B11(He3, α)B

Abstract

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

Study of the 13C(3He, α)12C reaction at energies of 50 and 60 MeV

“…The ( 3 He, α) reaction has been studied to a lesser extent than the (p, d) and (d, t) reactions partly due to the fact that not all laboratories have been able to accelerate 3 He. Most of the early studies were carried out at energies below 20 MeV [1][2][3][4][5][6][7][8], and as a rule were limited to measurements of transitions to the low-lying states of nuclei. In addition, the analysis of data obtained within the framework of the direct mechanism of neutron pickup is greatly complicated by the significant contributions of other mechanisms such as the formation of a compound nucleus.…”