Volume Reflection and Refraction of Relativistic Particles in Bent Crystals

The quasi-channeling of positive and negative relativistic particles in a bent crystal is studied using the classical deflection function. It was shown that the potential scattering in a central field of bounded ring-like potentials may produce the reflected'' and refracted’’ fractions of scattered particles. For particles with positive charge the reflected'' fraction is mainly presented; at the same time we predict that for particles with negative charge the refracted’’ fraction should dominate. The effect of empty core'' for central scattering is also discussed. The average deflection angles for volume reflection’’ and refraction'' are derived for accepted potential model of the crystal. The calculated average reflection’’ angle is in satisfactory agreement with recent experimental data \cite{ivanov_2006}