Fig. 1.
(a) The periodic planar potential in a straight crystal for positively charged particles. The arrows show a channelled particle oscillatory motion in the potential well and an unchannelled particle, with transverse energy greater than the depth of the potential well U0. (b) The same situation in a bent crystal. (c) Particle trajectories in a straight crystal. The arrows show volume-reflected, volume-captured, and channelled particles. (d) Trajectories in a bent crystal.