EXPERIMENTAL-STUDY OF WAVE-PROPAGATION THROUGH A RAPIDLY CREATED PLASMA

Frequency up conversion and converting a CW source microwave into a frequency up-shifted and chirped periodic pulse have been demonstrated by two experiments. In the first one, the CW source microwave propagates through a periodically microwave-discharged plasma. The CW source microwave is converted into a periodic pulse having up-shifted carrier frequency. The second one uses a high voltage (approximately 100 KV) DC discharge to generate a dense plasma suddenly between two parallel plates. A frequency up-shifted and chirped pulse (approximately 2 ns) converting from the CW source microwave interacting with the suddenly created plasma is observed. The central frequency (approximately 6.4 GHz) of the pulse is up-shifted from the frequency (approximately 4.7 GHz) of the source wave by about 40%. Moreover, frequency components which are up-shifted as high as 80% are also observed.