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The rotation of the angular correlation between the 7-group at about 820 keV and the 80 keV radiation in the decay of Tm l~ has been observed in an external magnetic field of 20300 gauss.The result : coR.r = 0,485 4-0,o5t yields for the gR-factor of the 80 keV state of Erl~The evaluation includes a paramagnetic correction factor of: /~= 7,26, (Belt =~ " Bext).The angular correlation is slightly attenuated by internal fields. For a liquid source of Tm (NO~)~ solved in 3 n HNO 3, a measurement of the differential angular correlation as a function of the delay time gave:X~(LS• 9 107sec -1, assuming A~(t)=A2(O) 9 e-;.2"t.The half life of the 80 keV state was found to be:2"1/2 = (t,92 :k 0,04) 9 I0 _9 sec in agreement with earlier measurements.

An isomeric state of Hf 177 with T_~_=(1,12_0,10)s was found by a fast chemical separation of the hafnium daughter from the 155 d Lu 177m activity. We measured the sanae half-life by observing the delayed fl-y-coincidences. A systematic investigation of the whole region 5s> T 89 10 -7 s by the technique of delayed coincidences gave no further isomerism. We assign the observed half-life to the ~ three particle state of Hf 177 at 1315 keV and assume that the second hypothetical three particle state at 1337 keV does not exist. The ~1 rotational state of the K=-~ band is populated by a strongly converted 14,16keV y-transition from the isomeric state at 1315 keV. The 14,16 keV M I and N I conversion lines were observed by use of a double focusing magnetic fl-spectrometer. The isomerism is caused by the K-selection rule. The retardation of the following three y-transitions by different degrees of K-forbiddeness is discussed. The pulse height spectrum, measured by means of a Li-drifted Ge-detector, does not show the 36,52 keV-y-transition which was previously assumed topopulate the 1301keVstate. In addition to the known y-transitions we found a 40,9 keV-line. This is probably the transition between the 1301,1 keV and the 1260,3 keV-states.

The rotations of FF-angular correlations in strong external magnetic fields were observed in the decay of 5.1 h Sb us and 5"8 d Sb 12~ Values of the gyromagnetic ratios of the 5-two particle states of Sn lls and Sn 1~~ were derived. In the case of 5"t hours Sb 11s the rotation of the 254 keV--t.22t MeV F7-angular correlation in a field of 40950 Gauss was measured as (o L 9 z = 0'417 -1-0'038, and the g-factor of the 5-state was derived asThis value is correct under the assumption that the rotation in the 4 + state is negligible. The half life of this state was found to be T 89 ~< 7 " 10 -1~ sec.In the case of 5"8 d Sb xe~ the rotation of the 200 keV--90 keV Tv-angular correlation in a field of 53200 Gauss was found to be o) L 9 "c ~ 0"150 -4-0"020, and the g-factor of the 5-state was derived as g = --O'O74 4-0.0t0.The evaluation implies a smM1 correction for the Compton-underground of the high energy ~-transitions. It is assumed that the rotation in the 4 + state is negligible. The half life of the 4 + state was found to be T~ ~ 6" I0 -1~ sec.The half lives of the 5-states of Sn ns and Sn 1~~ were determined as and T~ = (2t"7 i 0-2)" ~0-gsec respectively. T6 = (5'53 4-0'06) 9 t0 .9 sec Differential angular correlation measurements proved that attenuations in the 5-states by internal fields were very small for the liquid sources used in these experiments.The results for the gyromagnetic ratios of the 5-states are consistent with tile theoretical interpretation of these levels as mainly (hit/2, s 1/2) two-neutronconfigurations.Magnetische Momente der 5--Niveaus yon Sn ~s und Sn x~~ 37t

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