  Superconductors like other solids cannot relax instantaneously from thermally
excited (disturbed) states to thermodynamic equilibrium. In this paper,
relaxation of a multi-filamentary and of a thin film superconductor from
thermal excitations is simulated. Absorption of radiation or, under conductor
movement, release and transformation of mechanical tension to thermal energy
are examples. The paper applies numerical simulations of superconductor energy
states, as many-particle systems, under basic thermodynamic and standard,
multi-component heat transfer principles (solid conduction plus radiation in
thin films). A recently described microscopic stability model and application
of a traditional, continuum cell model allows to explain curvature of the
resistance vs. temperature excursion below critical temperature, TCrit, and
suggests an alternative to standard explanation of increased electrical
conductivity at temperature exceeding TCrit. A non-local, resistivity boundary
layer (a temperature uncertainty) is observed near critical temperature within
which the resistivity curve smoothly approaches, from the superconducting
state, the normal conduction resistivity.
  Keywords Superconductor; phase transition; relaxation; critical current
density; critical temperature; thermal fluctuations; boundary layers
