X-ray spectroscopy of L-shell krypton emission
Abstract
X-ray spectroscopy of direct- and indirect-drive implosions is a powerful diagnostic of the core plasma conditions achieved in experiments. We discuss the temperature and density dependence of the x-ray line emission of L-shell krypton ions afforded through the characteristic sensitivities of the atomic level populations and charged state distributions and detailed Stark-broadened spectral line shapes due to plasma electric microfields, respectively. We have found that krypton-tracer atomic concentrations in the range from 0.02% to 0.04% of the main fill gas produce krypton L-shell n =4-2 line emission with values of optical depth that are less than 1 and intensity comparable to previous observations of argon K-shell spectra. In particular, modeling calculations suggest that L-shell emission of Be- and Li-like krypton ions can be used to diagnose electron temperatures in the 1.5keV to 3keV range in dense implosion cores. Furthermore, since the photon energy ranges of krypton L-shell and argon K-shell emissions are comparable, streaked and imaging spectrometers employed for argon spectroscopy can be used for krypton L-shell as well.
This work was sponsored by DOE Cooperative agreement DE-NA0003868.- Publication:
-
APS Division of Plasma Physics Meeting Abstracts
- Pub Date:
- 2020
- Bibcode:
- 2020APS..DPPB10003G