FLUORESCENCE IN MG-IX EMISSION AT 48.340 ANGSTROM FROM MG PINCH PLASMAS PHOTOPUMPED BY AL-XI LINE RADIATION AT 48.338 ANGSTROM

Resonant photopumping of Be-like Mg IX ions by Li-like Al XI line radiation has been studied in pulsed-power-driven plasmas as a possible approach to achieve laser action in the extreme-ultraviolet wavelength region. An Al x-pinch or z-pinch plasma imploded by a 0.5-TW pulsed power generator produced intense line radiation at 48.338 angstrom. A separate Mg z-pinch plasma, driven by the same pulsed power generator, was created in parallel with 1 cm separating the two plasmas. Evidence for fluorescence (resonant scattering) was the appearance of 48.340-angstrom resonance line emission from the 4p level of Mg IX ions due to photopumping by the Al XI line radiation at 48.338 angstrom. Fluorescence may also have been observed on the Mg VIII line at 52.395 angstrom, photopumped by Al xi line radiation at 52.446 angstrom. Both Al and Mg plasmas were characterized in the experiments. Improvements to the pump geometry required to achieve gain on the Mg IX line at 228 angstrom are also discussed.