Neutral beam modulation for heating profile measurements
Modulation of the plasma heating power leads to a modulation of the electron temperature which can be measured spatially-resolved using ECE techniques. The T(e) amplitude is proportional to the local power density if the modulation frequency is so high that heat conduction effects can be neglected. If an injected neutral beam is modulated, the modulation of the resulting heating power is damped by the finite slowing-down time of the beam ions in the plasma. The damping factor is proportional to 1/lf if lf > 0.5/t(max) (f = modulation frequency, l = harmonic number, t(max) = complete slowing-down time). The expected modulation of the electron temperature is investigated here with special emphasis on the conditions with the stellarator experiment W7-AS.
Bibliographic Reference: Report: IPP4/276 EN (1997) 18pp.
Availability: Available from the Max-Planck-Institut für Plasmaphysik, 85748 Garching bei München (DE)
Record Number: 199710924 / Last updated on: 1997-07-23
Original language: en
Available languages: en