38 Matching Results

Search Results

Advanced search parameters have been applied.
in subjects: "Polarized Beams"  
Results: 1 - 24 next
open access

A compton backscattering polarimeter for measuring longitudinal electron polarization

Description: Compton backscattering polarimetry provides a fast measurement of the polarization of an electron beam in a storage ring. Since the method is non-destructive, the polarization of the electrons can be monitored during internal target experiments. At NIKHEF a Compton polarimeter has been constructed to measure the polarization of the longitudinally polarized electrons stored in the AmPS ring. First results obtained with the polarimeter, the first Compton polarimeter to measure the polarization of… more
Date: August 1, 1997
Creator: Passchier, I.; Higinbotham, Douglas W.; Vodinas, N.; Papadakis, N.; Jager, Kees de; Alarcon, Ricardo et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

First use of a laser-driven polarized H/D target at the IUCF cooler.

Description: The HERMES Laser-Driven Target Task Force (Argonne, Erlangen and Illinois) is charged with developing a polarized H/D target for use in the HERA ring at DESY. Rapid progress was made in the beginning of 1996, leading us to the decision to test the target in a realistic experimental environment. In particular, polarizations of 0.6 and flows above 10{sup 18} atoms{center_dot}s{sup {minus}1} have been achieved on the bench. The laser-driven target and a simple detector system are currently install… more
Date: December 5, 1997
Creator: Bailey, K.; Brack, J.; Cadman, R. V.; Cummings, W. J.; Fedchak, J.; Fox, B. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

A Helical Magnet Design for RHIC

Description: Helical dipole magnets are required in a project for the Relativistic Heavy Ion Collider (RHIC) to control and preserve the beam polarization in order to allow the collision of polarized proton beams. Specifications are for low current superconducting magnets with a 100 mm coil aperture and a 4 Tesla field in which the field rotates 360 degrees over a distance of 2.4 meters. A magnet meeting the requirements has been developed that uses a small diameter cable wound into helical grooves machined… more
Date: May 12, 1997
Creator: Willen, E.; Gupta, R.; Jain, A.; Kelly, E.; Morgan, G.; Muratore, J. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Neutron resonances in the compound nucleus: Parity nonconservation to dynamic temperature measurements

Description: Experiments using epithermal neutrons that interact to form compound-nuclear resonances serve a wide range of scientific applications. Changes in transmission which are correlated to polarization reversal in incident neutrons have been used to study parity nonconservation in the compound nucleus for a wide range of targets. The ensemble of measured parity asymmetries provides statistical information for the extraction of the rms parity-violating mean-square matrix element as a function of mass.… more
Date: August 1, 1997
Creator: Yuan, V.W.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

An injection modelocked Ti-sapphire laser for synchronous photoinjection

Description: The CEBAF 4 GeV accelerator has recently begun delivering spin-polarized electrons for nuclear physics experiments. Spin-polarized electrons are emitted from a GaAs photocathode that is illuminated with pulsed laser light from a diode laser system synchronized to the injector chopping frequency (499 MHz). The present diode laser system is compact, reliable and relatively maintenance-free; however, output power is limited to less than 500 mW. In an effort to obtain higher average power and there… more
Date: July 1, 1997
Creator: Hovater, C. & Poelker, M.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Transfer of a polarized proton beam from AGS to RHIC

Description: As part of the RHIC project, the RHIC machine will also be able to accelerate polarized proton beam bunches. The bunches will be extracted from the AGS machine, with kinetic energy T = 25 GeV, and transferred into RHIC via the AtR transfer line. When the RHIC machine accelerates polarized protons, it will operate with two full snakes, which define the stable spin direction of a polarized proton beam circulating in each ring, along the vertical. Therefore a polarized proton beam should be inject… more
Date: July 1, 1997
Creator: Tsoupas, N.; Roser, T.; Syphers, M.; Luccio, A. & Underwood, D.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Spin tracking study of the AGS

Description: In the recent polarized proton runs in the AGS, a 5% partial snake was used successfully to overcome the imperfection depolarizing resonances. Although some depolarization at intrinsic resonances are expected, the level of the depolarization does not agree with a simple model calculation. A spin tracking program is then used to simulate the real polarized proton beam in the AGS. The results show that, due to the linear coupling introduced by a solenoidal 5% partial snake, the polarized beam wil… more
Date: July 1, 1997
Creator: Huang, H.; Roser, T. & Luccio, A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Helical dipole magnets for polarized protons in RHIC

Description: Superconducting helical dipole magnets will be used in the Brookhaven Relativistic Heavy Ion Collider (RHIC) to maintain polarization of proton beams and to perform localized spin rotations at the two major experimental detector regions. Requirements for the helical dipole system are discussed, and magnet prototype work is reported.
Date: July 1, 1997
Creator: Syphers, M.; Courant, E. & Fischer, W.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Overcoming weak intrinsic depolarizing resonances with energy-jump

