128 Matching Results

Search Results

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

Acceleration of polarized proton at the AGS

Description: The unexpected importance of high energy spin effects and the success of the ZGS in correcting many intrinsic and imperfection depolarizing resonances led us to attempt to accelerate polarized protons in the AGS. A collaborative effort is underway by the groups in Argonne, Michigan, Rice, Yale and Brookhaven to improve and modify the AGS to accelerate polarized protons. With the appropriate funding the first polarized proton acceleration at the AGS should be possible by 1983.
Date: January 1, 1980
Creator: Lee, Y. Y.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Muon Diffusion in Noble Metals

Description: Diffusion-induced muon depolarization was measured in dilute AgGd and AgEr in the temperature range 200 to 700/sup 0/K and have thereby determined the muon diffusion parameters in Ag. The diffusion parameters for ..mu../sup +/ in Cu, Ag, and Au are compared with those of hydrogen. For Ag and Au, the ..mu../sup +/ parameters are similar to those of hydrogen, whereas for Cu, the ..mu../sup +/ parameters are much smaller. Lattice-activated tunneling and over-barrier hopping are investigated with c… more
Date: January 1, 1982
Creator: Schillaci, M. E.; Boekema, C.; Heffner, R. H.; Hutson, R. L.; Leon, M.; Olsen, C. E. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Techniques with H/sup 0/ produced from polarized H/sup -/ beams

Description: It is possible to perform useful manipulations by making H/sup 0/ beams from polarized H/sup -/ beams with stripper foils or stripping magnets. The hyperfine interaction modifies the behavior of the proton polarization in H/sup 0/, producing both useful and unwanted effects. Some depolarizing effects can be minimized.
Date: January 1, 1980
Creator: van Dyck, O.B.; Jason, A.J. & Hudgings, D.W.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Correcting the AGS depolarizing resonances

Description: For the 1986 AGS run, the technique of correcting an imperfection resonance using a beat harmonic instead of the direct harmonic was applied and found to be useful in achieving a 22 GeV/c polarized beam. Both conventional and modified techniques are explained. (LEW)
Date: January 1, 1986
Creator: Ratner, L. G.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Antiproton physics in the next decade

Description: Notes from a talk at the LAMPF II workshop are given. Topics include antinucleon physics in the next decade - the role of anti p and anti n beams in shedding light on some fundamental problems in nuclear and particle physics. Some particle aspects considered include; a) anti n as a source of antiquarks (anti NN provides a well-suited entrance channel for formation of new kind of mesons), and b) possibility of forming quark-gluon phase in anti N annihilations in nuclei. Some nuclear aspects disc… more
Date: February 1, 1982
Creator: Dover, C. B.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Polarization of a stored electron beam

Description: Synchrotron radiation by a point charge is a familiar subject in classical electrodynamics. Perhaps less familiar are some quantum mechanical corrections to the classical results. Some of those quantum aspects of synchrotron radiation are described. One of the quantum effects leads to the expectation that electrons in a storage ring will polarize themselves to 92% - a surprisingly high value. A semi-classical derivation of the quantum effects is given. An effort has been made to minimize the ne… more
Date: July 1, 1981
Creator: Chao, A.W.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Possible Depolarization Mechanism due to Low Beta Squeeze

Description: Simulations reveal a potential depolarization mechanism during low beta squeeze. This depolarization appears to be driven by a spin tune modulation caused by spin precession through the strong low beta quads due to the vertical fields. The modulation of the spin tune introduces an additional snake resonance condition at {nu}{sub s0} {+-} n{nu}{sub x} - {nu}{sub z}l = integer which while the same numerology as the well known sextupole resonance, can operate in the absence of sextupole elements.
Date: April 1, 2008
Creator: Ranjbar,V.; Luccio, A. & Bai, M.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Effect of various errors on the Spin Tune and Stable Spin Axis

Description: Even though RHIC has two full Siberian snakes in each ring, there are various perturbations to the ideal case including orbit errors at the snakes, experiment solenoids, injection bumps, and interlaced horizontal-vertical bumps at the hydrogen jet polarimeter. These errors can cause depolarization by shifting the spin tune and tilting the stable spin direction away from vertical. Tilting of the stable spin axis can enhance horizontal depolarizing resonances. This paper presents preliminary resu… more
Date: October 6, 2008
Creator: MacKay, W. W.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Acclerator R&D for a Linear Collider

Description: The goal of this project was to perform simulations of beam transport in linear colliders, with an emphasis on emittance dilution, spin polarization transport, and development and testing of beam based tuning algorithms. Our simulations are based on an existing object-oriented particle-tracking library, Bmad. To facilitate the efficient development of simulations, an accelerator design and analysis program based on Bmad has been developed called Tao (Tool for Accelerator Optics). The three beam… more
Date: November 26, 2008
Creator: Rubin, D.L.; Dugan, G.; Gibbons, L.; Palmer, M.; Patterson, R.; Sagan, D. et al.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

TOWARDS 100% POLARIZATION IN THE OPTICALLY-PUMPED POLARIZED ION SOURCE.

