Theory of dechanneling

Abstract

A theory of dechanneling is proposed. It is based on tL: solution of the boundary problem for t h e kinetic equation describing the evolution of channeled particles. The expressions for the dechanneled fraction, distribution function of the lifetime of the channeled particles, and half-thickness are obtained in a general form. The theory permits t o take into account in a simple manner the simultaneous action of many dechanneling factors as well as incomplete dechanneling on channel borders and rechanneling.

The Theory of Thermal Dechanneling from Axial Channels

“…In order to obtain a specific expression for qch(z) we start from the general formula for the distribution function of the lifetime t of particles in the channel given in [2], W is the part of the transverse phase space (2) accessible for channeled particles, @(z, 0) is the initial condition for the distribution function @(x, t ) which satisfies a Fokker-Planck equation of the type (16) (in the general case 2' is the second-order differential operator over xi variables), @ k ( x ) and A k are the eigenfunctions and eigenvalues of the Sturm-Liouville problem,…”

“…The investigation of the thermal dechanneling problem in all subsequent papers is based on this hypothesis as well. However, at present one can doubt the validity of the hypothesis [2]. Therefore, it is necessary to develop a new thermal dechanneling theory making no use of it.…”