The new data acquisition system for the HADES experiment

HADES (High Acceptance Di-Electron Spectrometer) is a running experiment installed at the SIS-18 synchrotron (GSI, Germany). The detector system has eighty thousands electronic channels provided by several different detectors: RICH (Ring Imaging Cherenkov Detector), RPC, Multi-wire Drift Chambers (MDCs), TOF (Time of flight wall), preShower (Shower) and beam detectors. During recent years, HADES has completed severals physics runs, from elementary reactions up to moderate ion systems. Currently, the detector undergoes an upgrade (“HADES-at-FAIR”) for both the experimental setup and the data acquisition, in order to be able to take data in the Au+Au collision system at 8 GeV/u with a sustained trigger rate of 20 kHz. The average amount of data is expected to be 300MB/s. The DAQ upgrade includes the digital readout, the trigger distribution and event builder electronics and, moreover, also part of the front end electronics.