AGET, the GET front-end ASIC, for the readout of the time projection chambers used in nuclear physic experiments

Today with the advent of intense radioactive beams, we have access to nuclear spectroscopy and reaction studies of nuclei far from stability. It has been demonstrated that Time Projection Chambers (TPC) method can be very effective as an active target for such studies yielding low thresholds, efficiency and luminosity. To this end a Generic Electronic system for TPCs (GET) is in development and will cover small to medium sized instrumentation (64 to 32 k channels) with a relatively wide charge dynamic ranges for event rates of up to 1 kHz. The 64-channel AGET (ASIC for GET) front-end circuit has been developed to perform the amplification, detection and analog storage of the shaped detector signal before its digitization by an external 12-bit ADC. This design offers a large flexibility in sampling frequency (100 MHz max.), peaking time (16 values from 50 ns to 1 μs), gain (4 ranges from 120 fC to 10 pC per channel) and signal polarity (negative or positive). Fabricated using 0.35 μm CMOS technology, the AGET prototype is under test and the first results are presented. (authors)