Back electron bombardment effect on independently tunable cells thermionic cathode RF gun

In order to study the free-electron laser technology, an independently tunable cells thermionic-cathode RF gun with two microwave feed-in ports is manufactured in CAEP. An experiment facility of power test is built, and experiment research on beam current and power of back electron bombardment is performed. Research result shows that a beam intensity over 500 mA can be measured at exit of the RF gun, and the back electron bombardment can be changed with adjustment of phase and amplitude of the electric field in the first cavity.