Electronic photomultiplier tube with sec. electron emission dynod - has one or two dynodes with truncated cone elements to improve multiplication factor

摘要

An electronic photomultiplier tube has secondary emission electron multiplication stages or dynodes. The tube has two dynodes with less tendency for the electrons emitted by the first dynode not hitting the second dynode. The tube (10) has a dynode (11). This dynode (11) comprises a plate with two thin crossed bars. The bars support truncated cone elements. The elements have similar height and are concentric about the axis of the tube. The element are coated with an emissive material. The cone elements are electrically interconnected. The first dynode (11) of the tube may have elements as described above. However the other dynodes may also have similar elements.