Sensitivity of positron annihilation to hydrogen in Zr

Positron annihilation spectroscopy has been applied to the quantitative determination of hydrogen in zirconium. The sensitivity of the positron annihilation was noted to be influenced not only by the presence of hydrogen but also by the heat treatment of the hydrided samples. The positron is attracted to the relatively negative, or ion-core-deficient regions of the metal, F regions commonly associated with vacancies, voids and dislocations. It was found to be very difficult to gauge the relative effects which hydrides and dislocations might have on the positron annihilation in zirconium