BEAM PROFILE MEASUREMENTS WITH THE 2-D LASER-WIRE ∗

The laser-wire will be an essential diagnostic tool at the International Linear Collider (ILC). It uses a finely fo-cused laser beam to measure the transverse profile of elec-tron bunches by detecting the Compton-scattered photons downstream of the interaction point (IP), where the laser beam intersects the electron beam. Such a system has been installed at the PETRA storage ring at DESY, which uses a piezo-driven mirror to scan the laser-light across the elec-tron beam. This paper reports recent upgrades to the PE-TRA system, including the implementation of a new laser