Plasma edge diagnostic by optical spectroscopy of He-beams
For the investigation of the plasma edge of a tokamak a new method for the determination of electron densities n(e) and temperatures T(e) by the emission of an injected He-atomic beam has been developed. The intensity ratio of two singlet lines gives n(e), the ratio of a singlet to a triplet line T(e). For the interpretation of the intensity ratios a collisional-radiative model has been evaluated, which takes 19 discrete levels into account. The parameter range with electron densities between 1.0 E11 and 1.0 E14/cm2 and temperatures between 5 eV and 1000 eV has been considered. The diagnostic method needs a beam injection and an observation port, which for good spatial resolution are nearly perpendicular to each other. Linear array cameras with interference filters are used for detection. Results obtained by this diagnostic are compared with those from other independent methods.
Bibliographic Reference: Article: 21st International Conference on Phenomena in Ionized Gases, Bochum (DE) : Proceedings, Vol. III (1993) pp. 310-317
Record Number: 199410045 / Last updated on: 1994-11-28
Original language: en
Available languages: en