Abstract
A cathode emission proflier based on anode-hole scanning method has been developed, which reveals emission density distrlbution and local emission characteristics in a cathode surface. The 411-type impregnated cathodes with O_s-Ru coating for CRT use are studied with this emission profller having a 20 micrometer anode-hole. Several new findings have been obtained particularly in the aging processes and the oxygen gas poisoning and recovery processes, which imply the importance of emission proflle studies in understanding cathodes.
