Download or read book The SLAC Polarized Electron Source written by and published by . This book was released on 1997 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since 1992, the SLAC 3-km linac has operated exclusively with polarized electrons. The polarized electron source is highly reliable, remotely operated and monitored, and able to produce a variety of electron bunch profiles for high-energy physics experiments. The source and its operating characteristics are described. Some implications drawn from the operating experience are discussed.

Download or read book The SLAC Polarized Electron Source and Beam for E 158 written by and published by . This book was released on 2003 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: SLAC E-158 is making the first measurement of parity violation in Moeller scattering. E-158 measures the right-left cross-section asymmetry, A{sub LR}, in the scattering of a 45-GeV polarized electron beam off unpolarized electrons in a liquid hydrogen target. E-158 plans to measure the expected Standard Model asymmetry of (almost equal to) 10−7 to an accuracy of better than 10−8. This paper discusses the performance of the SLAC polarized electron source and beam during E-158's first physics run in April/May 2002.

Download or read book Report on the May 1983 Polarized Electron Source Workshop at SLAC written by and published by . This book was released on 1984 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The work and conclusions of the 1983 Polarized Electron Source Workshop at SLAC are reviewed. Some mention of progress since that meeting is also included. 24 references.

Download or read book The SLAC Polarized Electron Source Laser System written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The Stanford Linear Collider (SLC) has operated a polarized photocathode electron source and titanium sapphire laser for high energy physics collisions for over 6,500 hours of nearly continuous operation. The laser system for the source has demonstrated> 98.5% total uptime for the duration of the experiment. The laser system uses a pair of titanium sapphire oscillators pumped by frequency doubled YAG lasers to produce 2ns, 250[micro]J pulses at wavelengths from 740nm to 870nm.

Download or read book SLAC s Polarized Electron Source LaserSystem and Minimization of Helicity Correlations for the E 158 Parity Violation Experiment written by and published by . This book was released on 2002 with total page 65 pages. Available in PDF, EPUB and Kindle. Book excerpt: SLAC E-158 is an experiment designed to make the first measurement of parity violation in Moeller scattering. E-158 will measure the right-left cross-section asymmetry, A{sub LR}{sup Moeller}, in the elastic scattering of a 45-GeV polarized electron beam off unpolarized electrons in a liquid hydrogen target. E-158 plans to measure the expected Standard Model asymmetry of (almost equal to) 10−7 to an accuracy of better than 10−8. To make this measurement, the polarized electron source requires for operation an intense circularly polarized laser beam and the ability to quickly switch between right- and left-helicity polarization states with minimal right-left helicity-correlated asymmetries in the resulting beam parameters (intensity, position, angle, spot size, and energy), {sup beam}A{sub LR}'s. This laser beam is produced by a unique SLAC-designed flashlamp-pumped Ti:Sapphire laser and is propagated through a carefully designed set of polarization optics. We analyze the transport of nearly circularly polarized light through the optical system and identify several mechanisms that generate {sup beam}A{sub LR}'s. We show that the dominant effects depend linearly on particular polarization phase shifts in the optical system. We present the laser system design and a discussion of the suppression and control of {sup beam}A{sub LR}'s. We also present results on beam performance from engineering and physics runs for E-158.

Download or read book High Intensity Polarized Electron Sources written by and published by . This book was released on 1980 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The status of the polarized electron source development program at SLAC will be reviewed. Emission currents of 60 A, corresponding to a space charge limited current density of 180 A/cm2, have been obtained from GaAs photocathodes. Electron beam polarization 20% greater than that obtainable from GaAs cathodes has been observed from multilayer GaAs-GaAlAs structures. Work in progress to produce high beam polarization from II-IV-V2 chalcopyrite photocathodes will also be described.

Download or read book Polarized Electron Beams at SLAC written by and published by . This book was released on 1992 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: SLAC has successfully accelerated high energy polarized electrons for the Stanford Linear Collider and fixed polarized nuclear target experiments. The polarized electron beams at SLAC use a gallium arsenide (GaAlAs for E-142) photon emission source to provide the beam of polarized electrons with polarization of approximately 28% (41% for E-142). While the beam emittance is reduced in the damping ring for SLC operation a system of bend magnets and superconducting solenoids preserve and orient the spin direction for maximum longitudinal polarization at the collision point. The electron polarization is monitored with a Compton scattering polarimeter, and was typically 22% at the e[plus]e[minus] collision point for the 1992 run. Improvements are discussed to increase the source polarization and to reduce the depolarization effects between the source and the collision point.

Download or read book Polarized Photocathodes Make the Grade written by and published by . This book was released on 2002 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: Future linear colliders will require high levels of performance from their electron sources. A group at SLAC has recently tested a structure that substantially exceeds current collider polarized electron source pulse-profile requirements.

Download or read book SLAC s Polarized Electron Source Laser System for the E 158 Parity Violation Experiment written by and published by . This book was released on 2002 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: SLAC E158 is an experiment to make the first measurement of parity violation in Moeller scattering. The left-right cross-section asymmetry in the elastic scattering of a 45-GeV polarized electron beam off unpolarized electrons in a liquid hydrogen target will be measured to an accuracy of better than 10−8, with the expected Standard Model asymmetry being approximately 10−7. An intense circularly polarized laser beam for the polarized electron source is required with the ability to quickly switch between left and right polarization states with minimal left-right asymmetries in the parameters of the electron beam. This laser beam is produced by a unique SLAC-designed, flash-lamp pumped, Ti:Sapphire laser. We present this laser system design and initial results from recent commissioning runs.

