An Experimental Investigation of a 0.8 THz Gyrotron with an Improved Mode Selection

In this paper, we present and discuss the latest experimental results from the investigation of the operational performance of a 0.8 THz double-beam gyrotron, which has been developed and manufactured recently in the framework of an international research project led by IAP-RAS and FIR UF. After the initial tests, the current experiments have been focused not only on the study of the operation at the design mode TE
_8,5
(at the second harmonic of the cyclotron frequency) but also of several other modes the generated radiation of which could be appropriate for various other applications besides the envisaged 1.2 GHz DNP-NMR spectroscopy. The obtained results give a deeper insight into the specifics of the operation of the double-beam gyrotron and especially on its capability to provide an improved mode selection and therefore a single mode second harmonic operation.