A marginal theory for critical velocity ionization

Summary form only given. All space based tests of Alfven's critical velocity ionization (CIV) hypothesis to date may be described as marginal. That is, no large excess of ionization has been observed, but in many experiments, such as Porcupine, the observed ionization seems to exceed that which can be explained by charge exchange and other collisional processes. This talk will advance the theory that the coupling of momentum to the background plasma by new born ions is more limited than previously thought, and that this limiting will restrict the build up of excess ion density at any point in space. One may generalize CIV theory to state that the free energy available for transfer from new born ions to electrons and subsequently available for additional ionization, depends on the relative velocity between the ions and electrons bound to the magnetic. It will be shown that maintaining the highest possible relative velocity depends on coupling the momentum of new ions to the ambient plasma. It will also be argued that the ambient thermal current places more severe limits on momentum coupling than generally allowed by MHD.