RELATING ION/NEUTRAL REACTION-RATE COEFFICIENTS AND CROSS-SECTIONS BY ACCESSING A DATABASE FOR ION-TRANSPORT PROPERTIES

A database is described that allows access to gaseous ion transport coefficients that have been calculated over wide ranges of reduced electric field strength and at several gas temperatures. Comparison of the computed transport coefficients with measured values allows an assessment to be made of the accuracy of the ion/buffer interaction potential assumed in the calculation. The database can also be used to compute rate coefficients for trace ions reacting with small amounts of a neutral reactant that is immersed in a larger amount of a nonreactive buffer gas. Comparison of the computed rate coefficients with values measured in drift tubes allows an assessment to be made of the accuracy of the ion/reactant cross-section assumed in the calculations. Application is made to Ar+ ions drifting through He gas and reacting with small amounts of CO.