A Monte Carlo code describing the neutral gas transport in pipe configurations with attenuating media (Q1802302)

A three-dimensional Monte Carlo description of the neutral gas transport in pipe configurations with almost arbitrary torsion and curvature is presented. To avoid quadratic or even transcendental expressions describing the pipe surfaces confining and guiding the neutral gas, a decomposition into plane geometrical elements is chosen. Furthermore, a combination of the pseudo collision, ``pseudo tracklength,'' and of the standard tracklength estimator is introduced. Applications to the pump limiter facility ALT-II show the practical expediency of the code.