title: Measuring electron-positron annihilation radiation from laser plasma interactions.
abstract: We investigated various diagnostic techniques to measure the 511 keV annihilation radiations. These include step-wedge filters, transmission crystal spectroscopy, single-hit CCD detectors, and streaked scintillating detection. While none of the diagnostics recorded conclusive results, the step-wedge filter that is sensitive to the energy range between 100 keV and 700 keV shows a signal around 500 keV that is clearly departing from a pure Bremsstrahlung spectrum and that we ascribe to annihilation radiation.
authors.affiliation: Lawrence Livermore National Laboratory, Livermore, California 94551, USA. chen33@llnl.gov
authors.forename: Hui
authors.initials: H
authors.lastname: Chen
authors.forename: R
authors.initials: R
authors.lastname: Tommasini
authors.forename: J
authors.initials: J
authors.lastname: Seely
authors.forename: C I
authors.initials: CI
authors.lastname: Szabo
authors.forename: U
authors.initials: U
authors.lastname: Feldman
authors.forename: N
authors.initials: N
authors.lastname: Pereira
authors.forename: G
authors.initials: G
authors.lastname: Gregori
authors.forename: K
authors.initials: K
authors.lastname: Falk
authors.forename: J
authors.initials: J
authors.lastname: Mithen
authors.forename: C D
authors.initials: CD
authors.lastname: Murphy