摘要:
This invention relates to such electron image devices as television camera tubes and image intensifier tubes and includes in one illustrative embodiment an electrically conductive member upon which there is disposed a first layer or region of a secondary emissive material deposited in a porous form to allow conduction of the secondary electrons through the voids of the porous material, and a second layer or region of greater density than the first layer disposed upon the first region to inhibit the escape of the secondary electrons emitted within the volume of the first layer.