Helium exhaust in plasmas with strong radiative edge cooling
The compatibility of radiative edge cooling by neon injection and He exhaust with the pump limiter ALT-II is studied on TEXTOR. It is demonstrated that in plasmas with strong auxiliary heating (2 MW NBI) and with the highest average electron densities (nbar(e) approximately equal to 5.5 x 1.0 E19/m3) the effective confinement time for He has a minimum. This good pumping performance is maintained even for cases in which up to 90 % of the heating power is radiated from the plasma boundary (cold radiative edge). The processes inside the scoops of the pump limiter (neutral particle transport, re-ionisation) and the variation of particle confinement in the main plasma dominate this behaviour.
Bibliographic Reference: Article: Journal of Nuclear Materials, Vol. 196-198 (1992) pp. 633-636
Record Number: 199310385 / Last updated on: 1994-11-29
Original language: en
Available languages: en