Simple analog computer for solving the Abel integral equation

A special, very simple analog computer is described which permits a rapid and direct calculation of the radial distribution of the emission coefficient of an axial symmetrical discharge column from 'side-on' observed light intensities. The different values of the emission coefficient can be obtained for arbitrarily following radial distances without beginning obligatory at the edge of the column or at the wall of the discharge tube. The computer is very easy to handle. The precision obtained with apparatus is shown using some practical examples. (authors)