Plasma End-Loss Studies on Scylla I-C

摘要

The end-loss process in the collision dominated Scylla I-C plasma has been investigated with a local pressure sensitive di¬agnostic, integrated density measurements and axially arrayed diamagnetic loop probes. The development of a plasma loss orifice, well within the theta-pinch coil, has been identified. The magni¬tude of the observed orifice is found to be in excellent agreement with that predicted from collisional MHD theories. The axially flowing plasma is well confined until it flows through the loss orifice. After passing through the orifice, rapid axial expan¬sion is observed. An indication of the existence of inward traveling rarefaction waves has been observed from the plasma midplane temperature data;an abrupt decrease in the plasma tem¬perature at t ~ 6.5 us corresponds to the predicted time of arrival of rarefaction waves at the coil midplane.