Oxide-cathode activation and surface temperature calculation of electron cooler

The pollution on electron gun ceramic insulation of electron cooler restricted the operation of electron cooler at HIRFL-CSR main ring. To cool and accumulate ion beam well, the pollution was cleared and a new oxidecoated cathode was assembled. The processes of cathode replacement, vacuum chamber baking-out, and thermal decomposition of coating binders and alkaline earth metal carbonates, and cathode activation are presented. The electron gun perveance of 10.6 μＡ/V1.5 was attained under the heating power of 60 W. The typical surface temperature of oxide-coated cathode that is calculated through grey-body radiation is 1 108 K which shows a comparable result to the experimental measurement 1 078 K. The perveance growth of electron gun during the electron cooler operation is also explaine