IPAC2011 - List of Authors (Kayran, D.)

Paper

Title

Page

Recirculating Electron Linacs (REL) for LHeC and eRHIC

1099

D. Trbojevic, J. Beebe-Wang, Y. Hao, D. Kayran, V. Litvinenko, V. Ptitsyn, N. Tsoupas
BNL, Upton, Long Island, New York, USA

Funding: Work performed under a Contract Number DE-AC02-98CH10886 with the auspices of the US Department of Energy.
We present a design of a CW Electron Recovery Linacs (ERL) for future electron hadron colliders eRHIC and LHeC. In eRHIC, a six-pass ERL would be installed in the existing tunnel of the present Relativistic Heavy Ion Collider (RHIC). The 5-30 GeV polarized electrons will collide with RHIC’s 50-250 (325) GeV polarized protons or 20-100 (130) GeV/u heavy ions. In LHeC a 3-pass 60 GeV CW ERL will produce polarized electrons for collisions with 7 TeV protons. After collision, electron beam energy is recovered and electrons are dumped at low energy. Two superconducting linacs are located in the two straight sections in both ERLs. The multiple arcs are made of Flexible Momentum Compaction lattice (FMC) allowing adjustable momentum compaction for electrons with different energies. The multiple arcs, placed above each other, are matched to the two linac’s straight sections with splitters and combiners.

THOBA02

Experimental Demonstration of Suppression of Coherent Synchrotron Radiation Wake-field

V. Yakimenko, A.V. Fedotov, M.G. Fedurin, D. Kayran, V. Litvinenko
BNL, Upton, Long Island, New York, USA
P. Muggli
MPI, Muenchen, Germany

In this paper we report on a first experimental demonstration of coherent synchrotron radiation (CSR) wake-field suppression by a narrow-gap vacuum chamber. Increase in the beam energy spread and emittance due to emission of coherent synchrotron radiation (CSR) is considered to be a limiting factor a high-current high-brightness beams. At the Brookhaven National Laboratory Accelerator Test Facility (ATF) we experimentally demonstrated the suppression of CSR wake-field - both the average energy loss and he energy spread growth – using polished Al plates. Well characterized electron bunches were propagated through a bending magnet with two parallel Al plates with gap controlled between 1 mm to 12 mm. Contrary to some theoretic predictions, our experimental results show that closing the plates significantly reduces both the beam energy loss and CSR-induced beam energy spread. In this paper we present our experimental results and compare then with rigorous analytical theory. These results open a possibility to predict analytically CSR shielding of future high-current high-brightness beams.

Slides THOBA02 [12.706 MB]

THPS009

Coherent Electron Cooling Demonstration Experiment

3442

V. Litvinenko, S.A. Belomestnykh, I. Ben-Zvi, J. Bengtsson, A.V. Fedotov, Y. Hao, D. Kayran, G.J. Mahler, W. Meng, T. Rao, T. Roser, B. Sheehy, R. Than, J.E. Tuozzolo, G. Wang, V. Yakimenko
BNL, Upton, Long Island, New York, USA
G.I. Bell, D.L. Bruhwiler, V.H. Ranjbar, B.T. Schwartz
Tech-X, Boulder, Colorado, USA
A. Hutton, G.A. Krafft, M. Poelker, R.A. Rimmer
JLAB, Newport News, Virginia, USA
M.A. Kholopov, P. Vobly
BINP SB RAS, Novosibirsk, Russia

Coherent electron cooling (CEC) is considered to be on of potential candidates capable of cooling high-energy, high-intensity hadron beams to very small emittances. It also has a potential to significantly boost luminosity of high-energy hadron-hadron and electron-hadron colliders. In a CEC system, a perturbation of the electron density caused by a hadron is amplified and fed back to the hadrons to reduce the energy spread and the emittance of the beam. Following the funding decision by DoE office of Nuclear Physics, we are designing and building coherent electron cooler for a proof-of-principle experiment at RHIC to cool 40 GeV heavy ion beam. In this paper, we describe the layout of the CeC installed into IP2 interaction region at RHIC. We present the design of the CeC cooler and results of preliminary simulations.

