Iron was ion implanted with He and deuterium (D) and then heated at a constant rate of 2 K/min. The evolving depth distribution of the D was monitored using the nuclear reaction2D(3He,p)4He, and resulting data were analyzed by applying the diffusion equation with appropriate trapping terms. Two defect traps for D were identified, the respective binding enthalpies being 0.53plusmn;0.07 and 0.71plusmn;0.07 eV when referenced to a solution site. The weaker of these traps is believed to be a monovacancy, while the stronger may be a vacancy cluster. A third type of trap, with strength 0.78plusmn;0.08 eV, was found to be associated with He. It is proposed that the responsible entities are sim;1 nm He bubbles which were observed by transmission electron microscopy, and that the D is bound to the walls of these bubbles by a mechanism similar to chemisorption. The analysis also yielded an estimate of the D recombination coefficient at the electropolished and airhyphen;exposed Fe surface, sim;5times;10minus;19cm4/s at a temperature of 500 K.
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