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Polarized protons from the source to 70 GeV

Description: This energy range covers the current project at the AGS and extends well beyond it. I shall report on our learning experience at BNL, discuss the potential for improvement, and the limitations of extending the AGS resonance jumping technique beyond 25 GeV.
Date: January 1, 1985
Creator: Makdisi, Y.I.
Partner: UNT Libraries Government Documents Department

Experimental results on spin physics at the AGS

Description: The AGS ran with polarized protons towards the end of 1985 and through the first two months of 1986. This comprised commissioning periods interleaved with two runs for physics at 13.5 GeV/c with beam polarization of 50 to 60%, and 18.5 GeV/c with an average beam polarization of 40%. Later, the AGS polarized beam reached peak energy of 22 GeV/c and polarization of 46%. This article describes the various spin related experimental efforts since the VI Symposium at Marseille. These will be grouped into those using unpolarized beams and the rest are the polarized proton beam users. Afterwards the future of the program is described as extensions of current experiments in addition to other measurements that are yet to be proposed.
Date: January 1, 1986
Creator: Makdisi, Y.I.
Partner: UNT Libraries Government Documents Department

The BNL Relativistic Heavy Ion Collider (A new frontier in nuclear physics)

Description: The Relativistic Heavy Ion Collider at Brookhaven is in its second year of construction with a target date for completion in late 1997. In this report, I will describe the status of the project, the designated milestones and the capabilities of this collider that set it apart as the premier facility to probe the new frontier of nuclear matter under extreme temperatures and densities. Two large detectors and a pair of smaller detectors, which are in various stages of approval, form the experimental program at this point. They provide a complementary set of probes to study quark gluon plasma formation through different signatures. The two ring design of this collider allows for collisions between different ion species ranging from protons to gold.
Date: January 1, 1992
Creator: Makdisi, Y.I.
Partner: UNT Libraries Government Documents Department

Polarized protons at RHIC

Description: The approval for construction of the Relativistic Heavy Ion Collider (RHIC) provides a potential opportunity to collide polarized proton beams at energies up to 500 GeV in the center of mass and high luminosities approaching 2 {times} 10{sup 32}/cm{sup 2}/sec. This capability is enhanced by the fact that the AGS has already accelerated polarized protons and relies on the newly completed Accumulator/Booster for providing the required polarized proton intensity and a system of spin rotators (Siberian snakes) to retain the polarization. The RHIC Spin Collaboration was formed and submitted a Letter of Intent to construct this polarized collider capability and utilize its physics opportunities. In this presentation, I will discuss the plans to upgrade the AGS, the proposed layout of the RHIC siberian snakes, and timetables. The physics focus is the measurement of the spin dependent parton distributions with such accessible probes including high p(t) jets, direct photons, and Drell Yan. The attainable sensitivities and the progress that has been reached in defining the detector requirements will be outlined.
Date: January 1, 1992
Creator: Makdisi, Y.
Partner: UNT Libraries Government Documents Department

Measuring the proton beam polarization from the source to RHIC.

Description: Polarimeters are necessary tools for measuring the beam polarization during the acceleration process as well as a yardstick for performing spin physics experiments. In what follows, I will describe the principles of measuring the proton beam polarization and the techniques that are employed at various energies. I will present a tour of the polarimetry employed at the BNL Relativistic Heavy Ion collider (RHIC) polarized proton complex as it spans the full spectrum from the source to collider energies.
Date: September 10, 2007
Creator: Makdisi,Y.
Partner: UNT Libraries Government Documents Department

Beam catcher/dump

Description: A simple, low cost aperture limiting device with an absorber block has been developed and installed in the AGS ring at Brookhaven National Laboratory. The device intercepts injection tails, transition losses, and the inward spiraling beam of an aborted acceleration or extraction cycle. The resultant consolidation of losses at one point reduces activation of components around the ring and radiation exposure to personnel. 3 refs., 6 figs.
Date: January 1, 1985
Creator: Makdisi, Y.; Rodger, E.; Glenn, J.W. & Brown, K.
Partner: UNT Libraries Government Documents Department

