We present the spectral and temporal radiative signatures expected within
the $quot;Supercritical Pile\" model of Gamma Ray Bursts (GRB). This model
is motivated by the need for a process that provides the dissipation
necessary in GRB and presents a well defined scheme for converting the
energy stored in the relativistic protons of theRelativistic Blast Waves (RBW) associated with GRB into radiation; at the
same time it leads to spectra which exhibit a peak in the burst $\nu
F_{\nu}$ distribution at an energy $E_p \simeq 1$ MeV in the
observer$apos;s frame, in agreement with observation and largely
independent of the Lorentz factor $\Gamma$ of the associated relativistic
outflow. Futhermore, this scheme does not require (but does not
preclude) acceleration of particles at the shock other than that provided
by the isotropization of the flow bulk kinetic energy on the RBW frame. In
the present paper we model in detail the evolution of protons, electrons
and photons from a RBW within the framework of this model to produce
detailed spectra of the prompt GRB phase as a function of time from across
a very broad range spanning roughly $4 \, {\rm
log}_{10} \Gamma$ decades$ in frequency. The model spectra are in general
agreement with observations and provide a means for the delineating of the
model parameters through direct comparison with trends observed in GRB
properties.