High resolution stopwatch for cents

A very low-cost, easy-to-make stopwatch is presented to support various experiments in mechanics. The high-resolution stopwatch is based on two photodetectors connected directly to the microphone input of the sound card. A dedicated free open-source software has been developed and made available to download. The efficiency is demonstrated by a free fall experiment

Desorption activation energies for tritium release from ceramic breeders

Desorption has been identified as an important process in determining the kinetics of tritium release from ceramic tritium breeder materials considered for use in fusion reactors. However, details of the desorption of tritium from ceramic materials are mostly unknown. Models of tritium release have treated desorption as a simple process with desorption occurring from one type of site with one activation energy. Recent measurements of the rates of water uptake by LiAlO/sub 2/, and evolution of water from LiAlO/sub 2/ exposed to water, indicate the presence of multiple types of desorption sites. Estimates of desorption activation energies were obtained from these data and from data in the literature suggesting multiple types of desorption sites for desorption from Li/sub 2/O and Li/sub 4/SiO/sub 4/. 15 refs., 4 figs