MEASUREMENT OF COMPOUND-NUCLEUS LIFETIME BY X-RAY SPECTROSCOPY IN THE CD-106(P,P')CD-106 REACTION

A new method for measuring compound-nucleus lifetimes in the range of 10-18-10-16 s is presented. The method is based on the comparison between the known lifetime of an atomic excited state used as a reference and the nuclear delay time to be measured. On-line coincidences performed between the nuclear reaction products and the emitted X-rays enable the selection of the atomic vacancies decaying during the compound stage of the nuclear interaction. The main characteristics of this technique are illustrated by measurements of lifetimes of the 107In compound nucleus excited at 13.6 and 15.6 MeV in the 106Cd(p, p')106Cd reaction. They are found in agreement with statistical model calculations. The spurious effect associated with decay by internal conversion of final states populated by the competitive (p, n) reaction is emphasized. © 1979.