Volume reflection and volume capture of protons in bent crystal

The dependence of volume reflection and volume capture of protons in the channeling regime on the particle energy and crystal bend radius has been studied by computer simulation. It was shown that the beam broadening due to multiple scattering at its volume reflection in a bent crystal becomes smaller than the reflection angle with increasing the particle energy, what allows one to observe the volume reflection in the experiment. Besides, the volume capture probability Pvc was calculated and it was shown that at a fixed crystal bend radius R or particle energy E, when the radius is far from the critical one, the probability is approximately proportional to RE-3/2. This confirms validity of its analytical estimation which was suggested before. On the other hand, when the crystal is bent with the same effective radius the energy dependence of the capture probability is weaker, Pvc∼E-1/2. (author). 10 refs., 10 figs