Description: In the recent polarized proton runs in the AGS, a 5% partial snake was used successfully to overcome the imperfection depolarizing resonances. Polarized proton beam was accelerated up to the required RHIC injection energy of 25 GeV. However, significant amount of polarization was lost at 0+{nu}{sub y}, 12+{nu}{sub y} and 36+{nu}{sub y}, which is believed to be partially due to the coupling resonances. To overcome the coupling resonance, an energy-jump was generated by rapidly changing the beam … more
Date: July 1, 1997
Creator: Huang, H.; Ahrens, L. & Alessi, J.G.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Growth of laser-induced damage during repetitive illumination of HfO2-SiO2 multilayer mirror and polarizer coatings

Description: As peak fluence of high power lasers is increased, it becomes necessary to tolerate damage on mirrors, polarizers. To study how different types of damage morphologies initiate and grow during repetitive illumination, hafnia-silica multilayer mirror and polarizer coatings were laser damage tested. The coatings were prepared by e-beam evaporation and irradiated with a 3-ns pulse at 1064 nm. The damage morphology was recorded after each shot to determine the types of damage that cause massive unst… more
Date: January 1, 1997
Creator: Genin, F. Y.; Stolz, C. J. & Kozlowski, M. R.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

RHIC spin program. Revision 07/97

Description: Colliding beams of high energy polarized protons at RHIC is an excellent way to probe the polarization of gluons, {anti u} and {anti d} quarks in a polarized proton. RHIC is the Relativistic Heavy Ion Collider being built now at Brookhaven in the ISABELLE tunnel. It is designed to collide gold ions on gold ions at 100 GeV/ nucleon. Its goal is to discover the quark-gluon plasma, and the first collisions are expected in March, 1999. RHIC will also make an ideal polarized proton collider with hig… more
Date: July 1, 1997
Creator: Bunce, G.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

The Drell-Hearn-Gerasimov sum-rule at polarized HERA

Description: The Drell-Hearn-Gerasimov sum-rule for spin dependent photoproduction relates the difference of the two cross-sections for the absorption of a real photon with spin anti-parallel {sigma}{sub A} and parallel {sigma}{sub P} to the target spin to the square of the anomalous magnetic moment of the target nucleon. The authors discuss the potential of polarized HERA to measure the spin dependent part of the total photoproduction cross section at large {radical}(s{sub {gamma}p}).
Date: November 1, 1997
Creator: Bass, S.D.; Brisudova, M.M. & De Roeck, A.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

An overview on the longitudinal Stern-Gerlach effect

Description: The TE rf cavity system is undoubtedly very appealing since it gives the possibility of polarizing both proton and antiproton beams at the end of their acceleration cycles. Practically, this process is similar to the e{+-} self-polarization induced by synchrotron radiation. Should this method prove unsuccessful, the small polarizer ring can still be used for attaining polarized antiprotons. In fact, the rf requirements for the low energy ring are less demanding than for high energy colliders: a… more
Date: November 17, 1997
Creator: Conte, M.; Parodi, R. & MacKay, W. W.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Polarization and charge limit studies of strained GaAs photocathodes

Description: This thesis presents studies on the polarization and charge limit behavior of electron beams produced by strained GaAs photocathodes. These photocathodes are the source of high-intensity, high-polarization electron beams used for a variety of high-energy physics experiments at the Stanford Linear Accelerator Center. Recent developments on P-type, biaxially-strained GaAs photocathodes have produced longitudinal polarization in excess of 80% while yielding beam intensities of {approximately} 2.5 … more
Date: March 1, 1997
Creator: Saez, P.J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Precision measurement of the neutron spin dependent structure functions

Description: In experiment E154 at the Stanford Linear Accelerator Center the spin dependent structure function g{sub 1}{sup n} (x, Q{sup 2}) of the neutron was measured by scattering longitudinally polarized 48.3 GeV electrons off a longitudinally polarized {sup 3}He target. The high beam energy allowed the author to extend the kinematic coverage compared to the previous SLAC experiments to 0.014 {le} x {le} 0.7 with an average Q{sup 2} of 5 GeV{sup 2}. The author reports the integral of the spin dependent… more
Date: February 1, 1997
Creator: Kolomensky, Y.G.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Spin tracking in RHIC

Description: In the acceleration of polarized protons in RHIC many spin depolarizing resonances are encountered. Helical Siberian snakes will be used to overcome depolarizing effects. The behavior of polarization can be studied by numerical tracking in a model accelerator. That allows one to check the strength of the resonances, to study the effect of snakes, to find safe lattice tune regions, and finally to study the operation of special devices like spin flippers. In this paper the authors describe numeri… more
Date: July 1, 1997
Creator: Luccio, A. U.; Katayama, T. & Wu, H.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Effect of SiO{sub 2} overcoat thickness on laser damage morphology of HfO{sub 2}/SiO{sub 2} Brewster`s angle polarizers at 1064 nm

