EXPERIMENTAL TEST OF 6mm DIAMETER D 2 PELLETS PRODUCED BY IN-SITU CONDENSATION

A prototype single-shot pneumatic pellet injector has been developed in collaboration between JET and EURATOM-CEA association. The main objective of this work is to test the mechanical properties of pellets produced by in-situ condensation, mainly with regard to the maximum acceleration they are able to sustain without being broken. 6 mm diameter D 2 pellets are produced and accelerated with compressed hydrogen gas delivered by a fast valve with 100 bar internal pressure. The length of the barrel is 0,5 m. At this stage of the experiment, pellets have been submitted to initial acceleration values up to 3,5 10 6 m/s 2 without apparent problem. Experiments remain to be made in order to test the pellets for higher initial acceleration values. Maximum velocity reached by the pellets is around 1390 m/s.