Accession Number : AD0612990

Title :   PENETRATION EFFECTS IN THE K AND L INTERNAL CONVERSION COEFFICIENTS OF THE 279 KEV TRANSITION IN T1203,

Corporate Author : ATOMIC ENERGY OF CANADA LTD CHALK RIVER (ONTARIO)

Personal Author(s) : Herrlander,C. J. ; Graham,R. L.

Report Date : 09 APR 1964

Pagination or Media Count : 17

Abstract : Conversion lines of the 279.16=0.02 and 401.27=0.05 keV transitions in T1203 have been studied at high resolution (=0.07% in momentum). From the measured line intensities and the known total conversion coefficient (0.2262=0.0019) measured by Taylor the following conversion coefficients are deduced for the 279 keV M1+E2 transition: alpha K = 0.163=0.003, alpha LI = 0.0245= 0.0004, alpha LII = 0.0162=0.0003, alpha LIII = 0.0077= 0.0003, alpha M = 0.0118=0.0003, alpha N+0 = 0.0035+ 0.0002. The measured L conversion ratios of the 401 keV transition show that it is pure M1 with <2%E2, in accordance with earlier results. In order to test the accuracy of E2 theoretical L conversion coefficients, precise experimental line intensity ratios are reported for five pure E2 transitions in the region 76 or = Z or = 80. The trend of these ratios when compared with theory indicates that the true LII and LIII coefficients may be a few percent lower than Sliv's theoretical predictions. The experiments were performed in order to study the nuclear structure effect on the internal conversion of the M1 part of the l forbidden 279 keV transition. The significance of the K and L conversion coefficients is discussed in detail. The effects of possible uncertainties in the present theoretical predictions are also considered and show that a solution with the penetration parameter V = 73 cannot be conclusively rejected although with present knowledge it seems unlikely.

Descriptors :   (*INTERNAL CONVERSION, THALLIUM), (*THALLIUM, INTERNAL CONVERSION), NUCLEAR ENERGY LEVELS, NUCLEAR BINDING ENERGY, PENETRATION, ELECTRON TRANSITIONS, GAMMA EMISSION, SELECTION RULES(PHYSICS), DECAY SCHEMES, BETA RAY SPECTROSCOPY, NUCLEAR RADIATION SPECTROMETERS

Distribution Statement : APPROVED FOR PUBLIC RELEASE