[en] We are measuring the production cross sections for hydrogen and helium production by neutrons from threshold to 100 MeV on structural materials of importance to the advanced accelerator application programme. Our approach is to measure the isotopes of hydrogen and helium as they are emitted in the nuclear reactions such as (n,xp), (n,xd), and (n,xalpha). The data include not only the production cross-sections but also the angular distributions and energy spectra of the emitted particles. These benchmark data also test nuclear reaction model calculations. Progress to date is reported. (author)