THE TA-181(LI-7,5N)OS-183 REACTION - MEASUREMENT AND ANALYSIS OF THE EXCITATION-FUNCTION AND ISOMERIC CROSS-SECTION RATIOS

Excitation function and isomeric cross-section ratios for the producti on of Os-183(m,g) by Li-7-induced reactions on Ta-181 are obtained fro m the measurements of the residual activities by the conventional stac ked-foils technique from threshold to 50 MeV. The excitation function and isomeric cross-section ratios for nuclear reaction Ta-181(Li-7,5n) Os-183(m,g) are compared with the theoretical statistical model calcul ation by using the ALICE/91, STAPRE, and CASCADE codes, In the energy range of the present measurement the excitation functions are fitted f airly well by both the geometry dependent hybrid (GDH) model and the h ybrid model of Blann with initial exciton number n(0)=7 (n(n)=4, n(p)= 3, n(h)=0) using the ALICE/91 code. The experimental isomeric cross-se ction ratios are also reproduced fairly well by the calculation using the STAPRE code. However, the CASCADE code calculations slightly under predict the cross section but reproduce the shape. In general, the sta tistical model under a suitable set of global assumptions, can reprodu ce the excitation function as well as isomeric cross-section ratios.