Precision measurements of the half-lives of the positon emitters 25Al, 26Alm, and 33Cl

Abstract

The half-lives of the positon emitters 25A1, 26Alm, and 33Cl, produced by (p,y) reactions at selected resonances, have been measured by means of two different methods:

a) with a 70-channel pulse-analyser using time-to-pulse-height conversion;

b) with an eleven-contact stepping switch and eleven sets of scales and mechanical registers.

The results are:

25Al 7.24 ± 0.03 sec;

26Alm 6.28 ±0.04 sec;

33Cl 2.53 ± 0.02 sec.