PAC2013 - List of Authors (Raparia, D.)

Paper

Title

Page

The RHIC Polarized Source Upgrade

49

A. Zelenski, G. Atoian, J.M. Fite, D. Raparia, J. Ritter, D. Steski
BNL, Upton, Long Island, New York, USA
V.I. Davydenko, A.A. Ivanov, A. Kolmogorov
BINP SB RAS, Novosibirsk, Russia
V.S. Klenov, V. Zubets
RAS/INR, Moscow, Russia

A novel polarization technique had been successfully implemented in the RHIC polarized H⁻ ion source upgrade to higher intensity and polarization for use in the RHIC polarization physics program at enhanced luminosity RHIC operation. In this technique a primary proton beam inside the high magnetic field solenoid is produced by charge-exchange ionization of the atomic hydrogen beam in the He-gas ionizer cell. Further proton polarization is produced in the process of polarized electron capture from the optically-pumped Rb vapour. Formation of the proton beam is produced by four-electrode spherical multi-aperture ion-optical system with geometrical focusing. Polarized beam intensity produced in the source exceeds 4.0 mA.Maximum polarization of 84% was measured at 0.3 mA beam intensity and 80% at 0.5 mA in 200 MeV polarimeter. This high beam intensity allowed reduction of the longitudinal and transverse beam emittances at injection to AGS to reduce polarization losses in AGS. The source reliably delivered polarized beam for 2013 run in RHIC at √s=510 GeV. This was a major contribution to the RHIC polarization increase to over 60 % for colliding beams.

Slides MOOBA2 [6.481 MB]

TUPHO01

The RHIC E-Lens Test Bench Experimental Results

580

X. Gu, Z. Altinbas, J.N. Aronson, E.N. Beebe, W. Fischer, D.M. Gassner, K. Hamdi, J. Hock, L.T. Hoff, P. Kankiya, R.F. Lambiase, Y. Luo, M. Mapes, J.-L. Mi, T.A. Miller, C. Montag, S. Nemesure, M. Okamura, R.H. Olsen, A.I. Pikin, D. Raparia, P.J. Rosas, J. Sandberg, Y. Tan, C. Theisen, P. Thieberger, J.E. Tuozzolo, W. Zhang
BNL, Upton, Long Island, New York, USA

Funding: Work supported by U.S. DOE under contract No DE-AC02-98CH10886 with the U.S. Department of Energy.
To commission some of the hard and software for the RHIC electron lenses (e-lenses), a test bench was built based on the EBIS test stand at BNL. After several months of operation, the electron gun, collector, high-voltage gun modulator, instrumentation, partial control system, and several software applications have been tested. The nominal DC beam current of 0.85 A was demonstrated and the electron beam transverse profiles were verified to be Gaussian. Some e-lens power supplies and the electronics for current measurement were also evaluated on the test bench. The properties of the cathode and the profile of the beam are measured. In this paper, we will present some experimental results.

Paper	Title	Page
MOOBA2	The RHIC Polarized Source Upgrade	49
	A. Zelenski, G. Atoian, J.M. Fite, D. Raparia, J. Ritter, D. Steski BNL, Upton, Long Island, New York, USA V.I. Davydenko, A.A. Ivanov, A. Kolmogorov BINP SB RAS, Novosibirsk, Russia V.S. Klenov, V. Zubets RAS/INR, Moscow, Russia
	A novel polarization technique had been successfully implemented in the RHIC polarized H⁻ ion source upgrade to higher intensity and polarization for use in the RHIC polarization physics program at enhanced luminosity RHIC operation. In this technique a primary proton beam inside the high magnetic field solenoid is produced by charge-exchange ionization of the atomic hydrogen beam in the He-gas ionizer cell. Further proton polarization is produced in the process of polarized electron capture from the optically-pumped Rb vapour. Formation of the proton beam is produced by four-electrode spherical multi-aperture ion-optical system with geometrical focusing. Polarized beam intensity produced in the source exceeds 4.0 mA.Maximum polarization of 84% was measured at 0.3 mA beam intensity and 80% at 0.5 mA in 200 MeV polarimeter. This high beam intensity allowed reduction of the longitudinal and transverse beam emittances at injection to AGS to reduce polarization losses in AGS. The source reliably delivered polarized beam for 2013 run in RHIC at √s=510 GeV. This was a major contribution to the RHIC polarization increase to over 60 % for colliding beams.
	Slides MOOBA2 [6.481 MB]

TUPHO01	The RHIC E-Lens Test Bench Experimental Results	580
	X. Gu, Z. Altinbas, J.N. Aronson, E.N. Beebe, W. Fischer, D.M. Gassner, K. Hamdi, J. Hock, L.T. Hoff, P. Kankiya, R.F. Lambiase, Y. Luo, M. Mapes, J.-L. Mi, T.A. Miller, C. Montag, S. Nemesure, M. Okamura, R.H. Olsen, A.I. Pikin, D. Raparia, P.J. Rosas, J. Sandberg, Y. Tan, C. Theisen, P. Thieberger, J.E. Tuozzolo, W. Zhang BNL, Upton, Long Island, New York, USA
	Funding: Work supported by U.S. DOE under contract No DE-AC02-98CH10886 with the U.S. Department of Energy. To commission some of the hard and software for the RHIC electron lenses (e-lenses), a test bench was built based on the EBIS test stand at BNL. After several months of operation, the electron gun, collector, high-voltage gun modulator, instrumentation, partial control system, and several software applications have been tested. The nominal DC beam current of 0.85 A was demonstrated and the electron beam transverse profiles were verified to be Gaussian. Some e-lens power supplies and the electronics for current measurement were also evaluated on the test bench. The properties of the cathode and the profile of the beam are measured. In this paper, we will present some experimental results.