Slowing-down of positronium: analysis of the age-momentum correlation

The problem of deconvoluting measurements of the slowing-down of positroniu m by means of the age-momentum correlation technique based on the Doppler b roadening of the annihilation-photon line is reduced to the solution of sys tems of linear equations. The solution gives directly the kinetic energy of positronium as function of the positronium age (= time passed since its fo rmation). A novel time-resolution function consisting of one Gaussian times an arbitrary number of Hermite polynomials is proposed. (C) 2000 Elsevier Science Ltd. All rights reserved.