Investigation of the plasma bremsstrahlung in the near infrared for the determination of Z(eff) and for the feedback control of the electron density
In the ASDEX Thomson scattering system the scattered light of a Nd:YAG laser beam (lambda = 1064 nm) is measured to obtain electron density and temperature profiles every 16 ms. The same system is used continuously to measure bremsstrahlung in the near infrared, allowing determination of radial Z(eff) profiles. Furthermore, the diagnostic can also be used for real time control of the electron density. This applies in particular cases where large sawteeth and pellet injection generate counting errors in the interferometer signal. The relation between the line density n and the central chord bremsstrahlung signal U(b) is investigated for different heating scenarios in a wide density range.
Bibliographic Reference: Report: IPP III/177 DE (1990) 64 pp.
Availability: Available from Max-Planck-Institut für Plasmaphysik, 8046 Garching bei München (DE)
Record Number: 199110884 / Last updated on: 1994-12-02
Original language: de
Available languages: de