Discussion: Session 4

H.R. VON GUNTEN InstitUt fur Reaktor forschung^ Switzerland

I was impressed by the accuracy that Mr Cabell reached in his measurements. Bulgarian workers about one year ago found different halflives for the same investigated nuclide depending on the chemical form of the compound; the variations were of the order of 1%. If I recall correctly, they measured 21+Na and 131I in different chemical compounds and in different aggregation state. I should like to hear Mr Cabells opinion about the possible influence of the chemical state on 3- decay, thus influencing the accuracy of half-life measurements.

M.J. CABELL

The effect of chemical environment on the apparent half-life of electron capture has long been known. The same phenomenon has been suggested for 3~ emitters before. In all previous cases it has been shown that the results were erroneous, the effect being caused by some other factor e.g. impurities, equipment unstability etc.