Electron beam diagnostics for short pulse FEL schemes at CLARA

CLARA (Compact Linear Accelerator for Research and Applications) [1] is a proposed 250 MeV, 100-400 nm FEL test facility at Daresbury Laboratory. The purpose of CLARA is to test and validate new FEL schemes in areas such as ultra-short pulse generation, temporal coherence and pulse-tailoring. Some of the schemes that can be tested at CLARA depend on a manipulation of the electron beam properties with characteristic scales shorter than the electron beam and require a 30 - 50 μm modulation of the beam energy acquired via the interaction with an infrared laser beam in a short undulator. In this article we describe the electron beam diagnostics required to carry on these experiments