Isomer shift calibration of /sup 129/I and /sup 127/I by life-time variations in the electron-capture decay of /sup 123/I

Abstract

The isomer shift of a Mossbauer isotope is proportional to the electronic density difference at the nucleus. The electron capture decay mode constant lambda is proportional to the electronic density at the nucleus. The authors performed direct measurements of Delta lambda for several pairs of iodine compounds labelled with /sup 123/I using differential ionisation chambers. The /sup 123/I activity was produced by /sup 127/I(p,5n)/sup 123/Xe decaying by electron capture to /sup 123/I.Anglai