Coaxcial Line Type Long Microwave Discharge Lamp

A microwave excited gas discharge lamp using a novel configuration of a coaxial line has been developed for application to VUV light source. The microwave propagated through the coaxial line consisted of the excited microwave plasma itself as the inner conductor and a metal tube as the outer conductor. The microwave power was launched directly from the antenna of the magnetron power source to the quartz discharge tube without using any impedance matching network. The length of the plasma was logarithmically increased with increasing the microwave power. A 2m-long uniform microwave plasma was obtained by using a couple of magnetron power sources on both the sides operated by alternating half-rectified sinusoidal wave high voltage source.