Download or read book Investigations of the Physical Properties of Photoemission Polarized Electron Sources for Accelerator Applications written by Bruce Matthew Dunham and published by . This book was released on 1993 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This experiment measured the polarization and quantum efficiency as a function of wavelength for the chalcopyrite semiconductor Zn(Ge$rmsb{0.7}Sisb{0.3})Assb2.$ Also, the onset of space charge growth of a 100 keV electron beam passing through the Illinois/CEBAF polarized electron injection system was studied by measuring the beam emittance as a function of current. Finally, the thermal properties of GaAs were investigated by measuring the beam emittance as functions of the excitation laser wavelength and the laser spot size. The experiments were performed at the University of Illinois Nuclear Physics Laboratory using a 100 keV photoemission polarized electron gun, a electron spin manipulation system of a novel design, a Mott polarimeter, and an emittance measuring system. The design and performance of the entire system is described. The maximum polarization of Zn(Ge$rm sb{0.7}Sisb{0.3})Assb2$ was measured to be $sim$19%, much lower than the expected 100%. Also, the expected transition of the polarization through zero was not observed. The beam emittance as a function of current was measured and the onset of space charge effects was found to be $sim$0.5 mA, much lower than predicted by the electron gun design program scEGUN. Finally, the effective transverse thermal energy of the electrons emitted from GaAs at 100 keV as a function of excitation wavelength was measured by a new method for low beam currents. The electron thermal energy for wavelengths between 840 and 633 nm was found to be $sim$33 meV, a factor of 3 lower than for a thermionic electron gun. It was also found to increase sharply for photon wavelengths less than 633 nm.
Download or read book Polarized Beam Dynamics and Instrumentation in Particle Accelerators written by François Méot and published by Springer Nature. This book was released on 2023-03-21 with total page 419 pages. Available in PDF, EPUB and Kindle. Book excerpt: This Open Access book is drawn from lectures dispensed at the U.S. Particle Accelerator School (USPAS) Summer 2021 Spin Class, by experts in the field. It is an introduction to the dynamics of spin in charged particle accelerators, and to the accelerator components and spin manipulation techniques, including helical snakes and spin rotators, which enable and allow preserving beam polarization. It is aimed at graduate students or upper division undergraduate students with an interest in this multi-disciplinary field, which includes the future electron-ion collider at the Brookhaven National Laboratory, high energy lepton and proton collider projects, and other electric dipole moment search storage rings. It is also aimed at physicists or engineers working in accelerator-related fields who wish to familiarize themselves with spin dynamics and polarized beam concepts, tools, components, and purposes. This is an open access book.
Download or read book Polarized Electrons written by Joachim Kessler and published by Springer Science & Business Media. This book was released on 2013-03-14 with total page 311 pages. Available in PDF, EPUB and Kindle. Book excerpt: The rapid growth of the subject since the first edition ten years ago has made it necessary to rewrite the greater part of the book. Except for the introductory portion and the section on Mott scattering, the book has been completely revised. In Chap. 3, sections on polarization violating reflection symmetry, on resonance scattering, and on inelastic processes have been added. Chapter 4 has been rewritten, taking account of the numerous novel results obtained in exchange scattering. Chapter 5 includes the recent discoveries on photoelectron polarization produced by unpolarized radiation with unpolarized targets and on Auger-electron polarization. In Chap. 6, a further discussion of relativistic polarization phenomena has been added to the book. The immense growth of polarization studies with solids and surfaces required an extension and new presentation of Chap. 7. All but one section of Chap. 8 has been rewritten and a detailed treatment of polarization analysis has been included. Again, a nearly comprehensive treatment has been attempted. Even so, substantial selectivity among the wide range of available material has been essential in order to accomplish a compact presentation. The reference list, selected along the same lines as in the first edition, is meant to lead the reader through the literature giving a guide for finding further references. I want to express my indebtedness to a number of people whose help has been invaluable.
Download or read book Polarized Electron Polarized Photon Physics written by Hans Kleinpoppen and published by Springer Science & Business Media. This book was released on 2013-06-29 with total page 350 pages. Available in PDF, EPUB and Kindle. Book excerpt: The EPSRC (Engineering and Physical Science Research Committee of the U. K. ) suggested two Workshops (York University, 22-23 September, 1993 and 15-16 April, 1994) for possible development of polarized electron/photon physics as targeted areas of research. The remit of these meetings included identifying research groups and their activities in polarized electron/polarized photon physics, listing relevant existing facilities (particularly electron spin sources and polarimeters), possible joint projects between research groups in the U. K. , recognizing future needs of projects for research of the highest scientific merit and referring to international comparisons of these research activities. Although very diverse but interconnected, the areas of research presented at the Workshops embrace atomic, molecular, surface, and solid state physics. In more detail these areas covered: electron spin correlations and photon polarization correlations in atomic and molecular collisions and photoionization, electron spin effects in scanning tunneling microscopy, surface and interface magnetism from X-ray scattering and polarized Auger electrons (including analysis of domain structures in solids and surfaces), polarized electrons from multiphoton ionization, quasi-atomic effects in solid state physics, dichroism in molecular and surface processes, Faraday rotation and high-field magneto-optics and polarization effects in simultaneous higher order electron-photon excitations. It is obvious from the spectrum of research fields presented at the Workshops that physicists of primarily two communities, namely those studying electron and photon spin interactions with gaseous atomic and molecular targets and those using condensed matter targets for their studies, interacted very closely with each other.
