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Title: High dimensional characterization of the longitudinal phase space formed in a radio frequency quadrupole

Abstract

Modern accelerator front ends almost exclusively include radio-frequency quadrupoles for initial capture and focusing of the low-energy beam. Dynamics in the RFQ define the longitudinal bunch parameters. Simulation of the SNS RFQ with PARMTEQ seeded with a realistic LEBT distribution produces a 2.5 MeV, 40 mA H- beam with root-mean-square emittance of 130 deg keV. In measurement, a detailed characterization of the longitudinal phase space is made, including a novel study of the dependence of longitudinal emittance on transverse coordinates. This work introduces a new virtual slit technique that provides subslit resolution in an energy spectrometer as well as an approach for visualizing 4D phase space data. Through simulation and measurement, the RFQ-formed bunch is confirmed to have significant internal correlated structure. The high-dimensional features are shown to be in qualitative agreement. However, the measured rms emittances are up to 30% lower than predicted, closer to the design value of 95 deg keV.

Authors:
ORCiD logo; ORCiD logo; ; ORCiD logo; ORCiD logo
Publication Date:
Research Org.:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES)
OSTI Identifier:
1734804
Alternate Identifier(s):
OSTI ID: 1735439
Grant/Contract Number:  
AC05-00OR22725
Resource Type:
Published Article
Journal Name:
Physical Review Accelerators and Beams
Additional Journal Information:
Journal Name: Physical Review Accelerators and Beams Journal Volume: 23 Journal Issue: 12; Journal ID: ISSN 2469-9888
Publisher:
American Physical Society (APS)
Country of Publication:
United States
Language:
English
Subject:
43 PARTICLE ACCELERATORS; Low-energy multiple-particle dynamics; space charge in beams; high-intensity accelerators; neutron spallation facilities

Citation Formats

Ruisard, K., Aleksandrov, A., Cousineau, S., Tzoganis, V., and Zhukov, A.. High dimensional characterization of the longitudinal phase space formed in a radio frequency quadrupole. United States: N. p., 2020. Web. https://doi.org/10.1103/PhysRevAccelBeams.23.124201.
Ruisard, K., Aleksandrov, A., Cousineau, S., Tzoganis, V., & Zhukov, A.. High dimensional characterization of the longitudinal phase space formed in a radio frequency quadrupole. United States. https://doi.org/10.1103/PhysRevAccelBeams.23.124201
Ruisard, K., Aleksandrov, A., Cousineau, S., Tzoganis, V., and Zhukov, A.. Tue . "High dimensional characterization of the longitudinal phase space formed in a radio frequency quadrupole". United States. https://doi.org/10.1103/PhysRevAccelBeams.23.124201.
@article{osti_1734804,
title = {High dimensional characterization of the longitudinal phase space formed in a radio frequency quadrupole},
author = {Ruisard, K. and Aleksandrov, A. and Cousineau, S. and Tzoganis, V. and Zhukov, A.},
abstractNote = {Modern accelerator front ends almost exclusively include radio-frequency quadrupoles for initial capture and focusing of the low-energy beam. Dynamics in the RFQ define the longitudinal bunch parameters. Simulation of the SNS RFQ with PARMTEQ seeded with a realistic LEBT distribution produces a 2.5 MeV, 40 mA H- beam with root-mean-square emittance of 130 deg keV. In measurement, a detailed characterization of the longitudinal phase space is made, including a novel study of the dependence of longitudinal emittance on transverse coordinates. This work introduces a new virtual slit technique that provides subslit resolution in an energy spectrometer as well as an approach for visualizing 4D phase space data. Through simulation and measurement, the RFQ-formed bunch is confirmed to have significant internal correlated structure. The high-dimensional features are shown to be in qualitative agreement. However, the measured rms emittances are up to 30% lower than predicted, closer to the design value of 95 deg keV.},
doi = {10.1103/PhysRevAccelBeams.23.124201},
journal = {Physical Review Accelerators and Beams},
number = 12,
volume = 23,
place = {United States},
year = {2020},
month = {12}
}

Journal Article:
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Works referenced in this record:

Beam-Halo Measurements in High-Current Proton Beams
journal, November 2002


Benchmarking of measurement and simulation of transverse rms-emittance growth
journal, September 2008

  • Groening, L.; Barth, W.; Bayer, W.
  • Physical Review Special Topics - Accelerators and Beams, Vol. 11, Issue 9
  • DOI: 10.1103/PhysRevSTAB.11.094201

Transport of intense ion beams and space charge compensation issues in low energy beam lines (invited)
journal, February 2012

  • Chauvin, N.; Delferrière, O.; Duperrier, R.
  • Review of Scientific Instruments, Vol. 83, Issue 2
  • DOI: 10.1063/1.3678658

Halo formation in three-dimensional bunches with various phase space distributions
journal, January 1999

  • Fedotov, A. V.; Gluckstern, R. L.; Kurennoy, S. S.
  • Physical Review Special Topics - Accelerators and Beams, Vol. 2, Issue 1
  • DOI: 10.1103/PhysRevSTAB.2.014201

SPIRAL2 RFQ bunch lengths and longitudinal emittance measurements
journal, November 2019


Design and commissioning of the Beam Test Facility at the Spallation Neutron Source
journal, January 2020

  • Zhang, Z.; Cousineau, S.; Aleksandrov, A.
  • Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 949
  • DOI: 10.1016/j.nima.2019.162826

Comparison of profile measurements and TRANSPORT beam envelope predictions along the 80-m LANSCE pRad beamline
journal, September 2018


First measurement of a 2.5 MeV RFQ output emittance with 1 part-per-million dynamic range
journal, January 2021

  • Aleksandrov, A.; Cousineau, S.; Ruisard, K.
  • Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 987
  • DOI: 10.1016/j.nima.2020.164829

Macroparticle simulation studies of a proton beam halo experiment
journal, December 2002

  • Qiang, J.; Colestock, P. L.; Gilpatrick, D.
  • Physical Review Special Topics - Accelerators and Beams, Vol. 5, Issue 12
  • DOI: 10.1103/PhysRevSTAB.5.124201

Particle-core model for transverse dynamics of beam halo
journal, December 1998

  • Wangler, T. P.; Crandall, K. R.; Ryne, R.
  • Physical Review Special Topics - Accelerators and Beams, Vol. 1, Issue 8
  • DOI: 10.1103/PhysRevSTAB.1.084201

Space charge dynamics of bright electron beams
journal, February 2003

  • Chao, Alexander W.; Pitthan, Rainer; Tajima, Toshiki
  • Physical Review Special Topics - Accelerators and Beams, Vol. 6, Issue 2
  • DOI: 10.1103/PhysRevSTAB.6.024201

PARMTEQ—A beam-dynamics code fo the RFQ linear accelerator
conference, January 1988

  • Crandall, Kenneth R.; Wangler, Thomas P.
  • AIP Conference Proceedings Volume 177
  • DOI: 10.1063/1.37798

First Six Dimensional Phase Space Measurement of an Accelerator Beam
journal, August 2018


Analytic Model for Halo Formation in High Current Ion Linacs
journal, August 1994


The Particle Accelerator Simulation Code PyORBIT
journal, January 2015


Measuring longitudinal beam parameters in the low energy section of the Oak Ridge Spallation Neutron Source accelerator
journal, September 2018


Mechanisms of halo formation
conference, January 2003

  • Fedotov, Alexei V.
  • BEAM HALO DYNAMICS, DIAGNOSTICS, AND COLLIMATION: 29th ICFA Advanced Beam Dynamics Workshop on Beam Halo Dynamics, Diagnostics, and Collimation HALO'03, AIP Conference Proceedings
  • DOI: 10.1063/1.1638311

The Spallation Neutron Source accelerator system design
journal, November 2014

  • Henderson, S.; Abraham, W.; Aleksandrov, A.
  • Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 763
  • DOI: 10.1016/j.nima.2014.03.067