Laplace inversion arithmetic on personal computers and its applications in materials science

摘要

Positron annihilation lifetime (PAL) spectroscopy is a powerful experimental method for electronic structure and defect study of solid and has been extensively applied in solid state physics, chemistry, materials science, etc. An experimental PAL spectrum is a convolution of the positron decay curve with the instrumental resolution function. Analysis of the PAL data is always a difficult problem, The conventional analysis method assumes that positrons are annihilated from finite positron states and decomposes the PAL spectrum into 2 -4 terms of negative exponential.