Density Imaging Diagnostic for Plasma Radiation Sources
Abstract
A technique to determine the radial distributions of the electron density and temperature in a plasma radiation source (PRS) from radially resolved spectra of optically thin dopants is described herein. A space and time resolved Johann spectrometer and a version with a modified high spectral resolution film circle were constructed for this purpose. The observed values for the temperature sensitive Ly(sub a) and He(sub a) plus intercombination (IC) line intensity ratio and the density sensitive IC/He(sub a) line ratio is compared to calculated values to determine local values n(sub e) and T(sub e). The density profile inferred this way from Si spectra observed on Double Eagle with Al wire loads coated with 5% Si have a minimum on-axis which increases with radius. The minimum on-axis is attributed to opacity effects whereas the larger value in the corona is attributed to He(sub a) radiation emitted in the core that is absorbed and remitted (scattered) by He ions in the corona. A density profile that monotonically decreases from an on-axis maximum is deduced if this scattering of core radiation is included in this analysis. The calculated spectra are sufficiently sensitive to the assumed radial distributions to provide confidence in their uniqueness.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 2005
- Accession Number
- ADA437521
Entities
People
- Edward J. Yadlowsky
- Eric Carlson
- Farid Barakat
- Robert C. Hazelton