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

Title: Demonstration of a Novel Positron Source Based on a Plasma Wiggler

Abstract

A new method for generating positrons has been proposed that uses betatron X-rays emitted by an electron beam in a high-K plasma wiggler. The plasma wiggler is an ion column produced by the head of the beam when the peak beam density exceeds the plasma density. The radial electric field of the beam blows out the plasma electrons transversely, creating an ion column. The focusing electric field of the ion column causes the beam electrons to execute betatron oscillations about the ion column axis. If the beam energy and the plasma density are high enough, these oscillations lead to synchrotron radiation in the 1-50 MeV range. A significant amount of electron energy can be lost to these radiated X-ray photons. These photons strike a thin (.5Xo), high-Z target and create e+/e- pairs. The experiment was performed at the Stanford Linear Accelerator Center (SLAC) where a 28.5 GeV electron beam with {sigma}r {approx_equal} 10{mu}m and {sigma}z {approx_equal} 25{mu}m was propagated through a neutral Lithium vapor (Li). The radial electric field of the dense beam was large enough to field ionize the Li vapor to form a plasma. The positron yield was measured as a function of plasma density, ion column lengthmore » and electron beam pulse length. A computational model was written to match the experimental data with theory. The measured positron spectra are in excellent agreement with those expected from the calculated X-ray spectral yield from the plasma wiggler. After matching the model with the experimental results, it was used to design a more efficient positron source, giving positron yields of 0.44 e+/e-, a number that is close to the target goal of 1-2 e+/e- for future positron sources.« less

Authors:
; ; ; ; ; ; ;  [1]; ; ; ; ; ; ; ; ; ; ; ;  [2]
  1. University of California, Los Angeles, CA 90095 (United States)
  2. Stanford Linear Accelerator Center, Stanford, CA 94309 (United States)
Publication Date:
OSTI Identifier:
20898746
Resource Type:
Journal Article
Journal Name:
AIP Conference Proceedings
Additional Journal Information:
Journal Volume: 877; Journal Issue: 1; Conference: 12. advanced accelerator concepts workshop, Lake Geneva, WI (United States), 10-15 Jul 2006; Other Information: DOI: 10.1063/1.2409122; (c) 2006 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0094-243X
Country of Publication:
United States
Language:
English
Subject:
43 PARTICLE ACCELERATORS; BEAM-PLASMA SYSTEMS; BETATRON OSCILLATIONS; BETATRONS; ELECTRIC FIELDS; ELECTRON BEAMS; GEV RANGE 10-100; LITHIUM; PHOTONS; PLASMA; PLASMA DENSITY; POSITRON SOURCES; STANFORD LINEAR ACCELERATOR CENTER; SYNCHROTRON RADIATION; WIGGLER MAGNETS; X RADIATION

Citation Formats

Johnson, D K, Clayton, C E, Huang, C, Joshi, C, Lu, W, Marsh, K A, Mori, W B, Zhou, M, Blumenfeld, I, Barnes, C D, Decker, F J, Emma, P, Hogan, M J, Ischebeck, R, Iverson, R, Kirby, N, Krejcik, P, O'Connell, C L, Siemann, R H, and Walz, D. Demonstration of a Novel Positron Source Based on a Plasma Wiggler. United States: N. p., 2006. Web. doi:10.1063/1.2409122.
Johnson, D K, Clayton, C E, Huang, C, Joshi, C, Lu, W, Marsh, K A, Mori, W B, Zhou, M, Blumenfeld, I, Barnes, C D, Decker, F J, Emma, P, Hogan, M J, Ischebeck, R, Iverson, R, Kirby, N, Krejcik, P, O'Connell, C L, Siemann, R H, & Walz, D. Demonstration of a Novel Positron Source Based on a Plasma Wiggler. United States. https://doi.org/10.1063/1.2409122
Johnson, D K, Clayton, C E, Huang, C, Joshi, C, Lu, W, Marsh, K A, Mori, W B, Zhou, M, Blumenfeld, I, Barnes, C D, Decker, F J, Emma, P, Hogan, M J, Ischebeck, R, Iverson, R, Kirby, N, Krejcik, P, O'Connell, C L, Siemann, R H, and Walz, D. 2006. "Demonstration of a Novel Positron Source Based on a Plasma Wiggler". United States. https://doi.org/10.1063/1.2409122.
@article{osti_20898746,
title = {Demonstration of a Novel Positron Source Based on a Plasma Wiggler},
author = {Johnson, D K and Clayton, C E and Huang, C and Joshi, C and Lu, W and Marsh, K A and Mori, W B and Zhou, M and Blumenfeld, I and Barnes, C D and Decker, F J and Emma, P and Hogan, M J and Ischebeck, R and Iverson, R and Kirby, N and Krejcik, P and O'Connell, C L and Siemann, R H and Walz, D},
abstractNote = {A new method for generating positrons has been proposed that uses betatron X-rays emitted by an electron beam in a high-K plasma wiggler. The plasma wiggler is an ion column produced by the head of the beam when the peak beam density exceeds the plasma density. The radial electric field of the beam blows out the plasma electrons transversely, creating an ion column. The focusing electric field of the ion column causes the beam electrons to execute betatron oscillations about the ion column axis. If the beam energy and the plasma density are high enough, these oscillations lead to synchrotron radiation in the 1-50 MeV range. A significant amount of electron energy can be lost to these radiated X-ray photons. These photons strike a thin (.5Xo), high-Z target and create e+/e- pairs. The experiment was performed at the Stanford Linear Accelerator Center (SLAC) where a 28.5 GeV electron beam with {sigma}r {approx_equal} 10{mu}m and {sigma}z {approx_equal} 25{mu}m was propagated through a neutral Lithium vapor (Li). The radial electric field of the dense beam was large enough to field ionize the Li vapor to form a plasma. The positron yield was measured as a function of plasma density, ion column length and electron beam pulse length. A computational model was written to match the experimental data with theory. The measured positron spectra are in excellent agreement with those expected from the calculated X-ray spectral yield from the plasma wiggler. After matching the model with the experimental results, it was used to design a more efficient positron source, giving positron yields of 0.44 e+/e-, a number that is close to the target goal of 1-2 e+/e- for future positron sources.},
doi = {10.1063/1.2409122},
url = {https://www.osti.gov/biblio/20898746}, journal = {AIP Conference Proceedings},
issn = {0094-243X},
number = 1,
volume = 877,
place = {United States},
year = {Mon Nov 27 00:00:00 EST 2006},
month = {Mon Nov 27 00:00:00 EST 2006}
}