IPAC2019 - List of Authors (Bruno, D.)

Paper	Title	Page
MOPMP046	Mitigation of Persistent Current Effects in the RHIC Superconducting Magnets	548
	C. Liu, D. Bruno, A. Marusic, M.G. Minty, P. Thieberger BNL, Upton, Long Island, New York, USA X. Wang LBNL, Berkeley, California, USA
	Funding: This work was supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy. Persistent currents in superconducting magnet introduce errors in the magnetic fields especially at low operating currents. In addition, their decay cause magnetic field variations therefore drifts of beam orbits, tunes and chromaticities. To reduce field errors and suppress magnetic field variations, new magnetic cycles were proposed for low energy beam operation at RHIC. In the new magnetic cycles, the magnet current oscillates around the operating current with diminishing amplitude a few times before it settles. The new magnetic cycle has been demonstrated experimentally to reduce field errors and the amplitude of magnetic field variations significantly and is essential for the ongoing RHIC Beam Energy Scan II (BES-II) program. This article will present beam-based experimental studies of the persistent current effects with the new magnetic cycle, and discuss its application in RHIC and accelerators based on superconducting magnet in general.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP046
About •	paper received ※ 30 April 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019
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MOPRB072	eRHIC in Electron-Ion Operation	738
	W. Fischer, E.C. Aschenauer, E.N. Beebe, M. Blaskiewicz, K.A. Brown, D. Bruno, K.A. Drees, C.J. Gardner, H. Huang, T. Kanesue, C. Liu, M. Mapes, G.T. McIntyre, M.G. Minty, C. Montag, S.K. Nayak, M. Okamura, V. Ptitsyn, D. Raparia, J. Sandberg, K.S. Smith, P. Thieberger, N. Tsoupas, J.E. Tuozzolo, F.J. Willeke, A. Zaltsman, A. Zelenski 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. The design effort for the electron-ion collider eRHIC has concentrated on electron-proton collisions at the highest luminosities over the widest possible energy range. The present design also provides for electron-nucleon peak luminosities of up to 4.7·10³³ cm^-2s⁻¹ with strong hadron cooling, and up to 1.7·10³³ cm^-2s⁻¹ with stochastic cooling. Here we discuss the performance limitations and design choices for electron-ion collisions that are different from the electron-proton collisions. These include the ion bunch preparation in the injector chain, acceleration and intrabeam scattering in the hadron ring, path length adjustment and synchronization with the electron ring, stochastic cooling upgrades, machine protection upgrades, and operation with polarized electron beams colliding with either unpolarized ion beams or polarized He-3.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB072
About •	paper received ※ 14 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
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MOPRB085	First Results from Commissioning of Low Energy RHIC Electron Cooler (LEReC)	769
	D. Kayran, Z. Altinbas, D. Bruno, M.R. Costanzo, K.A. Drees, A.V. Fedotov, W. Fischer, M. Gaowei, D.M. Gassner, X. Gu, R.L. Hulsart, P. Inacker, J.P. Jamilkowski, Y.C. Jing, J. Kewisch, C.J. Liaw, C. Liu, J. Ma, K. Mernick, T.A. Miller, M.G. Minty, L.K. Nguyen, M.C. Paniccia, I. Pinayev, V. Ptitsyn, V. Schoefer, S. Seletskiy, F. Severino, T.C. Shrey, L. Smart, K.S. Smith, A. Sukhanov, P. Thieberger, J.E. Tuozzolo, E. Wang, G. Wang, A. Zaltsman, H. Zhao, Z. Zhao 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. The brand new non-magnetized bunched beam electron cooler (LEReC) [1] has been built to provide luminosity improvement for Beam Energy Scan II (BES-II) physics program at the Relativistic Heavy Ion Collider (RHIC) BES-II [2]. The LEReC accelerator includes a photocathode DC gun, a laser system, a photocathode delivery system, magnets, beam diagnostics, a SRF booster cavity, and a set of Normal Conducting RF cavities to provide sufficient flexibility to tune the beam in the longitudinal phase space. This high-current high-power accelerator was successfully commissioned in period of March -September 2018. Beam quality suitable for cooling has been demonstrated. In this paper we discuss beam commissioning results and experience learned during commissioning. [1] A. Fedotov et al., ’Status of bunched beam electron cooler LEReC’ in these proceedings. [2] C.Liu et al., ’Improving luminosity of Beam Energy Scan II at RHIC’ in these proceedings.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB085
About •	paper received ※ 15 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Mitigation of Persistent Current Effects in the RHIC Superconducting Magnets

