PLASMA IMPEDANCE AND ELECTRON-DENSITY IN A PULSED-LASER CHANNEL

The representation of plasma impedance of gas laser discharge and spar k gap channels by an inductance-capacitance (L(p)-C-p) tank circuit ha s been useful in describing the frequency response of a pulsed superra diant laser charging circuit. The impedance matching of these plasma c hannels can lead to resonant narrowing of the laser pulsewidth in supe rradiant nitrogen lasers. Using fluid equations to model the electron and ion plasmas, the impedance of plasma channels is formulated. This derived impedance supports the phenomenological L(p)-C-p tank circuit configuration, and provides the means to calculate the inductance and capacitance in terms of the plasma density and discharge dimensions. C onjugating this model with the pulse width narrowing via plasma impeda nce matching, the electron density at the very moment of lasing in a s uperradiant gas laser channel can be estimated by using the measured L (p) and C-p. (C) 1996 American Institute of Physics.