sup 34/ cm/sup -2/ s/sup -1/. Many of these designs are very advanced, however, to attain the high luminosity, the colliders require very small beam emittances, strong focusing, and very good stability. In this paper, some of the outstanding issues related to the small spot sizes are discussed. Although the different designs are based very different RF technologies, many of these problems are common to all designs.
{"title":"Accelerator physics challenges in future linear colliders","authors":"T. Raubenheimer","doi":"10.1109/PAC.1999.795674","DOIUrl":"https://doi.org/10.1109/PAC.1999.795674","url":null,"abstract":"At the present time, there are a number of future linear collider designs with a center-of-mass energy of 500 GeV or more that have luminosities in excess of 10/sup 34/ cm/sup -2/ s/sup -1/. Many of these designs are very advanced, however, to attain the high luminosity, the colliders require very small beam emittances, strong focusing, and very good stability. In this paper, some of the outstanding issues related to the small spot sizes are discussed. Although the different designs are based very different RF technologies, many of these problems are common to all designs.","PeriodicalId":20453,"journal":{"name":"Proceedings of the 1999 Particle Accelerator Conference (Cat. No.99CH36366)","volume":"23 1","pages":"240-244 vol.1"},"PeriodicalIF":0.0,"publicationDate":"1999-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74322224","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}
S. Benson, G. Biallas, C. Bohn, I. Campisi, D. Douglas, R. Evans, R. Hill, K. Jordan, G. Krafft, R. Li, L. Merminga, G. Neil, P. Piot, J. Preble, M. Shinn., T. Siggins, R. Walker, B. Yunn
A recirculating, energy-recovering linac is used as driver accelerator for Jefferson Lab's high average power FEL. CW beam of 5 mA design current is transported from the superconducting RF (SRF) linac to the wiggler for lasing, and then recirculated back to the linac for deceleration and energy recovery. About 75% of the beam power is extracted before the beam is transported to the beam dump. Energy recovery reduces power consumption, RF equipment capital costs, and beam dump shielding requirements. It is arguably essential as FEL technology is scaled to higher average power levels. To date, 4 mA of CW beam has been energy recovered successfully. There is no evidence of RF instabilities due to the energy aperture of the transport system, momentum compaction or the phase of the decelerating beam. HOM power from the beam has interfered with the operation of the IR interlock detectors, designed to protect the warm waveguide window from thermal runaway. Installation of copper screens appears to have solved the problem. More detailed studies of the HOM spectra and their correlation to the beam properties are planned.
{"title":"First results on energy recovery in the Jefferson Lab IRFEL","authors":"S. Benson, G. Biallas, C. Bohn, I. Campisi, D. Douglas, R. Evans, R. Hill, K. Jordan, G. Krafft, R. Li, L. Merminga, G. Neil, P. Piot, J. Preble, M. Shinn., T. Siggins, R. Walker, B. Yunn","doi":"10.1109/PAC.1999.792724","DOIUrl":"https://doi.org/10.1109/PAC.1999.792724","url":null,"abstract":"A recirculating, energy-recovering linac is used as driver accelerator for Jefferson Lab's high average power FEL. CW beam of 5 mA design current is transported from the superconducting RF (SRF) linac to the wiggler for lasing, and then recirculated back to the linac for deceleration and energy recovery. About 75% of the beam power is extracted before the beam is transported to the beam dump. Energy recovery reduces power consumption, RF equipment capital costs, and beam dump shielding requirements. It is arguably essential as FEL technology is scaled to higher average power levels. To date, 4 mA of CW beam has been energy recovered successfully. There is no evidence of RF instabilities due to the energy aperture of the transport system, momentum compaction or the phase of the decelerating beam. HOM power from the beam has interfered with the operation of the IR interlock detectors, designed to protect the warm waveguide window from thermal runaway. Installation of copper screens appears to have solved the problem. More detailed studies of the HOM spectra and their correlation to the beam properties are planned.","PeriodicalId":20453,"journal":{"name":"Proceedings of the 1999 Particle Accelerator Conference (Cat. No.99CH36366)","volume":"83 1","pages":"2456-2458 vol.4"},"PeriodicalIF":0.0,"publicationDate":"1999-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76208581","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 injector for the second axis of the Dual-Axis Radiographic Hydrotest Facility (DARHT) is being designed and constructed at LBNL. The injector consists of a single gap diode extracting 2 /spl mu/s, 2 kA, 3.2 MeV electron beam from a 6.5 inches diameter thermionic dispenser cathode. The injector is powered through a ceramic column by a Marx generator. We also investigated the possibility of extracting a beam current of 4 kA. The focusing system for the electron beam consists of a Pierce electrostatic focusing electrode at the cathode and three solenoidal focusing magnets positioned between the anode and induction accelerator input.
双轴射线照相水力试验设备(DARHT)第二轴的注入器正在LBNL设计和建造中。注入器由一个单间隙二极管组成，从直径6.5英寸的热离子分配器阴极中提取2 /spl mu/s, 2 kA, 3.2 MeV的电子束。注入器由马克思发电机通过陶瓷柱提供动力。我们还研究了提取4 kA束流的可能性。电子束聚焦系统由位于阴极的皮尔斯静电聚焦电极和位于阳极和感应加速器输入之间的三个螺线管聚焦磁铁组成。
{"title":"Time dependent beam focusing at the DARHT-II injector diode","authors":"S. Eylon, E. Henestroza, W. Fawley, S. Yu","doi":"10.1109/PAC.1999.794319","DOIUrl":"https://doi.org/10.1109/PAC.1999.794319","url":null,"abstract":"The injector for the second axis of the Dual-Axis Radiographic Hydrotest Facility (DARHT) is being designed and constructed at LBNL. The injector consists of a single gap diode extracting 2 /spl mu/s, 2 kA, 3.2 MeV electron beam from a 6.5 inches diameter thermionic dispenser cathode. The injector is powered through a ceramic column by a Marx generator. We also investigated the possibility of extracting a beam current of 4 kA. The focusing system for the electron beam consists of a Pierce electrostatic focusing electrode at the cathode and three solenoidal focusing magnets positioned between the anode and induction accelerator input.","PeriodicalId":20453,"journal":{"name":"Proceedings of the 1999 Particle Accelerator Conference (Cat. No.99CH36366)","volume":"28 1","pages":"1934-1936 vol.3"},"PeriodicalIF":0.0,"publicationDate":"1999-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83535331","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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