Making use of a proportional counter, alpha particles have been observed from the reactions Al
27(
p, α)Mg
24 resulting in the ground and first excited states of Mg
24 and Cr
52(
p, α)V
49 resulting in the lowest three and a few higher states. Excitation curves have been measured at a laboratory angle of 50° with respect to the bombarding beam, from 12.7 to 14.1 Mev for Al
27(
p, α)Mg
24 and from 9.0 to 14.8 Mev for Cr
52(
p, α)V
49. The former shows a sharp energy dependence, while the latter shows a fairly smooth structure. Angular distributions have been measured at 14.1, 13.0 and 12.8 Mev for Al
27(
p, α)Mg
24 and at 14.2, 13.0, 12.0, 11.0, 10.0, 9.5 and 9.0 Mev for Cr
52(
p, α)V
49. Although the Al
27(
p, α
0)Mg
24 data can be partially fitted by [
j2(
Qr0)]
2 of Butler’s theory, some angular distributions show strong backward peaking. Either interference between various direct interaction processes or between direct interaction and compound nuclear processes, or both are responsible for this reaction. The approximate 90° symmetry of Cr
52(
p, α)V
49 angular distribution does not appear to be inconsistent with the statistical theory of nuclear reactions. However, the conspicuous forward peak at higher energies, especially at 14.2 Mev, is considered to indicate the increasing contribution of direct interaction processes.
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