Differential cross sections of the B u (He 3 , a)B 10 reaction leading to seven states up to 5.2-MeV excitation energy have been measured at forward angles at an incident energy 12(He 3 ) =33 MeV. The angular distributions have been analyzed in terms of the distorted-wave Born approximation on the assumption that the direct neutron-pickup process is predominant. Relative spectroscopic factors have been extracted and are found to be in good agreement with Cohen and Kurath's theoretical predictions and with the results of the B 11 (p, d)B 10 experiment at 33.6 MeV.
I. INTRODUCTIONT HE B n (d,t)B 10 reaction 1 at 21.6 MeV and the B n (p, d)B 10 reaction 2 at 18.9 MeV have revealed some inconsistencies in relative spectroscopic factors, particularly for the states at 0.717 and 2.15 MeV in B 10 . Results for the B n (p, d) reaction 3 at 155 MeV and more recently 4 at 33.6 MeV have yielded spectroscopic factors in good agreement with each other and with the theoretical predictions of Cohen and Kurath. 6 The B n (d, OB 10 reaction has also been studied at 11.8 MeV 6 and at 20 MeV, 7 the data show only poor agreement with each other, probably because of the low energy of the outgoing tritons at E d =11.8 MeV. At 20 MeV the experiment was analyzed merely with the planewave Born approximation. The B n (p, d) reaction has been studied 8 at 40 MeV with poor energy resolution. The B u (He, a) reaction has been studied previously at the rather low incident energies of 1.0-2.15 9 and 2.2-5.5 MeV. 10 Although the forward peaking and oscillatory shapes of the angular distributions seem to indicate a directreaction mechanism, the relative strengths of the transitions to the various states in B 10 are in disagreement with the values obtained from the (d, t) reaction and with theory. Distorted-wave calculations are not too meaningful for the (He 3 , a) reaction at this low