Electrostatic quadrupole lens simulation in potential array relaxation programs

Lens and ion trajectory simulation programs, such as the popular program SIMION, which employ potential array relaxation methods, are very useful in designing and modifying ion lens systems. Unfortunately, these programs cannot simulate lenses of certain geometries such as quadrupoles. Several approaches for portraying static DC quadrupole lenses accurately in such programs have been investigated. These include user programming, an option in the latest version of SIMION, and array modification. The most convenient and accurate method involves modifications to the lens arrays employing relaxation techniques similar to those used in SIMION itself. These have been incorporated into a self‐contained computer program named QREFINE, which is available to interested parties.