Non-maxwellian plasma electrons in the inversion population of Ne-like ions

Level populations and line intensities are calculated for a pure Ne-like argon plasma showing their dependence on plasma parameters (electron temperature, density, plasma column diameter, electron energy distribution, etc.). It is shown that intensity ratios for 2-3 resonance transitions in the Ne-like ion can be used for plasma diagnostics. These intensity ratios are sensitive enough to detect the fraction of suprahot electrons in the plasma. Suprahot electrons cause a strong inversion effect for highly excited levels, e.g., 15:2p3p [J=0], 29:2s3s [J=0]. For these levels, collisional excitation strengths are large at almost any energy of impact electron above threshold. The inversion changes in time with a maximum at t∼80 psec at an electron density of ne∼8x1018 cm-3. The inversion increases with electron energy