The SE-CpFM Detector for the Crystal-Assisted Extraction at CERN-SPS

The UA9 experiment at CERN-SPS investigates the manipulation of high energy hadron beams using bent silicon crystals since 2009. Monitoring and characterization of channeled beams in the high energy accelerators environment ideally requires in-vacuum and radiation hard detectors. For this purpose the Cherenkov detector for proton Flux Measurement (CpFM) was designed and developed. It features a fused silica bar in the beam pipe vacuum which intercepts charged particles and generates Cherenkov light. In this contribution the SE-CpFM (Slow Extraction CpFM) detector is described in detail. It has been installed in early 2016 in the TT20 extraction line of SPS to study the feasibility of the crystal-assisted extraction from the SPS. Before the installation the detector has been fully characterized in 2015, during the UA9 data taking in the H8-SPS extraction line with 180 GeV pions. The single particle detection efficiency and the photoelectron yield per proton have been estimated and are shown in this contribution.