Dechanneling by gas bubbles in a solid

Abstract

Abstract The dechanneling probability for a particle hitting a bubble in a solid is evaluated theoretically in the case of planar channeling. This probability p is found to be independant on the radius of the bubble and on the energy of the particle. In the simple case of a harmonic potential, p is found equal to 1 − (π/4)(c/b), where 2b is the interplanar distance and c the maximum allowed oscillation amplitude in the channel. This probability has been measured in the particular case of α particles and helium bubbles in aluminium. The experimental value p = 0.27 ± 0.09 compares reasonably well with the theoretical values: p = 0.34 for a harmonic potential, p = 0.24 for a more realistic potential.