METHOD FOR DETERMINING SUPERFINE COUPLING CONSTANT OF FREE RADICAL BY POSITRON ANNIHILATION

摘要

PROBLEM TO BE SOLVED: To provide a method enabling direct observation of a short-lived free radical.;SOLUTION: The method for determining the superfine coupling constant of a free radical includes steps of: generating a free radical by allowing positrons generated by a positron source to enter a sample; generating positronium from electrons emitted upon formation of the free radical and the incident positrons; performing a cyclic radical reaction between the free radical and ortho-positronium constituting 75% of the positronium; observing time dependency of a yield of the radical reaction as cyclic oscillations observed in the time dependency of the spin exchange reaction of the ortho-positronium which is a competition reaction of the radical reaction and can be observed by AMOC, which have been developed; and determining a superfine coupling constant a of the free radical using the cyclic oscillations observed in a spectrum obtained by AMOC.;COPYRIGHT: (C)2010,JPO&INPIT