Experimental evaluation of the dynamic range of the FARCOS microstrip frontend with a pulsed proton beam

FARCOS (Femtoscope ARray for Correlation and Spectroscopy) frontend has to feature a dynamic range up to half GeV with 4 different selectable gain values and an energy resolution of the order of 10 keV FWHM. 16-channel charge preamplifiers are integrated in a single chip in AMS 0.35μm C35B4C3 technology. In order to experimentally probe the achievable dynamic range, we exploited the pulsed monoenergetic proton beam of one of the beamlines of the 3MV Tandetron accelerator of the LaBEC (Laboratorio di Tecniche Nucleari per i Beni Culturali of INFN), Sesto Fiorentino (FI), Italy. The bunch multiplicity can be increased up to cover the full designed dynamic range. From the measured histogram, by least square fitting of each proton peak one can derive the centroid, integral non linearity and resolution as a function of the deposited energy. The paper presents the designed frontend system and the results of the on-beam qualification.