Theory of a continuous optical discharge near a target

A one-dimensional model of a continuous optical discharge burning in a radiation cone close to a refractory target is investigated analytically and numerically. Formulas are obtained for the characteristic parameters of such a discharge. It is found that, for discharges burning in a stream of gas, in addition to a lower threshold power, there is also an upper limit and the transparency of the jet decreases with increasing power and gas pressure. For a sufficiently fast gas flow rate in the opposite direction to the beam the jet becomes unstable and splits into layers.