Mesh dynode

The return beam vidicon (Fig. 9) uses a photocathode to detect the light image. The photoelectrons are formed on a target composed of a secondary electron emitter similar to the dynodes in a photomultiplier, and secondary electrons produced are collected by a mesh, leaving the target with an image stored in... 

Fig. 6.2 PMT dynode geometries. Circular dynode arrangement, linear focused, fine mesh, Venetian blind, metal channel type. C Cathode, D dynodes, A anode, F focusing electrode,...

Of special interest for time-correlated single photon counting are the linear fo-cused dynodes, which give fast single electron response and low transit-time jitter, and the fine mesh and metal channel types, which offer position sensitivity when used with an array of anodes. Moreover, PMTs with fine-mesh and metal channel dynodes can be made extremely small, which results in low transit time, low transit-time jitter, and a fast single-electron response. 

Another type of PMT is the head-on design (figure 2.26). This (tesign is used with various types of dynode chains, such as the box and grid, blind, and mesh designs. For time-resolved fluorescence, the head-on PMTs are... 

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