PAC2013 - List of Authors (Dawson, W.C.)

Paper

Title

Page

Commissioning RHIC's Electron Lens

416

X. Gu, Z. Altinbas, M. Anerella, D. Bruno, M.R. Costanzo, W.C. Dawson, K.A. Drees, W. Fischer, B. Frak, D.M. Gassner, K. Hamdi, J. Hock, L.T. Hoff, A.K. Jain, J.P. Jamilkowski, R.F. Lambiase, Y. Luo, M. Mapes, A. Marone, C. Mi, R.J. Michnoff, T.A. Miller, M.G. Minty, C. Montag, S. Nemesure, W. Ng, D. Phillips, A.I. Pikin, S.R. Plate, P.J. Rosas, P. Sampson, J. Sandberg, L. Snydstrup, Y. Tan, R. Than, C. Theisen, P. Thieberger, J.E. Tuozzolo, P. Wanderer, 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.
In the 2013 RHIC polarized proton run, it was found that the RHIC bunch intensity has reached a limit due to the head-on beam-beam interaction at 2x10¹¹, as expected by simulations. To overcome this limitation, two electron lenses will be used for compensation. We report on the commissioning of new lattices that reduce beam-beam driven resonance driving terms, and bunch-by-bunch proton diagnostic during 2013 run. The effect of electron beam transport solenoids on the proton orbit was tested. The instrumentation for Blue electron lens was tested and electron beam was propagated from the gun to the collector. A timing system was implemented for the electron beam. Control software, machine protection and synoptic display were developed and tested during commissioning. Both Blue and Yellow electron lens superconducting magnets are installed and their field straightness was measured and corrected in the tunnel using a magnetic needle. The Yellow vacuum system and backscattered electron detectors installation are also completed now.

Slides TUOCA2 [3.466 MB]

WEPBA05

Combining Multiple BPM Measurements for Precession AC Dipole Bump Closure

892

P. Oddo, M. Bai, W.C. Dawson, J. Kewisch, Y. Makdisi, C. Pai, P.H. Pile, T. Roser
BNL, Upton, Long Island, New York, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy Energy and RIKEN, Japan.
For the RHIC spin flipper to achieve a rotating field, it requires operating five AC dipoles as a pair of closed orbit bumps. One key requirement is to minimize the remnant AC dipole driven betatron oscillation outside of the spin flipper by 50dB. In the past, due to its inherent sensitivity, a single pickup with a direct-diode detector (3D) and dynamic signal analyzer (DSA) were used to measure bump closure by measuring the remnant oscillations. This however proved to be inadequate, as the betatron phase advance between the AC dipoles is non-zero. A method of combining multiple BPMs into a sensitive measure of bump closure has been developed and will be tested during RHIC polarized proton operation in 2013. This technique as well as the experimental results will be presented.

Paper	Title	Page
TUOCA2	Commissioning RHIC's Electron Lens	416
	X. Gu, Z. Altinbas, M. Anerella, D. Bruno, M.R. Costanzo, W.C. Dawson, K.A. Drees, W. Fischer, B. Frak, D.M. Gassner, K. Hamdi, J. Hock, L.T. Hoff, A.K. Jain, J.P. Jamilkowski, R.F. Lambiase, Y. Luo, M. Mapes, A. Marone, C. Mi, R.J. Michnoff, T.A. Miller, M.G. Minty, C. Montag, S. Nemesure, W. Ng, D. Phillips, A.I. Pikin, S.R. Plate, P.J. Rosas, P. Sampson, J. Sandberg, L. Snydstrup, Y. Tan, R. Than, C. Theisen, P. Thieberger, J.E. Tuozzolo, P. Wanderer, 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. In the 2013 RHIC polarized proton run, it was found that the RHIC bunch intensity has reached a limit due to the head-on beam-beam interaction at 2x10¹¹, as expected by simulations. To overcome this limitation, two electron lenses will be used for compensation. We report on the commissioning of new lattices that reduce beam-beam driven resonance driving terms, and bunch-by-bunch proton diagnostic during 2013 run. The effect of electron beam transport solenoids on the proton orbit was tested. The instrumentation for Blue electron lens was tested and electron beam was propagated from the gun to the collector. A timing system was implemented for the electron beam. Control software, machine protection and synoptic display were developed and tested during commissioning. Both Blue and Yellow electron lens superconducting magnets are installed and their field straightness was measured and corrected in the tunnel using a magnetic needle. The Yellow vacuum system and backscattered electron detectors installation are also completed now.
	Slides TUOCA2 [3.466 MB]

WEPBA05	Combining Multiple BPM Measurements for Precession AC Dipole Bump Closure	892
	P. Oddo, M. Bai, W.C. Dawson, J. Kewisch, Y. Makdisi, C. Pai, P.H. Pile, T. Roser BNL, Upton, Long Island, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy Energy and RIKEN, Japan. For the RHIC spin flipper to achieve a rotating field, it requires operating five AC dipoles as a pair of closed orbit bumps. One key requirement is to minimize the remnant AC dipole driven betatron oscillation outside of the spin flipper by 50dB. In the past, due to its inherent sensitivity, a single pickup with a direct-diode detector (3D) and dynamic signal analyzer (DSA) were used to measure bump closure by measuring the remnant oscillations. This however proved to be inadequate, as the betatron phase advance between the AC dipoles is non-zero. A method of combining multiple BPMs into a sensitive measure of bump closure has been developed and will be tested during RHIC polarized proton operation in 2013. This technique as well as the experimental results will be presented.