PERLE is a high brightness, 500 MeV energy ERL facility with a phase 1 at 250 MeV. This workshop want to adress the physics opportunities having in mind :
a) the scientific motivation for this to be interesting and competitive in 5-10 years, and
b) the instrumental consequences on PERLE footprint, including apparatus sketches in interaction region and nearby. The operation demands (Required beam parameters, the duration of an experiment, other particular experimental requirements…).