HB2014 - Table of Session: THO3LR (Working Group CA)

Paper

Title

Page

Ring Simulation and Beam Dynamics Studies for ISIS Upgrades 0.5 to 10 MW

374

D.J. Adams, B. Jones, B.G. Pine, H. V. Smith, C.M. Warsop, R.E. Williamson
STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
C.R. Prior, G.H. Rees
STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom

Various upgrade routes are under study for the ISIS spallation neutron source at RAL in the UK. Recent work has concentrated on upgrading the injector, increasing injection energy from 70 to 180 MeV, and studying the challenging possibility of reaching powers up to 0.5 MW in the existing 800 MeV RCS. Studies for the longer term are exploring the possibilities of a 5 MW, 3.2 GeV RCS that could form part of a new stand-alone 10+ MW next generation “ISIS II” facility. A central part of these ring studies is the use of computer simulations to guide designs, for example optimising the injection painting configuration and providing an indication of expected loss levels. Here we summarise the computer models used, indicate where benchmarking has been possible, describe optimisations and results from studies, and outline the main uncertainties. Understanding the limitations in high power RCS accelerators is an important part of determining optimal facility designs for the future.

Slides THO3LR02 [2.658 MB]

THO3LR03

The Physics and Use of Electron Lenses at BNL

W. Fischer, Z. Altinbas, D. Bruno, M.R. Costanzo, X. Gu, J. Hock, A.K. Jain, Y. Luo, C. Mi, R.J. Michnoff, T.A. Miller, A.I. Pikin, T. Samms, Y. Tan, R. Than, P. Thieberger, S.M. White
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 compensate for the beam-beam effects from the proton-proton interactions at the two interaction points in the Relativistic Heavy Ion Collider (RHIC), two electron lenses (e-lenses) have been installed and commissioned in 2014. In this report, the physics of electron lens is briefly introduced, followed by the electron lens hardware and electron beam commissioning results in 2014 RHIC run. Although in 2014, RHIC is operating with gold and 3He beams, and the luminosity is not limited by head on beam-beam interactions, we still aligned the electron beam with the hadron beam to get the first experience with the electron-hadron beam interaction. The demonstration of electron and gold beam overlap has been achieved via electron backscattered detector, as well as the demonstration of electron beam parameters that are sufficiently stable to have no negative impact on the gold beam life time. With the experience of using electron lens on hadron beam, head on beam-beam compensation can be commissioned in the following year with proton beams, with a lattice which phase advance has a multiple of 180 degrees between the beam-beam interaction and electron lens locations.

Slides THO3LR03 [4.736 MB]

THO3LR04

Recent Results on Beam-Beam Effects in Space Charge Dominated Colliding Ion Beams at RHIC

379

C. Montag
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 search for the critical point in the QCD phase diagram, RHIC has been colliding gold ions at a variety of beam energies ranging from 2.5 GeV/n to 9.8 GeV/n. During these low energy operations below the regular injection energy, significant lifetime reductions due to the beam-beam interaction in conjunction with large space charge tune shifts have been observed. Extensive simulation studies as well as beam experiments have been performed to understand this phenomenon, leading to improved performance during the 7.3 GeV run in FY2014.

Slides THO3LR04 [0.334 MB]

Paper	Title	Page
THO3LR02	Ring Simulation and Beam Dynamics Studies for ISIS Upgrades 0.5 to 10 MW	374
	D.J. Adams, B. Jones, B.G. Pine, H. V. Smith, C.M. Warsop, R.E. Williamson STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom C.R. Prior, G.H. Rees STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
	Various upgrade routes are under study for the ISIS spallation neutron source at RAL in the UK. Recent work has concentrated on upgrading the injector, increasing injection energy from 70 to 180 MeV, and studying the challenging possibility of reaching powers up to 0.5 MW in the existing 800 MeV RCS. Studies for the longer term are exploring the possibilities of a 5 MW, 3.2 GeV RCS that could form part of a new stand-alone 10+ MW next generation “ISIS II” facility. A central part of these ring studies is the use of computer simulations to guide designs, for example optimising the injection painting configuration and providing an indication of expected loss levels. Here we summarise the computer models used, indicate where benchmarking has been possible, describe optimisations and results from studies, and outline the main uncertainties. Understanding the limitations in high power RCS accelerators is an important part of determining optimal facility designs for the future.
	Slides THO3LR02 [2.658 MB]

THO3LR03	The Physics and Use of Electron Lenses at BNL
	W. Fischer, Z. Altinbas, D. Bruno, M.R. Costanzo, X. Gu, J. Hock, A.K. Jain, Y. Luo, C. Mi, R.J. Michnoff, T.A. Miller, A.I. Pikin, T. Samms, Y. Tan, R. Than, P. Thieberger, S.M. White 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 compensate for the beam-beam effects from the proton-proton interactions at the two interaction points in the Relativistic Heavy Ion Collider (RHIC), two electron lenses (e-lenses) have been installed and commissioned in 2014. In this report, the physics of electron lens is briefly introduced, followed by the electron lens hardware and electron beam commissioning results in 2014 RHIC run. Although in 2014, RHIC is operating with gold and 3He beams, and the luminosity is not limited by head on beam-beam interactions, we still aligned the electron beam with the hadron beam to get the first experience with the electron-hadron beam interaction. The demonstration of electron and gold beam overlap has been achieved via electron backscattered detector, as well as the demonstration of electron beam parameters that are sufficiently stable to have no negative impact on the gold beam life time. With the experience of using electron lens on hadron beam, head on beam-beam compensation can be commissioned in the following year with proton beams, with a lattice which phase advance has a multiple of 180 degrees between the beam-beam interaction and electron lens locations.
	Slides THO3LR03 [4.736 MB]

THO3LR04	Recent Results on Beam-Beam Effects in Space Charge Dominated Colliding Ion Beams at RHIC	379
	C. Montag 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 search for the critical point in the QCD phase diagram, RHIC has been colliding gold ions at a variety of beam energies ranging from 2.5 GeV/n to 9.8 GeV/n. During these low energy operations below the regular injection energy, significant lifetime reductions due to the beam-beam interaction in conjunction with large space charge tune shifts have been observed. Extensive simulation studies as well as beam experiments have been performed to understand this phenomenon, leading to improved performance during the 7.3 GeV run in FY2014.
	Slides THO3LR04 [0.334 MB]