Asymmetry in inclusive {pi}{sup {+-}}, p production at 22 GeV, BNL E925

Description: Preliminary results from Experiment E925 on inclusive pion asymmetries from a 22 GeV/c polarized proton beam on a carbon target show significant asymmetries for {pi}{sup {+-}} production similar to those observed earlier at the ZGS and Fermilab with beams of 12 and 200 GeV respectively. This experiment demonstrates the viability of using the analyzing power in inclusive pion production for high energy beam polarimetry at RHIC. Inclusive proton asymmetries are consistent with zero.
Date: December 31, 1998
Creator: Makdisi, Y.; Allgower, C. & Bai, M.
Partner: UNT Libraries Government Documents Department

SPIN DEPENDENCE IN ELASTIC SCATTERING IN THE CNI REGION.

Description: The interference of the electromagnetic spin-flip amplitude with a hadronic spin-nonflip amplitude in the elastic scattering of hadrons leads to significant spin dependencies at very low 4-momentum transfer t (0.001 < |t| < 0.01 (GeV/c){sup 2}). This kinematical region is known as the Coulomb Nuclear Interference (CNI) region. First results on spin effects in polarized proton-proton elastic scattering in the CNI region at 100 GeV from the 2004 polarized proton run at RHIC are presented. Preliminary results on A{sub N} in the elastic scattering of polarized protons off a carbon target over a wide energy range from 4 GeV to 100 GeV from AGS and RHIC are presented as well. These results allow us to further investigate the spin dependence in elastic scattering and the mechanisms at work.
Date: October 10, 2004
Creator: BRAVAR, A.; MAKDISI, Y. & AL., ET
Partner: UNT Libraries Government Documents Department

Conversion of the BNL 200 MeV Linac to H/sup -/ and polarized H/sup -/ acceleration

Description: Planning for the conversion of the AGS Linac to H/sup -/ acceleration was begun in 1979; installation was completed in 1983. Discussion of this work and of the operational experience will be presented. The AGS Polarized Beam Project was begun in 1980. The design of the new H/sup -/ polarized source, the low Energy Beam Transport line (LEBT), and Radio-Frequency Quadrupole (RFQ) will be described. Current status and future plans will be presented. 14 references, 5 figures.
Date: January 1, 1984
Creator: Witkover, R.L.; Alessi, J.; Barton, D.; Kponou, A.; Makdisi, Y. & McNerney, A.
Partner: UNT Libraries Government Documents Department

Acceleration of polarized H/sup -/ in the BNL 200 MeV Linac

Description: The AGS Polarized Beam Project was started in 1980. The first beam was accelerated in March 1984, followed by commissioning studies and a high energy physics run at 16.5 GeV at an average 30% polarization. The Linac portion of the project included a new polarized H/sup -/ ion source and a Radio-Frequency Quadrupole (RFQ). These will be described as will the design of the new Low Energy Beam Transport (LEBT) line and beam instrumentation for the Linac. Operational results, current status and future plans will be discussed. 13 refs., 6 figs.
Date: January 1, 1985
Creator: Makdisi, Y.; Witkover, R.; Alessi, J.; Brown, H.; Barton, D.; Kponou, A. et al.
Partner: UNT Libraries Government Documents Department

p-Carbon polarimetry at RHIC.

Description: The polarization measurement through elastic ({rvec p},C) reaction plays a crucial role in the polarized proton beam operation of Relativistic Heavy Ion collider at Brookhaven National Laboratory. As well as measuring the polarization, the unknown analyzing power A{sub N} of elastic ({rvec p},C) is determined as well in combination with the absolute polarization measurement by a H-jet polarimeter. The systematic uncertainty of the Run05 measurements are discussed as well as introducing the experimental apparatus of the polarimeter system.
Date: September 10, 2007
Creator: Nakagawa,I.; Makdisi,Y.; Alekseev, I.; Bazilesky, A.; Bravar, A.; Bunce, G. et al.
Partner: UNT Libraries Government Documents Department

