HIGH FREQUENCY OHMIC LOSSES IN TERAHERTZ FREQUENCY RANGE CW CLINOTRONS

Abstract

Reliable simulations of electron-vacuum devices’ opera-tion parameters are an actual challenge during the R&D process. One of the most important problems is determining high frequency ohmic losses and taking them into account in the simulation. The surface roughness investigation of the clinotrons’ slow-wave structures, manufactured by electro discharge machining, with the methods of optical microscopy is proposed in this paper. As a result the real values of the surface roughness were considered for the high frequency ohmic losses estimation of the real slow-wave structures. Taking into account the electron beam interception with the slow-wave structure surface, the temperature load simulations have been carried out and the temperature gradient of the clinotrons’ slow-wave structures of 2-mm, 0.75-mm and 0.33-mm wavelength ranges was found. The electric conductivity decrease caused by surface roughness and increase of temperature of a slow-wave structure with beam current has been taken into account at the simulation of the clinotron output power. The qualitative and quantitative agreement between experimental data and simulation results was achieved for the 136 GHz and 301 GHz clinotrons.

Keywords

• beam-wave interaction
• clinotron
• electric conductivity
• high frequency losses
• surface roughness
• thz radiation sources