The impedance of the laser head of a 100 W copper-vapor laser is investigated. The laser head is of a coaxial geometry which is commonly used for longitudinally electrically excited, pulsed-gas lasers.The plasma conductivity is estimated using the available data on plasma parameters. The effect of radial gradient of the gas-temperature is considered. The tube inductance and capacitance are estimated and the combined effect is demonstrated. The skin-effect is considered. A method to calculate the exact influence of the skin-effect on the tube impedance is presented.
The full calculation procedure is demonstrated for the case of a 100 W, 8 cm diameter, copper vapor laser. The consequent impedance is used to calculate the laser current under given excitation conditions. Very good agreement exists between the calculated and measured laser current.An optimal metal-sleeve diameter with respect to power matching is found.