The ' 6Ge(d, He) 9 ' Ga reactions have been studied at 26 MeV with 15-keV resolution full width at half maximum using a tandem accelerator and split pole magnetic spectrometer. The spectroscopic factors are determined for 15 levels in Ga and 11 levels in each of the 3 other Ga isotopes. Level schemes are proposed for the practically unknown 3Ga and 'Ga. Anomalies in the occupation numbers are observed between Z = 31 and 32 and between N = 40 and 42, this last one corresponding to the structural transition observed recently in acomparison of the (p, t) and (t, p) reactions. These anomalies could be related to changes in the nuclear shape. NUCLEAR REACTIONS 7 ' '74' Ge(d, 3He), E=26 MeV; measured 0. (0)~~G a, Ga, 3Ga,~Ga deduced levels, E, l, j, 7i, C~S; deduced Ge ground-state proton occupation numbers.

Tunnelling of α particles through the Coulomb barrier is considered. The main attention is given to the effect of sharp peaks arising in the case of coincidence of the α energy with that of a quasistaionary state within the barrier. The question of the α-nucleus potential is discussed in this light. The method is applied to the α decay of a compound nucleus of 135Pr. The appearance of the peaks in the spectrum of emitted particles is predicted. They can give rise to ‘anomalous’ properties of some neutron resonances. The peaks can also be observed in the incoming α-nucleus channel. Observation of the peaks would give unique information about the α-nucleus potential.

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