High performance JET plasmas for DT operation with the Mk II Divertor
The objectives of planned Joint European Torus (JET) experiments require high fusion performance, and alpha-particle heating effects will be best detected by the achievement of high Q(DT) in stationary conditions. So far in JET deuterium plasmas, the highest neutron rates have been obtained in the edge localized mode (ELM) free hot-ion H-mode. Magnetohydrodynamic (MHD) events appear to trigger confinement loss after 1-2 s. Long MHD-free periods are only obtained with sufficient triangular component in the plasma shape, consistent with increased edge ballooning and kink stability. High recycling reduces both ELM-free period and confinement. The Mk II divertor is more closed to recirculating neutrals, and this, together with maintaining the target tiles at elevated temperature during vessel baking, is being exploited to minimize the adverse effects of recycling. Recent experiments have shown the importance of other vessel surfaces as recycling sources. The ability to heat the central plasma without fuelling provides a promising means of obtaining more favourable pressure profiles and higher normalized beta.
Bibliographic Reference: Article: Bulletin of the American Physical Society, Vol. 41 (1996) No. 7, pp. 1418-1419
Record Number: 199710420 / Last updated on: 1997-04-23
Original language: en
Available languages: en