Time-resolved grating spectroscopy of a N capillary discharge plasma for a recombination pumped x-ray laser

• Published in: Journal of quantitative spectroscopy & radiative transfer 2013-09, Vol.127, p.176-182
• Main Authors: Gissis, I., Rikanati, A., Be'ery, I., Fisher, A., Behar, E.
• Format: Article
• Language: English
• Subjects: Capillary; Collisional-radiative atomic code; Nitrogen; Transmission grating spectrometer; x-ray diode; x-ray laser; z-pinch
• ISSN: 0022-4073; 1879-1352
• DOI: 10.1016/j.jqsrt.2013.05.014

Capillary discharge plasmas can serve for recombination-pumped x-ray lasers. We present time-resolved x-ray spectra and density measurements of a nitrogen capillary discharge z-pinch plasma. We use a free-standing transmission grating spectrometer and a gated MCP camera. This is the first time both K-shell and L-shell line emission of the nitrogen plasma are recorded simultaneously. Comparison of the spectra with a 4-ion collisional-radiative atomic model, which accounts for opacity effects, shows that the plasma reaches a maximum temperature of kTe=75–85eV during the pinch, and adiabatically cools in less than 4ns. This is slightly less than the newly estimated goal temperature of 110eV. The fast cooling demonstrates the feasibility of a recombination-scheme laser in the nitrogen Hα line at 13.37nm, if higher plasma temperature is achieved. •We study the recombination pumping scheme for x-ray laser in nitrogen.•We used a capillary discharge z-pinch apparatus with current pulse of 60kA in 60ns.•We measured time resolved x-ray spectra using transmission grating spectrometer.•We developed a collisional-radiative atomic model to analyze the spectra.•The CR model takes opacity effects under account.