Measurement of ion beam profiles in a superconducting linac with a laser wire

Abstract

A laser wire based ion beam profile measurement system has been developed in the Spallation Neutron Source accelerator complex. The laser wire system uses a single laser source to track horizontal and vertical profiles of a pulsed hydrogen ion (H-) beam along a 230-m long superconducting linac which accelerates H- from 200 MeV to 1 GeV. In this paper, we describe the laser optics requirement for the system, performance of the profile measurement, and the effects of laser parameters on the measurement reliability. The result provides a practical guideline for the development of a large-scale, operational, laser based diagnostics in accelerator facilities.