THPZ020

eRHIC Interaction Region Design

3729

D. Trbojevic, J. Beebe-Wang, Y. Hao, D. Kayran, Y. Luo, V. Ptitsyn, N. Tsoupas
BNL, Upton, Long Island, New York, USA
V. Litvinenko
Stony Brook University, Stony Brook, USA

Funding: *Work performed under a Contract Number DE-AC02-98CH10886 with the auspices of the US Department of Energy.
Interaction region design of the future electron ion collider at Relativistic Heavy Ion Collider (eRHIC) is presented. Polarized protons/Helium and heavy ions will collider with 5-30 GeV polarized electrons with a 10 mrad angle by using the crab cavity crossing. The interaction region is designed without bending electrons to avoid problems with synchrotron radiation. Use of the combined function magnet in the ion side allows detection of neutrons. Design allows detection of deep virtual scattering as well as detection of partons with lower energies (po/2.5). The betatron function at collisions is 5 cm assuming use of three dimensional electron beam cooling. Special chromaticity correction is applied in both sides of the ion straight section interaction region. Electrons arrive with avoiding completely synchrotron radiation at the detector. Special superconducting combined function magnet is designed to allow passage of electrons through the field free region.

THPZ019

High Luminosity Electron-hadron Collider eRHIC

3726

V. Ptitsyn, E.C. Aschenauer, J. Beebe-Wang, S.A. Belomestnykh, I. Ben-Zvi, R. Calaga, X. Chang, A.V. Fedotov, H. Hahn, L.R. Hammons, Y. Hao, P. He, A.K. Jain, E.C. Johnson, D. Kayran, J. Kewisch, V. Litvinenko, G.J. Mahler, W. Meng, B. Parker, A.I. Pikin, T. Rao, T. Roser, B. Sheehy, J. Skaritka, R. Than, D. Trbojevic, N. Tsoupas, J.E. Tuozzolo, G. Wang, Q. Wu, W. Xu
BNL, Upton, Long Island, New York, USA

We present the design of a future high-energy high-luminosity electron-hadron collider at RHIC called eRHIC. We plan adding 20 (30) GeV energy recovery linacs to accelerate and to collide polarized and unpolarized electrons with hadrons in RHIC. The center-of-mass energy of eRHIC will range from 30 to 200 GeV. The luminosity exceeding 10³4 cm^-2s⁻¹ can be achieved in eRHIC using the low-beta interaction region which a 10 mrad crab crossing. A natural staging scenario of step-by-step increases of the electron beam energy by builiding-up of eRHIC's SRF linacs. We report on the eRHIC design and cost estimates for it stages. We discuss the progress of eRHC R&D projects from the polarized electron source to the coherent electron cooling.

Paper	Title	Page
TUPC045	Recirculating Electron Linacs (REL) for LHeC and eRHIC	1099
	D. Trbojevic, J. Beebe-Wang, Y. Hao, D. Kayran, V. Litvinenko, V. Ptitsyn, N. Tsoupas BNL, Upton, Long Island, New York, USA
	Funding: Work performed under a Contract Number DE-AC02-98CH10886 with the auspices of the US Department of Energy. We present a design of a CW Electron Recovery Linacs (ERL) for future electron hadron colliders eRHIC and LHeC. In eRHIC, a six-pass ERL would be installed in the existing tunnel of the present Relativistic Heavy Ion Collider (RHIC). The 5-30 GeV polarized electrons will collide with RHIC’s 50-250 (325) GeV polarized protons or 20-100 (130) GeV/u heavy ions. In LHeC a 3-pass 60 GeV CW ERL will produce polarized electrons for collisions with 7 TeV protons. After collision, electron beam energy is recovered and electrons are dumped at low energy. Two superconducting linacs are located in the two straight sections in both ERLs. The multiple arcs are made of Flexible Momentum Compaction lattice (FMC) allowing adjustable momentum compaction for electrons with different energies. The multiple arcs, placed above each other, are matched to the two linac’s straight sections with splitters and combiners.

THOBA02	Experimental Demonstration of Suppression of Coherent Synchrotron Radiation Wake-field
	V. Yakimenko, A.V. Fedotov, M.G. Fedurin, D. Kayran, V. Litvinenko BNL, Upton, Long Island, New York, USA P. Muggli MPI, Muenchen, Germany
	In this paper we report on a first experimental demonstration of coherent synchrotron radiation (CSR) wake-field suppression by a narrow-gap vacuum chamber. Increase in the beam energy spread and emittance due to emission of coherent synchrotron radiation (CSR) is considered to be a limiting factor a high-current high-brightness beams. At the Brookhaven National Laboratory Accelerator Test Facility (ATF) we experimentally demonstrated the suppression of CSR wake-field - both the average energy loss and he energy spread growth – using polished Al plates. Well characterized electron bunches were propagated through a bending magnet with two parallel Al plates with gap controlled between 1 mm to 12 mm. Contrary to some theoretic predictions, our experimental results show that closing the plates significantly reduces both the beam energy loss and CSR-induced beam energy spread. In this paper we present our experimental results and compare then with rigorous analytical theory. These results open a possibility to predict analytically CSR shielding of future high-current high-brightness beams.
	Slides THOBA02 [12.706 MB]

