COLLECTOR PROBE MEASUREMENT OF FUSION TRITONS IN TFTR

The production of fusion tritons in the Tokamak Fusion Test Reactor (TFTR) has been measured using Si collector probes. Four probes at two toroidal and two poloidal positions were exposed to about 1200 plasma discharges over a six month period and subsequently analyzed using high-sensitivity secondary-ion mass spectrometry (SIMS). SIMS depth profiles show that the incident tritons had an average projected range of about 10 μm in the Si, which is characteristic of 1 MeV tritons produced by DD fusion. The triton fluences observed at the various sample locations ranged from 5×1011 to 5×1012 T/cm2. First-orbit loss code calculations, scaled by the measured total neutron production during the exposure period, were used to predict the expected triton fluence to the samples. The predicted and observed triton fluences agree to within an order of magnitude.