Deuterium ice pellet injection during pulsed poloidal current drive operation in toroidal pinch Experiment-RX reversed-field pinch device

Deuterium ice pellet injection has been used to control the density profile and expand the operation region of a reversed-field pinch (RFP) experiment on a toroidal pinch experiment-RX (TPE-RX) device. With pellet injection during the pulsed poloidal current drive (PPCD) operation, which is one of the good confinement operation conditions in RFP, electron density increases to more than three times that of standard discharge. The pellet is ablated within only approximately 1 ms, nevertheless, this high density can be almost constantly sustained for ~10 ms until completion of the PPCD period. When compared with ordinary discharge without PPCD, particle confinement time increases by a factor of five in the latter part of the PPCD period when the pellet is injected at the start of PPCD discharge.