Boiling patterns of neutron-rich
nuclear matter, J. Toke, University
of Rochester, USA − Limits of thermodynamic stability of
self-bound
neutron-rich nuclear matter are explored within the framework of
microcanonical
thermodynamics of interacting Fermi Gas model in Thomas-Fermi
approximation. It
is found that at certain excitation energy the 2x2 curvature
matrix of the
entropy (as a function of excitation energy and iso-asymmetry)
ceases to be
negative definite in a way indicating onset of thermo-chemical
instability. This
leads to boiling off more and more
neutrons as the excitation energy per nucleon is raised in a
process identified
as distillation. Eventually,
the boiling
point of iso-symmetric matter is reached as the system has shed
all excess
neutrons, such that any additional excitation energy brought into
the system is
expended in the form of latent heat of boiling while the residual
system stays
at constant excitation energy per nucleon and temperature.