H-mode confinement in JET with enhanced performance by pellet-peaked density profilesFunded under: FP2-FUSION 10C
The combination of two regimes of enhanced performance, the H mode and the pellet-enhanced-performance (PEP) mode, has been achieved in JET. The strong enhancement of the central plasma parameters, obtained with pellet injection and subsequent auxiliary heating, are found to persist well into the H mode phase. A characteristic of the PEP regime is that an improvement of the fusion reactivity over non-pellet discharges is obtained under the condition of near-equal electron and ion temperature. A maximum neutron production rate of 0.95 x 1.0 E16/s was obtained in a double-null X-point discharge with 2.5 MW of neutral beam heating and 9 MW of ion cyclotron resonance heating, with central ion and electron temperatures of about 10 keV and a central deuterium density of 8.0 x 1.0 E19/m3. The corresponding fusion product (D)T(i)tau(E) is between 7.0 and 8.6 x 1.0 E20/m3s keV. The enhanced neutron production is predominantly of thermonuclear origin. The compatibility of these regimes is an important issue in the context of tokamak ignition strategies.
Bibliographic Reference: Report: JET-P(90)67 EN (1990)
Availability: Available from the Publications Officer, JET Joint Undertaking, Abingdon, Oxon. OX14 3EA (GB)
Record Number: 199110536 / Last updated on: 1994-12-02
Original language: en
Available languages: en