Novel electronic readout systems for photon-counting imagers

Abstract

Previously we have described several types of charge division electronic image readouts for microchannel plate based imaging detectors developed at MSSL, primarily for space astronomy applications. These have included the wedge and strip anode<SUP>1</SUP> (WSA), the Vernier anode<SUP>2</SUP> - a high resolution readout, capable of exploiting the limiting spatial resolution offered by the microchannel plate, and FIRE<SUP>3</SUP> - an imaging device operating at event rates in excess of 10 MHz. MSSL and Photek have now joined in collaboration to develop an intensifier based imaging system designed to employ this range of readout systems for general laboratory use. The image intensifier uses the image charge technique<SUP>4,5</SUP> whereby the event charge is used to induce electrical signals on the capacitively coupled readout pattern, obviating the requirement for the readout to be inside the vacuum enclosure. The image readout is manufactured as a separate component, and can be interchanged to suit the specific application requirements. The intensifier tube design can be generic enabling it to be used with a variety if image readouts designs. We describe the image intensifier and electronic design, including the common charge amplifier, event timing and computer interface. We discuss the anticipated performance of the various readout systems - Wedge and Strip, Vernier and FIRE in terms of spatial resolution, maximum count rate, and timing resolution.