An experiment to investigate parametric interaction and mixing of microwaves in plasma*

Building on earlier research, investigating the mechansim for Auroral Kilometric Radiation [1,2], a “linear plasma” experiment is being developed to investigate the coupling of multiple microwave beams in magnetised plasma. The magnetic flux desnity is expected to reach 0.09T. The plasma will be generated by a helicon system using a 'flat sprial' type of antenna. This will produce a large (~0.5m diameter, 2-3m long), dense, cool plasma, potentially with a high ionisation fraction. Microwave beams from fixed frequency magnetrons and wideband TWT ampligiers will be used in multi-signal interaction experiments. The paper will present progress on this system. [1] Ronald K., Speirs D.C., McConville S.L., Phelps A.D.R., Robertson C.W., Whyte C.G., He W., Gillespie K.M., Cross A.W., Bingham R., 2008, Phys. Plasmas, 15, art.056503 [2] Speirs D.C., Bingham R., Cairns R.A., Vorgul I., Kellett B.J., Phelps A.D.R., Ronald K., 2014, Phys. Rev. Lett., 113, art 155002