Simulation of a depressed collector for millimeter wave gyrotron

Abstract

The trajectories of spent electron beam were simulated from the mode converter to the single-stage depressed collector for a W-band gyrotron. The spent beam trajectories and power distribution data obtained from large signal analysis were fed to the simulation model. The collector geometry and the magnetic field were profiled to ensure the landing of the electrons to the wider cylindrical section of the collector electrode for better thermal management, which was ensured with ±5% variation in the magnetic field and no electron interception. The power dissipation and the maximum thermal loading on the collector were 80.55 kW and 0.377 kW/cm², respectively. The collector efficiency was ∼48% for 120 kW RF generation. The thermal analysis of the collector in pulsed condition with 10 and 40 L per minute flow rates predicted the maximum temperature at the collector electrode as 151.8°C and 133.3°C, respectively.

KEYWORDS:

• Depressed collector
• millimeter-wave gyrotron
• W-band gyrotron
• electron trajectory simulation
• thermal analysis

Disclosure statement

No potential conflict of interest was reported by the authors.

ORCID

Vishal Kesari http://orcid.org/0000-0002-6347-3433

Additional information

Notes on contributors

Vishal Kesari

Vishal Kesari received M. Sc. (Physics) from Purvanchal University, India, and Ph. D. (Electronics Engineering) from Institute of Technology, Banaras Hindu University, Varanasi, India, in 2001 and in 2006, respectively. He is a scientist at Microwave Tube R&D Centre, DRDO, Bengaluru, India. His research interest includes microwave and millimeter-wave vacuum electronic devices. He has authored two books and numerous research papers in peer-reviewed journals and conference proceedings.

R. Sudhakar

R. Sudhakar received B. E. in Mechanical Engineering from Basava Academy of Engineering, Vishwesvaraya University, Bengaluru, India, in 2013. He is currently a CAD Operator with Microwave Tube R&D Centre, DRDO, Bengaluru, India. His research interest includes the structural and thermal design of gyrotrons.

D. Jayateertha

D. Jayateertha received B. E. in Computer Science and Engineering from Gulbarga University, Gulbarga, India and M. Tech. in Computer Science and Engineering from Defence Institute of Advanced Technology, Pune, India in 2000 and in 2018, respectively. He is a scientist with Microwave Tube R&D Centre, DRDO Bengaluru, India.

P. Srikrishna

P. Srikrishna received B. E. in Mechanical Engineering from Sathyabama Engineering College, University of Madras, Chennai, India, in 1996, and M. E. in Mechanical Engineering from the Indian Institute of Science, Bengaluru, India. He is pursuing his Ph. D. in Mechanical Engineering from Indian Institute of Science, Bengaluru, India. He is a scientist with the Microwave Tube R&D Centre, DRDO, Bengaluru.

R. Seshadri

R. Seshadri received M. Sc. (Physics) from Bharthidasan University Trichy, India in 1985, M. Tech. (Microwave Electronics) from Delhi University, India in 2001 and Ph.D. (Electronics Engineering) from Institute of Technology, Banaras Hindu University, India in 2010. Since 1989, he has been a scientist with Microwave Tube R&D Centre, DRDO, Bengaluru, India.