ABSOLUTE MEASUREMENT OF THE POLARIZATION OF HIGH ENERGY PROTON BEAMS AT RHIC

Description: The spin physics program at the Relativistic Heavy Ion Collider (RHIC) requires knowledge of the beam polarization to better than 5%. Such a goal is made the more difficult by the lack of knowledge of the analyzing power of high energy nuclear physics processes. To overcome this, a polarized hydrogen jet target was constructed and installed at one intersection region in RHIC where it intersects both beams and utilizes the precise knowledge of the jet atomic hydrogen beam polarization to measure the analyzing power in proton-proton elastic scattering in the Nuclear Coulomb Interference (CNI) region at the prescribed RHIC proton beam energy. The reverse reaction is used to assess the absolute beam polarization. Simultaneous measurements taken with fast high statistics polarimeters that measure the p-Carbon elastic scattering process also in the CNI region use the jet results to calibrate the latter.
Date: June 25, 2007
Creator: MAKDISI,Y.; BRAVAR, A. BUNCE, G. GILL, R.; HUANG, H. & AL., ET
Partner: UNT Libraries Government Documents Department

Preliminary results on single spin asymmetry measurements in inclusive p + p reactions at high P/sub perpendicular to/ and 16. 5 GeV/c

Description: Preliminary results are presented on the scattering asymmetries of pions, kaons, and protons produced inclusively from a 16.5 GeV/c polarized proton beam incident on an unpolarized hydrogen target. The data are for transverse momenta between 1.0 and 2.7 GeV/c and X/sub F/ near zero. 8 references.
Date: January 1, 1984
Creator: Barton, D.; Bunce, G.; Carroll, A.; Makdisi, Y.; Remsberg, L.; Baller, B. et al.
Partner: UNT Libraries Government Documents Department

Design and operating experience with electric systems for high rate liquid argon calorimeters

Description: A number of experiments have been instrumented by an ADC scheme utilizing an integrated amplifier, a packaged delay line, the difference of two samples taken Before and After the signal exits the delay, and a multiplexer to a single ADC for a system. Design features, operating peculiarities, and experience to date are discussed.
Date: January 1, 1979
Creator: Droege, T.F.; Hibbard, M.C.; Nelson, C.A. Jr.; Thompson, P.A.; Makdisi, Y. & Lipton, R.
Partner: UNT Libraries Government Documents Department

Studies and proposed changes to the RHIC p-Carbon polarimeters for the upcoming RUN-11

Description: The RHIC polarized proton complex utilizes polarimeters in each of the Blue and Yellow beams that measure the beam polarization through the p-Carbon elastic scattering process in the Coulomb Nuclear Interference kinematic region. This along with a Polarized Hydrogen Jet Target that utilizes the proton-proton elastic scattering process to first measure the analyzing power of the reaction and using the reverse process to measure the beam polarization. The latter is used to calibrate the p-Carbon polarimeters at the desired beam energy. In Run 9 RHIC ran with beams at center-of-mass energies of 200 and 500 GeV respectively. The higher beam intensities as well as the fact that the 250 GeV beam size is much smaller than that at 100 GeV resulted in significantly higher rates seen by the polarimeters and led to observed instability. In this paper, we will discuss the problems encountered and the tests that were carried out using the AGS as a proxy in an attempt to solve the problems and the path forward we took towards the upcoming polarized proton Run11.
Date: September 27, 2010
Creator: Makdisi, Y.; Alekseev, I.; Aschenauer, E.; Atoian, G.; Bazilevsky, A.; Gill, R. et al.
Partner: UNT Libraries Government Documents Department

