Deposition of carbon, deuterium and metals on the wall and limiters of TFTR

Following a two year operational period the TFTR graphite fixed bumper limiter has been examined by a variety of methods. The areal density of metals was mapped in-situ by beta-backscattering. Several tiles were examined in detail by nuclear-reaction analysis, Rutherford backscattering and proton-induced x-ray emission to measure areal densities of deuterium and impurities. Some areas of the limiters were found to be covered by deposited material several microns thick. Other areas where the incident plasma flux is higher were much cleaner. Long-term collection coupons were also examined to characterize deposition on the wall. From these results the total amount of deuterium on the limiter and wall in TFTR is estimated to be about 1.3 x 10/sup 24/ atoms. The implications of this for wall-pumping effects and future tritium inventory are discussed. 11 refs., 5 figs., 1 tab.