We study, using Rindler coordinates, the quantization of a charged scalar h
eld interacting with a constant (Poincare invariant), external, electric fi
eld in (1+1) dimensionnal flatspace: our main motivation is pedagogy. We il
lustrate in this framework the equivalence between various approaches to fi
eld quantization commonly used in the framework of curved backgrounds. Firs
t we establish the expression of the Schwinger vacuum decay rate, using the
operator formalism. Then we rederive it in the framework of the Feynman pa
th integral method. Our analysis reinforces the conjecture which identifies
the zero winding sector of the Minkowski propagator with the Rindler propa
gator. Moreover, we compute the expression of the Unruh's modes that allow
us to make a connection between the Minkowskian and Rindlerian quantization
schemes by purely algebraic relations. We use these modes to study the phy
sics of a charged two level detector moving in an electric field whose tran
sitions are due to the exchange of charged quanta. In the limit where the S
chwinger pair production mechanism of the exchanged quanta becomes negligib
le we recover the Boltzman equilibrium ratio for the population of the leve
ls of the detector. Finally we explicitly show how the detector can be take
n as the large mass and charge limit of an interacting fields system. (C) 2
000 Academic Press.