THPS009	Coherent Electron Cooling Demonstration Experiment	3442
	V. Litvinenko, S.A. Belomestnykh, I. Ben-Zvi, J. Bengtsson, A.V. Fedotov, Y. Hao, D. Kayran, G.J. Mahler, W. Meng, T. Rao, T. Roser, B. Sheehy, R. Than, J.E. Tuozzolo, G. Wang, V. Yakimenko BNL, Upton, Long Island, New York, USA G.I. Bell, D.L. Bruhwiler, V.H. Ranjbar, B.T. Schwartz Tech-X, Boulder, Colorado, USA A. Hutton, G.A. Krafft, M. Poelker, R.A. Rimmer JLAB, Newport News, Virginia, USA M.A. Kholopov, P. Vobly BINP SB RAS, Novosibirsk, Russia
	Coherent electron cooling (CEC) is considered to be on of potential candidates capable of cooling high-energy, high-intensity hadron beams to very small emittances. It also has a potential to significantly boost luminosity of high-energy hadron-hadron and electron-hadron colliders. In a CEC system, a perturbation of the electron density caused by a hadron is amplified and fed back to the hadrons to reduce the energy spread and the emittance of the beam. Following the funding decision by DoE office of Nuclear Physics, we are designing and building coherent electron cooler for a proof-of-principle experiment at RHIC to cool 40 GeV heavy ion beam. In this paper, we describe the layout of the CeC installed into IP2 interaction region at RHIC. We present the design of the CeC cooler and results of preliminary simulations.

THPZ020	eRHIC Interaction Region Design	3729
	D. Trbojevic, J. Beebe-Wang, Y. Hao, D. Kayran, Y. Luo, V. Ptitsyn, N. Tsoupas BNL, Upton, Long Island, New York, USA V. Litvinenko Stony Brook University, Stony Brook, USA
	Funding: *Work performed under a Contract Number DE-AC02-98CH10886 with the auspices of the US Department of Energy. Interaction region design of the future electron ion collider at Relativistic Heavy Ion Collider (eRHIC) is presented. Polarized protons/Helium and heavy ions will collider with 5-30 GeV polarized electrons with a 10 mrad angle by using the crab cavity crossing. The interaction region is designed without bending electrons to avoid problems with synchrotron radiation. Use of the combined function magnet in the ion side allows detection of neutrons. Design allows detection of deep virtual scattering as well as detection of partons with lower energies (po/2.5). The betatron function at collisions is 5 cm assuming use of three dimensional electron beam cooling. Special chromaticity correction is applied in both sides of the ion straight section interaction region. Electrons arrive with avoiding completely synchrotron radiation at the detector. Special superconducting combined function magnet is designed to allow passage of electrons through the field free region.

THPZ019	High Luminosity Electron-hadron Collider eRHIC	3726
	V. Ptitsyn, E.C. Aschenauer, J. Beebe-Wang, S.A. Belomestnykh, I. Ben-Zvi, R. Calaga, X. Chang, A.V. Fedotov, H. Hahn, L.R. Hammons, Y. Hao, P. He, A.K. Jain, E.C. Johnson, D. Kayran, J. Kewisch, V. Litvinenko, G.J. Mahler, W. Meng, B. Parker, A.I. Pikin, T. Rao, T. Roser, B. Sheehy, J. Skaritka, R. Than, D. Trbojevic, N. Tsoupas, J.E. Tuozzolo, G. Wang, Q. Wu, W. Xu BNL, Upton, Long Island, New York, USA
	We present the design of a future high-energy high-luminosity electron-hadron collider at RHIC called eRHIC. We plan adding 20 (30) GeV energy recovery linacs to accelerate and to collide polarized and unpolarized electrons with hadrons in RHIC. The center-of-mass energy of eRHIC will range from 30 to 200 GeV. The luminosity exceeding 10³4 cm^-2s⁻¹ can be achieved in eRHIC using the low-beta interaction region which a 10 mrad crab crossing. A natural staging scenario of step-by-step increases of the electron beam energy by builiding-up of eRHIC's SRF linacs. We report on the eRHIC design and cost estimates for it stages. We discuss the progress of eRHC R&D projects from the polarized electron source to the coherent electron cooling.