Session RP1 - Poster Session VIII.
POSTER session, Thursday afternoon, October 30
Fran Hill Southeast Exhibit Hall, ACC
The characteristics of a fast pellet injector for the Ignitor ignition experiment have been identified. In order to produce sufficiently peaked density profiles during the initial phase of the current ramp and to sustain them along the flat top phase, a multiple injector capable of shooting pellets of variable sizes will be developed. The program involves the collaboration of the ENEA Laboratory at Frascati and the Fusion Technology Group of Oak Ridge. The initial activities will be devoted to the development of a 4 barrel, double stage gun able to reach speeds up to 4 km/s. The compact size of the Ignitor machine makes injection from the high field side unpractical, while it is unclear that a vertical injection close to the magnetic axis will be beneficial. Simulations performed with the PELLET code(W.A. Houlberg, et al., Nuclear Fusion) 28, 595 (1988), on the other hand, indicate that pellet speeds of 3-4 km/s would allow a sufficient particle penetration from the low field side, particularly during the initial current ramp up phase, when the plasma temperature is still relatively low and good control of the density profile is most desirable.