Multi-Channel Photomultiplier Tube Assembly

An inspection system, comprising:

• an illumination source configured to illuminate a portion of a sample surface;
• a set of illumination optics configured to direct and focus the illumination onto the sample surface;
• and
• a photomultiplier tube detector assembly, comprising:
• a first dynode channel, the first dynode channel including a first set of dynode pathways, at least some of the first set of dynode pathways including a plurality of dynode stages configured to receive a first portion of the photoelectrons and direct a first amplified photoelectron current onto a first anode of a first set of anodes;
• an additional dynode channel, the additional dynode channel including an additional set of dynode pathways, at least some of the additional set of dynode pathways including a plurality of dynode stages configured to receive an additional portion of the photoelectrons and direct an additional amplified photoelectron current onto an additional anode of an additional set of anodes;
• and
• a grid configured to direct the first portion of the photoelectrons emanating from the photocathode to one or more of the first set of pathways of the first dynode channel, wherein the grid is further configured to direct the additional portion of the photoelectrons emanating from the photocathode to one or more of the additional set of pathways of the additional dynode channel.