Experimental observation of kinetic Alfvén wave generated by magnetic reconnection

The transient nature of magnetic reconnection dictates that it must be accompanied by rich electromagnetic wave activity, which can in turn affect the reconnection process. Interaction between Alfvén waves and reconnection has been simulated and recently observed in space. In this paper we report the first laboratory observation of a kinetic Alfvén wave (KAW) mode during reconnection in a linear device. The reconnection was measured by magnetic probes and the enhancement of light emission during reconnection was captured by a fast camera. The perpendicular wave pattern suggests it is an m = −2 mode rotating in ion diamagnetism direction. The wave data agrees with the theoretical prediction of KAW. The temporal correlation between KAW amplitude and reconnection rate indicates waves are generated by reconnection. (paper)