Tritium handling experience in vacuum systems at TSTA

Compound cryopumps have been added to the Tritium Systems Test Assembly (TSTA) integrated fusion fuel loop. Operations have been performed which closely simulate an actual fusion reactor pumping scenario. In addition, performance data have been taken that support the concept of using coconut charcoal as a sorbent at 4 K for pumping helium. Later tests show that coconut charcoal may be used to co-pump D, T and He mixtures on a single 4 K panel. Rotary spiral pumps have been used successfully in several applications at TSTA and have acquired more than 9000 h of maintenance-free operation. Metal bellows pumps have been used to back the spiral pumps and have been relatively trouble-free in loop operations. Bellows pumps also have more than 9000 h of maintenance-free operation. (author)