Abstract
Experimental level densities for and are analyzed within the microcanonical ensemble. In the even isotopes at excitation energies the Helmholtz free energy F signals the transition from zero to two quasiparticles. For the odd and even isotopes reveal a surprisingly constant F at a critical temperature indicating the continuous melting of nucleon Cooper pairs as function of excitation energy.
- Received 19 September 2002
DOI:https://doi.org/10.1103/PhysRevC.68.034311
©2003 American Physical Society