On the empirical success of Boag’s box model in describing cluster and columnar recombination

In this paper, we study the fraction of electric charges that escape recombination in homogeneous clusters and columns. In high electric fields, when the Coulomb interactions and diffusion processes can be neglected, we show that Boag’s box model reproduces the theoretical predictions resulting from the solution of the charge propagation equations. Starting from this comparison, we improve Boag’s formula by introducing an angular dependence required for a better description of columnar recombination.