Properties of plasma radiation diagnostics

A number of diagnostics utilizing the radiation emitted from high-temperature plasmas have been developed at Los Alamos. Photoemissive x-ray diodes with photon energy bandpass filters provide time resolved rough spectral data from bout 6 eV to > 10 keV photon energy. Filtered silicon photodiodes can be used down to 1 eV and offer the advantages of nominally flat response and ability to operate in poor vacuum conditions. Both types of diodes will provide a rough time resolved spectrum and both are relatively inexpensive, reliable, and passive (i.e. no synchronization problems). For higher energy resolution bent crystal spectrographs are used in the x-ray region. With the addition of streak cameras or gated microchannel plates these systems provide data with high energy and high time resolution. To measure the total energy output a thin foil bolometer is used that measures the change in foil resistance as it is heated by the plasma radiation. Information on the physical location of the plasma is provided by a suite of visible framing cameras and x-ray pinhole cameras. By combining these diagnostics into a complementary set good diagnostic information can be guaranteed on any plasma experiment.