THE EMISSION OF L RADIATION IN THE DISINTEGRATION OF ThC AND RaD

Abstract

The amount of L radiation resulting from the K conversion of γ-radiation emitted in the disintegration of ThB has been measured and found to be in general agreement with the calculations of the preceding paper. This amount, which is determined mainly by the fluorescence yield of the L3 level, confirms the results of Küstner and Arends; selective absorption measurements confirm the calculated value for the ratio of the fluorescence yields of the L2 and L3 levels for the product element (bismuth). The yields of L radiation resulting from the L conversion of the low energy γ-radiation emitted in the disintegrations of ThC and of RaD have been measured and compared. In the first case the yield is too high, and in the second it is too low compared with the calculated values. Selective absorption measurements indicate that the yields of the L1 and L2 levels, taken together, are equal to that of the L3 level. It is shown that the experimental result for ThC can be explained on the assumption that Auger transitions of the type L1 → L2N play some part in the distribution of energy in the spectrum; the result for RaD, which is consistent with the results of Stahel (1935), indicates that the low energy γ-transitions emitted by that element and converting in the L levels are excited in less than 100% of the disintegrations.