First BHM performance plots

A new detector to measure the machine induced background at large radii (1.8 m from beam axis) has been developed and installed in the CMS experiment at LHC. It consists of 40 modules, each comprising a quartz bar read out by a photomultiplier. Since Cherenkov radiation is emitted in a forward cone around the charged particle trajectory, these detectors can distinguish the directions of the machine induced background. The back-end consists of a microTCA readout with excellent time resolution. The performance of the detector modules measured in several test-beam campaigns will be reported. The installation in CMS is described, and first results about operating the detector during data taking is given.