Magnetized Plasma Apparatus for Investigating Non-Linear Interactions at Microwave Frequencies

Following on from a series of laboratory plasma experiments1, 2 that simulated natural plasma instabilities3, a larger plasma apparatus is being constructed. This laboratory plasma will be used for studying nonlinear wave coupling between one or more electromagnetic (EM) waves interacting in plasma. Coupling of injected EM waves to Langmuir and ion acoustic waves is of interest for a number of laser plasma interactions and in ionospheric physics experiments. Long (and short) pulse signals with normalized intensities approaching those used in some recent laser plasma interactions can be generated using flexible microwave amplifiers. Multi -wave microwave interactions are also directly relevant to the delivery of heating and current drive in future magnetic confinement fusion reactors. Microwave sources and amplifiers will be used to precisely launch and electronically control multiple EM signals. The relatively long lived, benign and accessible plasma relevant to coupling of microwave frequency signals will enable the use of insertion diagnostics in addition to analyzing the EM signals.