Study of 50Â GeV proton ionization loss by semiconductor detector with smoothly tunable thickness

The possibility of the measurement of proton ionization loss in the Silicon (Si) layer of smoothly tunable thickness was demonstrated in an experiment with a 50-GeV proton beam. The Si surface-barrier detector with the depleted layer thickness controlled by the value of high-voltage power supply was used in the experiment. The measured spectra of ionization loss are discussed and compared with the calculated spectra. The possibilities of research of the evolution of electromagnetic field of ultrarelativistic particles traversing the media interface and the study of dynamics of particles moving in the channeling regime or the volume reflection regime with the use of detectors with smoothly tunable thickness are indicated.