Diagnostics and correction of the electron beam trajectory in the Cornell wiggler at the Accelerator Test Facility

A high-gain harmonic generation experiment is underway at the ATF. This experiment utilizes 41 MeV electron beam produced by photocathode electron gun and s-band linac. The strict requirements on the electron beam trajectory in a 2-m long, 60 period undulator are essential for the success of the experiment. The simulation demands that trajectory errors should be less than 100 μm in the wiggler. Five pop-in monitors are used to measure the electron beam trajectory along the wiggler. A HeNe laser defines reference line. We present our results and experience concerning different aspects of the electron beam alignment