Muon-induced fission: A probe for nuclear dissipation and fission dynamics.

Abstract

Excited muonic atoms in the actinide region may induce prompt fission. Following atomic muon capture, some of the inner-shell transitions proceed by inverse internal conversion, i.e., the excitation energy of the muonic atom is transferred to the nucleus. In particular, the ([ital E]2:3[ital d][r arrow]1[ital s]) muonic transition energy is close to the peak of the isoscalar giant quadrupole resonance in actinide nuclei which exhibits a large fission width. Prompt fission in the presence of a bound muon allows us to study the dynamics of large-amplitude collective motion. We solve the time-dependent Dirac equation for the muonic spinor wave function in the Coulomb field of the fissioning nucleus on a three-dimensional lattice and demonstrate that the muon attachment probability to the light fission fragment is a measure of the nuclear energy dissipation between the outer fission barrier and the scission point.