A new luminescence beam profile monitor for intense proton and heavy ion beams

Description: A new luminescence beam profile monitor is realized in the polarized hydrogen gas jet target at the Relativistic Heavy Ion Collider (RHIC) facility. In addition to the spin polarization of the proton beam being routinely measured by the hydrogen gas jet, the luminescence produced by beam-hydrogen excitation leads to a strong Balmer series lines emission. A selected hydrogen Balmer line is spectrally filtered and imaged to produce the transverse RHIC proton beam shape with unprecedented details on the RHIC beam profile. Alternatively, when the passage of the high energy RHIC gold ion beam excited only the residual gas molecules in the beam path, sufficient ion beam induced luminescence is produced and the transverse gold ion beam profile is obtained. The measured transverse beam sizes and the calculated emittances provide an independent confirmation of the RHIC beam characteristics and to verify the emittance conservation along the RHIC accelerator. This optical beam diagnostic technique by making use of the beam induced fluorescence from injected or residual gas offers a truly noninvasive particle beam characterization, and provides a visual observation of proton and heavy ion beams. Combined with a longitudinal bunch measurement system, a 3-dimensional spatial particle beam profile can be reconstructed tomographically.
Date: October 1, 2008
Creator: Tsang,T.; Bellavia, S.; Connolly, R.; Gassner, D.; Makdisi, Y.; Russo, T. et al.
Partner: UNT Libraries Government Documents Department

ABSOLUTE POLARIMETRY AT RHIC.

Description: Precise and absolute beam polarization measurements are critical for the RHIC spin physics program. Because all experimental spin-dependent results are normalized by beam polarization, the normalization uncertainty contributes directly to final physics uncertainties. We aimed to perform the beam polarization measurement to an accuracy Of {Delta}P{sub beam}/P{sub beam} < 5%. The absolute polarimeter consists of Polarized Atomic Hydrogen Gas Jet Target and left-right pairs of silicon strip detectors and was installed in the RHIC-ring in 2004. This system features proton-proton elastic scattering in the Coulomb nuclear interference (CNI) region. Precise measurements of the analyzing power A{sub N} of this process has allowed us to achieve {Delta}P{sub beam}/P{sub beam} = 4.2% in 2005 for the first long spin-physics run. In this report, we describe the entire set up and performance of the system. The procedure of beam polarization measurement and analysis results from 2004-2005 are described. Physics topics of AN in the CNI region (four-momentum transfer squared 0.001 < -t < 0.032 (GeV/c){sup 2}) are also discussed. We point out the current issues and expected optimum accuracy in 2006 and the future.
Date: September 10, 2007
Creator: OKADA; BRAVAR, A.; BUNCE, G.; GILL, R.; HUANG, H.; MAKDISI, Y. et al.
Partner: UNT Libraries Government Documents Department

RHIC spin flipper commissioning results

Description: The five AC dipole RHIC spin flipper design in the RHIC Blue ring was first tested during the RHIC 2012 polarized proton operation. The advantage of this design is to eliminate the vertical coherent betatron oscillations outside the spin flipper. The closure of each ac dipole vertical bump was measured with orbital response as well as spin. The effect of the rotating field on the spin motion by the spin flipper was also confirmed by measuring the suppressed resonance at Q{sub s} = 1 - Q{sub osc}.
Date: May 20, 2012
Creator: M., Bai; Roser, T.; Dawson, C.; Kewisch, J.; Makdisi, Y.; Oddo, P. et al.
Partner: UNT Libraries Government Documents Department

Relativistic Heavy Ion Collider spin flipper commissioning plan

Description: The commissioning of the RHIC spin flipper in the RHIC Blue ring during the RHIC polarized proton run in 2009 showed the detrimental effects of global vertical coherent betatron oscillation induced by the 2-AC dipole plus 4-DC dipole configuration. This global orbital coherent oscillation of the RHIC beam in the Blue ring in the presence of collision modulated the beam-beam interaction between the two RHIC beams and affected Yellow beam lifetime. The experimental data at injection with different spin tunes by changing the snake current also demonstrated that it was not possible to induce a single isolated spin resonance with the global vertical coherent betatron oscillation excited by the two AC dipoles. Hence, RHIC spin flipper was re-designed to eliminate the coherent vertical betatron oscillation outside the spin flipper by adding three additional AC dipoles. This paper presents the experimental results as well as the new design.
Date: September 27, 2010
Creator: Bai, M.; Dawson, C.; Makdisi, Y.; Meng, W.; Meot, F.; Oddo, P. et al.
Partner: UNT Libraries Government Documents Department