Download or read book Recent Advances in Polarized Electron Sources written by and published by . This book was released on 1999 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Current experimental physics programs at a number of electron accelerator laboratories worldwide require the delivery of high average current highly polarized electron beams for long periods of time. The polarized electrons are produced by near bandgap photoemission from certain semiconductor photocathodes. The authors observe the quantum efficiency of these cathodes to be inversely related to the total charge they have delivered. Recent developments in ultrahigh vacuum technology, electron trajectory control, photocathode preparation, and lasers have led to operationally reliable delivery of many hundreds of coulombs of polarized electrons, at rates as high as 8 coulombs/day. Currently, their photocathode operational lifetime is almost completely dominated by ion backbombardment. Further gains in the high average current lifetime of these cathodes may be expected, which will allow photoemission electron guns to be used for accelerator applications other than polarized sources.
Download or read book Dissertation Abstracts International written by and published by . This book was released on 1993 with total page 738 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Handbook of Spintronics written by Yongbing Xu and published by Springer. This book was released on 2015-10-14 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Over two volumes and 1500 pages, the Handbook of Spintronics will cover all aspects of spintronics science and technology, including fundamental physics, materials properties and processing, established and emerging device technology and applications. Comprising 60 chapters from a large international team of leading researchers across academia and industry, the Handbook provides readers with an up-to-date and comprehensive review of this dynamic field of research. The opening chapters focus on the fundamental physical principles of spintronics in metals and semiconductors, including an introduction to spin quantum computing. Materials systems are then considered, with sections on metallic thin films and multilayers, magnetic tunnelling structures, hybrids, magnetic semiconductors and molecular spintronic materials. A separate section reviews the various characterisation methods appropriate to spintronics materials, including STM, spin-polarised photoemission, x-ray diffraction techniques and spin-polarised SEM. The third part of the Handbook contains chapters on the state of the art in device technology and applications, including spin valves, GMR and MTJ devices, MRAM technology, spin transistors and spin logic devices, spin torque devices, spin pumping and spin dynamics and other topics such as spin caloritronics. Each chapter considers the challenges faced by researchers in that area and contains some indications of the direction that future work in the field is likely to take. This reference work will be an essential and long-standing resource for the spintronics community.
Download or read book Polarized Gas Targets and Polarized Beams written by Roy J. Holt and published by American Institute of Physics. This book was released on 1998-02-20 with total page 574 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this book, the author begins with the elementary theory of Markov chains and very progressively brings the reader to the more advanced topics. He gives a useful review of probability that makes the book self-contained, and provides an appendix with detailed proofs of all the prerequisites from calculus, algebra, and number theory. A number of carefully chosen problems of varying difficulty are proposed at the close of each chapter, and the mathematics are slowly and carefully developed, in order to make self-study easier. The author treats the classic topics of Markov chain theory, both in discrete time and continuous time, as well as the connected topics such as finite Gibbs fields, nonhomogeneous Markov chains, discrete- time regenerative processes, Monte Carlo simulation, simulated annealing, and queuing theory. The result is an up-to-date textbook on stochastic processes. Students and researchers in operations research and electrical engineering, as well as in physics and biology, will find it very accessible and relevant.
Download or read book Nuclear Science Abstracts written by and published by . This book was released on 1975 with total page 1166 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Hydrogen in Materials and Vacuum Systems written by Ganapati R. Myneni and published by American Institute of Physics. This book was released on 2003-07-16 with total page 364 pages. Available in PDF, EPUB and Kindle. Book excerpt: All papers were peer-reviewed. Hydrogen plays a key role in materials, beneficial in some cases, problematic in others. In all such systems a detailed understanding of the hydrogen-based interaction is necessary for control, improvements, and for possible new applications. This hydrogen workshop proceeding incorporates contributions from semi-conducting, normal conducting (metals) and superconducting materials, as well as vacuum communities who deal with the hydrogen-materials issue. The technical areas covered in these proceedings include hydrogen in materials, hydrogen interactions and dynamics in semiconductors, hydrogen adsorption-storage-generation and distribution, hydrogen in niobium, hydrogen in vacuum systems, gaseous hydrogen accelerator structures, and magnetically suspended liquid hydrogen transfer lines.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 376 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.
Download or read book Proceedings of the Workshop on Photocathodes for Polarized Electron Sources for Accelerators written by M. Chatwell and published by . This book was released on 1993 with total page 466 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 1993 with total page 754 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Polarized Electron Photoemission Studies of Spin Relaxation in Thin GaAs Epitaxial Films written by Yuri A. Mamaev and published by . This book was released on 2001 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt: The results of systematic study of polarized electron emission from unstrained GaAs thin epitaxial layers with varying thickness are presented. Excitation spectra of the polarized photoemission reflect the optical spin orientation of the electrons produced by the circularly polarized light excitation and spin relaxation kinetics. The interpretation of the spectra and their temperature dependencies shows the importance of valence band wrapping and correlation between the spin and the momentum of an electron. For thin overlayers the residual polarization losses occur in the band-bending region.
Download or read book The Department of Energy s FY 1997 Budget Request for the Office of Energy Research OER written by United States. Congress. House. Committee on Science. Subcommittee on Energy and Environment and published by . This book was released on 1996 with total page 1348 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Proceedings of the Workshop on Photocathodes for Polarized Electron Sources for Accelerators Stanford Linear Accelerator Center Stanford California September 8 10 1993 written by M. Chatwell and published by . This book was released on 1994 with total page 465 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book NBS Special Publication written by and published by . This book was released on 1968 with total page 684 pages. Available in PDF, EPUB and Kindle. Book excerpt:
