Positron production by X rays emitted by Betatron motion in a plasma wiggler

D. K. Johnson, D. Auerbach, I. Blumenfeld, C. D. Barnes, C. E. Clayton, F. J. Decker, S. Deng, P. Emma, M. J. Hogan, C. Huang, R. Ischebeck, R. Iverson, C. Joshi, T. C. Katsouleas, N. Kirby, P. Krejcik, W. Lu, K. A. Marsh, W. B. Mori, P. MuggliC. L. O'Connell, E. Oz, R. H. Siemann, D. Walz, M. Zhou

Research output: Contribution to journalArticlepeer-review

35 Scopus citations


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.

Original languageEnglish (US)
Article number175003
JournalPhysical Review Letters
Issue number17
StatePublished - 2006
Externally publishedYes

ASJC Scopus subject areas

  • General Physics and Astronomy


Dive into the research topics of 'Positron production by X rays emitted by Betatron motion in a plasma wiggler'. Together they form a unique fingerprint.

Cite this