Nonintrusive emittance measurement of 1 GeV H− beam

A laser wire based transverse phase space measurement system has been developed at the Spallation Neutron Source (SNS). The system enables a direct measurement of the transverse emittance in both directions on a 1 GeV hydrogen ion (H−) beam at the high energy beam transport (HEBT) beam line. The measurement is non-destructive and has been conducted on a neutron production H− beam. This paper describes the design, implementation, and measurement performance of the system. The experience on the installation and commissioning of the laser emittance measurement system will also be discussed.