IPAC2011 - Classification: 01 Circular Colliders / A17 Electron-Hadron Colliders

Paper

Title

Page

Design Concepts for the Large Hadron Electron Collider

1942

M. Klein
The University of Liverpool, Liverpool, United Kingdom

A report is presented on the design concepts for a high luminosity electron-nucleon collider of 1.3 TeV centre of mass energy, realized with the addition of a 60 GeV electron ring or linear accelerator to the existing proton and ion LHC beam facility, comprising machine magnets, optics, interaction region, cryogenics, rf, civil engineering and further components of the LHeC. The report on behalf of the LHeC study team is a summary of the 2011 LHeC CDR and feedback received from an international review panel.

Slides WEODA03 [9.780 MB]

THPZ014

LHeC Lattice Design

3714

M. Fitterer, O.S. Brüning, H. Burkhardt, B.J. Holzer, J.M. Jowett, K.H. Meß, T. Risselada
CERN, Geneva, Switzerland
M. Klein
The University of Liverpool, Liverpool, United Kingdom
A.-S. Müller
KIT, Karlsruhe, Germany

The Large Hadron Electron Collider (LHeC) aims at lepton-proton and lepton-nucleus collisions with centre of mass energies of 1-2 TeV at ep luminosities in excess of 10³3 cm^-2 s^-1. We present here a lattice design for the electron ring option, which meets the design parameters and also the constraints imposed by the integration of the new electron ring in the LHC tunnel.

THPZ015

Synchrotron Radiation in the Interaction Region for a Ring-Ring and Linac-Ring LHeC

3717

N.R. Bernard
UCLA, Los Angeles, California, USA
R. Appleby, L.N.S. Thompson
UMAN, Manchester, United Kingdom
N.R. Bernard
ETH, Zurich, Switzerland
B.J. Holzer, R. Tomás, F. Zimmermann
CERN, Geneva, Switzerland
M. Klein
The University of Liverpool, Liverpool, United Kingdom
P. Kostka
DESY Zeuthen, Zeuthen, Germany
B. Nagorny, U. Schneekloth
DESY, Hamburg, Germany

The Large Hadron electron Collider (LHeC) aims at bringing hadron-lepton collisions to CERN with center of mass energies in the TeV scale. The LHeC will utilize the existing LHC storage ring with the addition of a 60 GeV electron accelerator. The electron beam will be stored and accelerated in either a storage ring in the LHC tunnel (Ring-Ring) or a linac tangent to the LHC tunnel (Linac-Ring). Synchrotron Radiation (SR) in the Interaction Region (IR) of this machine requires an iterative design process in which luminosity is optimized while the SR is minimized. This process also requires attention to be given to the detector as the beam pipe must be designed such that damaging effects, such as out-gasing, are minimized while the tracking remains close to the IP. The machinery of GEANT4 has been used to simulate the SR load in the IR and also to design absorbers/masks to shield SR from backscattering into the detector or propagating with the electron beam. The outcome of these simulations, as well as cross checks, are described in the accompanying poster which characterizes the current status of the IR design for both the Ring-Ring and Linac-Ring options of the LHeC in terms of SR.

THPZ016

Interaction Region Design for a Ring-Ring LHeC

3720

L.N.S. Thompson, R. Appleby
UMAN, Manchester, United Kingdom
N.R. Bernard
UCLA, Los Angeles, California, USA
M. Fitterer
KIT, Karlsruhe, Germany
B.J. Holzer
CERN, Geneva, Switzerland
M. Klein
The University of Liverpool, Liverpool, United Kingdom
P. Kostka
DESY Zeuthen, Zeuthen, Germany
L.N.S. Thompson
Cockcroft Institute, Warrington, Cheshire, United Kingdom

The Large Hadron Electron Collider project is a proposal to study e-p and e-A interactions at the LHC. Using one of the LHC's proton beams, an electron beam of relatively low energy and moderately high intensity provides high luminosity TeV-scale e-p collisions at one of the LHC interaction points, running simultaneously with existing experiments. Two designs are studied; an electron ring situated in the LHC tunnel, and an electron linac. The focus of this paper is on the ring design. Designing an e-p machine presents interesting accelerator physics and design challenges, particularly when considering the interaction region. These include coupled optics, beam separation and unconventional mini-beta focusing schemes. Designs are constrained by an array of interdependent factors, including beam-beam interaction, detector dimensions and acceptance, luminosity and synchrotron radiation. Methods of addressing these complex issues are discussed. The current designs for the LHeC Ring-Ring interaction region and long straight section are presented and discussed, in the context of the project goals and design challenges encountered. Future developments and work are also discussed.

THPZ017

Achromatic Low-beta Interaction Region Design for an Electron-ion Collider

3723

V.S. Morozov, Y.S. Derbenev
JLAB, Newport News, Virginia, USA

Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. Supported in part by Muons, Inc.
An achromatic Interaction Region (IR) design concept is presented with an emphasis on its application at an electron-ion collider. A specially-designed symmetric Chromaticity Compensation Block (CCB) induces an angle spread in the passing beam such that it cancels the chromatic kick of the final focusing quadrupoles. Two such CCB’s placed symmetrically around an interaction point (IP) allow simultaneous compensation of the 1st-order chromaticities and chromatic beam smear at the IP without inducing significant 2nd-order aberrations. Special attention is paid to the difference in the electron and ion IR design requirements. We discuss geometric matching of the electron and ion IR footprints. We investigate limitations on the momentum acceptance in this IR design.

