An improvement in the algorithm for absorption correction by the analytical method

The most time-consuming step in the analytical method for absorption correction is the examination for each Howells polyhedron of the large number of tetrahedra formed from all possible sets of one auxiliary point with the faces of previously found tetrahedra. In the present method, a formula is presented for the absorption of a polyhedron (a slice) with two parallel faces, which are planes of constant absorption. With this formula, the absorption of a Howells polyhedron can be calculated, with much less effort, by systematically dividing it into slices.