NAPAC2019 - List of Authors (Drees, K.A.)

Paper	Title	Page
MOOHC2	The US Electron Ion Collider Accelerator Designs	1
	A. Seryi, S.V. Benson, S.A. Bogacz, P.D. Brindza, M.W. Bruker, A. Camsonne, E. Daly, P. Degtiarenko, Y.S. Derbenev, M. Diefenthaler, J. Dolbeck, R. Ent, R. Fair, D. Fazenbaker, Y. Furletova, B.R. Gamage, D. Gaskell, R.L. Geng, P. Ghoshal, J.M. Grames, J. Guo, F.E. Hannon, L. Harwood, S. Henderson, H. Huang, A. Hutton, K. Jordan, D.H. Kashy, A.J. Kimber, G.A. Krafft, R. Lassiter, R. Li, F. Lin, M.A. Mamun, F. Marhauser, R. McKeown, T.J. Michalski, V.S. Morozov, P. Nadel-Turonski, E.A. Nissen, G.-T. Park, H. Park, M. Poelker, T. Powers, R. Rajput-Ghoshal, R.A. Rimmer, Y. Roblin, D. Romanov, P. Rossi, T. Satogata, M.F. Spata, R. Suleiman, A.V. Sy, C. Tennant, H. Wang, S. Wang, C. Weiss, M. Wiseman, W. Wittmer, R. Yoshida, H. Zhang, S. Zhang, Y. Zhang, Z.W. Zhao JLab, Newport News, Virginia, USA D.T. Abell, D.L. Bruhwiler, I.V. Pogorelov RadiaSoft LLC, Boulder, Colorado, USA E.C. Aschenauer, G. Bassi, J. Beebe-Wang, J.S. Berg, M. Blaskiewicz, A. Blednykh, J.M. Brennan, S.J. Brooks, K.A. Brown, K.A. Drees, A.V. Fedotov, W. Fischer, D.M. Gassner, W. Guo, Y. Hao, A. Hershcovitch, H. Huang, W.A. Jackson, J. Kewisch, A. Kiselev, V. Litvinenko, C. Liu, H. Lovelace III, Y. Luo, F. Méot, M.G. Minty, C. Montag, R.B. Palmer, B. Parker, S. Peggs, V. Ptitsyn, V.H. Ranjbar, G. Robert-Demolaize, T. Roser, S. Seletskiy, V.V. Smaluk, K.S. Smith, S. Tepikian, P. Thieberger, D. Trbojevic, N. Tsoupas, E. Wang, W.-T. Weng, F.J. Willeke, H. Witte, Q. Wu, W. Xu, A. Zaltsman, W. Zhang BNL, Upton, New York, USA D.P. Barber DESY, Hamburg, Germany I.V. Bazarov Cornell University, Ithaca, New York, USA G.I. Bell, J.R. Cary Tech-X, Boulder, Colorado, USA Y. Cai, Y.M. Nosochkov, A. Novokhatski, G. Stupakov, M.K. Sullivan, C.-Y. Tsai SLAC, Menlo Park, California, USA Z.A. Conway, M.P. Kelly, B. Mustapha, U. Wienands, A. Zholents ANL, Lemont, Illinois, USA S.U. De Silva, J.R. Delayen, H. Huang, C. Hyde, S. Sosa, B. Terzić ODU, Norfolk, Virginia, USA K.E. Deitrick, G.H. Hoffstaetter Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA D. Douglas Douglas Consulting, York, Virginia, USA V.G. Dudnikov, R.P. Johnson Muons, Inc, Illinois, USA B. Erdelyi, P. Piot Northern Illinois University, DeKalb, Illinois, USA J.D. Fox Stanford University, Stanford, California, USA J. Gerity, T.L. Mann, P.M. McIntyre, N. Pogue, A. Sattarov Texas A&M University, College Station, USA E. Gianfelice-Wendt, S. Nagaitsev Fermilab, Batavia, Illinois, USA Y. Hao, P.N. Ostroumov, A.S. Plastun, R.C. York FRIB, East Lansing, Michigan, USA T. Mastoridis CalPoly, San Luis Obispo, California, USA J.D. Maxwell, R. Milner, M. Musgrave MIT, Cambridge, Massachusetts, USA J. Qiang, G.L. Sabbi LBNL, Berkeley, California, USA D. Teytelman Dimtel, Redwood City, California, USA R.C. York NSCL, East Lansing, Michigan, USA
	With the completion of the National Academies of Sciences Assessment of a US Electron-Ion Collider, the prospects for construction of such a facility have taken a step forward. This paper provides an overview of the two site-specific EIC designs: JLEIC (Jefferson Lab) and eRHIC (BNL) as well as brief overview of ongoing EIC R&D.
	Slides MOOHC2 [14.774 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-MOOHC2
About •	paper received ※ 29 August 2019 paper accepted ※ 04 September 2019 issue date ※ 08 October 2019
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MOYBA4	eRHIC Design Update	18
TUPLO11	use link to see paper's listing under its alternate paper code
