Design and simulation investigations of high-power millimeter-wave gyrotron

ABSTRACT

In this paper, a high power millimeter wave gyrotron cavity was modelled and studied for its beam-wave interaction, beam-misalignment, and thermal issues. The sub-assemblies including the magnetron injection gun (MIG), RF output window, and electron beam collector were investigated. The MIG has produced an annular electron beam with transverse velocity spread less than ∼4%. The Particle–In–Cell simulation predicted an RF output of  470 kW in TE10,4 mode at ∼139.52 GHz for a DC drive of 80 kV, 20 A. The temperature on the inner, outer surfaces of the cavity and the corresponding average radial expansion of the cavity were calculated. Due to the radial expansion of the cavity, the resonant frequency and RF output power has changed to ∼0.514 GHz and ∼50 kW, respectively. Finally, the overall efficiency of the present gyrotron was improved from ∼29% to ∼47% by using a single–stage depressed collector.

KEYWORDS:

• Beam-misalignment
• depressed collector
• millimeter wave gyrotron
• PIC simulation
• and thermal analysis

ORCID

Akash http://orcid.org/0000-0002-6155-1821

Additional information

Notes on contributors

Rajanish Kumar Singh

Rajanish Kumar Singh received BTech in Electronics and Communication Engineering from Uttar Pradesh Technical University, Lucknow, India, in 2007 and MTech degree in Microwave Engineering from Indian Institute of Technology (BHU), Varanasi, India, in 2010. He is currently pursuing a PhD degree in Department of Electronics Engineering with the Indian Institute of Technology (BHU), Varanasi, India. His current research interest includes computational electromagnetics, fast-wave devices, low power microwave sources in millimeter wave and sub-millimeter wave regime.

Akash

Akash received the BTech degree from Uttar Pradesh Technical University, Uttar Pradesh, India in 2013. He is currently pursuing the PhD degree in Electronics Engineering from the Indian Institute of Technology (BHU), Varanasi, India. His current research interests include millimeter-wave vacuum electron devices and their applications.

M. Thottappan

M. Thottappan received the PhD degree in microwave engineering from the Indian Institute of Technology (BHU) Varanasi, India, in 2013. He is currently an Associate Professor with the Department of Electronics Engineering, IIT (BHU) Varanasi. His current research interests include the fast wave electron beam devices including gyrotron amplifiers and sources, high-power microwave (HPM) sources, and their sub-assemblies. Dr Thottappan is a Senior Member of IEEE.