Резонансная перезарядка в электростатическом поле

The estimation of the electrostatic field influence that exits, e.g., in plasma, on resonant charge exchange under collision velocities substantially less than that of an active electron is made in the frame of the zero range potential model. It is determined that the electric field of sufficient value leads to decreasing the charge exchange cross section. For example, the field about 10^7V/cm decreases the cross section on an order of magnitude.

Кинетическая теория пристеночного слоя при произвольных условиях в газоразрядной плазме

For an arbitrary relation of the Debye length to the ion free path, based on the kinetic approach, it was solved the self consistent problem of the structure of the perturbed wall sheath in a DC plasma gas discharge, near a flat surface at a negative potential in relation to the plasma. The solution was obtained without an artificial separation of the perturbed wall sheath into a quasineutral "presheath" and a wall sheath where quasineutrality is substantially violated. They were taken into account the real ion distribution function in the unperturbed plasma, the dependence of the charge exchange cross section on the ion energy, and the nonzero electric field in the unperturbed plasma. It was found that, if the mean electron energy is preserved, the structure of the perturbed wall sheath weakly depends on the form of the electron distribution function. It was shown that, even under the assumption that the mean electron energy is much higher than the mean ion energy, is the mean ion energy in the unperturbed plasma the one that has a significant effect both on the structure of the quasineutral "presheath" and on the structure of a part of the wall sheath, where there is no quasineutrality. The calculations of the parameters of the ion flux and the structure of the perturbed wall sheath are in agreement with other authors’ experimental results that didn’t have previously an adequate interpretation.

Search for long-lived states of the heavier rare gas negative ions

A pure quartet state is expected in the energy spectrum of all the heavier rare gas negative ions which is metastable for autoionization to the ground state of the neutral atom. If this state occurs below the energy of the parent np5(2P3/2)(n + 1)s[3/2] state then it may be possible to produce accelerated beams of the heavier rare gas negative ions as is now done using the (1s2s2p)4P state of He−. A search was made for the negative ions Ne−, Ar−, Kr−, and Xe− following double electron capture in a krypton target at energies near 50 and 100 keV in the energy range where the He+ double charge exchange cross section is at its maximum. No definite evidence was found for any of these heavier rare gas negative ions, and they must all therefore have lifetimes less than 10−6 s.