Concepedia

Abstract

This paper presents a new structure of a 2-D imaging system devoted to radiology. The detection upper medium, made with bulk cadmium telluride, is connected to the electronic 2D readout circuit through indium bumps. The 60 X 60 micrometers <SUP>2</SUP> electrodes, 100 micrometers pitch, are made on the CdTe:Cl detector with standard lithography and ion etching techniques. The silicon circuit is made of n X n independent integrated amplifiers with serial multiplexing readout. The feasibility of such arrangement is made with 64 X 64 pixels. The thickness of 900 micrometers is well suited for 100 keV x rays. Characterization is performed with 10 ms x-ray pulses. Due to electric field the charges are well channelled and high spatial resolution is available in addition with a very high absorption efficiency. The direct absorption of x ray in the readout circuit is negligible. It does not affect either the signal to noise ratio, or the lifetime of the silicon low level analogue ASIC. The presentation includes linearity, sensitivity, noise FTM, and dynamic image discussion.