Integrated circuits for particle physics experiments

High energy particle physics experiments investigate the nature of matter through the identification of subatomic particles produced in collisions of protons, electrons, or heavy ions which have been accelerated to very high energies. Future experiments will have hundreds of millions of detector channels to observe the interaction region where collisions take place at a 40 MHz rate. This paper gives an overview of the electronics requirements for such experiments and explains how data reduction, timing distribution, and radiation tolerance in commercial CMOS circuits are achieved for these big systems. As a detailed example, the electronics for the innermost layers of the future tracking detector, the pixel vertex detector, is discussed with special attention to system aspects. A small-scale prototype (130 channels) implemented in standard 0.25 mu m CMOS remains fully functional after a 30 Mrad(SiO/sub 2/) irradiation. A full-scale pixel readout chip containing 8000 readout channels in a 14 by 16 mm/sup 2/ area has been designed. (24 refs). The Large Hadron Collider (LHC) under construction at CERN (Geneva, Switzerland) will be operational in the year 2005. The LHC will host four detectors, ATLAS, ALICE, CMS and LHCb. They each will have tens of millions of sensor channels and will be the "electronic eyes" looking at the intersection regions where collisions of protons of 7 TeV energy will take place at a frequency of 40 MHz, each producing a spray of several thousand particles. As the newly created particles fly away from the collision point, they traverse several detector layers: the tracker, the calorimeter and finally the muon detector. The authors discuss the electronics required for such detectors in high-energy physics experiments. They conclude that modern commercial deep submicron CMOS technology offers the required density and performance for the electronics, and provides through special layout techniques the radiation tolerance essential for the experiments at LHC. (5 refs).