IPAC2013 - List of Authors (Valishev, A.)

Paper

Title

Page

Hollow Electron Lens Simulation for the SPS

990

V. Previtali, G. Stancari, A. Valishev
Fermilab, Batavia, USA
S. Redaelli
CERN, Geneva, Switzerland

Funding: Fermilab is operated by Fermi Research Alliance, LLC, Contract No. DE-AC02-07CH11359 with the United States Dep. of Energy. This work was supported by the US LHC Accelerator Research Program (LARP).
The hardware of the Tevatron hollow electron lens, which has been used in the past for collimation purposes, is presently available. Possible applications of similar devices in the LHC are under evaluation, but a realistic date for installation of electron lenses in the LHC would be not earlier than the machine shutdown scheduled for 2018. We investigated the possibility of beam tests with the available hardware in the meantime in the SPS. This article aims to answer this question by presenting the results of dedicated numerical simulations.

MOPWO044

Numerical Simulations of a Hollow Electron Lens as a Scraping Device for the LHC

993

V. Previtali, G. Stancari, A. Valishev
Fermilab, Batavia, USA
S. Redaelli
CERN, Geneva, Switzerland

Funding: Fermilab is operated by Fermi Research Alliance, LLC, Contract No.DE-AC02-07CH11359 with the United States Dep. of Energy. This work was partially supported by US LHC Accelerator Research Program(LARP)
The use of hollow electron beam lens for scraping high energy proton beams has been extensively tested at Fermilab's Tevatron collider. In order to evaluate a possible application of a similar a device in the LHC, a dedicated new routine has been implemented in the standard 6D tracking code used at CERN for the design of the LHC collimation system. The effects of a finite length cylinder of electrons encompassing the main proton beam and traveling in the opposite direction is described in the routine. Realistic electron distributions, including measured radial imperfections, have been included in the model. Various operating modes have been simulated for the 7 TeV machine operation with sextupoles and octupoles included. The loss rate caused by the electron lens has been studied through an extended simulation campaign; the obtained halo removal rates for the different electron lens operating modes are presented.

THYB101

Suppressing Transverse Beam Halo with Nonlinear Magnetic Fields

3099

S.D. Webb, D.T. Abell, D.L. Bruhwiler, J.R. Cary
Tech-X, Boulder, Colorado, USA
V.V. Danilov
ORNL, Oak Ridge, Tennessee, USA
S. Nagaitsev, A. Valishev
Fermilab, Batavia, USA

Funding: This work was supported in part by the US Department of Energy's Office of Science, Office of High Energy Physics, under grant No. DE-SC0006247.
Traditional space charge driven resonances, such as beam halo, arise due to the underlying linear nature of accelerator lattices. In this talk, we present initial results on a new class of intrinsically nonlinear lattices, which introduce a large tune spread naturally. The resulting nonlinear decoherence suppresses the onset of beam halo.

Slides THYB101 [63.510 MB]

Paper	Title	Page
MOPWO043	Hollow Electron Lens Simulation for the SPS	990
	V. Previtali, G. Stancari, A. Valishev Fermilab, Batavia, USA S. Redaelli CERN, Geneva, Switzerland
	Funding: Fermilab is operated by Fermi Research Alliance, LLC, Contract No. DE-AC02-07CH11359 with the United States Dep. of Energy. This work was supported by the US LHC Accelerator Research Program (LARP). The hardware of the Tevatron hollow electron lens, which has been used in the past for collimation purposes, is presently available. Possible applications of similar devices in the LHC are under evaluation, but a realistic date for installation of electron lenses in the LHC would be not earlier than the machine shutdown scheduled for 2018. We investigated the possibility of beam tests with the available hardware in the meantime in the SPS. This article aims to answer this question by presenting the results of dedicated numerical simulations.

MOPWO044	Numerical Simulations of a Hollow Electron Lens as a Scraping Device for the LHC	993
	V. Previtali, G. Stancari, A. Valishev Fermilab, Batavia, USA S. Redaelli CERN, Geneva, Switzerland
	Funding: Fermilab is operated by Fermi Research Alliance, LLC, Contract No.DE-AC02-07CH11359 with the United States Dep. of Energy. This work was partially supported by US LHC Accelerator Research Program(LARP) The use of hollow electron beam lens for scraping high energy proton beams has been extensively tested at Fermilab's Tevatron collider. In order to evaluate a possible application of a similar a device in the LHC, a dedicated new routine has been implemented in the standard 6D tracking code used at CERN for the design of the LHC collimation system. The effects of a finite length cylinder of electrons encompassing the main proton beam and traveling in the opposite direction is described in the routine. Realistic electron distributions, including measured radial imperfections, have been included in the model. Various operating modes have been simulated for the 7 TeV machine operation with sextupoles and octupoles included. The loss rate caused by the electron lens has been studied through an extended simulation campaign; the obtained halo removal rates for the different electron lens operating modes are presented.

THYB101	Suppressing Transverse Beam Halo with Nonlinear Magnetic Fields	3099
	S.D. Webb, D.T. Abell, D.L. Bruhwiler, J.R. Cary Tech-X, Boulder, Colorado, USA V.V. Danilov ORNL, Oak Ridge, Tennessee, USA S. Nagaitsev, A. Valishev Fermilab, Batavia, USA
	Funding: This work was supported in part by the US Department of Energy's Office of Science, Office of High Energy Physics, under grant No. DE-SC0006247. Traditional space charge driven resonances, such as beam halo, arise due to the underlying linear nature of accelerator lattices. In this talk, we present initial results on a new class of intrinsically nonlinear lattices, which introduce a large tune spread naturally. The resulting nonlinear decoherence suppresses the onset of beam halo.
	Slides THYB101 [63.510 MB]