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.

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.

Paper	Title	Page
WEODA03	Design Concepts for the Large Hadron Electron Collider	1942
	M. Klein The University of Liverpool, Liverpool, United Kingdom
	A report is presented on the design concepts for a high luminosity electron-nucleon collider of 1.3 TeV centre of mass energy, realized with the addition of a 60 GeV electron ring or linear accelerator to the existing proton and ion LHC beam facility, comprising machine magnets, optics, interaction region, cryogenics, rf, civil engineering and further components of the LHeC. The report on behalf of the LHeC study team is a summary of the 2011 LHeC CDR and feedback received from an international review panel.
	Slides WEODA03 [9.780 MB]

THPZ014	LHeC Lattice Design	3714
	M. Fitterer, O.S. Brüning, H. Burkhardt, B.J. Holzer, J.M. Jowett, K.H. Meß, T. Risselada CERN, Geneva, Switzerland M. Klein The University of Liverpool, Liverpool, United Kingdom A.-S. Müller KIT, Karlsruhe, Germany
	The Large Hadron Electron Collider (LHeC) aims at lepton-proton and lepton-nucleus collisions with centre of mass energies of 1-2 TeV at ep luminosities in excess of 10³3 cm^-2 s^-1. We present here a lattice design for the electron ring option, which meets the design parameters and also the constraints imposed by the integration of the new electron ring in the LHC tunnel.

THPZ015	Synchrotron Radiation in the Interaction Region for a Ring-Ring and Linac-Ring LHeC	3717
	N.R. Bernard UCLA, Los Angeles, California, USA R. Appleby, L.N.S. Thompson UMAN, Manchester, United Kingdom N.R. Bernard ETH, Zurich, Switzerland B.J. Holzer, R. Tomás, F. Zimmermann CERN, Geneva, Switzerland M. Klein The University of Liverpool, Liverpool, United Kingdom P. Kostka DESY Zeuthen, Zeuthen, Germany B. Nagorny, U. Schneekloth DESY, Hamburg, Germany
	The Large Hadron electron Collider (LHeC) aims at bringing hadron-lepton collisions to CERN with center of mass energies in the TeV scale. The LHeC will utilize the existing LHC storage ring with the addition of a 60 GeV electron accelerator. The electron beam will be stored and accelerated in either a storage ring in the LHC tunnel (Ring-Ring) or a linac tangent to the LHC tunnel (Linac-Ring). Synchrotron Radiation (SR) in the Interaction Region (IR) of this machine requires an iterative design process in which luminosity is optimized while the SR is minimized. This process also requires attention to be given to the detector as the beam pipe must be designed such that damaging effects, such as out-gasing, are minimized while the tracking remains close to the IP. The machinery of GEANT4 has been used to simulate the SR load in the IR and also to design absorbers/masks to shield SR from backscattering into the detector or propagating with the electron beam. The outcome of these simulations, as well as cross checks, are described in the accompanying poster which characterizes the current status of the IR design for both the Ring-Ring and Linac-Ring options of the LHeC in terms of SR.

THPZ016	Interaction Region Design for a Ring-Ring LHeC	3720
	L.N.S. Thompson, R. Appleby UMAN, Manchester, United Kingdom N.R. Bernard UCLA, Los Angeles, California, USA M. Fitterer KIT, Karlsruhe, Germany B.J. Holzer CERN, Geneva, Switzerland M. Klein The University of Liverpool, Liverpool, United Kingdom P. Kostka DESY Zeuthen, Zeuthen, Germany L.N.S. Thompson Cockcroft Institute, Warrington, Cheshire, United Kingdom
	The Large Hadron Electron Collider project is a proposal to study e-p and e-A interactions at the LHC. Using one of the LHC's proton beams, an electron beam of relatively low energy and moderately high intensity provides high luminosity TeV-scale e-p collisions at one of the LHC interaction points, running simultaneously with existing experiments. Two designs are studied; an electron ring situated in the LHC tunnel, and an electron linac. The focus of this paper is on the ring design. Designing an e-p machine presents interesting accelerator physics and design challenges, particularly when considering the interaction region. These include coupled optics, beam separation and unconventional mini-beta focusing schemes. Designs are constrained by an array of interdependent factors, including beam-beam interaction, detector dimensions and acceptance, luminosity and synchrotron radiation. Methods of addressing these complex issues are discussed. The current designs for the LHeC Ring-Ring interaction region and long straight section are presented and discussed, in the context of the project goals and design challenges encountered. Future developments and work are also discussed.

THPZ017	Achromatic Low-beta Interaction Region Design for an Electron-ion Collider	3723
	V.S. Morozov, Y.S. Derbenev JLAB, Newport News, Virginia, USA
	Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. Supported in part by Muons, Inc. An achromatic Interaction Region (IR) design concept is presented with an emphasis on its application at an electron-ion collider. A specially-designed symmetric Chromaticity Compensation Block (CCB) induces an angle spread in the passing beam such that it cancels the chromatic kick of the final focusing quadrupoles. Two such CCB’s placed symmetrically around an interaction point (IP) allow simultaneous compensation of the 1st-order chromaticities and chromatic beam smear at the IP without inducing significant 2nd-order aberrations. Special attention is paid to the difference in the electron and ion IR design requirements. We discuss geometric matching of the electron and ion IR footprints. We investigate limitations on the momentum acceptance in this IR design.

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.

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.