A fast readout and processing electronics for photon counting intensified charge-coupled device

The design features and the performances of a prototype photon counting ima ging detector, being developed for the international ultraviolet (UV) space mission Spectrum UV, are presented. The photon counter is an intensified c harge coupled device (ICCD) in which photon events, generating an electron cascade through a high gain microchannel plate (MCP) stack, are transduced, via a phosphor screen and a fiber optics reducer, into a 3 x 3 pixel(2), q uasi-Gaussian charge distributions on a 15 x 15 mu m(2),512 x 512 pixel(2) format CCD matrix. The CCD is read out in the frame-transfer mode at a pixe l rate of 19.75 MHz, and its output data flow is acquired serially as to ge nerate a 3 x 3 pixel(2) event sash that sweeps dynamically the CCD matrix a t the 50.6 ns rate of the readout clock. Each and every event sash is searc hed for the presence of events whose charge content lie within proper limit s and satisfy a given set of morphological rules, i.e., a single peak charg e profile. The centroid coordinates of identified events are determined wit h subpixel accuracy (up to a 2(10) bin/pixel) and subsequently stored as ph oton list coordinate pairs. The data acquisition and processing system is b ased on field programmable gate array technology and is capable of satisfyi ng the requirements of real-time operation. The modular construction of the data acquisition and processing electronics provides a great deal of flexi bility for supporting advancements in CCD readout techniques (multiple outp ut and higher clocking speed) and of MCPs (larger formats, smaller pore, an d higher dynamic range). The results of the performance verification of the data acquisition and processing system integrated with a laboratory ICCD p rototype are presented and discussed. (C) 2000 American Institute of Physic s. [S0034-6748(00)04502-0].