CHARACTERIZATION OF ENERGETIC DEUTERIUM STRIKING THE DIVERTOR OF THE DIII-D TOKAMAK

Measurements of the deuterium particle flux and energy to the divertor of the DIII-D tokamak during a series of plasmas that terminated in d isruptions have been made using a silicon collector probe installed on the DiMES (divertor materials exposure system) mechanism; During the steady state portion of each discharge, the probe was located in the p rivate flux region, but immediately before disrupting the plasma, by i njecting either Ar or Dp gas, the strike point of the outer divertor l eg was positioned over the probe. Comparison of the amount of retained D in the probe for the two types of disruptions indicates that much o f the trapped D could have resulted from exposure in the private flux zone prior to the disruption. Measurements of the depth distribution o f the trapped D in the Si imply that the incident ion energy was appro ximately 100 eV at normal incidence arid decreased slightly at oblique angles. The measurements give an upper bound to the energy of deutero ns striking the divertor floor in the vicinity of the strikepoint duri ng disruptions.