Volume reflection observations in bent crystals with 13 GeV/c particles

The article presents the results on the investigation of the channeling and volume reflection effects in a bent silicon crystal with 13 GeV/c positive and negative hadrons (mainly pi(+), p and pi-) at the CERN PS T9 line. In particular, this is the first study carried out on volume reflection at this energy providing a deflection angle of 69.4 +/- 4.7 mu rad and an efficiency of 92.7 +/- 3.3%, with positive particles.
The measurements have been carried out on a bent silicon strip crystal, using a high precision tracking system based on microstrip silicon detectors: this setup is allowed to trigger on the desired beam portion and to select the incoming particle angular range. The article presents a brief introduction on the bent crystal phenomena, the experimental setup and the results of the measurements.