Tritium profiling using the T(d, 4He)n reaction

A detailed analysis has been carried out in the use of the T(d, 4He)n reaction for profiling tritium in solids over depths to ~ l μm. Calculations have been undertaken to show how the depth resolution and detection sensitivity vary with the profiling geometry. Degradation of the depth resolution as a function of depth has been determined considering energy and angular straggling effects as well as experimental factors, such as detector resolution, acceptance angle subtended by the detector, beam diameter and incident beam energy spread. A preferred experimental geometry has been identified with an angle of incidence, 60° from normal, and a detection angle 40° from the incident beam trajectory, which results in a reasonable compromise between depth sensitivity and depth resolution. Experimental depth profiles have been obtained on tritium implanted amorphous Si samples and a tritiated Ti thin film.