Detector charge-sensing using an integrated GaAs operational amplifier

We have examined the use a GaAs operational amplifier (op amp) for charge-sensing in radiation detectors. Our analyses have indicated that a properly designed high-gain op amp can meet most of the requirements for charge-sensing and the circuit can also be readily integrated with a strip detector or a CCD pixel detector. The capacitance matching between the detector output and the amplifier input (for noise reduction) can be accommodated by using a cascode configuration for the op amp and a wide bandwidth (>200 MHz) can be achieved using GaAs MESFETs.