New density diagnostic method based on emission line intensity ratio of neutral hydrogen in an ionizing phase plasma

Abstract

For high temperature hydrogen plasmas in the ionizing phase, the population density of the excited levels has been calculated for a wide range of electron densities and temperatures. In the calculation we employed the most recent and reliable cross-section data for excitation between discrete levels and the ionization cross-section data from these levels. The line intensity ratios calculated under conditions of optical thinness are presented graphically for the Lyman and Balmer series lines. The intensity ratios are found to be rather insensitive to the electron temperature for temperatures higher than 10 eV. These values may be used for determining the electron density in the region of 10 17 ⪅ n e ⪅ 10 21 m −3 , which is relevant to fusion research plasmas. Radiation loss from the plasma and energy loss from the plasma electrons are also presented for a wide range of electron densities and temperatures.