High-power Multi-beam Klystrons Research Articles

An Overview of Multibeam Klystron Technology

The multibeam klystron (MBK) is a compact high-power microwave vacuum electronic device that features low beam voltage, high efficiency, wide bandwidth, and low volume and weight. Since the 1960s, high-performance broadband MBKs have been developed that cover the entire microwave frequency band with relative instantaneous bandwidths <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$&gt;$</tex-math> </inline-formula> 15%, peak power <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$&gt;$</tex-math> </inline-formula> 1 MW, average power up to 40 kW, and efficiencies <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$&gt;$</tex-math> </inline-formula> 40%. In recent years, driven by the needs of high-energy particle accelerators, ultra high frequency (UHF) and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\textit{L}$</tex-math> </inline-formula> -band MBKs with peak powers of more than 20 MW and efficiencies of nearly 80% are being developed. This article presents an overview of the development of broadband MBKs used in microwave electronic systems, such as radar and communication, and high-power MBKs used in the RF systems of particle accelerators. It also introduces the latest progress and development trends in MBKs leading to higher frequency, output power, bandwidth, efficiency, and lifetime.

The Physical Limitations of the Efficiency of High Power Multibeam Klystrons

The Physical Limitations of the Efficiency of High Power Multibeam Klystrons

Research and Development of S-Band High Power Multibeam Klystron

The design, manufacture, and test of an S-band high power multibeam klystron (MBK) are presented in this paper. The test results indicate that the performance of the MBK satisfies the design requirement. Several technical problems, such as the oscillation of high-order modes, a decrease of the beam current under no-driver (oscillating) conditions, and the high-voltage breakdown are also discussed. Some improvements have been taken to overcome these problems. The improved tube has a beam transmission rate over 98%, and operates very stably under DC and RF conditions.

Preliminary study of the characteristic of multi-beam in intense multi-beam relativistic klystron

Compared with the conventional klystron, high power multi-beam klystron makes use of many low perveance beams, then it has a high output efficiency and low operating voltage, but it brings new problems. There fore, the multi-beam intense relativistic electron beam transmission in the multi-beam klystron is investigated by experiment and simulation. The results show that the multi-beam rotates around the center of the system due to the interaction of the multi-beam, and simultaneously the multi-beam rotates around its own center due to the space charge effect of each beam's own. All the process can result in electron beams loss.