Effective K. cap alpha. x-ray excitation rates for plasma impurity measurements
Metal impurity concentrations are measured by the Pulse-Height-Analyzer (PHA) diagnostic from K..cap alpha.. x-ray peak intensities by use of an averaged excitation rate . Low-Z impurity concentrations are inferred from the continuum enhancement (relative to a pure plasma) minus the enhancement due to metals. Since the PHA does not resolve lines from different charge states, is a weighted sum of rates; coronal equilibrium is usually assumed. The used earlier omitted the intercombination and forbidden lines from the dominant helium-like state. The result was an overestimate of metals and an underestimate of low-Z impurities in cases where metals were significant. Improved values of using recent calculations for H-, He-, and Li-like Fe range from 10 to 50% larger than the earlier rates and yield metal concentrations in better agreement with those from VUV spectroscopy.
- Research Organization:
- Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States)
- DOE Contract Number:
- AC02-76CH03073
- OSTI ID:
- 5405757
- Report Number(s):
- PPPL-2348; ON: DE86013631
- Resource Relation:
- Other Information: Portions of this document are illegible in microfiche products. Original copy available until stock is exhausted
- Country of Publication:
- United States
- Language:
- English
Similar Records
Excitation rates for plasma impurity measurements by x-ray diagnostics
Tokamak physics studies using x-ray diagnostic methods