FREE-VOLUME HOLE DISTRIBUTIONS OF POLYMERS PROBED BY POSITRON-ANNIHILATION SPECTROSCOPY - EXPERIENCES OF USING THE CONTIN PROGRAM

A Laplace inversion technique has been employed to invert positron annihilation lifetime spectra to continuous lifetime distributions by using the CONTIN program. Free-volume hole distributions are determined directly from the results of ortho-positronium distributions. The obtained lifetime distributions are highly affected by various experimental factors: the statistics, the instrument instability, and the choice of the reference spectrum. Experiences of using the CONTIN program for the determination of free-volume hole distributions of polymers are discussed,