Time domain wave phenomena in rapidly created periodic plasmas

Summary form only given. Experimental and numerical results will be presented. It will be shown that under the appropriate condition, i.e., the initial frequency of the wave is less than the maximum plasma frequency, the downshifted modes will be trapped within the periodic plasma structure until the plasma decay away. This trapping has the practical effect of greatly enhancing the efficiency of the interaction process for the generation of frequency downshifted spectral lines. The experiment is simulated numerically and good agreement is demonstrated. A theory based on the impedance distribution of the plasma for each Floquet mode is formulated to explain the wave trapping phenomenon.