	C. Montag, G. Bassi, J. Beebe-Wang, J.S. Berg, M. Blaskiewicz, A. Blednykh, J.M. Brennan, S.J. Brooks, K.A. Brown, K.A. Drees, A.V. Fedotov, W. Fischer, D.M. Gassner, Y. Hao, A. Hershcovitch, C. Hetzel, D. Holmes, H. Huang, W.A. Jackson, J. Kewisch, Y. Li, C. Liu, H. Lovelace III, Y. Luo, F. Méot, M.G. Minty, R.B. Palmer, B. Parker, S. Peggs, V. Ptitsyn, V.H. Ranjbar, G. Robert-Demolaize, S. Seletskiy, V.V. Smaluk, K.S. Smith, S. Tepikian, P. Thieberger, D. Trbojevic, N. Tsoupas, S. Verdú-Andrés, W.-T. Weng, F.J. Willeke, H. Witte, Q. Wu, W. Xu, A. Zaltsman, W. Zhang BNL, Upton, New York, USA Y. Cai, Y.M. Nosochkov SLAC, Menlo Park, California, USA E. Gianfelice-Wendt Fermilab, Batavia, Illinois, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. The future electron-ion collider (EIC) aims at an electron-proton luminosity of 10³³ to 10³⁴ cm^-2 sec^-1 and a center-of-mass energy range from 20 to 140 GeV. The eRHIC design has been continuously evolving over a couple of years and has reached a considerable level of maturity. The concept is generally conservative with very few risk items which are mitigated in various ways.
	Slides MOYBA4 [5.466 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-MOYBA4
About •	paper received ※ 24 August 2019 paper accepted ※ 31 August 2019 issue date ※ 08 October 2019
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MOYBA6	Accelerator Performance During the Beam Energy Scan II at RHIC in 2019	26
	C. Liu, I. Blacker, M. Blaskiewicz, K.A. Brown, D. Bruno, K.A. Drees, A.V. Fedotov, W. Fischer, C.J. Gardner, C.E. Giorgio, X. Gu, T. Hayes, H. Huang, R.L. Hulsart, D. Kayran, N.A. Kling, Y. Luo, D. Maffei, G.J. Marr, B. Martin, A. Marusic, K. Mernick, R.J. Michnoff, M.G. Minty, C. Montag, J. Morris, C. Naylor, S. Nemesure, I. Pinayev, S. Polizzo, V.H. Ranjbar, D. Raparia, G. Robert-Demolaize, T. Roser, J. Sandberg, V. Schoefer, F. Severino, T.C. Shrey, K.S. Smith, S. Tepikian, P. Thieberger, A. Zaltsman, K. Zeno, I.Y. Zhang, W. Zhang BNL, Upton, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. RHIC provided Au-Au collisions at beam energies of 9.8, 7.3, 4.59 and 3.85 GeV/nucleon during the first year of the Beam Energy Scan II in 2019. The physics goals at the first two higher beam energies were achieved. At the two lower beam energies, bunched electron beam cooling has been demonstrated successfully. The accelerator performance was improved compared to when RHIC was operated at these energies in earlier years. This article will introduce the challenges to operate RHIC at low energies and the corresponding countermeasures, and review the improvement of accelerator performance during the operation in 2019.
	Slides MOYBA6 [6.579 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-MOYBA6
About •	paper received ※ 21 August 2019 paper accepted ※ 06 September 2019 issue date ※ 08 October 2019
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TUZBA1	Commissioning of the Electron Accelerator LEReC for Bunched Beam Cooling	330
	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, W. Xu, A. Zaltsman, H. Zhao, Z. Zhao BNL, Upton, 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 state of the art electron accelerator, LEReC, was built and commissioned at BNL. 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. Electron beam quality suitable for cooling in the Relativistic Heavy Ion Collider (RHIC) was achieved [1], which lead to the first demonstration of bunched beam electron cooling of hadron beams [2]. This presentation will discuss commissioning results, achieved beam parameters and performance of the LEReC systems. [1] D.Kayran et al., First results from Commissioning of LEReC, in Proc of IPAC2019 [2] A.Fedotov et al., First electron cooling of hadron beams using a bunched electron beam, presented at NAPAC2019
	Slides TUZBA1 [18.343 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-TUZBA1
About •	paper received ※ 27 August 2019 paper accepted ※ 31 August 2019 issue date ※ 08 October 2019
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TUZBB3	Precise Beam Velocity Matching for the Experimental Demonstration of Ion Cooling With a Bunched Electron Beam	356
	S. Seletskiy, M. Blaskiewicz, K.A. Drees, A.V. Fedotov, W. Fischer, D.M. Gassner, R.L. Hulsart, D. Kayran, J. Kewisch, K. Mernick, R.J. Michnoff, T.A. Miller, G. Robert-Demolaize, V. Schoefer, H. Song, P. Thieberger, P. Wanderer BNL, Upton, New York, USA
	The first ever electron cooling based on the RF acceleration of electron bunches was experimentally demonstrated on April 5, 2019 at the Low Energy RHIC Electron Cooler (LEReC) at BNL. The critical step in obtaining successful cooling of the Au ion bunches in the RHIC cooling sections was the accurate matching of average longitudinal velocities of electron and ion beams corresponding to a relative error of less than 5·10^-4 in the e-beam momentum. Since the electron beam kinetic energy is just 1.6 MeV, measuring the absolute e-beam energy with sufficient accuracy and eventually achieving the electron-ion velocity matching was a nontrivial task. In this paper we describe our experience with measuring and setting the e-beam energy at LEReC.
	Slides TUZBB3 [1.340 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-TUZBB3
About •	paper received ※ 26 August 2019 paper accepted ※ 31 August 2019 issue date ※ 08 October 2019
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TUPLO05	Fixed Target Operation at RHIC in 2019	542
	C. Liu, I. Blacker, M. Blaskiewicz, K.A. Brown, D. Bruno, K.A. Drees, A.V. Fedotov, W. Fischer, C.J. Gardner, C.E. Giorgio, X. Gu, T. Hayes, H. Huang, R.L. Hulsart, D. Kayran, N.A. Kling, Y. Luo, D. Maffei, G.J. Marr, B. Martin, A. Marusic, K. Mernick, R.J. Michnoff, M.G. Minty, C. Montag, J. Morris, C. Naylor, S. Nemesure, I. Pinayev, S. Polizzo, V.H. Ranjbar, D. Raparia, G. Robert-Demolaize, T. Roser, J. Sandberg, V. Schoefer, F. Severino, T.C. Shrey, K.S. Smith, S. Tepikian, P. Thieberger, A. Zaltsman, K. Zeno, I.Y. Zhang, W. Zhang BNL, Upton, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. RHIC operated in fixed target mode at beam energies 4.59, 7.3, and 31.2 GeV/nucleon in 2019 as a part of the Beam Energy Scan II program. To scrape beam halo effectively at the fixed target which is 2.05 m away from the center of the STAR detectors, lattice design with relative large beta function at STAR was implemented at the two lower energies. The kickers of the base-band tune (BBQ) measurement system were engaged to dilute the beam transversely to maintain the event rate except for 31.2 GeV/nucleon. In addition, beam orbit control, tune and chromaticity adjustments were used to level the event rate. This paper will review the operational experience of RHIC in fixed target mode at various energies.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-TUPLO05
About •	paper received ※ 21 August 2019 paper accepted ※ 15 September 2019 issue date ※ 08 October 2019
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WEPLS04	Simulations of Low Energy Au⁷⁸⁺ Losses in RHIC	775
	G. Robert-Demolaize, K.A. Drees, Y. Luo BNL, Upton, 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 RHIC Run19 BES-II program features the commissioning of the Low Energy RHIC electron Cooling (LEReC) Project, which uses electron cooling techniques to compensate for intra-beam scattering and thus to improve the luminosity lifetime. During RHIC operations at 3.85 GeV (beam energy) with LEReC, one needs to ensure that the electron beam energy is properly matched for cooling purposes: if so, some of the circulating Au-79 ions can recombine with an electron, turning into Au-78 and circulating with a large momentum offset. Part of the LEReC commissioning steps is therefore to drive a maximized number of Au-78 ions towards a chosen location of the RHIC mechanical aperture to generate particle showers that can be detected by a Recombination Monitor outside the cryostat. This article introduces the baseline lattice design, then discusses the few scenarios considered for optimizing Au-78 losses at a given location. Each scenario is then simulated using new tracking tools for generating beam loss maps.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-WEPLS04
About •	paper received ※ 27 August 2019 paper accepted ※ 03 September 2019 issue date ※ 08 October 2019
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WEPLH11	RHIC Quench Protection Diode Radiation Damage	831
	K.A. Drees, O. Biletskyi, D. Bruno, A. Di Lieto, J. Escallier, G. Heppner, C. Mi, T. Samms, J. Sandberg BNL, Upton, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. Each of RHIC’s superconducting magnets is protected by a silicon quench protection diode (QPD). In total, RHIC has over 800 diodes installed inside the cryostat close to the vacuum pipe~[RHICconfig]. After years of operation with high energy heavy ion beams we experienced a first permanently damaged QPD in the middle of our FY2016 Au Au run and a second damaged diode in the following year. In 2016 the run had to be interrupted by 19 days to replace the diode, in 2017 RHIC could still operate with a reduced ramping speed of the superconducting magnets. Both diodes were replaced and examined "cold" as well as "warm". This paper reports on what we have learned so far about the conditions leading up to the damage as well as the damage itself.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-WEPLH11
About •	paper received ※ 23 August 2019 paper accepted ※ 05 September 2019 issue date ※ 08 October 2019
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THZBA5	First Electron Cooling of Hadron Beams Using a Bunched Electron Beam	957
	A.V. Fedotov, Z. Altinbas, M. Blaskiewicz, J.M. Brennan, D. Bruno, J.C. Brutus, M.R. Costanzo, K.A. Drees, W. Fischer, J.M. Fite, M. Gaowei, D.M. Gassner, X. Gu, J. Halinski, K. Hamdi, L.R. Hammons, T. Hayes, R.L. Hulsart, P. Inacker, J.P. Jamilkowski, Y.C. Jing, P.K. Kankiya, D. Kayran, J. Kewisch, D. Lehn, C.J. Liaw, C. Liu, J. Ma, G.J. Mahler, M. Mapes, A. Marusic, K. Mernick, C. Mi, R.J. Michnoff, T.A. Miller, M.G. Minty, S.K. Nayak, L.K. Nguyen, M.C. Paniccia, I. Pinayev, S. Polizzo, V. Ptitsyn, T. Rao, G. Robert-Demolaize, T. Roser, J. Sandberg, V. Schoefer, S. Seletskiy, F. Severino, T.C. Shrey, L. Smart, K.S. Smith, H. Song, A. Sukhanov, R. Than, P. Thieberger, S.M. Trabocchi, J.E. Tuozzolo, P. Wanderer, E. Wang, G. Wang, D. Weiss, B.P. Xiao, T. Xin, W. Xu, A. Zaltsman, H. Zhao, Z. Zhao BNL, Upton, New York, USA
	Funding: Work supported by the U.S. Department of Energy. The Low Energy RHIC electron Cooler (LEReC) was recently constructed and commissioned at BNL. The LEReC is the first electron cooler based on the RF acceleration of electron bunches (previous electron coolers all used DC beams). Bunched electron beams are necessary for cooling hadron beams at high energies. The challenges of such an approach include generation of electron beams suitable for cooling, delivery of electron beams of the required quality to the cooling sections without degradation of beam emittances and energy spread, achieving required small angles between electrons and ions in the cooling sections, precise energy matching between the two beams, high-current operation of the electron accelerator, as well as several physics effects related to bunched beam cooling. Following successful commissioning of the electron accelerator in 2018, the focus of the LEReC project in 2019 was on establishing electron-ion interactions and demonstration of cooling process using electron energy of 1.6MeV (ion energy of 3.85GeV/n), which is the lowest energy of interest. Here we report on the first demonstration of Au ion cooling in RHIC using this new approach.
	Slides THZBA5 [16.417 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-THZBA5
About •	paper received ※ 16 August 2019 paper accepted ※ 31 August 2019 issue date ※ 08 October 2019
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Paper

Title

Page

The US Electron Ion Collider Accelerator Designs

1

A. Seryi, S.V. Benson, S.A. Bogacz, P.D. Brindza, M.W. Bruker, A. Camsonne, E. Daly, P. Degtiarenko, Y.S. Derbenev, M. Diefenthaler, J. Dolbeck, R. Ent, R. Fair, D. Fazenbaker, Y. Furletova, B.R. Gamage, D. Gaskell, R.L. Geng, P. Ghoshal, J.M. Grames, J. Guo, F.E. Hannon, L. Harwood, S. Henderson, H. Huang, A. Hutton, K. Jordan, D.H. Kashy, A.J. Kimber, G.A. Krafft, R. Lassiter, R. Li, F. Lin, M.A. Mamun, F. Marhauser, R. McKeown, T.J. Michalski, V.S. Morozov, P. Nadel-Turonski, E.A. Nissen, G.-T. Park, H. Park, M. Poelker, T. Powers, R. Rajput-Ghoshal, R.A. Rimmer, Y. Roblin, D. Romanov, P. Rossi, T. Satogata, M.F. Spata, R. Suleiman, A.V. Sy, C. Tennant, H. Wang, S. Wang, C. Weiss, M. Wiseman, W. Wittmer, R. Yoshida, H. Zhang, S. Zhang, Y. Zhang, Z.W. Zhao
JLab, Newport News, Virginia, USA
D.T. Abell, D.L. Bruhwiler, I.V. Pogorelov
RadiaSoft LLC, Boulder, Colorado, USA
E.C. Aschenauer, G. Bassi, J. Beebe-Wang, J.S. Berg, M. Blaskiewicz, A. Blednykh, J.M. Brennan, S.J. Brooks, K.A. Brown, K.A. Drees, A.V. Fedotov, W. Fischer, D.M. Gassner, W. Guo, Y. Hao, A. Hershcovitch, H. Huang, W.A. Jackson, J. Kewisch, A. Kiselev, V. Litvinenko, C. Liu, H. Lovelace III, Y. Luo, F. Méot, M.G. Minty, C. Montag, R.B. Palmer, B. Parker, S. Peggs, V. Ptitsyn, V.H. Ranjbar, G. Robert-Demolaize, T. Roser, S. Seletskiy, V.V. Smaluk, K.S. Smith, S. Tepikian, P. Thieberger, D. Trbojevic, N. Tsoupas, E. Wang, W.-T. Weng, F.J. Willeke, H. Witte, Q. Wu, W. Xu, A. Zaltsman, W. Zhang
BNL, Upton, New York, USA
D.P. Barber
DESY, Hamburg, Germany
I.V. Bazarov
Cornell University, Ithaca, New York, USA
G.I. Bell, J.R. Cary
Tech-X, Boulder, Colorado, USA
Y. Cai, Y.M. Nosochkov, A. Novokhatski, G. Stupakov, M.K. Sullivan, C.-Y. Tsai
SLAC, Menlo Park, California, USA
Z.A. Conway, M.P. Kelly, B. Mustapha, U. Wienands, A. Zholents
ANL, Lemont, Illinois, USA
S.U. De Silva, J.R. Delayen, H. Huang, C. Hyde, S. Sosa, B. Terzić
ODU, Norfolk, Virginia, USA
K.E. Deitrick, G.H. Hoffstaetter
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
D. Douglas
Douglas Consulting, York, Virginia, USA
V.G. Dudnikov, R.P. Johnson
Muons, Inc, Illinois, USA
B. Erdelyi, P. Piot
Northern Illinois University, DeKalb, Illinois, USA
J.D. Fox
Stanford University, Stanford, California, USA
J. Gerity, T.L. Mann, P.M. McIntyre, N. Pogue, A. Sattarov
Texas A&M University, College Station, USA
E. Gianfelice-Wendt, S. Nagaitsev
Fermilab, Batavia, Illinois, USA
Y. Hao, P.N. Ostroumov, A.S. Plastun, R.C. York
FRIB, East Lansing, Michigan, USA
T. Mastoridis
CalPoly, San Luis Obispo, California, USA
J.D. Maxwell, R. Milner, M. Musgrave
MIT, Cambridge, Massachusetts, USA
J. Qiang, G.L. Sabbi
LBNL, Berkeley, California, USA
D. Teytelman
Dimtel, Redwood City, California, USA
R.C. York
NSCL, East Lansing, Michigan, USA

With the completion of the National Academies of Sciences Assessment of a US Electron-Ion Collider, the prospects for construction of such a facility have taken a step forward. This paper provides an overview of the two site-specific EIC designs: JLEIC (Jefferson Lab) and eRHIC (BNL) as well as brief overview of ongoing EIC R&D.

Slides MOOHC2 [14.774 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-MOOHC2

About •

paper received ※ 29 August 2019 paper accepted ※ 04 September 2019 issue date ※ 08 October 2019

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MOYBA4

eRHIC Design Update

18

TUPLO11

use link to see paper's listing under its alternate paper code

C. Montag, G. Bassi, J. Beebe-Wang, J.S. Berg, M. Blaskiewicz, A. Blednykh, J.M. Brennan, S.J. Brooks, K.A. Brown, K.A. Drees, A.V. Fedotov, W. Fischer, D.M. Gassner, Y. Hao, A. Hershcovitch, C. Hetzel, D. Holmes, H. Huang, W.A. Jackson, J. Kewisch, Y. Li, C. Liu, H. Lovelace III, Y. Luo, F. Méot, M.G. Minty, R.B. Palmer, B. Parker, S. Peggs, V. Ptitsyn, V.H. Ranjbar, G. Robert-Demolaize, S. Seletskiy, V.V. Smaluk, K.S. Smith, S. Tepikian, P. Thieberger, D. Trbojevic, N. Tsoupas, S. Verdú-Andrés, W.-T. Weng, F.J. Willeke, H. Witte, Q. Wu, W. Xu, A. Zaltsman, W. Zhang
BNL, Upton, New York, USA
Y. Cai, Y.M. Nosochkov
SLAC, Menlo Park, California, USA
E. Gianfelice-Wendt
Fermilab, Batavia, Illinois, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
The future electron-ion collider (EIC) aims at an electron-proton luminosity of 10³³ to 10³⁴ cm^-2 sec^-1 and a center-of-mass energy range from 20 to 140 GeV. The eRHIC design has been continuously evolving over a couple of years and has reached a considerable level of maturity. The concept is generally conservative with very few risk items which are mitigated in various ways.

Slides MOYBA4 [5.466 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-MOYBA4

About •

paper received ※ 24 August 2019 paper accepted ※ 31 August 2019 issue date ※ 08 October 2019

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MOYBA6

Accelerator Performance During the Beam Energy Scan II at RHIC in 2019

26

C. Liu, I. Blacker, M. Blaskiewicz, K.A. Brown, D. Bruno, K.A. Drees, A.V. Fedotov, W. Fischer, C.J. Gardner, C.E. Giorgio, X. Gu, T. Hayes, H. Huang, R.L. Hulsart, D. Kayran, N.A. Kling, Y. Luo, D. Maffei, G.J. Marr, B. Martin, A. Marusic, K. Mernick, R.J. Michnoff, M.G. Minty, C. Montag, J. Morris, C. Naylor, S. Nemesure, I. Pinayev, S. Polizzo, V.H. Ranjbar, D. Raparia, G. Robert-Demolaize, T. Roser, J. Sandberg, V. Schoefer, F. Severino, T.C. Shrey, K.S. Smith, S. Tepikian, P. Thieberger, A. Zaltsman, K. Zeno, I.Y. Zhang, W. Zhang
BNL, Upton, New York, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
RHIC provided Au-Au collisions at beam energies of 9.8, 7.3, 4.59 and 3.85 GeV/nucleon during the first year of the Beam Energy Scan II in 2019. The physics goals at the first two higher beam energies were achieved. At the two lower beam energies, bunched electron beam cooling has been demonstrated successfully. The accelerator performance was improved compared to when RHIC was operated at these energies in earlier years. This article will introduce the challenges to operate RHIC at low energies and the corresponding countermeasures, and review the improvement of accelerator performance during the operation in 2019.

Slides MOYBA6 [6.579 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-MOYBA6

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paper received ※ 21 August 2019 paper accepted ※ 06 September 2019 issue date ※ 08 October 2019

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TUZBA1

Commissioning of the Electron Accelerator LEReC for Bunched Beam Cooling

330

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, W. Xu, A. Zaltsman, H. Zhao, Z. Zhao
BNL, Upton, 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 state of the art electron accelerator, LEReC, was built and commissioned at BNL. 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. Electron beam quality suitable for cooling in the Relativistic Heavy Ion Collider (RHIC) was achieved [1], which lead to the first demonstration of bunched beam electron cooling of hadron beams [2]. This presentation will discuss commissioning results, achieved beam parameters and performance of the LEReC systems.
[1] D.Kayran et al., First results from Commissioning of LEReC, in Proc of IPAC2019
[2] A.Fedotov et al., First electron cooling of hadron beams using a bunched electron beam, presented at NAPAC2019

Slides TUZBA1 [18.343 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-TUZBA1

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paper received ※ 27 August 2019 paper accepted ※ 31 August 2019 issue date ※ 08 October 2019

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TUZBB3

Precise Beam Velocity Matching for the Experimental Demonstration of Ion Cooling With a Bunched Electron Beam

356

S. Seletskiy, M. Blaskiewicz, K.A. Drees, A.V. Fedotov, W. Fischer, D.M. Gassner, R.L. Hulsart, D. Kayran, J. Kewisch, K. Mernick, R.J. Michnoff, T.A. Miller, G. Robert-Demolaize, V. Schoefer, H. Song, P. Thieberger, P. Wanderer
BNL, Upton, New York, USA

The first ever electron cooling based on the RF acceleration of electron bunches was experimentally demonstrated on April 5, 2019 at the Low Energy RHIC Electron Cooler (LEReC) at BNL. The critical step in obtaining successful cooling of the Au ion bunches in the RHIC cooling sections was the accurate matching of average longitudinal velocities of electron and ion beams corresponding to a relative error of less than 5·10^-4 in the e-beam momentum. Since the electron beam kinetic energy is just 1.6 MeV, measuring the absolute e-beam energy with sufficient accuracy and eventually achieving the electron-ion velocity matching was a nontrivial task. In this paper we describe our experience with measuring and setting the e-beam energy at LEReC.

Slides TUZBB3 [1.340 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-TUZBB3

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paper received ※ 26 August 2019 paper accepted ※ 31 August 2019 issue date ※ 08 October 2019

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TUPLO05

Fixed Target Operation at RHIC in 2019

542

C. Liu, I. Blacker, M. Blaskiewicz, K.A. Brown, D. Bruno, K.A. Drees, A.V. Fedotov, W. Fischer, C.J. Gardner, C.E. Giorgio, X. Gu, T. Hayes, H. Huang, R.L. Hulsart, D. Kayran, N.A. Kling, Y. Luo, D. Maffei, G.J. Marr, B. Martin, A. Marusic, K. Mernick, R.J. Michnoff, M.G. Minty, C. Montag, J. Morris, C. Naylor, S. Nemesure, I. Pinayev, S. Polizzo, V.H. Ranjbar, D. Raparia, G. Robert-Demolaize, T. Roser, J. Sandberg, V. Schoefer, F. Severino, T.C. Shrey, K.S. Smith, S. Tepikian, P. Thieberger, A. Zaltsman, K. Zeno, I.Y. Zhang, W. Zhang
BNL, Upton, New York, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
RHIC operated in fixed target mode at beam energies 4.59, 7.3, and 31.2 GeV/nucleon in 2019 as a part of the Beam Energy Scan II program. To scrape beam halo effectively at the fixed target which is 2.05 m away from the center of the STAR detectors, lattice design with relative large beta function at STAR was implemented at the two lower energies. The kickers of the base-band tune (BBQ) measurement system were engaged to dilute the beam transversely to maintain the event rate except for 31.2 GeV/nucleon. In addition, beam orbit control, tune and chromaticity adjustments were used to level the event rate. This paper will review the operational experience of RHIC in fixed target mode at various energies.

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reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-TUPLO05

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paper received ※ 21 August 2019 paper accepted ※ 15 September 2019 issue date ※ 08 October 2019

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WEPLS04

Simulations of Low Energy Au⁷⁸⁺ Losses in RHIC

775

G. Robert-Demolaize, K.A. Drees, Y. Luo
BNL, Upton, 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 RHIC Run19 BES-II program features the commissioning of the Low Energy RHIC electron Cooling (LEReC) Project, which uses electron cooling techniques to compensate for intra-beam scattering and thus to improve the luminosity lifetime. During RHIC operations at 3.85 GeV (beam energy) with LEReC, one needs to ensure that the electron beam energy is properly matched for cooling purposes: if so, some of the circulating Au-79 ions can recombine with an electron, turning into Au-78 and circulating with a large momentum offset. Part of the LEReC commissioning steps is therefore to drive a maximized number of Au-78 ions towards a chosen location of the RHIC mechanical aperture to generate particle showers that can be detected by a Recombination Monitor outside the cryostat. This article introduces the baseline lattice design, then discusses the few scenarios considered for optimizing Au-78 losses at a given location. Each scenario is then simulated using new tracking tools for generating beam loss maps.

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reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-WEPLS04

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paper received ※ 27 August 2019 paper accepted ※ 03 September 2019 issue date ※ 08 October 2019

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WEPLH11

RHIC Quench Protection Diode Radiation Damage

831

K.A. Drees, O. Biletskyi, D. Bruno, A. Di Lieto, J. Escallier, G. Heppner, C. Mi, T. Samms, J. Sandberg
BNL, Upton, New York, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
Each of RHIC’s superconducting magnets is protected by a silicon quench protection diode (QPD). In total, RHIC has over 800 diodes installed inside the cryostat close to the vacuum pipe~[RHICconfig]. After years of operation with high energy heavy ion beams we experienced a first permanently damaged QPD in the middle of our FY2016 Au Au run and a second damaged diode in the following year. In 2016 the run had to be interrupted by 19 days to replace the diode, in 2017 RHIC could still operate with a reduced ramping speed of the superconducting magnets. Both diodes were replaced and examined "cold" as well as "warm". This paper reports on what we have learned so far about the conditions leading up to the damage as well as the damage itself.

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reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-WEPLH11

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paper received ※ 23 August 2019 paper accepted ※ 05 September 2019 issue date ※ 08 October 2019

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THZBA5

First Electron Cooling of Hadron Beams Using a Bunched Electron Beam

957

A.V. Fedotov, Z. Altinbas, M. Blaskiewicz, J.M. Brennan, D. Bruno, J.C. Brutus, M.R. Costanzo, K.A. Drees, W. Fischer, J.M. Fite, M. Gaowei, D.M. Gassner, X. Gu, J. Halinski, K. Hamdi, L.R. Hammons, T. Hayes, R.L. Hulsart, P. Inacker, J.P. Jamilkowski, Y.C. Jing, P.K. Kankiya, D. Kayran, J. Kewisch, D. Lehn, C.J. Liaw, C. Liu, J. Ma, G.J. Mahler, M. Mapes, A. Marusic, K. Mernick, C. Mi, R.J. Michnoff, T.A. Miller, M.G. Minty, S.K. Nayak, L.K. Nguyen, M.C. Paniccia, I. Pinayev, S. Polizzo, V. Ptitsyn, T. Rao, G. Robert-Demolaize, T. Roser, J. Sandberg, V. Schoefer, S. Seletskiy, F. Severino, T.C. Shrey, L. Smart, K.S. Smith, H. Song, A. Sukhanov, R. Than, P. Thieberger, S.M. Trabocchi, J.E. Tuozzolo, P. Wanderer, E. Wang, G. Wang, D. Weiss, B.P. Xiao, T. Xin, W. Xu, A. Zaltsman, H. Zhao, Z. Zhao
BNL, Upton, New York, USA

Funding: Work supported by the U.S. Department of Energy.
The Low Energy RHIC electron Cooler (LEReC) was recently constructed and commissioned at BNL. The LEReC is the first electron cooler based on the RF acceleration of electron bunches (previous electron coolers all used DC beams). Bunched electron beams are necessary for cooling hadron beams at high energies. The challenges of such an approach include generation of electron beams suitable for cooling, delivery of electron beams of the required quality to the cooling sections without degradation of beam emittances and energy spread, achieving required small angles between electrons and ions in the cooling sections, precise energy matching between the two beams, high-current operation of the electron accelerator, as well as several physics effects related to bunched beam cooling. Following successful commissioning of the electron accelerator in 2018, the focus of the LEReC project in 2019 was on establishing electron-ion interactions and demonstration of cooling process using electron energy of 1.6MeV (ion energy of 3.85GeV/n), which is the lowest energy of interest. Here we report on the first demonstration of Au ion cooling in RHIC using this new approach.

Slides THZBA5 [16.417 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-THZBA5

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paper received ※ 16 August 2019 paper accepted ※ 31 August 2019 issue date ※ 08 October 2019

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