SIMION’s fast adjust feature (.PA# files) is convenient compared to basic arrays (.PA files), in allowing electrode potentials to be quickly changed without the relatively slow process of refining the potential array again. The downside, however, is that each adjustable potential involves an additional solution array (e.g. .PA1, .PA2, etc.), which consumes more RAM and disk space and lengthens the Refine time. The problem is heightened if you have dozens or hundreds of electrodes of distinct potentials, as can occur in systems with resistor chains (common in IMS tubes and ion funnels), as well as other systems. There is, however, a middle ground in this. There are many cases where potentials in a system need to be quickly adjustable, but the electrode potentials are not all completely independent. For example, a series of 10 electrodes connected via resistors in a chain formation will have electrode potentials that are linearly dependent and uniquely determined if known potentials are applied on only the two end electrodes. In this case we only really need two solution arrays (controlled by two adjustable potentials), or perhaps one if the potential on one end is fixed while the other may vary.
Earlier versions of SIMION (e.g. 7.0) supported a fast (proportional) scaling solution array (.PA_ file), which is a solution array like the others but represents more than one electrode. The potentials of the electrodes represented in this fast scalable set can be rescaled only proportionately to each other during Fast Adjust. SIMION 8.0.3 generalizes this concept further, as described below, thereby supporting things like multiple independent resistor chains.
NoteThis page is abridged from the full SIMION 8.1.1 “Supplemental Documentation” (Help file). The following additional sections can be found in the full version of this page accessible via the “Help > Supplemental Documentation” menu in SIMION 8.1.1:
- See Also