The recently reported unusual behaviour of fusion cross-sections at extreme sub-barrier energies has been examined. The adiabatic limit of fusion barriers has been determined from experimental data using the barrier penetration model. These adiabatic barriers are consistent with the adiabatic fusion barriers derived from the modified Wilzynska-Wilzynski prescription. The fusion barrier systematics has been obtained for a wide range of heavy-ion systems.

The ²³²Th$(n, \gamma)$ reaction cross-section at average neutron energies of 13.5, 15.5 and 17.28 MeV from the ⁷Li$(p, n)$ reaction has been determined for the first time using activation and off-line 𝛾-ray spectrometric technique. The ²³²Th$(n, 2n)$ cross-section at 17.28 MeV neutron energy has also been determined using the same technique. The experimentally determined ²³²Th$(n, \gamma)$ and ²³²Th$(n, 2n)$ reaction cross-sections from the present work were compared with the evaluated data of ENDF/BVII and JENDL-4.0 and were found to be in good agreement. The present data, along with literature data in a wide range of neutron energies, were interpreted in terms of competition between ²³²Th$(n, \gamma)$, $(n, f)$, $(n, nf)$ and $(n, xn)$ reaction channels. The ²³²Th$(n, \gamma)$ and ²³²Th$(n, 2n)$ reaction cross-sections were also calculated theoretically using the TALYS 1.2 computer code and were found to be in good agreement with the experimental data from the present work but were slightly higher than the literature data at lower neutron energies.

An overview of the experimental result on simultaneous measurement of pre-scission neutron, proton, 𝛼-particle and GDR 𝛾-ray multiplicities for the reaction ²⁸Si+¹⁷⁵Lu at 159 MeV using the BARC–TIFR Pelletron–LINAC accelerator facility is given. The data were analysed using deformation-dependent particle transmission coefficients, binding energies and level densities which are incorporated in the code JOANNE2 to extract fission time-scales and mean deformation of the saddle-to-scission emitter. The neutron, light charged particle and GDR 𝛾-ray multiplicity data could be explained consistently. The emission of neutrons seems to be favoured towards larger deformation as compared to charged particles. The pre-saddle time-scale is deduced as (0–2) × 10⁻²¹ s whereas the saddle-to-scission time-scale is (36–39) × 10⁻²¹ s. The total fission time-scale is deduced as (36–41) × 10⁻²¹ s.

Management of long-lived nuclear waste produced in a reactor is essential for long-term sustenance of nuclear energy programme. A number of strategies are being explored for the effective transmutation of long-lived nuclear waste in general, and long-lived fission products (LLFP), in particular. Some of the options available for the transmutation of LLFP are discussed.