DEVELOPMENT AND CHARACTERIZATION OF AN INNOVATIVE LOW-NOISE HIGH-DYNAMIC-RANGE VLSI CHARGE-SENSITIVE PREAMPLIFIER FOR SOLID-STATE DETECTORS EMPLOYED IN NUCLEAR PHYSICS EXPERIMENTS WITH RADIOACTIVE ION BEAMS

The latest experimental results of the multichannel front-end ASIC of TRACE are shown. The device submitted to the foundry in the middle of 2014 and received at the end of the same year has been installed on a dedicated PCB and tested using a pulser. We then designed and realized a preamplifier board with eight ASICs for a total of 32 front channels and one back channel. We connected it to a highly-segmented planar silicon detector and acquired the spectrum of a 241Am-244Cm-239Pu triple alpha source obtaining an overall resolution around 3.5‰. The chip comprises four channels specifically designed for hole signals and one channel for electron signals. The power consumption is around 10 mW per channel as required by the specifications of TRACE. The main design goals are low noise and fast rise time. With proper shaping of the signals this device is capable of producing energy spectra with resolution of approximatively 1 keV. An innovative circuit architecture based on a Time-Over-Threshold technique boosts the dynamic range of the CSP by more than one order of magnitude. The rise time of the leading edge of the signals is fast enough to perform pulse-shape analysis of the waveforms. A peculiar feature of this device is the possibility to easily adjust a host of key parameters through an I2C bus. The bandwidth and sensitivity of the preamplifier can so be optimized according to the experimental needs on a case-by-case basis.