Determination of impurity concentrations and Z(eff) by VUV spectroscopy on ASDEX
The impurity concentrations and corresponding Z(eff) contributions as well as the dilution of the deuterium background plasma in ASDEX are determined by VUV spectroscopy. The methods used are presented in detail. The absolute calibration of the VUV survey spectrometer with two different calibration sources, as well as the ZEDIFF time dependent transport code, used for interpreting the spectroscopic measurements, are described. The assessed spectroscopic Z(eff) compares quite well with the bremsstrahlung Z(eff), as demonstrated for a number of representative ohmically and additionally heated discharges. In order to obtain these results readily on a shot-to-shot basis at the end of each discharge, a simplified fast evaluation method is introduced. This fast analysis method yields the central impurity concentrations, the central Z(eff) contributions and the dilution of the deuterons. The results from the fast analysis method agree well with those from the extended transport code treatment and with the bremsstrahlung Z(eff).
Bibliographic Reference: Report: IPP III/147 EN (1990) 45 pp.
Availability: Available from Max-Planck-Institut für Plasmaphysik, 8046 Garching bei München (DE)
Record Number: 199011267 / Last updated on: 1994-12-01
Original language: en
Available languages: en