Temperature Coefficient of γ-Ray Absorption

Abstract

RECENT improvements in design and technique for a gold-leaf electrometer, details of which will be published shortly, have made it possible to apply the instrument with success to the problem of a possible temperature coefficient of γ-ray absorption. Preliminary measurements with lead as absorber, over a temperature range of about 250°C., indicate that when due allowance has been made for the expansion of the lead, there occurs an increase in the absorption coefficient of approximately 0.2 per cent. per hundred degrees rise of temperature. That the effect is dependent on temperature, or indeed on any incidental at all, is somewhat of a surprise; and considerable interest is added by the recent account by H. S. Read (Phys. Rev., 27, p. 373, 1926) of an effect of temperature on X-ray absorption, in which he records, for lead and the five other metals examined, a temperature increase in the coefficient of the same magnitude as here reported. Further investigation is contemplated.