IPAC2019 - Classification: MC4: Hadron Accelerators / A16 Advanced Concepts

Paper	Title	Page
MOPRB103	A Phase Shifter for Multi-Pass Recirculating Proton LINAC	802
	J. Qiang, L.N. Brouwer, S. Prestemon LBNL, Berkeley, California, USA
	Funding: This work was supported by the U.S. Department of Energy under Contract No. DE-AC02-05CH11231 and used computer resources at the National Energy Research Scientific Computing Center. The multi-pass recirculating proton linac can significantly improve the usage efficiency of RF superconducting cavities by passing the proton beam through the same cavity multiple times. However, in order to achieve the multiple acceleration, synchronous conditions in phase have to be satisfied. In this paper, we propose a fixed field superconducting magnet system as a phase shifter to meet the synchronous conditions.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB103
About •	paper received ※ 09 May 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019
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MOPRB116	Laser Sculpted Cool Proton Beams	826
	S.M. Gibson, L.J. Nevay Royal Holloway, University of London, Surrey, United Kingdom S.E. Alden, S.M. Gibson, L.J. Nevay JAI, Egham, Surrey, United Kingdom
	Funding: We acknowledge support by STFC grant ST/P003028/1 Hydrogen ion accelerators, such as CERN’s Linac4, are increasingly used as the front end of high power proton drivers for high energy physics, spallation neutron sources and other applications. Typically, a foil strips the hydrogen ion beam to facilitate charge-exchange injection of protons into orbits of high energy accelerators, in which the resulting emittance is dominated by phase-space painting. In this paper, a new method to laser extract a narrow beam of neutralised hydrogen from the parent H⁻ ion beam is proposed. Subsequent foil stripping and capture of protons into a storage ring generates cool proton bunches with significantly reduced emittance compared to the parent beam. The properties of the extracted proton beam can be precisely controlled and sculpted by adjusting the optical parameters of the laser beam. Recirculation of the parent beam allows time for space-charge effects to repopulate the emittance phase space prior to repeated laser extraction. We present particle tracking simulations of the proposed scheme, including the laser-particle interaction with realistic optical parameters and show the resulting emittance is reduced. Developments for an experimental demonstration of a laser controlled particle beam are outlined. In principle, the proposed scheme could considerably reduce the emittance of protons bunches injected into an accelerator, such as the LHC.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB116
About •	paper received ※ 16 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

A Phase Shifter for Multi-Pass Recirculating Proton LINAC

802

J. Qiang, L.N. Brouwer, S. Prestemon
LBNL, Berkeley, California, USA

Funding: This work was supported by the U.S. Department of Energy under Contract No. DE-AC02-05CH11231 and used computer resources at the National Energy Research Scientific Computing Center.
The multi-pass recirculating proton linac can significantly improve the usage efficiency of RF superconducting cavities by passing the proton beam through the same cavity multiple times. However, in order to achieve the multiple acceleration, synchronous conditions in phase have to be satisfied. In this paper, we propose a fixed field superconducting magnet system as a phase shifter to meet the synchronous conditions.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB103

About •

paper received ※ 09 May 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019

Export •

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

MOPRB116

Laser Sculpted Cool Proton Beams

826

S.M. Gibson, L.J. Nevay
Royal Holloway, University of London, Surrey, United Kingdom
S.E. Alden, S.M. Gibson, L.J. Nevay
JAI, Egham, Surrey, United Kingdom

Funding: We acknowledge support by STFC grant ST/P003028/1
Hydrogen ion accelerators, such as CERN’s Linac4, are increasingly used as the front end of high power proton drivers for high energy physics, spallation neutron sources and other applications. Typically, a foil strips the hydrogen ion beam to facilitate charge-exchange injection of protons into orbits of high energy accelerators, in which the resulting emittance is dominated by phase-space painting. In this paper, a new method to laser extract a narrow beam of neutralised hydrogen from the parent H⁻ ion beam is proposed. Subsequent foil stripping and capture of protons into a storage ring generates cool proton bunches with significantly reduced emittance compared to the parent beam. The properties of the extracted proton beam can be precisely controlled and sculpted by adjusting the optical parameters of the laser beam. Recirculation of the parent beam allows time for space-charge effects to repopulate the emittance phase space prior to repeated laser extraction. We present particle tracking simulations of the proposed scheme, including the laser-particle interaction with realistic optical parameters and show the resulting emittance is reduced. Developments for an experimental demonstration of a laser controlled particle beam are outlined. In principle, the proposed scheme could considerably reduce the emittance of protons bunches injected into an accelerator, such as the LHC.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB116

About •

paper received ※ 16 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

Export •

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