Excitation Functions and Angular Distributions of the Reactions Al27(p, α)Mg24 at 12.7∼14.1 Mev and Cr52(p, α)V49 at 9.0∼14.2 Mev

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 [ j 2 ( Q γ 0 ] 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 respons...