548

C. Liu, D. Bruno, A. Marusic, M.G. Minty, P. Thieberger
BNL, Upton, Long Island, New York, USA
X. Wang
LBNL, Berkeley, California, USA

Funding: This work was supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy.
Persistent currents in superconducting magnet introduce errors in the magnetic fields especially at low operating currents. In addition, their decay cause magnetic field variations therefore drifts of beam orbits, tunes and chromaticities. To reduce field errors and suppress magnetic field variations, new magnetic cycles were proposed for low energy beam operation at RHIC. In the new magnetic cycles, the magnet current oscillates around the operating current with diminishing amplitude a few times before it settles. The new magnetic cycle has been demonstrated experimentally to reduce field errors and the amplitude of magnetic field variations significantly and is essential for the ongoing RHIC Beam Energy Scan II (BES-II) program. This article will present beam-based experimental studies of the persistent current effects with the new magnetic cycle, and discuss its application in RHIC and accelerators based on superconducting magnet in general.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP046

About •

paper received ※ 30 April 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPRB072

eRHIC in Electron-Ion Operation

738

W. Fischer, E.C. Aschenauer, E.N. Beebe, M. Blaskiewicz, K.A. Brown, D. Bruno, K.A. Drees, C.J. Gardner, H. Huang, T. Kanesue, C. Liu, M. Mapes, G.T. McIntyre, M.G. Minty, C. Montag, S.K. Nayak, M. Okamura, V. Ptitsyn, D. Raparia, J. Sandberg, K.S. Smith, P. Thieberger, N. Tsoupas, J.E. Tuozzolo, F.J. Willeke, A. Zaltsman, A. Zelenski
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.
The design effort for the electron-ion collider eRHIC has concentrated on electron-proton collisions at the highest luminosities over the widest possible energy range. The present design also provides for electron-nucleon peak luminosities of up to 4.7·10³³ cm^-2s⁻¹ with strong hadron cooling, and up to 1.7·10³³ cm^-2s⁻¹ with stochastic cooling. Here we discuss the performance limitations and design choices for electron-ion collisions that are different from the electron-proton collisions. These include the ion bunch preparation in the injector chain, acceleration and intrabeam scattering in the hadron ring, path length adjustment and synchronization with the electron ring, stochastic cooling upgrades, machine protection upgrades, and operation with polarized electron beams colliding with either unpolarized ion beams or polarized He-3.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB072

About •

paper received ※ 14 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPRB085

First Results from Commissioning of Low Energy RHIC Electron Cooler (LEReC)

769

D. Kayran, Z. Altinbas, D. Bruno, M.R. Costanzo, K.A. Drees, A.V. Fedotov, W. Fischer, M. Gaowei, D.M. Gassner, X. Gu, R.L. Hulsart, P. Inacker, J.P. Jamilkowski, Y.C. Jing, J. Kewisch, C.J. Liaw, C. Liu, J. Ma, K. Mernick, T.A. Miller, M.G. Minty, L.K. Nguyen, M.C. Paniccia, I. Pinayev, V. Ptitsyn, V. Schoefer, S. Seletskiy, F. Severino, T.C. Shrey, L. Smart, K.S. Smith, A. Sukhanov, P. Thieberger, J.E. Tuozzolo, E. Wang, G. Wang, A. Zaltsman, H. Zhao, Z. Zhao
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.
The brand new non-magnetized bunched beam electron cooler (LEReC) [1] has been built to provide luminosity improvement for Beam Energy Scan II (BES-II) physics program at the Relativistic Heavy Ion Collider (RHIC) BES-II [2]. The LEReC accelerator includes a photocathode DC gun, a laser system, a photocathode delivery system, magnets, beam diagnostics, a SRF booster cavity, and a set of Normal Conducting RF cavities to provide sufficient flexibility to tune the beam in the longitudinal phase space. This high-current high-power accelerator was successfully commissioned in period of March -September 2018. Beam quality suitable for cooling has been demonstrated. In this paper we discuss beam commissioning results and experience learned during commissioning.
[1] A. Fedotov et al., ’Status of bunched beam electron cooler LEReC’ in these proceedings.
[2] C.Liu et al., ’Improving luminosity of Beam Energy Scan II at RHIC’ in these proceedings.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB085

About •

paper received ※ 15 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)