Deuterium microscopy using 17MeV deuteron–deuteron scattering

Using 17MeV deuterons as a micrometer focused primary beam, we performed deuterium microscopy by using the deuteron–deuteron (dd) scattering reaction. We describe our new box like detector setup consisting of four double sided silicon strip detectors (DSSSD) with 16 strips on each side, each covering up to 0.5sr solid angle for coincidence detection. This method becomes a valuable tool for studies of hydrogen incorporation or dynamic processes using deuterium tagging. The background from natural hydrocarbon or water contamination is reduced by the factor 150ppm of natural abundance of deuterium in hydrogen. Deuterium energies of up to 25MeV, available at the microprobe SNAKE, are ideal for the analysis of thin freestanding samples so that the scattered particles are transmitted to the detector. The differential cross section for the elastic scattering reaction is about the same as for pp-scattering (~100mb/sr). The main background due to nuclear reactions is outside the energy window of interest. Deuteron–proton (dp) scattering events give an additional signal for hydrogen atoms, so the H/D-ratio can be monitored in parallel. A deuterium detection limit due to accidental coincidences of 3at-ppm down to less than 1at-ppm is demonstrated on deuterated polypropylen sheets as well as thick polycarbonate sheets after various stages of coincidence filtering that is possible with our granular detector.