  A particle subject to a white noise external forcing moves like a Langevin
process. Consider now that the particle is reflected at a boundary which
restores a portion c of the incoming speed at each bounce. For c strictly
smaller than the critical value 0.1630, the bounces of the reflected process
accumulate in a finite time.
  We show that nonetheless the particle is not necessarily absorbed after this
time. We define a "resurrected" reflected process as a recurrent extension of
the absorbed process, and study some of its properties. We also prove that this
resurrected reflected process is the unique solution to the stochastic partial
differential equation describing the model. Our approach consists in defining
the process conditioned on never being absorbed, via an h-transform, and then
giving the Ito excursion measure of the recurrent extension thanks to a formula
fairly similar to Imhof's relation.
