Development of Cathode-grid Assembly for Accelerator Application

In order to meet the emission current requirement for the electron gun in accelerators such as BEPCII and HEPS, a cathode-grid assembly was developed at Institute of High Energy Physics by cooperating with domestic cathode manufacturers in China. A cathode-grid assembly consists of a thermionic cathode and a controlled grid. The M-type dis-penser cathode impregnated with 612 barium calcium alumi-nate is applied for its good emission characteristics, long life-time and environmental stability. The grid is woven with tungsten-rhenium wire with transparency of about 80%. The peak current of 14 A with 1ns beam pulse width was obtained on the electron gun test bench. In this paper, the detailed de-sign parameters and test results are described.