256-anode channel plate device for simultaneous ion detection in time of flight measurements

A 256-anode channel plate device with dedicated electronics has been built for the detection and accurate timing of a large number of simultaneous particle impacts in counting mode. In addition, a method is described which extends the performance of this detector by providing access to the amplitude response without any encoding. This experimental amplitude is extracted for each pixel using a threshold discriminator variation procedure. A detailed description of the detection processes allows calculation of the detector output signal amplitude for single as well as for multiple impacts per pixel. These calculations take into account the geometrical design of the pixelated anode structure. From a comparison between calculated and experimental amplitudes the number of incident particles per pixel can be deduced and thus the total number of particles impinging on the MCP surface. An illustration is given that uses the spatial distribution of swift C-60 carbon constituents that exit a thin carbon foil. (C) 2003 American Institute of Physics.