Investigation of the radiation properties of L- and M-shell X-pinch plasma x-ray sources using a transmission grating spectrometer

A transmission grating spectrometer (TGS) with one dimensional spatial resolution was used to investigate the radiative properties of X-pinch plasmas produced using wires made of NiCr and CoNiCr alloys, and Mo. Experiments were carried out on the Cornell XP machine. The TGS was used to estimate of the energy yields of L-shell Cr and Ni, and M-shell Mo radiation. The absolute energy yields in the wavelength range 10<lambda<15 Angstrom were 1-5% of the total energy delivered to the load (10-40 J for L-shell NiCr, and 20-50 J for M-shell Mo). An analysis of the spatial structure of X-pinch emission regions in different wavelength ranges shows that the source structure is changing with wavelength and the size varies from less than 0.1 up to 1 mm. For example, in one Mo X-pinch test shown, three separate soft x-ray sources radiating in the wavelength range lambda<42 Angstrom can be seen, but only one of those sources radiates in the wavelength range lambda>42 Angstrom. The results are compared with data obtained previously with the TGS on a 1 MA pulse powered machine Zebra. (C) 2004 American Institute of Physics.