Observation of focusing of 400 GeV/ c proton beam with the help of bent crystals

The results of observation and studies of focusing of 400 GeV/ c proton beam with the help of bent single crystals are presented. Two silicon crystals have been used in the measurements. The focal length of the first and second crystals is found to be 1.48 m and 0.68 m, respectively. The mean square size of the horizontal profile in the focus was 3.1 and 4.3 times as small as at the exit of the crystals

About the probability of close collisions during stochastic deflection of positively charged particles by a bent crystal

The probability of close interactions of high-energy positively charged particle with atoms in a bent crystal was considered as a function of the angle between the initial particle momentum and the bending plane. The results of simulation of particle motion presented in the article show the great efficiency of high-energy positively charged particle deflection by a bent crystal due to the stochastic deflection mechanism and strong reduction of the probability of close collisions during the stochastic deflection in comparison to the planar channeling in a bent crystal