Download or read book Performance of the SLC Polarized Electron Source with High Polarization written by and published by . This book was released on 1993 with total page 3 pages. Available in PDF, EPUB and Kindle. Book excerpt: For the 1992 operating cycle of the SLAC Linear Collider (SLC), the polarized electron source (PES) during its maiden run successfully met the pulse intensity and overall efficiency requirements of the SLC. However, the polarization of the bulk GaAs cathode was low ((approximately)27%) and the pulse-to-pulse stability was marginal. We have shown that adequate charge for the SLC can be extracted from a strained layer cathode having P{sub e}(approximately)80% even though the quantum efficiency (QE) is

Download or read book Physics Results with Polarized Electrons at SLAC written by and published by . This book was released on 1996 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: Polarized electron beams can play an important role in the dynamics of interactions at high energies. Polarized electron beams at SLAC have been an important part of the physics program since 1970, when they were first proposed for use in testing the spin structure of the proton. Since 1992, the SLAC linear accelerator and the SLC have operated solely with polarized electrons, providing data for tests of QCD in studies of the spin structure of the nucleon and tests of the electroweak sector of the Standard Model. In the following sections, the performance of the source is summarized, and some of the recent results using the polarized beams are discussed.

Download or read book Polarized Light Sources for Photocathode Electron Guns at SLAC written by and published by . This book was released on 1992 with total page 3 pages. Available in PDF, EPUB and Kindle. Book excerpt: We describe current and future Polarized Light Sources at SLAC for use with photocathode electron guns to produce polarized electron beams. The SLAC experiments SLD and E142 are considered, and are used to define the required parameters for the Polarized Light Sources.

Download or read book The Polarized Electron Beam for the SLAC Linear Collider written by and published by . This book was released on 1996 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: The SLAC Linear Collider has been colliding a polarized electron beam with an unpolarized positron beam at the Z° resonance for the SLD experiment since 1992. An electron beam polarization of close to 80% has been achieved for the experiment at luminosities up to 8 · 1029 cm−2 s−1. This is the world's first and only linear collider, and is a successful prototype for the next generation of high energy electron linear colliders. This paper discusses polarized beam operation for the SLC, and includes aspects of the polarized source, spin transport and polarimetry.

Download or read book Polarization at SLAC written by and published by . This book was released on 1995 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt: A highly polarized electron beam is a key feature. for the Current physics program at SLAC. An electron beam polarization of 80% can now be routinely achieved for typically 5000 hours of machine operation per year. Two main Physics programs utilize the polarized beam. Fixed target experiments in End Station A study the collision of polarized electrons with polarized nuclear targets to elucidate the spin structure of the nucleon and to provide an important test of QCD. Using the SLAC Linear Collider, collisions of polarized electrons with unpolarized positrons allow precise measurements of parity violation in the Z-fermion couplings and provide a very precise measurement of tile weak mixing angle. This paper discusses polarized beam operation at SLAC, and gives an overview of the polarized physics program.

Download or read book The Polarized Electron Source for the International Collider ILC Project written by J. Turner and published by . This book was released on 2006 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt: ILC project will be the next large high energy physics tool that will use polarized electrons (and positrons). For this machine spin physics will play an important role. The polarized electron source design is based on electron injectors built for the Stanford Linear Collider (polarized) and Tesla Test Facility (un-polarized). The ILC polarized electron source will provide a 5GeV spin polarized electron beam for injection into the ILC damping ring. Although most ILC machine parameters have been achieved by the SLC or TTF source, features of both must be integrated into one design. The bunch train structure presents unique challenges to the source laser drive system. A suitable laser system has not yet been demonstrated and is part of the ongoing R & D program for ILC at SLAC. Furthermore, ILC injector R & D incorporates photocathode development, increasing available polarization, and improving operational properties in gun vacuum systems. Another important area of research and development is advancing the design of DC and RF electron gun technology for polarized sources. This presentation presents the current status of the design and outlines aspects of the relevant R & D program carried out within the ILC community.

Download or read book Polarized Beams And Polarized Gas Targets Proceedings Of The International Workshop written by Hans Paetz Gen Schieck and published by World Scientific. This book was released on 1996-03-21 with total page 478 pages. Available in PDF, EPUB and Kindle. Book excerpt: The International Workshop on Polarized Beams and Polarized Gas Targets was held in Cologne, Germany from June 6 to 9, 1995 as the last in a series held at 2-3 years intervals. It was attended by about 110 scientists; there were 47 invited and contributed talks, 5 round-table discussions and 17 poster contributions, all of which will appear as a written contribution in the Proceedings. The main subjects were Optically-Pumped Polarized Targets, Polarized Electron Sources, Atomic-Beam Polarized-Ion Sources, Optically-Pumped Polarized Ion Sources, Targets and Storage Rings. Significant progress and latest developments in this field were covered as well as future developments both from the technical, but also from the physics aspects.

Download or read book High Polarization Photocathode R D at SLAC written by and published by . This book was released on 1993 with total page 3 pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper describes recent progress on the development of high polarization photocathodes for polarized electron sources. A strained InGaAs cathode has achieved a maximum electron-spin polarization of 71% and has demonstrated the strain enhancement of polarization for the first time. Strained GaAs cathodes have yielded polarizations as high as 90% with much higher quantum efficiency.