Download or read book Progress on a Cryogenically Cooled RF Gun Polarized Electron Source written by H. Edwards and published by . This book was released on 2006 with total page 3 pages. Available in PDF, EPUB and Kindle. Book excerpt: RF guns have proven useful in multiple accelerator applications. An RF gun capable of producing polarized electrons is an attractive electron source for the ILC or an electron-ion collider. Producing such a gun has proven elusive. The NEA GaAs photocathode needed for polarized electron production is damaged by the vacuum environment in an RF gun. Electron and ion back bombardment can also damage the cathode. These problems must be mitigated before producing an RF gun polarized electron source. In this paper we report continuing efforts to improve the vacuum environment in a normal conducting RF gun by cooling it with liquid nitrogen after a high temperature vacuum bake out. We also report on a design of a cathode preparation chamber to produce bulk GaAs photocathodes for testing in such a gun. Future directions are also discussed.
Download or read book Progress on Using NEA Cathodes in an RF Gun written by T. Anderson and published by . This book was released on 2005 with total page 3 pages. Available in PDF, EPUB and Kindle. Book excerpt: RF guns have proven useful in multiple accelerator applications, and are an attractive electron source for the ILC. Using a NEA GaAs photocathode in such a gun allows for the production of polarized electron beams. However the lifetime of a NEA cathode in this environment is reduced by ion and electron bombardment and residual gas oxidation. We report progress made with studies to produce a RF gun using a NEA GaAs photocathode to produce polarized electron beams. We discuss simulations of ion back bombardment and attempts to reduce the residual gas pressure in the gun are discussed. Future directions are also discussed.
Download or read book Polarized RF Guns written by and published by . This book was released on 1998 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: RF guns employing photocathodes are now well established as viable electron sources for accelerator applications. For high energy accelerators the desirable properties of such sources include the relative ease of pulse formation (using the source laser system to establish the pulse shape and number) and a low transverse beam emittance, eliminating the need for rf chopping and bunching systems and reducing the demands on emittance-reducing damping rings. However, most high-energy accelerators now require polarized electrons. Polarized electron beam scan in principle be generated by substituting a 3--5 semiconductor, such as GaAs, for the traditional photocathode in a conventional rf gun structure. In the past, the principal criterion for selection of photocathodes for rf guns has been the ability to maintain a reasonable quantum yield from the cathode over a relatively long operating period. It is well known that GaAs is significantly more sensitive to the vacuum environment than any of the cathode types that have been used to date. However, advances in the understanding of how to operate GaAs cathodes in hostile environments combined with similar advances in the ability to prepare gun structures that will significantly reduce dark current and rf breakdown lend credibility to the prospect of successfully operating an rf gun with the activated GaAs cathode. The status of research related to polarized rf guns is reviewed and the outline of a future polarized rf source combining the best of what is known. Today.
Download or read book Polarized RF Guns for Linear Colliders written by and published by . This book was released on 2002 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The ICFA Workshop on Polarized RF Guns for Linear Colliders was held at Fermilab during April 18-20, 2001. It was attended by 37 scientists from 14 institutions. A list of participants is appended. An RF photoemission gun that delivers polarized electrons at low emittance would be an attractive electron source for a linear collider. Moreover, recently it has been demonstrated that an RF gun in conjunction with nearby injection system optics can deliver a beam with a high ratio of transverse emittances; a simplification of a linear collider's damping system could result. However, at present RF electron gun technology has not developed sufficiently to assure that such a source is feasible. The purpose of the workshop was to review the status of polarized RF gun development with linear collider application in mind, and outline a possible program for the future. A table lists the requirements for the electron injector for proposed linear colliders. The specifications are given for the beam before and after the electron damping ring.
Download or read book Polarized Sources Targets And Polarimetry Proceedings Of The 13th International Workshop written by Marco Contalbrigo and published by World Scientific. This book was released on 2011-01-19 with total page 350 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book collects the most recent experimental results, new ideas and prototypes in the field of nuclear gaseous and solid polarized targets and polarimetry. It contains the contribution of the biennial meeting on the topics of Polarized Sources, Targets and Polarimetry. Therefore includes the most recent developments and performances in the field and new proposals. The contributing authors are the experts of the field.The topics covered include: Polarized Electron Sources, Polarized Proton and Deuterium Sources, Polarized Internal Targets, Polarized 3He Ion Sources and Targets, Polarimetry (e, p, d) at Low and High Energy, Polarized antiprotons, Polarized Solid Targets.br>
Download or read book RF Guns for Generation of Polarized Electron Beams written by R. E. Kirby and published by . This book was released on 2005 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: Several accelerators, including the SLC, JLAB, Mainz, Bates/MIT, and Bonn have successfully operated for medium and high energy physics experiments using polarized electron beams generated by dc-biased guns employing GaAs photocathodes. Since these guns have all used a bias on the order of 100 kV, the longitudinal emittance of the extracted bunch is rather poor. Downstream rf bunching systems increase the transverse emittance. An rf gun with a GaAs photocathode would eliminate the need for separate rf bunchers, resulting in a simpler injection system. In addition, the thermal emittance of GaAs-type cathodes is significantly lower than for other photocathode materials. The environmental requirements for operating activated GaAs photocathodes cannot be met by rf guns as currently designed and operated. These requirements, including limits on vacuum and electron back bombardment, are discussed in some detail. Modifications to actual and proposed rf gun designs that would allow these requirements to be met are presented.
Download or read book The Polarized SRF Gun Experiment written by and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: An experiment is under way to prove the feasibility of a super-conducting RF gun for the production of polarized electrons. We report on the progress of the experiment and on simulations predicting the possibility of success.
Download or read book Fusion Energy Update written by and published by . This book was released on 1986 with total page 160 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book High Energy Physics Index written by and published by . This book was released on 1994 with total page 624 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1991 with total page 304 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book EPAC 92 written by H. Henke and published by Atlantica Séguier Frontières. This book was released on 1992 with total page 910 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Novel ideas for accelerators particle detection and data challenges at future colliders written by Alessandro Tricoli and published by Frontiers Media SA. This book was released on 2023-07-21 with total page 237 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book High Energy Physics Facilities written by United States. Congress. House. Committee on Science and Technology. Subcommittee on Energy Development and Applications and published by . This book was released on 1984 with total page 660 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book PSTP 2007 written by Ahovi Kponou and published by American Institute of Physics. This book was released on 2008-02-25 with total page 452 pages. Available in PDF, EPUB and Kindle. Book excerpt: Upton, New York, 10-14 September 2007
Download or read book Quests with U S Accelerators 50 Years the High Energy Physics and Nuclear Physics Research Programs written by Fusion Advisory Panel (U.S.) and published by . This book was released on 1981 with total page 472 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Energy Research Abstracts written by and published by . This book was released on 1994 with total page 464 pages. Available in PDF, EPUB and Kindle. Book excerpt:
