IPAC2016 - List of Authors (Berg, J.S.)

Paper	Title	Page
TUPMY044	Carbon and Mercury Target Systems for Muon Colliders and Neutrino Factories	1641
	K.T. McDonald PU, Princeton, New Jersey, USA J.S. Berg, H.G. Kirk, D. Stratakis BNL, Upton, Long Island, New York, USA X.P. Ding UCLA, Los Angeles, California, USA
	Funding: Work supported in part by US DOE Contract NO. DE-AC02-98CH110886 A high-power target is required to convert a powerful MW-class proton beam into an intense muon source or neutrino source in support of physics at the intensity frontier. The first phase of a Muon Collider or Neutrino Factory program may use a 6.75-GeV proton driver with beam power of only 1 MW. At this lower power it is favorable to use a graphite target with beam and target tilted slightly to the axis of a 20-T pion-capture solenoid around the target. Using the MARS15 (2014) code, we optimized the geometric parameters of the beam and target to maximize particle production at low energies by an incoming proton beam with kinetic energy of 6.75 GeV impinging on this carbon target. We also studied beam-dump configurations to suppress the rate of undesirable high-energy secondary particles in the beam. For a possible upgrade to a proton beam of multi-MW power, we considered a free-flowing mercury jet.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPMY044
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WEPMW023	Higher Luminosity eRHIC Ring-Ring Options and Upgrade	2472
	R.B. Palmer, J.S. Berg, M. Blaskiewicz, A.V. Fedotov, C. Montag, B. Parker, H. Witte BNL, Upton, Long Island, New York, USA
	Funding: This manuscript has been authored by employees of Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy. Lower risk ring-ring alternatives to the BNL linac-ling~[linacring] eRHIC electron ion collider (EIC) are discussed. The baseline from the Ring-Ring Working Group~[ringring] has a peak proton-electron luminosity of ≈§I{1.2e33}{cm^-2.s^-1}. An option has final focus quadrupoles starting immediately after the detector at 4.5~m, instead of at 32~m in the baseline. This allows the use of lower β^*s. It also uses more, 720, lower intensity, bunches, giving reduced IBS emittance growth and requiring only low energy pre-cooling. It has a peak luminosity of ≈§I{7e33}{cm^-2.s^-1}. An upgrade of this option, requiring magnetic, or coherent, electron cooling, has 1440 bunches and peak luminosity of ≈§I{15e33}{cm^-2.s^-1}.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPMW023
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WEPMW025	Optimizing the Design of Linear Non-scaling Fixed Field Alternating Gradient Arcs for the Electron Rings of eRHIC	2475
	J.S. Berg BNL, Upton, Long Island, New York, USA
	Funding: This manuscript has been authored by employees of Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy. I describe a process for producing optimal linear non-scaling fixed field alternating gradient (FFAG) arc designs for the electron rings of eRHIC, an electron-ion collider in the RHIC tunnel at Brookhaven National Laboratory. The electrons are accelerated in two FFAG rings (low and high energy), which in addition to the arcs optimized here, contain straight sections, splitter/combiner sections, and a linac shared between the rings. The optimization process I use has two layers, an inner one meeting constraints and an outer optimization that minimizes a target function. The target function is an approximation to the FFAG arc cost, for which I give the function used and the basis for that choice. While reducing synchrotron radiation is important, I show that optimizing for synchrotron radiation alone leads to significant cost an performance penalties for the rest of the machine design for very little reduction in synchrotron radiation. I describe important constraints on the design, in particular minimum drift lengths, maximum and minimum tunes, and clearance from the beam to the beam pipe. Finally, I present possible eRHIC FFAG parameters resulting from this optimization.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPMW025
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WEPMW027	The ERL-based Design of Electron-Hadron Collider eRHIC	2482
	V. Ptitsyn, E.C. Aschenauer, I. Ben-Zvi, J.S. Berg, M. Blaskiewicz, S.J. Brooks, K.A. Brown, J.C. Brutus, O.V. Chubar, A.V. Fedotov, D.M. Gassner, H. Hahn, Y. Hao, A. Hershcovitch, H. Huang, W.A. Jackson, Y.C. Jing, R.F. Lambiase, V. Litvinenko, C. Liu, Y. Luo, G.J. Mahler, B. Martin, G.T. McIntyre, W. Meng, F. Méot, T.A. Miller, M.G. Minty, B. Parker, I. Pinayev, V.H. Ranjbar, T. Roser, J. Skaritka, R. Than, P. Thieberger, D. Trbojevic, N. Tsoupas, J.E. Tuozzolo, E. Wang, G. Wang, H. Witte, Q. Wu, C. Xu, W. Xu, A. Zaltsman BNL, Upton, Long Island, New York, USA S.A. Belomestnykh 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. Recent developments of the ERL-based design of future high luminosity electron-hadron collider eRHIC focused on balancing technological risks present in the design versus the design cost. As a result a lower risk design has been adopted at moderate cost increase. The modifications include a change of the main linac RF frequency, reduced number of SRF cavity types and modified electron spin transport using a spin rotator. A luminosity-staged approach is being explored with a Nominal design (L ~ 10³³ cm^-2 s^-1) that employs reduced electron current and could possibly be based on classical electron cooling, and then with the Ultimate design (L > 10³⁴ cm^-2 s^-1) that uses higher electron current and an innovative cooling technique (CeC). The paper describes the recent design modifications, and presents the full status of the eRHIC ERL-based design.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPMW027
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WEPOY057	The 2015 eRHIC Ring-Ring Design	3126
	C. Montag, E.C. Aschenauer, J. Beebe-Wang, J.S. Berg, M. Blaskiewicz, J.M. Brennan, A.V. Fedotov, W. Fischer, V. Litvinenko, R.B. Palmer, B. Parker, S. Peggs, V. Ptitsyn, V.H. Ranjbar, S. Tepikian, D. Trbojevic, F.J. Willeke 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. To reduce the technical risk of the future electron-ion collider eRHIC currently under study at BNL, the ring-ring scheme has been revisited over the summer of 2015. The goal of this study was a design that covers the full center-of-mass energy range from 32 to 141 GeV with an initial luminosity around 10³³ cm^-2 sec^-1, upgradeable to 10³⁴ cm^-2 sec^-1 later on. In this presentation the baseline design will be presented, and future upgrades will be discussed.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPOY057
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Paper

Title

Page

Carbon and Mercury Target Systems for Muon Colliders and Neutrino Factories

1641

K.T. McDonald
PU, Princeton, New Jersey, USA
J.S. Berg, H.G. Kirk, D. Stratakis
BNL, Upton, Long Island, New York, USA
X.P. Ding
UCLA, Los Angeles, California, USA

Funding: Work supported in part by US DOE Contract NO. DE-AC02-98CH110886
A high-power target is required to convert a powerful MW-class proton beam into an intense muon source or neutrino source in support of physics at the intensity frontier. The first phase of a Muon Collider or Neutrino Factory program may use a 6.75-GeV proton driver with beam power of only 1 MW. At this lower power it is favorable to use a graphite target with beam and target tilted slightly to the axis of a 20-T pion-capture solenoid around the target. Using the MARS15 (2014) code, we optimized the geometric parameters of the beam and target to maximize particle production at low energies by an incoming proton beam with kinetic energy of 6.75 GeV impinging on this carbon target. We also studied beam-dump configurations to suppress the rate of undesirable high-energy secondary particles in the beam. For a possible upgrade to a proton beam of multi-MW power, we considered a free-flowing mercury jet.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPMY044

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

WEPMW023

Higher Luminosity eRHIC Ring-Ring Options and Upgrade

2472

R.B. Palmer, J.S. Berg, M. Blaskiewicz, A.V. Fedotov, C. Montag, B. Parker, H. Witte
BNL, Upton, Long Island, New York, USA

Funding: This manuscript has been authored by employees of Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy.
Lower risk ring-ring alternatives to the BNL linac-ling~[linacring] eRHIC electron ion collider (EIC) are discussed. The baseline from the Ring-Ring Working Group~[ringring] has a peak proton-electron luminosity of ≈§I{1.2e33}{cm^-2.s^-1}. An option has final focus quadrupoles starting immediately after the detector at 4.5~m, instead of at 32~m in the baseline. This allows the use of lower β^*s. It also uses more, 720, lower intensity, bunches, giving reduced IBS emittance growth and requiring only low energy pre-cooling. It has a peak luminosity of ≈§I{7e33}{cm^-2.s^-1}. An upgrade of this option, requiring magnetic, or coherent, electron cooling, has 1440 bunches and peak luminosity of ≈§I{15e33}{cm^-2.s^-1}.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPMW023

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WEPMW025

Optimizing the Design of Linear Non-scaling Fixed Field Alternating Gradient Arcs for the Electron Rings of eRHIC

2475

J.S. Berg
BNL, Upton, Long Island, New York, USA

Funding: This manuscript has been authored by employees of Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy.
I describe a process for producing optimal linear non-scaling fixed field alternating gradient (FFAG) arc designs for the electron rings of eRHIC, an electron-ion collider in the RHIC tunnel at Brookhaven National Laboratory. The electrons are accelerated in two FFAG rings (low and high energy), which in addition to the arcs optimized here, contain straight sections, splitter/combiner sections, and a linac shared between the rings. The optimization process I use has two layers, an inner one meeting constraints and an outer optimization that minimizes a target function. The target function is an approximation to the FFAG arc cost, for which I give the function used and the basis for that choice. While reducing synchrotron radiation is important, I show that optimizing for synchrotron radiation alone leads to significant cost an performance penalties for the rest of the machine design for very little reduction in synchrotron radiation. I describe important constraints on the design, in particular minimum drift lengths, maximum and minimum tunes, and clearance from the beam to the beam pipe. Finally, I present possible eRHIC FFAG parameters resulting from this optimization.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPMW025

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WEPMW027

The ERL-based Design of Electron-Hadron Collider eRHIC

2482

V. Ptitsyn, E.C. Aschenauer, I. Ben-Zvi, J.S. Berg, M. Blaskiewicz, S.J. Brooks, K.A. Brown, J.C. Brutus, O.V. Chubar, A.V. Fedotov, D.M. Gassner, H. Hahn, Y. Hao, A. Hershcovitch, H. Huang, W.A. Jackson, Y.C. Jing, R.F. Lambiase, V. Litvinenko, C. Liu, Y. Luo, G.J. Mahler, B. Martin, G.T. McIntyre, W. Meng, F. Méot, T.A. Miller, M.G. Minty, B. Parker, I. Pinayev, V.H. Ranjbar, T. Roser, J. Skaritka, R. Than, P. Thieberger, D. Trbojevic, N. Tsoupas, J.E. Tuozzolo, E. Wang, G. Wang, H. Witte, Q. Wu, C. Xu, W. Xu, A. Zaltsman
BNL, Upton, Long Island, New York, USA
S.A. Belomestnykh
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.
Recent developments of the ERL-based design of future high luminosity electron-hadron collider eRHIC focused on balancing technological risks present in the design versus the design cost. As a result a lower risk design has been adopted at moderate cost increase. The modifications include a change of the main linac RF frequency, reduced number of SRF cavity types and modified electron spin transport using a spin rotator. A luminosity-staged approach is being explored with a Nominal design (L ~ 10³³ cm^-2 s^-1) that employs reduced electron current and could possibly be based on classical electron cooling, and then with the Ultimate design (L > 10³⁴ cm^-2 s^-1) that uses higher electron current and an innovative cooling technique (CeC). The paper describes the recent design modifications, and presents the full status of the eRHIC ERL-based design.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPMW027

Export •

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

WEPOY057

The 2015 eRHIC Ring-Ring Design

3126

C. Montag, E.C. Aschenauer, J. Beebe-Wang, J.S. Berg, M. Blaskiewicz, J.M. Brennan, A.V. Fedotov, W. Fischer, V. Litvinenko, R.B. Palmer, B. Parker, S. Peggs, V. Ptitsyn, V.H. Ranjbar, S. Tepikian, D. Trbojevic, F.J. Willeke
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.
To reduce the technical risk of the future electron-ion collider eRHIC currently under study at BNL, the ring-ring scheme has been revisited over the summer of 2015. The goal of this study was a design that covers the full center-of-mass energy range from 32 to 141 GeV with an initial luminosity around 10³³ cm^-2 sec^-1, upgradeable to 10³⁴ cm^-2 sec^-1 later on. In this presentation the baseline design will be presented, and future upgrades will be discussed.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPOY057

Export •

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