Description: The depolarization factors in the multi-step spin-transfer polarization technique and basic limitations on maximum polarization in the OPPIS (Optically-Pumped Polarized H{sup -} Ion Source) are discussed. Detailed studies of polarization losses in the RHIC OPPIS and the source parameters optimization resulted in the OPPIS polarization increase to 86-90%. This contributed to increasing polarization in the AGS and RHIC to 65-70%.
Date: June 25, 2007
Creator: ZELENSKI,A.; ALESSI, J.; KOKHANOVSKI, S.; KPONOU, A.; RITTER, B.J. & ZUBETS, V.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Hydrogen Production and Delivery Research

Description: In response to DOE's Solicitation for Grant Applications DE-PS36-03GO93007, 'Hydrogen Production and Delivery Research', SRI International (SRI) proposed to conduct work under Technical Topic Area 5, Advanced Electrolysis Systems; Sub-Topic 5B, High-Temperature Steam Electrolysis. We proposed to develop a prototype of a modular industrial system for low-cost generation of H{sub 2} (<$2/kg) by steam electrolysis with anodic depolarization by CO. Water will be decomposed electrochemically into… more
Date: October 15, 2007
Creator: Balachov, Iouri
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Spectroscopic Characterization of Intermediates in the Iron Catalyzed Activation of Alkanes

Description: The present report begins with a brief survey of recent hypervalent iron chemistry and mentions two previously reported ferrate papers funded by the DOE/BES grant. The focus is then shifted to the seven publications acknowledging support of the grant that have not been reported since the last Progress Report, DOE/ER/14340-9, was prepared. These papers deal with: (a) the successful use of an ATR element in a stopped-flow infrared spectrometer, (b) the rationalization of a depolarization of a LiC… more
Date: May 28, 2007
Creator: Eyring, Edward M.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

The RHIC Optically-Pumped Polarized H Ion Source.

Description: The depolarization factors in the multi-step spin-transfer polarization technique and basic limitations on maximum polarization in the OPPIS (Optically-Pumped Polarized H{sup -} Ion Source) are discussed. Detailed studies of polarization losses in the RHIC OPPIS and the source parameters optimization resulted in the OPPIS polarization increase to 86-90%. This contributed to increasing polarization in the AGS and RHIC to 65-70%.
Date: September 10, 2007
Creator: Zelenski,A.; Zelenski, A.; Kokhanovski, S.; Kponou, A.; Ritter, J. & Zubets, V.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

On the Feasibility of a Spin Decoherence Measurement.

Description: In this paper, I study the feasibility of making a turn-by-turn spin measurement to extract the spin tune from a polarized beam injected perpendicular to the stable spin direction. For the ideal case of a zero-emittance beam with no spin-tune spread, there would be no spin decoherence, and a measurement of the spin tune could easily be made by collecting turn-indexed polarization data over several million turns. However, in a real beam there is a momentum spread which provides a spin-tune sprea… more
Date: June 23, 2006
Creator: MacKay, W. W.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Temperature response of 129Xe depolarization transfer and its application for ultra-sensitive NMR detection

Description: Temporary trapping of atomic xenon in functionalized cryptophane cages makes the high sensitivity of hyperpolarized (hp) 129Xe available for highly specific NMR detection of biomolecules like proteins in solution. Here, we study the signal transfer onto a reservoir of unbound hp xenon by gating the residence time of the nuclei in the cage through the temperature-dependent exchange rate. Temperature changes were detectable immediately as an altered reservoir signal and yielded a sensitivity of 0… more
Date: March 20, 2008
Creator: Schroeder, Leif; Schroder, Leif; Meldrum, Tyler; Smith, Monica; Lowery, Thomas J.; Wemmer, David E. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Temperature-controlled molecular depolarization gates in nuclear magnetic resonance

Description: Down the drain: Cryptophane cages in combination with selective radiofrequency spin labeling can be used as molecular 'transpletor' units for transferring depletion of spin polarization from a hyperpolarized 'source' spin ensemble to a 'drain' ensemble. The flow of nuclei through the gate is adjustable by the ambient temperature, thereby enabling controlled consumption of hyperpolarization.
Date: February 27, 2008
Creator: Schroder, Leif; Schroder, Leif; Chavez, Lana; Meldrum, Tyler; Smith, Monica; Lowery, Thomas J. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Polarized Proton Acceleration in AGS and RHIC

Description: As the first hadron accelerator and collider consisting of two independent superconducting rings RHIC has operated with a wide range of beam energies and particle species including polarized proton beams. The acceleration of polarized beams in both the injector and the collider rings is complicated by numerous depolarizing spin resonances. Partial and full Siberian snakes have made it possible to overcome the depolarization and beam polarizations of up to 65% have been reached at 100 GeV in RHI… more
Date: September 10, 2007
Creator: Roser, T.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Personal history of nucleon polarization experiments

Description: The history of nucleon scattering experiments is reviewed, starting with the observation of large proton polarizations in scattering from light elements such as carbon, and ending with the acceleration of polarized proton beams in high-energy synchrotrons. Special mention is made about significant contributions made by C.L. Oxley, L. Wolfenstein, R.D. Tripp, T. Ypsilantis, A. Abragam, M. Borghini, T. Niinikoski, Froissart, Stora, A.D. Krisch, and L.G. Ratner.
Date: September 1, 1984
Creator: Chamberlain, O.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Accelerating and storing polarized hadron beams

Description: Polarization hadron experiments at high energies continue to generate surprises. Many questions remain unanswered or unanswerable within the frame work of QCD. These include such basic questions as to why at high energies the polarization analyzing power in pp elastic scattering remains high, why hyperons are produced with high polarizations etc. It is, therefore, interesting to investigate the possibilities of accelerating and storing polarized beams in high energy colliders. On the technical … more
Date: October 1, 1990
Creator: Teng, L.C.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
Back to Top of Screen