Status of the apex project at LBNL

The Advanced Photo-injector Experiment (APEX) at the Lawrence Berkeley NationalLaboratory is focused on the development of a high-brightness high-repetition rate(MHz-class) electron injector for X-ray FEL applications. The injector is based on a newconcept gun, utilizing a normal conducting 186 MHz RF cavity operating in CW mode inconjunction with high quantum efficiency photocathodes capable of delivering the requiredrepetition rates with available laser technology. The APEX activities are staged in 3 mainphases. In Phases 0 and I, the gun is tested at its nominal energy of 750 keV and severaldifferent photocathodes are tested at full repetition rate. In Phase II, a pulsed linac isadded for accelerating the beam at several tens of MeV to reduce space charge effects andmeasure the high-brightness performance of the gun when integrated in an injector scheme.At Phase II energies, the radiation shielding configuration of the bunker where APEX islocated limits the repetition rate to a maximum of several Hz. Phase 0 is undercommissioning, Phase I components under fabrication, and initial activities for Phase IIare underway. This paper presents an update on the status of all these activities.