Search Menu
DOE PAGES title logo U.S. Department of Energy
Office of Scientific and Technical Information
Search Scholarly Publications

Title: Low emittance growth in a low energy beam transport line with un-neutralized section

Abstract

In a Low Energy Beam Transport line (LEBT), the emittance growth due to the beam's space charge is typically suppressed by way of neutralization from either electrons or ions, which originate from ionization of the background gas. In cases where the beam is chopped, the neutralization pattern usually changes throughout the beginning of the pulse, causing the Twiss parameters to differ significantly from their steady state values, which, in turn, may result in beam losses downstream. For a modest beam perveance, there is an alternative solution, in which the beam is kept un-neutralized in the portion of the LEBT that contains the chopper. The emittance can be nearly preserved if the transition to the un-neutralized section occurs where the beam exhibits low transverse tails. This report introduces the rationale for the proposed scheme and formulates the physical arguments for it as well as its limitations. In conclusion, an experimental realization of the scheme was carried out at Fermilab's PIP2IT where low beam emittance dilution was demonstrated for a 5 mA, 30 keV $$H^{-}$$ beam.

Authors:
; ;
Publication Date:
Research Org.:
Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States)
Sponsoring Org.:
USDOE Office of Science (SC), High Energy Physics (HEP)
OSTI Identifier:
1419706
Alternate Identifier(s):
OSTI ID: 1415629
Report Number(s):
Fermilab-Pub-17-599-AD; arXiv:1805.01920; FERMILAB-PUB-17-599-AD
Journal ID: ISSN 2469-9888; PRABCJ; 020101
Grant/Contract Number:  
AC02-07CH11359
Resource Type:
Published Article
Journal Name:
Physical Review Accelerators and Beams
Additional Journal Information:
Journal Name: Physical Review Accelerators and Beams Journal Volume: 21 Journal Issue: 2; Journal ID: ISSN 2469-9888
Publisher:
American Physical Society
Country of Publication:
United States
Language:
English
Subject:
43 PARTICLE ACCELERATORS

Citation Formats

Prost, L., Carneiro, J. -P., and Shemyakin, A. Low emittance growth in a low energy beam transport line with un-neutralized section. United States: N. p., 2018. Web. doi:10.1103/PhysRevAccelBeams.21.020101.
Copy to clipboard
Prost, L., Carneiro, J. -P., & Shemyakin, A. Low emittance growth in a low energy beam transport line with un-neutralized section. United States. https://doi.org/10.1103/PhysRevAccelBeams.21.020101
Copy to clipboard
Prost, L., Carneiro, J. -P., and Shemyakin, A. Tue . "Low emittance growth in a low energy beam transport line with un-neutralized section". United States. https://doi.org/10.1103/PhysRevAccelBeams.21.020101.
Copy to clipboard
@article{osti_1419706,
title = {Low emittance growth in a low energy beam transport line with un-neutralized section},
author = {Prost, L. and Carneiro, J. -P. and Shemyakin, A.},
abstractNote = {In a Low Energy Beam Transport line (LEBT), the emittance growth due to the beam's space charge is typically suppressed by way of neutralization from either electrons or ions, which originate from ionization of the background gas. In cases where the beam is chopped, the neutralization pattern usually changes throughout the beginning of the pulse, causing the Twiss parameters to differ significantly from their steady state values, which, in turn, may result in beam losses downstream. For a modest beam perveance, there is an alternative solution, in which the beam is kept un-neutralized in the portion of the LEBT that contains the chopper. The emittance can be nearly preserved if the transition to the un-neutralized section occurs where the beam exhibits low transverse tails. This report introduces the rationale for the proposed scheme and formulates the physical arguments for it as well as its limitations. In conclusion, an experimental realization of the scheme was carried out at Fermilab's PIP2IT where low beam emittance dilution was demonstrated for a 5 mA, 30 keV $H^{-}$ beam.},
doi = {10.1103/PhysRevAccelBeams.21.020101},
journal = {Physical Review Accelerators and Beams},
number = 2,
volume = 21,
place = {United States},
year = {Tue Feb 06 00:00:00 EST 2018},
month = {Tue Feb 06 00:00:00 EST 2018}
}
Copy to clipboard
Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record
https://doi.org/10.1103/PhysRevAccelBeams.21.020101
Copyright Statement
Other availability
Search WorldCat Search WorldCat to find libraries that may hold this journal
Citation Metrics:
Cited by: 3 works
Citation information provided by
Web of Science

Figures / Tables:

Figure 1 Figure 1: Emittance growth as a function of the H- beam current simulated with TraceWin [8]. The beam energy is 30 keV. Blue - Double-Gaussian initial distribution; Red - UG initial distribution. The drift length is 251 mm, the initial rms beam size is 7.5 mm, and the initial anglemore » is adjusted for each current to provide the final rms size equal to the initial’s. Initial beam emittance is 25 µm (rms, unnormalized) for both distributions. There is no beam loss.« less
All figures and tables (13 total)
Save / Share:
Export Metadata
Save to My Library
You must Sign In or Create an Account in order to save documents to your library.

Works referenced in this record:

H− beam neutralization measurements in a solenoidal beam transport system
conference, January 1992

  • Sherman, Joseph; Pitcher, Eric; Stevens, Ralph
  • Production and neutralization of negative ions and beams, AIP Conference Proceedings
  • DOI: 10.1063/1.44814

Relation between Field Energy and RMS Emittance in Intense Particle Beams
journal, January 1985

  • Wangler, T. P.; Crandall, K. R.; Mills, R. S.
  • IEEE Transactions on Nuclear Science, Vol. 32, Issue 5
  • DOI: 10.1109/TNS.1985.4333859

Negative ion beam space charge compensation by residual gas
journal, August 2015

  • Valerio-Lizarraga, Cristhian A.; Leon-Monzon, Ildefonso; Scrivens, Richard
  • Physical Review Special Topics - Accelerators and Beams, Vol. 18, Issue 8
  • DOI: 10.1103/PhysRevSTAB.18.080101

Theory and Design of Charged Particle Beams
book, January 1994

Generation of initial kinetic distributions for simulation of long-pulse charged particle beams with high space-charge intensity
journal, November 2009

  • Lund, Steven M.; Kikuchi, Takashi; Davidson, Ronald C.
  • Physical Review Special Topics - Accelerators and Beams, Vol. 12, Issue 11
  • DOI: 10.1103/PhysRevSTAB.12.114801
    Sort by:
    [ × clear filter / sort ]

    Figures / Tables found in this record:

    Figure 1 (p. 2)figure
    Figure 2 (p. 3)figure
    Figure 3 (p. 3)figure
    Figure 4 (p. 4)figure
    Figure 5 (p. 4)figure
    Figure 6 (p. 5)figure
    Figure 7 (p. 5)figure
    Figure 8 (p. 6)figure
    Figure 9 (p. 6)figure
    Figure 10 (p. 7)figure
    Figure 11 (p. 8)figure
    Table 1 (p. 8)table
    Figure 12 (p. 9)figure
      [ × clear filter / sort ]
      Figures/Tables have been extracted from DOE-funded journal article accepted manuscripts.

      Similar Records in DOE PAGES and OSTI.GOV collections: