On “measurements” of radiation damage by backscattering experiments

It is generally meaningless to extract a measurement of the “number of disordered atoms” from a backscattering experiment. The only case where this is a measurable quantity is that of amorphous regions imbedded in a perfect crystal. In all other cases (particularly in metals), a backscattering experiment can yield only an indication about the degree of lattice disorder. The number and nature of defects cannot be determined by a backscattering experiment, but it is suggested that the energy dependence of the dechannelling could be of some help to distinguish between different possible types of defects.