skip to main content
DOE PAGES title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Characteristics of the fourth order resonance in high intensity linear accelerators

Abstract

For the 4σ = 360° space-charge resonance in high intensity linear accelerators, the emittance growth is surveyed for input Gaussian beams, as a function of the depressed phase advance per cell σ and the initial tune depression (σ o – σ). For each data point, the linac lattice is designed such that the fourth order resonance dominates over the envelope instability. Additionally, the data show that the maximum emittance growth takes place at σ ≈ 87° over a wide range of the tune depression (or beam current), which confirms that the relevant parameter for the emittance growth is σ and that for the bandwidth is σ o – σ. An interesting four-fold phase space structure is observed that cannot be explained with the fourth order resonance terms alone. Analysis attributes this effect to a small negative sixth order detuning term as the beam is redistributed by the resonance. Analytical studies show that the tune increases monotonically for the Gaussian beam which prevents the resonance for σ > 90°. Lastly, frequency analysis indicates that the four-fold structure observed for input Kapchinskij-Vladmirskij beams when σ < 90°, is not the fourth order resonance but a fourth order envelope instability because the 1/4more » = 90°/360° component is missing in the frequency spectrum.« less

Authors:
ORCiD logo [1];  [2]
  1. Institute for Basic Science, Daejeon (South Korea)
  2. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
Publication Date:
Research Org.:
Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
Sponsoring Org.:
USDOE Office of Science (SC)
OSTI Identifier:
1436155
Alternate Identifier(s):
OSTI ID: 1364184
Grant/Contract Number:  
AC02-05CH11231
Resource Type:
Accepted Manuscript
Journal Name:
Physics of Plasmas
Additional Journal Information:
Journal Volume: 24; Journal Issue: 6; Journal ID: ISSN 1070-664X
Publisher:
American Institute of Physics (AIP)
Country of Publication:
United States
Language:
English
Subject:
43 PARTICLE ACCELERATORS

Citation Formats

Jeon, D., and Hwang, Kyung Ryun. Characteristics of the fourth order resonance in high intensity linear accelerators. United States: N. p., 2017. Web. doi:10.1063/1.4985685.
Jeon, D., & Hwang, Kyung Ryun. Characteristics of the fourth order resonance in high intensity linear accelerators. United States. doi:10.1063/1.4985685.
Jeon, D., and Hwang, Kyung Ryun. Mon . "Characteristics of the fourth order resonance in high intensity linear accelerators". United States. doi:10.1063/1.4985685. https://www.osti.gov/servlets/purl/1436155.
@article{osti_1436155,
title = {Characteristics of the fourth order resonance in high intensity linear accelerators},
author = {Jeon, D. and Hwang, Kyung Ryun},
abstractNote = {For the 4σ = 360° space-charge resonance in high intensity linear accelerators, the emittance growth is surveyed for input Gaussian beams, as a function of the depressed phase advance per cell σ and the initial tune depression (σo – σ). For each data point, the linac lattice is designed such that the fourth order resonance dominates over the envelope instability. Additionally, the data show that the maximum emittance growth takes place at σ ≈ 87° over a wide range of the tune depression (or beam current), which confirms that the relevant parameter for the emittance growth is σ and that for the bandwidth is σo – σ. An interesting four-fold phase space structure is observed that cannot be explained with the fourth order resonance terms alone. Analysis attributes this effect to a small negative sixth order detuning term as the beam is redistributed by the resonance. Analytical studies show that the tune increases monotonically for the Gaussian beam which prevents the resonance for σ > 90°. Lastly, frequency analysis indicates that the four-fold structure observed for input Kapchinskij-Vladmirskij beams when σ < 90°, is not the fourth order resonance but a fourth order envelope instability because the 1/4 = 90°/360° component is missing in the frequency spectrum.},
doi = {10.1063/1.4985685},
journal = {Physics of Plasmas},
number = 6,
volume = 24,
place = {United States},
year = {2017},
month = {6}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record

Figures / Tables:

FIG. 1 FIG. 1: 2D plot of emittance growth factor (= εfinal / εinitial) by the 4σ= 360° space-charge resonance as a function of the initial tune depression (σ° - σ) and depressed phase advance per cell σ. Regardless of the tune depression (or beam current), maximum emittance growth happens at σmore » ≈ 87° just below 90°. For each data point, the linac lattice is designed such that σ is kept constant along the linac to ensure that only the fourth order resonance is manifested and the envelope instability suppressed. And there is no resonance, nor associated emittance growth for σ > 90°.« less

Save / Share:

Works referenced in this record:

Experimental evidence of space charge driven resonances in high intensity linear accelerators
journal, January 2016


Evidence of a halo formation mechanism in the Spallation Neutron Source linac
journal, April 2013


Interplay of space-charge fourth order resonance and envelope instability
journal, October 2016

  • Jeon, D.; Jang, J. H.; Jin, H.
  • Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 832
  • DOI: 10.1016/j.nima.2016.06.036

Practical transverse matching of the high-intensity SNS Linac
journal, August 2009

  • Jeon, D.; Chu, C. M.; Stovall, J.
  • Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 607, Issue 3
  • DOI: 10.1016/j.nima.2009.06.012

Core-halo issues for a very high intensity beam
journal, February 2014

  • Nghiem, P. A. P.; Chauvin, N.; Simeoni, W.
  • Applied Physics Letters, Vol. 104, Issue 7
  • DOI: 10.1063/1.4866400

Self-consistent study of space-charge-driven coupling resonances
journal, May 2006


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

The IFMIF-EVEDA challenges in beam dynamics and their treatment
journal, October 2011

  • Nghiem, P. A. P.; Chauvin, N.; Comunian, M.
  • Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 654, Issue 1
  • DOI: 10.1016/j.nima.2011.06.102

On halo formation from space-charge dominated beams
journal, June 1994

  • Lagniel, Jean-Michel
  • Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 345, Issue 1
  • DOI: 10.1016/0168-9002(94)90970-9

Steady-State Transport of High-Current Beams in a Focused Channel
journal, May 1979


Effects of resonances on halo formation in high-intensity storage rings
journal, December 1999


Anisotropic Free-Energy Limit of Halos in High-Intensity Accelerators
journal, June 2002


RMS Envelope Equations with Space Charge
journal, January 1971


Possible Emittance Increase through Filamentation Due to Space Charge in Continuous Beams
journal, January 1971


Fourth order resonance of a high intensity linear accelerator
journal, May 2009

  • Jeon, D.; Groening, L.; Franchetti, G.
  • Physical Review Special Topics - Accelerators and Beams, Vol. 12, Issue 5
  • DOI: 10.1103/PhysRevSTAB.12.054204

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


Experimental Evidence of the 90° Stop Band in the GSI UNILAC
journal, June 2009


Formation and mitigation of halo particles in the Spallation Neutron Source linac
journal, September 2002

  • Jeon, D.; Stovall, J.; Aleksandrov, A.
  • Physical Review Special Topics - Accelerators and Beams, Vol. 5, Issue 9
  • DOI: 10.1103/PhysRevSTAB.5.094201

Space-Charge Structural Instabilities and Resonances in High-Intensity Beams
journal, November 2015


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

Beam Dynamics for High-Power Superconducting Heavy-Ion Linear Accelerator of RAON
journal, April 2016

  • Hwang, Ji-Gwang; Kim, Eun-San; Kim, Hye-Jin
  • IEEE Transactions on Nuclear Science, Vol. 63, Issue 2
  • DOI: 10.1109/TNS.2015.2500909

Design of the RAON accelerator systems
journal, October 2014

  • Jeon, D.; Hong, I. S.; Kim, H. J.
  • Journal of the Korean Physical Society, Vol. 65, Issue 7
  • DOI: 10.3938/jkps.65.1010

Sixth-Order Resonance of High-Intensity Linear Accelerators
journal, May 2015


    Figures/Tables have been extracted from DOE-funded journal article accepted manuscripts.