EVIDENCE OF PENETRATION EFFECTS FOR THE 94 KEV K-ALLOWED UNHINDERED TRANSITION IN TM-169

From the time differential angular correlation measurement of the 94-6 3 keV cascade in Tm-169, a pure M1 character of the 94 keV gamma ray i s suggested in contrast to the 4% E2 admixture observed in conversion coefficient measurements. Our result indicates ''penetration effects'' on the internal conversion processes for the 94 keV transition. The o bservation of penetration effects for a K-allowed unhindered transitio n is probably the first. The magnetic moment of the 379 keV state has been remeasured, and the value [mu = (3.04 +/- 0.14)mu(N)] is in close agreement with the theoretical prediction (4.5 mu(N)).