JUNOCopyright: © JUNO Collaboration
In the last few years, important discoveries have been made in the field of low energy neutrino physics. Flavour transitions of solar electron to muon and tau neutrinos have been clearly shown in the SNO experiment. Further evidence for neutrino oscillations has been found in the KamLAND experiment by a disappearence measurement of electron antineutrinos emitted by nuclear reactors. In 2007, the Borexino experiment started to take data, demonstrating the great potential of the liquid-scintillator technique for the detection of solar and geoneutrinos. Based on this experience, LENA and JUNO have been proposed as a next-generation neutrino detectors:
JUNO (Jiangmen Underground JUNO Observatory) is planed as a spheric 20 kiloton liquid scintillator detector near Jiangmen , China. The main goal of the experiment is the determination of the neutrino mass hierarchy by measuring oscillation effects of neutrinos from nearby nuclear power plants.
Osiris is a pre-detector of JUNO, which is used to measure the radio-purity of the used liquid scintillator. The detector was built in Aachen and transported to China. The first measurement data of the experiment are expected soon and the necessary analyses are also developed here in Aachen.
The participation of our institute is divided into two main directions:
The hardware group developed a new concept to read out JUNO and other large detectors using photomultipliers. The idea is to mount the read-out electronics to the PMT to increase the performance and simplify the readout systems.
The analog signal will be digitized by a special ADC, currently designed at the ZEA-2 in Jülich, and processed by an FPGA. One long-term objective is to do all signal processing at the PMT.
The analysis group develops algorithms to reconstruct and select events. Classical analytical as well as neural concepts are under investigation to archive the best results. Due to the high symmetry of the detector and the large number of channels JUNO seems to be excellent for neural networks.
Currently the focus of the working group is the discrimination of electrons and positrons in the detector, the myon reconstruction and the suppression of the radioactive background. In addition, the sensitivity to different types of supernova is studied.