EXCITATION OF THE LOW LEVELS OF Li$sup 7$, Be$sup 8$, Be$sup 9$, AND Be$sup 10$ IN THE ALPHA-PARTICLE BOMBARDMENT OF LITHIUM

The range spectra in the photographic plates of the particles from the reactions ( alpha , alpha /sup 1/), ( alpha ,t), ( alpha ,d), and ( alpha ,p) on lithium nuclei were investigated for the bombarding alphaparticle energy E/sub alpha = 13.2 and 14.7 Mev. Typical examples of spectra are shown. The reactions and the levels observed are listed. The angular distribution of the reaction Li/sup 7/ ( alpha , alpha /sup 1/)Li/sup 7/* (Q = -6.5 Mev) was investigated in the forward angle region for E/sub alpha / = 13.2 Mev and also the angular distributions of the reactions Li/sup 7/( alpha ,t/sup 1/)Be/sup 8*/ (Q =-5.46 Mev) and Li/sup 7/( alpha , p/sup 1/)Be/sup 10*/ (Q = -5.928 Mev) for E alpha = 14.7 Mev. Al l angular distributions show the strong anisotropy and have maxima at small forvard angles. There are indications of the direct interaction mechanism in these reactions. From an interpretation of the experimental angular distribution of the reaction ( alpha , alpha /sup 1/) within the frame work of Butler's theory it follows that the parity of the 6.5 Mev level in Li/sup 7/ nucleus is even and the spin is equal tomore » one of the following three values: 1/2, 3/2, and 5/2. The experimental angular distribution of the reaction ( alpha ,t/sup 1/) can be described in the framework of the Butler type alpha- particle stripping theory with the two values of the parameter 1: 1 and 3. (auth)« less