Ion-end-loss rate for rf-plugged mirrors and its application to electrostatically plugged mirrors

Improvement of plasma confinement attributed to both ion heating and quasipotential is experimentally investigated by imposing rf electric fields with the ion-cyclotron range of frequency near both ends and one end of a minimum-B mirror, respectively. An expression of the ion-end-loss rate for rf-plugged mirrors is compared with the experimental results for one-end plugging by the quasipotential. The expression agrees with a Pastukhov for large potentials. The same expression applied to end losses from electrostatically plugged mirrors shows a good fit to the Fokker--Planck and Monte Carlo code results within the accuracies for both plug potential and mirror ratio and is good for arbitrary values of plug potential and at least for mirror ratios larger than or equal to 2