A triode electron gun has been developed and built in the ESRF RF Group. A grid cathode assembly manufactured by EIMAC (Y646B) has been chosen for its very high reliability, referring to the experience of SLAC and CLIO. Beam simulations performed by THOMSON Accelerators Division for the SOLEIL project have been used for the design of the gun. The first results look promising: between 10 and 600 mA peak current, 1ms pulse length were obtained. The measured beam parameters confirmed the simulations in terms of size (R = 3 mm) and normalised emittance (20 mm mrad).

The next step will consist in adding an electrostatic deflector in order to produce 1 ns short pulses of 600 mA peak current with an expected initial purity above 106 (intensity ratio between selected and nominally empty buckets after transfer into the storage ring).