Abstract

In-air D(3He, p)4He nuclear reaction analysis (NRA) using external 3He ion beams is now routinely used to characterize deuterium in both fusion and fission reactor materials. The depth resolution, lateral resolution, and detection sensitivity attainable in these ex-vacuo analyses is influenced by the energy spread, the spatial divergence, and the nuclear reaction background produced by extraction of the 3He ion beam through a suitable exit window foil and subsequent transmission of the beam through one or more millimeters of air to the target. In the present paper, the energy and spatial distributions of ex-vacuo MeV 3He ion beams are measured for transmission distances in air of 0 to 15 mm. Exit windows made from both commercially produced foils (3.81 μm thick Au/Al) and foils prepared in the laboratory (1.14 μm thick Au/Al) by e-beam evaporation onto NaCl have been examined. The measured distributions are compared to TRIM simulations, and the resolution of in-air D(3He, p)4He NRA is assessed. Finally, interfering background nuclear reaction yields in air are measured as a function of ex-vacuo 3He beam energy, and the resulting deuterium detection sensitivity is discussed.

Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call