Abstract
The fission-fragment mass and total kinetic energy (TKE) distributions are evaluated in a quantum mechanical framework using elongation, mass asymmetry, neck degree of freedom as the relevant collective parameters in the Fourier shape parametrization recently developed by us. The potential energy surfaces (PES) are calculated within the macroscopic-microscopic model based on the Lublin-Strasbourg Drop (LSD), the Yukawa-folded (YF) single-particle potential and a monopole pairing force. The PES are presented and analysed in detail for even-even Plutonium isotopes with A = 236–246. They reveal deep asymmetric valleys. The fission-fragment mass and TKE distributions are obtained from the ground state of a collective Hamiltonian computed within the Born-Oppenheimer approximation, in the WKB approach by introducing a neck-dependent fission probability. The calculated mass and total kinetic energy distributions are found in good agreement with the data.
Highlights
Our present understanding of nuclear fission is still based on the idea of Lisa Meitner and Otto Frisch [1] of a deformed charged liquid drop
The potential energy surfaces (PES), relative to the corresponding spherical Lublin-Strasbourg Drop (LSD) energy, were calculated for even-even Plutonium isotopes 236−246Pu in the 3D (q2, q3, q4) deformation space, where q2 describes the elongation of the nucleus, q3 its reflection asymmetry, and q4 controls the neck size [8,9]
The neck dimension, which for a given elongation q2 and asymmetry q3 depends on q4, decides when fission occurs
Summary
Our present understanding of nuclear fission is still based on the idea of Lisa Meitner and Otto Frisch [1] of a deformed charged liquid drop. Following the Bohr-Wheeler paper, one sometimes still uses up to now the Lord Rayleigh expansion of the nuclear surface into spherical harmonics. [3]) that such an expansion is not rapidly converging for large deformations and one needs to include terms up to multipolarity 16 in order to describe shapes close to the scission point. The first two of the above quoted parametrizations are not analytical and closed (e.g. do no allow for the inclusion of higher order terms) while the last one is not easy to handle and its parameters do not have a clear physical interpretation
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
