Abstract: We present and compared two different approaches for modelling microchannel plate (MCP) devices in regime of gain saturation. In our numerical model an MCP is described as a ladder network of interacting R and C lumped elements. The Kirchhoff equations of the network are coupled to a gain equation describing the amplification of input pulses as they progress into the microchannels. This non-linear system can be solved numerically and can be included into a best-fit algorithm capable of determining the model parameters from experimental data. An alternative analytical model was developed assuming a simplified network and describing pulse amplification and wall charge replenishment with a pair of differential equations. In this way, simpler analytical equations are found that describe an MCP in a broad range of operating conditions. Measurements on a Z-stack MCP photomultiplier showed that the numerical model provides a fairly accurate description of the MCP in pulse mode. The analytical model, although less accurate, is more suited to best- fit algorithms, allowing a remarkable reduction of computer time and of convergence problems.!15
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