A new linear plasma device for the study of plasma waves in the electron magnetohydrodynamics regime

摘要

A new, user-friendly, linear plasma device has been developed in our laboratory where a quiescent ($Delta n pprox 1%$), low temperature (1a??10 eV), pulsed (3a??10 ms) plasma can be produced over a large uniform region of 30a??40 cm diameter and 40 cm length. Salient features of the device include the flexibility of tuning the plasma density in the range of $10^{10}$ to $10^{12} m{cm}^{a??3}$ and capability of scanning the plasma and field parameters in two dimensions with a precision of 1 mm. The plasma is produced by a multifilamentary cathode and external magnetic field by Helmholtz coils, both designed and constructed in-house. The plasma parameters can be measured by Langmuir probes and electromagnetic field parameters by miniature magnetic probes and Rogowski coils. The plasma produced is uniform and essentially unbounded for performing experiments on waves and turbulence. The whole device can be operated single-handedly by undergraduate or graduate students. The device can be opened, serviced, new antennas/probes installed and ready for operation in a matter of hours. Some results on the excitation of electromagnetic structures in the context of electron magnetohydrodynamics (EMHD) are also presented to demonstrate the suitability of the device for carrying out such experiments.