  We study the particle creation process in the Schwinger model coupled with an
external classical source. One can approach the problem by taking advantage
that the full quantized model is solvable and equivalent to a (massive) gauge
field with a non-local effective action. Alternatively, one can also face the
problem following the standard semiclassical route. This means quantizing the
massless Dirac field and considering the electromagnetic field as a classical
background. We evaluate the energy created by a generic, homogeneous, and
time-dependent source. The results exactly match in both approaches. This
proves in a very direct and economical way the validity of the semiclassical
approach for the (massless) Schwinger model, in agreement with previous
analysis based on the linear response equation. Our discussion suggests that a
similar analysis for the massive Schwinger model could be used as a non-trivial
laboratory to confront a fully quantized solvable model with its semiclassical
approximation, therefore mimicking the long-standing confrontation of quantum
gravity with quantum field theory in curved spacetime.
