Stability limits of highhyphen;power ionhyphen;laser discharges

摘要

Highly ionized plasmas (degree of ionization 0.1,...,0.5) with electron temperatureskTegsim;4 eV are required for highhyphen;power generation from ion lasers. In stationary lowhyphen;pressure arcs, however, these requirements are limited by discharge instabilities. The stability limits are investigated in the case of Ar and Hg lowhyphen;pressure discharges. It is shown that the main limitation processes are due to neutral gas depletion by ionization and axial plasma inhomogeneities. The stability ranges of ionhyphen;laser discharges are represented using the geometryhyphen;independent parametersjRandpR(thinsp;j: discharge current density;p: filling pressure;R: discharge radius). These instabilities, together with saturation effects in the laser mechanism, limit the output power of ion lasers by restricting the operational range of the discharges.