3-D-MICRO-ERDA MICROSCOPY OF TRACE HYDROGEN DISTRIBUTIONS IN DIAMOND USING A 2-D-PSD WITH EVENT RECONSTRUCTION

A fast-imaging technique for the total elemental hydrogen concentratio n distribution is described, which is helpful in the study of its chem istry and dynamics in the diamond system. The micro-scanned Heavy-Ion Elastic Recoil Detection Analysis (HI-ERDA) technique can deliver info rmation on hydrogen distributions in three dimensions. In our system, the count rate is enhanced by use of a 2-D position and energy sensiti ve detector for the hydrogen recoils. Software geometry collimation an d recoil energy rebinning ensure that the increased rate is in fact ac companied by an improvement in effective energy resolution. The system has been used to study the mobility and trapping behaviour of a colli mated implant of hydrogen into a pre-damaged natural type IIa diamond sample as well as the mobility and trapping behaviour of collimated im plants of hydrogen into diamond, which has not been pre-damaged. (C) 1 997 Elsevier Science B.V.