A prototype of self-triggering front-end unit for radio detection of ultra high energy neutrinos

Since the Tianshan Radio Experiment for Neutrino Detection (TREND) has successfully announced its first result, the Giant Radio Array for Neutrino Detection (GRAND) prototype is proposed to validate the concept of extensive air shower detection with a very high background rejection. High speed digitizing (1GHz), 12bits dynamic range and less than 10ns timing precision based on GPS are expected in the GRAND prototype experiment. This paper describes the overall structure of the data acquisition for GRAND prototype, concentrating on the development of the front-end electronics. The self-triggering front-end unit is a key part of the electronics system. It generally consists of two trigger boards (FTRIG), one digitizing board (DFADC), and one timestamp board (GPSTIM). Its main function is to get the amplitude and time stamp information of the input signal from the antenna. FTRIG board is for fast hardware trigger; GPSTIM board is for time stamp based on GPS (RMS <; 10ns); DFADC board is for dual 12bits 1GHz digitizing and fiber transmission. A prototype of the self-triggering front-end unit was built and a field test confirmed the full functionality of the prototype. The new prototype is considered to be evaluated on the speed and reliability as the ultimate design.