Study of Some of the Parameters Affecting Knudsen Effusion. VI. Monte Carlo Analyses of Channel Orifices

Techniques for Monte Carlo simulation of real particle behavior have been extended to study the performance of channel orifices. Transmission coefficient calculations and wall‐flux gradient behavior are considered. For the particular case $\text{L\hspace{0.17em}/\hspace{0.17em}R\hspace{0.17em}=\hspace{0.17em}4.0}$ , functions are derived to allow for variable orifice‐to‐collimator distances when the target collection method is used. A “state‐of‐the‐art” discussion on orifice behavior is included to help delineate the purposes of this study. It is concluded that use of both knife‐edged and channel orifices is sometimes necessary to establish the cell‐orifice behavior of some systems; information derived from experimental studies, and from Monte Carlo analysis of flux relationships appropriate to the geometry of the system, seems to indicate that the channel orifice is a better choice for most effusion work.