The Leading Proton Spectrometer of ZEUS

The ZEUS experiment at HERA has operated a Leading Proton Spectrometer (LPS) from 1993 to 2000. The LPS was used to detect leading particles produced in the fragmentation of the proton. The LPS was made of six stations equipped with silicon microstrip detectors positioned very close to the proton beam, between 20 and 90 m from the interaction vertex. The track deflection induced by the proton beam magnets was used to determine the scattered proton momentum.