The design and calculation of P-Band 1.2MW multi-beam Klystron

Comparing with single beam klystron, Multi-Beam Klystron (MBK) can operate at low beam voltage, and has small volume and weight. To satisfy the requirement of high energy proton accelerator for Spallation Source and ADS (Accelerator Driven Sub-critical System), the design and calculation of a P-band 1.2MW MBK was made in Institute of Electronics, Chinese Academy of Sciences (IECAS). By using 30 beams, P-band MBK can work at beam voltage of 35 kV with cathode loading of <;2.5A/cm². By using 5 cavity (one of them is second harmonic cavity), the P-band MBK can obtain peak power of 1.282MW, efficiency of 69.7 %, and gain of 45.6 dB with length of the interaction section (600mm). It makes the total length of MBK less than 2000mm. The design consideration and calculation results are present in the paper. Also the comparison among MBK, Multi-Beam-IOT, and single beam klystron was made.