High‐frequency gyrotron scattering diagnostic for instability studies on TARA

A 1‐ to 10‐kW,>30‐ms pulsed, narrow linewidth (<1 MHz), 137‐GHz gyrotron is being fabricated for collective Thomson scattering plasma diagnostics on the TARA tandem mirror experiment. The drift cyclotron loss cone, the axial loss cone, harmonics of these instabilities, and the ion two stream instability in the TARA plugs will be studied with this diagnostic.