The Preliminary Design and Calculation of Compact P-Band Multi-beam Klystron

As a microwave source of proton accelerators, P-band klystron needs high efficiency and miniaturization as the key indicators. The traditional single beam klystron has a high voltage, a long length and a large volume. Compared with single beam klystron, multi-beam klystron(MBK) can improve the efficiency and reduce the operating voltage of the klystron by reducing the perveance of single beam and increasing the total beam perveance. At the same time, the introduction of high harmonic cavity can effectively reduce the interaction length and achieve high efficiency. This article introduces the preliminary simulation and calculation of 714 MHz, 2 MW continuous wave (CW) MBK. Through the simulation by 1D klystron code KLY6, more than 80% efficiency is obtained. The gain reaches 50 dB and the length of the interaction section is controlled at 1200 mm.