THERMAL-DESORPTION SPECTROSCOPY OF BORON CARBON-FILMS AFTER KEV DEUTERIUM IRRADIATION

Thermal desorption spectroscopy (TDS) of D2 and CD4 was done on boron/ carbon films (B/(B + C) = 0-74%), after 3 keV D3+ irradiation to 4.5 x 10(17) D/cm2 at 473 K. The D2 desorption peaks were observed at 1050, 850 and 650 K. For a sputter B/C film (0%), only the 1050 K peak was observed. With increasing boron concentration to 3%, a sharp peak appe ared at 850 K, the intensity of which was found to increase with incre asing boron concentration to 23%, and then to decrease at 74%. The 650 K shoulder, which was observed for high boron concentration specimens , was speculated to be deuterium trapped by boron atoms in the boron c lusters. The relative amount of CD4 desorption was found to decrease w ith increasing boron concentration, which was attributed to the decrea se in the trapped deuterium concentration in the implantation layer at temperatures at which CD4 desorption proceeds.