Plasma Conditions Required for Attainment of Maximum Gain in Resonantly Photo-Pumped A1 XII and Ne IX.
Abstract
We present a detailed analysis of the plasma conditions required to optimize gain in two proposed x-ray lasing schemes using resonant photo-pumping. In one proposed configuration, the Si XIII line 1s2-1s2p1P at 6.650 A pumps A1 XII 1s2-1s3p1P at 6.635 A, inverting the A1 XII n=3 and N=2 levels which are separated by 44 A. A similar approach which utilizes the Na X 1s2-1s2p1P line at 11.00 A to pump the Ne IX 1s2-1s4p 1P line at 11.001 A would invert the n=3 and n=2 levels of Ne IX, separated by 82 A. Conditions in the pumped neon and aluminum plasmas, and in the pumping silicon plasma, are calculated using a multistage, multilevel atomic model with multi-frequency radiation transport. Temperatures required to maximize gain in the pumped plasmas are found to be 50 eV and 100 eV, for neon and aluminum, respectively. Plasmas of lower temperature do not contain enough of the active ion species, whereas at higher temperatures the photon pumping of the upper levels results in excessive ionization from these levels to the hydrogen-like species. Finally, since the pumping silicon and pumped aluminum lines are slightly off resonance, we have investigated the effect of streaming the plasmas toward each other at various velocities to offset some or all of the wavelength difference.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 09, 1981
- Accession Number
- ADA105779
Entities
People
- J. P. Apruzese
- Jack F. Davis
- K. G. Whitney
Organizations
- United States Naval Research Laboratory