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Uncoupled achromatic tilted S-bend

Description: A particular section of the electron beam transport line, to be used in the e-cooling project [l] of the Relativistic Heavy Ion Collider (RHIC), is constrained to displace the trajectory with both horizontal and vertical offsets so that the outgoing beamline is parallel to the incoming beamline. We also require that section be achromatic in both planes. This mixed horizontal and vertical achromatic Sbend is accomplished by rotating the two dipoles and the quadrupoles of the line, about the long… more
Date: June 23, 2008
Creator: Tsoupas, N.; Kayran, D.; Litvinenko, V. & MacKay, W. W.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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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
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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
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Prospects for Acceleration of Deuterons and Helions.

Description: In order to study the spin structure of the neutron at high energy, a beam rich in polarized neutrons needs to be developed. The neutron has no charge and cannot be accelerated, so either deuterons or helions must be considered. When it comes to spin manipulation and stability of the polarization in a circular accelerator, it is the anomalous part of the magnetic moment which is important. If the anomaly is too small, then manipulation becomes difficult as in the case of deuterons--spin rotator… more
Date: September 10, 2007
Creator: MacKay, W. W.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Energy Scaling of Spin Tune due to RHIC Snakes

Description: For a ring like RHIC with two full Siberian snakes on opposite sides of the ring, the spin tune for a flat orbit will be 1/2 if the snake rotation axes are perpendicular, {Delta}{phi} = {phi}{sub 9}-{phi}{sub 3} = {pi}/2. Here {phi}{sup 9} and {phi}{sub 3} are respectively the direction of the rotation axes of the 9 o'clock and 3 o'clock snakes relative to the design trajectory as shown in Figure 1. If the two snakes are slightly detuned by the same amount such that the rotation axes are no lon… more
Date: January 2, 2009
Creator: MacKay, W. W.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

R_transport_matrices of the Fast Extraction Beam (FEB) of the AGS, and Beam Parameters at the Starting point of the AtR Line

Description: As part of the task to improve and further automate the 'AtR BPM Application' we provide the theoretically calculated R-transport-matrices for the following beam line sections, which are shown schematically in Figure 1: (a) the Fast Extraction Beam section (FEB) of the AGS synchrotron. The FEB section starts at the middle of the GlO-kicker and ends at the middle of the H1 0{_}septum. (b) the Drift Extraction Channel (DEC) section of the AGS synchrotron. The DEC section starts at the middle of t… more
Date: January 1, 2008
Creator: Tsoupas, N.; MacKay, W. W.; Satogata, T.; Glenn, W.; Ahrens, L.; Brown, K. et al.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

AGS polarized proton operation in run 8.

Description: Dual partial snake scheme has been used for the Brookhaven AGS (Alternating Gradient Synchrotron) polarized proton operation for several years. It has provided polarized proton beams with 1.5 x 10{sup 11} intensity and 65% polarization for RHIC spin program. There is still residual polarization loss. Several schemes such as putting horizontal tune into the spin tune gap, and injection-on-the-fly were tested in the AGS to mitigate the loss. This paper presents the experiment results and analysis. more
Date: June 23, 2008
Creator: Huang, H.; Ahrens, L.; Bai, M.; Brown, K. A.; Gardner, C.; Glenn, J. W. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Matching the BtA line to the bare-AGS (Part 1)

Description: The Booster to AGS (BtA) transfer line [Ref for BtA line] transports the beam bunches from the AGS-Booster to the AGS synchrotron, and also matches the beam parameters ({beta}{sub x,y}, {alpha}{sub x,y}) and dispersion functions ({eta}{sub x,y}, {eta}{prime}{sub x,y}) of the transported beam to the corresponding quantities of the circulating beam in AGS, at the AGS injection point. In this technical note we describe in details, the calculations of the matching procedure of the BtA line to the b… more
Date: November 1, 2008
Creator: Tsoupas, N.; Glenn, J. W.; Huan, H.; MacKay, W. W.; Raparia, D. & Zeno, K.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

20% Partial Siberian Snake in the AGS.

Description: An 11.4% partial Siberian snake was used to successfully accelerate polarized proton through a strong intrinsic depolarizing spin resonance in the AGS. No noticeable depolarization was observed. This opens up the possibility of using a 20% to 30% partial Siberian snake in the AGS to overcome all weak and strong depolarizing spin resonances. Some design and operation issues of the new partial Siberian snake are discussed.
Date: November 6, 2002
Creator: Huang, H.; Bai, M.; Brown, K. A.; Glenn, W.; Luccio, A. U.; MacKay, W. W. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Commissioning Spin Rotators in RHIC.

Description: During the summer of 2002, eight superconducting helical spin rotators were installed into RHIC in order to control the polarization directions independently at the STAR and PHENIX experiments. Without the rotators, the orientation of polarization at the interaction points would only be vertical. With four rotators around each of the two experiments, we can rotate either or both beams from vertical into the horizontal plane through the interaction region and then back to vertical on the other s… more
Date: May 12, 2003
Creator: MacKay, W. W.; Bai, M.; Courant, E. D.; Fischer, W.; Huang, H.; Luccio, A. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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RHIC PC CNI Polarimeter:Status and Performance From the First Collider Run.

Description: Polarimeters using the proton carbon elastic scattering process in Coulomb Nuclear Interference (CNI) region were installed in two RHIC rings. Polarization measurements were successfully carried out with the high energy polarized proton beams for the first polarized pp collision run. The physics principles, performance, and polarization measurements are presented.
Date: September 9, 2002
Creator: Jinnouchi, O.; Bland, L. C.; Bravar, A.; Bunce, G.; Cadman, R.; Deshpande, A. D. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Configuration Manual Polarized Proton Collider at RHIC

Description: In this report, the authors present their design to accelerate and store polarized protons in RHIC, with the level of polarization, luminosity, and control of systematic errors required by the approved RHIC spin physics program. They provide an overview of the physics to be studied using RHIC with polarized proton beams, and a brief description of the accelerator systems required for the project.
Date: March 1, 2001
Creator: Roser, T.; MacKay, W. W.; Alekseev, I.; Bai, M.; Brown, K.; Bunce, G. et al.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

RHIC Polarized proton operation

Description: The Relativistic Heavy Ion Collider (RHIC) operation as the polarized proton collider presents unique challenges since both luminosity(L) and spin polarization(P) are important. With longitudinally polarized beams at the experiments, the figure of merit is LP{sup 4}. A lot of upgrades and modifications have been made since last polarized proton operation. A 9 MHz rf system is installed to improve longitudinal match at injection and to increase luminosity. The beam dump was upgraded to increase … more
Date: March 28, 2011
Creator: Huang, H.; Ahrens, L.; Alekseev, I. G.; Aschenauer, E.; Atoian, G.; Bai, M. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

The AGS synchrotron with four helical magnets

Description: The idea of using two partial helical magnets was applied successfully to the AGS synchrotron to preserve the proton beam polarization. In this paper we explore in details the idea of using four helical magnets placed symmetrically in the AGS ring. The placement of four helical magnets in the AGS ring provides many advantages over the present setup of the AGS which uses two partial helical magnets. First, the symmetric placement of the four helical magnets allows for a better control of the AGS… more
Date: May 20, 2012
Creator: Tsoupas, N.; Huang, H.; Roser, T.; MacKay, W. W. & Trbojevic, D.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Energy upgrade as regards quench performance

Description: Since the cross section for W production increases rapidly with energy, we consider the possibility of increasing the collision energy of polarized protons at RHIC. The limits of present hardware are examined with a particular emphasis on the quench training performance of magnets. Ignoring the limits of the DX magnets, the short-sample currents for the main arc (8 cm) dipoles could allow an increase of more than 30%, however we estimate 400 to 500 training quenches for the just 8 cm dipoles to… more
Date: January 1, 2011
Creator: MacKay, W. W. & Tepikian, S.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Transfer of polarized 3He ions in the AtR beam transfer line

Description: In addition to collisions of electrons with various unpolarized ion species as well as polarized protons, the proposed electron-hadron collider (eRHIC) will facilitate the collisions of electrons with polarized {sup 3}He ions. The AGS is the last acceleration stage, before injection into one of the RHIC's collider ring for final acceleration. The AtR (AGS to RHIC) transfer line will be utilized to transport the polarized {sup 3}He ions from AGS into one of the RHIC's collider rings. Some of the… more
Date: May 20, 2012
Creator: Tsoupas, N.; MacKay, W. W.; Meot, F.; Roser, T. & Trbojevic, D.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Near integer tune for polarization preservation in the AGS

Description: The high energy (T = 250 GeV) polarized proton beam experiments performed in RHIC, require high polarization of the beam. In order to preserve the polarization of the proton beam, during the acceleration in the AGS, which is the pre-injector to RHIC, we have installed in AGS two partial helical magnets which minimize the loss of the beam polarization caused by the various intrinsic spin resonances occurring during the proton acceleration. The minimization of the polarization loss during the acc… more
Date: May 20, 2012
Creator: Tsoupas, N.; Ahrens, L.; Bai, M.; Brown, K.; Glenn, J. W.; Huang, H. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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