Development of a flight qualified 100 x 100 mm MCP UV detector using advanced cross strip anodes and associated ASIC electronics

Abstract

ABSTRACT Photon counting microchannel plate (MCP) imagers have been the detector of choice for most UV astronomical missions over the last three decades (e.g. EUVE, FUSE, COS on Hubble etc.) and been mentioned for instruments on future large telescopes in space such as LUVOIR 14 . Using cross strip anodes, improvements in the MCP laboratory readout technology have resulted in better spatial resolution (x10), temporal resolution (x 1000) and output event rate (x100), all the while opera ting at lower gain (x10) resulting in lower high voltage requirements and longer MCP lifetimes. A crossed strip anode MCP readout starts with a set of orthogonal conducting strips (e.g. 80 x 80), typically spaced at a 635 micron pitch onto which charge clo uds from MCP amplified events land. Each strip has its own charge sensitive amplifier that is sampled continuously by a dedicated analog to digital converter (ADC). All of the ADC digital output lines are fed into a field programmable gate array (FGPA) whi ch can detect charge events landing on the strips, measure the peak amplitudes of those charge events and calculate their spatial centroid along with their time of arrival (X,Y,T) and pass this information to a downstream computer. Laboratory versions of t hese electronics have demonstrated < 20 microns FWHM spatial resolution, count rates on the order of 2 MHz, and temporal resolution of ~ 1ns. In 2012 our group at U.C. Berkeley, along with our partners at the U. Hawaii, received a NASA St rategic Astrophys ics Technology (SAT) grant to raise the TRL of a cross strip detector from 4 to 6 by replacing most of the 19 rack mounted, high powered electronics with application specific integrated circuits (ASICs) which will lower the power, mass, and volume require ments of the detector electronics. We were also tasked to design and fabricate a standard 50mm square active area MCP detector incorporating these electronics that can be environmentally qualified for flight (temperature, vacuum, vibration). ASICs desig ned for this program have been successfully fabricated and are undergoing extensive testing. We will present the latest progress on these ASIC designs and their performance. We will also show our preliminary work on scaling these designs (detector and elec tronics) to a flight qualified 100 x 100 mm cross strip detector, which has recently been funded through a follow on SAT grant. Keywords: MCPs, MCP detectors, photon counting, ASICs, UV detectors , ROICs