Positron production by x rays emitted by betatron motion in a plasma wiggler.


Journal Article

Positrons in the energy range of 3-30 MeV, produced by x rays emitted by betatron motion in a plasma wiggler of 28.5 GeV electrons from the SLAC accelerator, have been measured. The extremely high-strength plasma wiggler is an ion column induced by the electron beam as it propagates through and ionizes dense lithium vapor. X rays in the range of 1-50 MeV in a forward cone angle of 0.1 mrad collide with a 1.7 mm thick tungsten target to produce electron-positron pairs. The positron spectra are found to be strongly influenced by the plasma density and length as well as the electron bunch length. By characterizing the beam propagation in the ion column these influences are quantified and result in excellent agreement between the measured and calculated positron spectra.

Full Text

Cited Authors

  • Johnson, DK; Auerbach, D; Blumenfeld, I; Barnes, CD; Clayton, CE; Decker, FJ; Deng, S; Emma, P; Hogan, MJ; Huang, C; Ischebeck, R; Iverson, R; Joshi, C; Katsouleas, TC; Kirby, N; Krejcik, P; Lu, W; Marsh, KA; Mori, WB; Muggli, P; O'Connell, CL; Oz, E; Siemann, RH; Walz, D; Zhou, M

Published Date

  • October 27, 2006

Published In

Volume / Issue

  • 97 / 17

Start / End Page

  • 175003 -

PubMed ID

  • 17155479

Pubmed Central ID

  • 17155479

Electronic International Standard Serial Number (EISSN)

  • 1079-7114

International Standard Serial Number (ISSN)

  • 0031-9007

Digital Object Identifier (DOI)

  • 10.1103/physrevlett.97.175003


  • eng