Low energy regime for optical transition radiation emission

OTR has been widely investigated in the literature as an electron beam diagnostic tool in the high energy region (E>50 MeV). At lower energy both the model of OTR emission and the experimental observation of the phenomena require a different and more complex approach. Nevertheless the information which can be drawn from OTR spectra at these low energies play a relevant role in new injectors. In this paper we present and discuss the theoretical work carried out in the last year to provide a suitable background to OTR measurements at energies below 50 MeV.