Development of new data acquisition system at Super-Kamiokande for nearby supernova bursts

Super-Kamiokande (SK) is a 50-kiloton Water Cherenkov detector and. it is able to detect a large number of supernova burst neutrinos with its large target mass. According to a simulation study based on the Livermore model, the neutrino event rate will be more than 30 MHz if a supernova occurs within several hundreds of light years, and the system can record only about first 20% of the events. To overcome this inefficiency, we developed a new DAQ system, which can store sufficient information without any loss. This new DAQ system records the number of hit PMTs so that we can obtain a time profile of the number of neutrinos emitted at the supernova. The design and production of the new module was completed and it was confirmed the new DAQ module does not interfere with the current DAQ system. We finalized the firmware for the module and readout software. We have installed this new DAQ system in SK and started commissioning.