Description: HfO{sub 2}/SiO{sub 2} Brewster`s angle polarizers are being developed at LLNL for the National Ignition Facility. Damage threshold studies using a 3-ns pulse length 1064-nm laser have revealed a number of different damage morphologies such as nodular ejection pits, plasma scalds, flat bottom pits, and overcoat delaminations. Of these laser damage morphologies, delaminations have the most negative impact on the multilayer stability. By selecting the proper SiO{sub 2} overcoat thickness, the dela… more
Date: March 3, 1997
Creator: Stolz, C. J.; Genin, F. Y.; Reitter, T. A.; Molau, N. E.; Bevis, R. P.; von Gunten, M. K. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Overcoming intrinsic spin resonance by using an AC dipole

Description: Depolarization from an intrinsic spin resonance can be avoided by adiabatically exciting a coherent betatron oscillation. Sustained coherent transverse beam oscillations have been achieved in the AGS using a high frequency AC driven dipole magnet. The amplitude of the oscillations using the present system has been as large as 2.6 times the rms beam size, and the oscillations were held at this level for over 1,000 revolutions. By adiabatically increasing and decreasing the dipole field amplitude… more
Date: July 1, 1997
Creator: Bai, M.; Ahrens, L. & Glenn, J.W.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

EPR in B physics and elsewhere

Description: The application of Einstein-Podolsky-Rosen correlations in {Upsilon}(4s) {yields} B{anti B} decays to research in CP violation is the first and probably only use of EPR as a technique for research in new physics. Elsewhere highly sophisticated EPR projects question EPR and test its predictions to look for violations of quantum mechanics, hidden variables, Bell`s inequalities, etc.
Date: September 1, 1997
Creator: Lipkin, Harry J.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

A high energy phase retarder for the simultaneous production of right- and left-handed circularly polarized x-rays

Description: The authors have fabricated and characterized the performance of a monolithic Ge Bragg-Laue phase retarder capable of simultaneously producing both right- and left-handed circularly polarized x rays. The energy range of operation of the phase retarder is between 50 and 100 keV making it well suited to the measurement of spin-dependent Compton profiles within the impulse approximation, primarily because of the increased momentum resolution and larger Compton scattering cross section available at… more
Date: September 1, 1997
Creator: Venkataraman, C. T.; Lang, J. C.; Nelson, C. S.; Srajer, G.; Haeffner, D. R. & Shastri, S. D.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Proceedings of the workshop on new kinds of positron sources for linear colliders

Description: It has been very clear from the beginning of studies for future linear colliders that the conventional positron source approach, as exemplified by the SLC source, is pushing uncomfortably close to the material limits of the conversion target. Nonetheless, since this type of positron source is better understood and relatively inexpensive to build, it has been incorporated into the initial design studies for the JLC/NLC. New ideas for positron sources for linear colliders have been regularly repo… more
Date: June 1, 1997
Creator: Clendenin, J. & Nixon, R.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Soft x-ray spectroscopy undulator beamline at the Advanced Photon Source

Description: Construction of the high-resolution soft x ray spectroscopy undulator beamline, 2ID-C, at the Advanced Photon Source (APS) has been completed. The beamline, one of two soft x ray beamlines at the APS, will cover the photon energy range from 500 to 3,000 eV, with a maximum resolving power between 7,000 and 14,000. The optical design is based on a spherical grating monochromator (SGM) giving both high resolution and high flux throughput. Photon flux is calculated to be approximately 10{sup 12}--1… more
Date: September 1, 1997
Creator: Randall, K.J.; Xu, Z.; Moore, J.F. & Gluskin, E.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Physics with low energy hadrons

Description: The prospects for low energy hadron physics at the front end of a muon collider (FMC) are discussed. The FMC, as conceived for the purposes of this workshop, is pretty close to a classical idea of a koan factory. There is an order of magnitude advantage of the FMC front end over the AGS for K{sup {minus}} and {anti p} production below 5 GeV/c.
Date: October 1, 1997
Creator: Guttierez, G. & Littenberg, L.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Synchrotron radiation instrumentation collaborative access team SRI-CAT sector 4

Description: The research objective for this sector of the Advanced Photon Source (APS) is the development of sources and applications of polarized x-rays covering the energy range from 0.5 to 50 keV. Both linearly and circularly polarized x-rays have been very successfully applied to the study of magnetic properties of materials. However, the applications have been limited due primarily to the lack of energy-tunable, high-brilliance x-ray beams with adjustable polarization properties. It is the authors` in… more
Date: August 1, 1997
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
Back to Top of Screen