Stainless steel 316 specimens have been implanted with deuterium ions at 7 keV up to doses of 2×1018 D/cm2 at −120°C. Trapped quantities and depth profiles of the implanted atoms have been determined using the 3He (d,p) 4He nuclear reaction, using both the product particles for making the analyses. Up to doses of 5×1017 D/cm2 the implanted deuterons were retained within the analyzing zone, but at higher fluences the amounts retained no longer increased linearly with the bombardment dose. Deuterium to metal atom ratios of nearly 1:1 were observed. The density of retained deuterium was not a function of holding time at −120°C, but upon warming, the loss of deterium could be measured. At roughly −50°C the rate of loss was a maximum, and by +40°C only a few percent of the original amount of deuterium remained.