High resolution soft x-ray spectroscopy of low Z K-shell emission from laser-produced plasmas

A large radius, R=44.3 m, high resolution grating spectrometer (HRGS) with 2400 lines/mm variable line spacing has been designed for laser-produced plasma experiments conducted at the Lawrence Livermore National Laboratory Jupiter Laser Facility. The instrument has been run with a low-noise, charge-coupled device detector to record high signal-to-noise spectra in the 10-50 A wavelength range. The instrument can be run with a 10-20 μm wide slit to achieve the best spectral resolving power, approaching 1000 and similar to crystal spectrometers at 12-20 A, or in slitless operation with a small symmetrical emission source. We describe preliminary spectra emitted from various H-like and He-like low Z ion plasmas heated by 100-500 ps (full width at half maximum), 527 nm wavelength laser pulses. This instrument can be developed as a useful spectroscopy platform relevant to laboratory-based astrophysics as well as high energy density plasma studies.