An alternate injection system for the BNL Accelerator Test Facility

The BNL (Brookhaven National Laboratory) Accelerator Test Facility is a user's facility for experiments in laser acceleration, free electron laser, and accelerator physics experiments. To preserve a low emittance and high brightness beam for these experiments, the author presents a new configuration (a second entry port and beamline) scheme for the ATF injection system. Where the laser driven photoelectrons are injected into a 50 MeV linac via a straight (ahead) beamline, in contrast to the present scheme of 180 degrees achromatic double bend transport line (now in operation), to improve the beam quality. A beam dynamic analysis of the laser driven high brightness photoelectrons is also given