Magnetic stabilization of the plasma column in flowing molecular lasers

Abstract

A technique of magnetically stabilizing the position of the plasma column and the resulting inversion region in lower pressure flowing molecular lasers is described.A transverse magnetic field, mutually perpendicular to the discharge axial electric field and the gas flow velocity, is employed to maintain the electrical discharge column parallel with the optic axis. The magnetic stabilization of the discharge is analyzed in terms of the Lorantz forces and the resulting ambipolar drifts of the plasma. A comparison with magnetically stabilized arcs is presented. Supporting experimental data obtained for pure gases and typical laser gas mixtures are given. The operating characteristics of the cross-field CO, laser which employs a premixed gas flow channeled transvarse to the stabilized discharge t o provide convective gas cooling are discussed. The experimental results of a parametric study on the dependence of gain and power output upon gas flow velocities, magnetic field, gas mixtures, and pressure are presented. The operation of the first premixed CW electrically initiated chemical laser has been achieved using cross-field magnetic discharge stabilization. Preliminary operating characteristics of this chemical laser for the 3-p rotational-vibrational transitions in HF and the 4-p transitions in DF are presented.

Magnetic field stabilization of low current DC arc discharge in cross flow in argon gas at atmospheric pressure—a numerical modelling study

“…In addition, our configuration considers a bounded domain (see figure 1), with distance between the walls in the same order of magnitude as the arc diameter. Again, this is not a new development and similar configurations were studied in the past [6,[13][14][15][16]. In [15], the setup was also bounded with small distance between the walls but the pressure was much lower (few Torrs).…”

“…Again, this is not a new development and similar configurations were studied in the past [6,[13][14][15][16]. In [15], the setup was also bounded with small distance between the walls but the pressure was much lower (few Torrs). In the above mentioned studies, the balance between the magnetic force and gas flow drag was examined and it was concluded that the experimental data is well described by the equality of the Lorentz force and the aerodynamic drag for a rigid cylinder, which can be written for the force per unit length of the arc as [6,16]:…”

Review of CW high-power CO2lasers

“…The data folrFigs. 12-14 were obtained with the magnetically stabilized convectively cooled COZ laser configuration described in [44] and [45]. The data were presented here to show the general qualitative parametric behavior of convectively cooled Cot lasers.…”

“…20: The bowing of the discharge downstream by the gas flow is prevented in this configuration by the application of a magnetic field mutually perpendicular to the gas flow and the collinear optical and discharge axis [44], [45]. This laser configuration is called the transverseflow magnetically stabilized coaxialzdischarge laser (OIs, Vu, B z ) .…”