96 (i) Sketch the Coulomb potential barrier encountered in the alpha decay of 244 Cm to 240 Pu for which Q = 5.901 MeV. On the same diagram, show the Coulomb-plus-centrifugal barrier for the 2 decay to the first excited state (0.043 MeV). (ii) Estimate the reduction in the decay probability caused by this additional barrier, and correspondingly estimate the ratio of the alpha branching intensities to the ground and first excited states of 240 Pu. Compare your estimate with the actual intensities given in the figure below. 244Cm 94 0.036% 6° 0.296 MeV 4* 0.142 MeV 2+ 0.043 MeV 0° 0 MeV 240Pu (iii) Explain why, as shown in the figure below, in the case of 243 Am, the principal decay mode is to the 0.075 MeV state of the 233 Np daughter rather than its 93 ground state. 243 Am 5/2 9/2 0.172 MeV 7/2 0.118 MeV 5/2 0.075 MeV 7/2 0.031 MeV 5/2 0 MeV 23Np

96 (i) Sketch the Coulomb potential barrier encountered in the alpha decay of 244 Cm to 240 Pu for which Q = 5.901 MeV. On the same diagram, show the Coulomb-plus-centrifugal barrier for the 2 decay to the first excited state (0.043 MeV). (ii) Estimate the reduction in the decay probability caused by this additional barrier, and correspondingly estimate the ratio of the alpha branching intensities to the ground and first excited states of 240 Pu. Compare your estimate with the actual intensities given in the figure below. 244Cm 94 0.036% 6° 0.296 MeV 4* 0.142 MeV 2+ 0.043 MeV 0° 0 MeV 240Pu (iii) Explain why, as shown in the figure below, in the case of 243 Am, the principal decay mode is to the 0.075 MeV state of the 233 Np daughter rather than its 93 ground state. 243 Am 5/2 9/2 0.172 MeV 7/2 0.118 MeV 5/2 0.075 MeV 7/2 0.031 MeV 5/2 0 MeV 23Np