JUNO physics and detector
Progress in particle and nuclear physics,
03/2022, Volume:
123
Journal Article
Peer reviewed
Open access
The Jiangmen Underground Neutrino Observatory (JUNO) is a 20 kton liquid scintillator detector in a laboratory at 700-m underground. An excellent energy resolution and a large fiducial volume offer ...exciting opportunities for addressing many important topics in neutrino and astro-particle physics. With six years of data, the neutrino mass ordering can be determined at a 3–4σ significance and the neutrino oscillation parameters sin2θ12, Δm212, and |Δm322| can be measured to a precision of 0.6% or better, by detecting reactor antineutrinos from the Taishan and Yangjiang nuclear power plants. With ten years of data, neutrinos from all past core-collapse supernovae could be observed at a 3σ significance; a lower limit of the proton lifetime, 8.34×1033 years (90% C.L.), can be set by searching for p→ν̄K+; detection of solar neutrinos would shed new light on the solar metallicity problem and examine the vacuum-matter transition region. A typical core-collapse supernova at a distance of 10 kpc would lead to ∼5000 inverse-beta-decay events and ∼2000 (300) all-flavor neutrino–proton (electron) elastic scattering events in JUNO. Geo-neutrinos can be detected with a rate of ∼400 events per year. Construction of the detector is very challenging. In this review, we summarize the final design of the JUNO detector and the key R&D achievements, following the Conceptual Design Report in 2015 (Djurcic et al., 2015). All 20-inch PMTs have been procured and tested. The average photon detection efficiency is 28.9% for the 15,000 MCP PMTs and 28.1% for the 5000 dynode PMTs, higher than the JUNO requirement of 27%. Together with the >20 m attenuation length of the liquid scintillator achieved in a 20-ton pilot purification test and the >96% transparency of the acrylic panel, we expect a yield of 1345 photoelectrons per MeV and an effective relative energy resolution of 3.02%/E(MeV ) in simulations (Abusleme et al., 2021). To maintain the high performance, the underwater electronics is designed to have a loss rate <0.5% in six years. With degassing membranes and a micro-bubble system, the radon concentration in the 35 kton water pool could be lowered to <10 mBq/m3. Acrylic panels of radiopurity <0.5 ppt U/Th for the 35.4-m diameter liquid scintillator vessel are produced with a dedicated production line. The 20 kton liquid scintillator will be purified onsite with Alumina filtration, distillation, water extraction, and gas stripping. Together with other low background handling, singles in the fiducial volume can be controlled to ∼10Hz. The JUNO experiment also features a double calorimeter system with 25,600 3-inch PMTs, a liquid scintillator testing facility OSIRIS, and a near detector TAO.
Mass testing of the JUNO experiment 20-inch PMT readout electronics Coppi, Alberto; Jelmini, Beatrice; Bergnoli, Antonio ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
July 2023, 2023-07-00, Volume:
1052
Journal Article
Peer reviewed
Open access
The Jiangmen Underground Neutrino Observatory (JUNO) is a multi-purpose, large size, liquid scintillator experiment under construction in China. JUNO will perform leading measurements detecting ...neutrinos from different sources (reactor, terrestrial and astrophysical neutrinos) covering a wide energy range (from 200keV to several GeV). This paper focuses on the design and development of a test protocol for the 20-inch PMT underwater readout electronics. The protocol has been employed for 10 months during the mass production and validation of all the electronics that will be installed in JUNO. A total number of 6950 electronic boards were tested with an acceptance yield of 99.1%.
Abstract The physics potential of detecting 8 B solar neutrinos will be exploited at the Jiangmen Underground Neutrino Observatory (JUNO), in a model-independent manner by using three distinct ...channels of the charged current (CC), neutral current (NC), and elastic scattering (ES) interactions. Due to the largest-ever mass of 13 C nuclei in the liquid scintillator detectors and the expected low background level, 8 B solar neutrinos are observable in the CC and NC interactions on 13 C for the first time. By virtue of optimized event selections and muon veto strategies, backgrounds from the accidental coincidence, muon-induced isotopes, and external backgrounds can be greatly suppressed. Excellent signal-to-background ratios can be achieved in the CC, NC, and ES channels to guarantee the observation of the 8 B solar neutrinos. From the sensitivity studies performed in this work, we show that JUNO, with 10 yr of data, can reach the 1 σ precision levels of 5%, 8%, and 20% for the 8 B neutrino flux, sin 2 θ 12 , and Δ m 21 2 , respectively. Probing the details of both solar physics and neutrino physics would be unique and helpful. In addition, when combined with the Sudbury Neutrino Observatory measurement, the world's best precision of 3% is expected for the measurement of the 8 B neutrino flux.
Validation and integration tests of the JUNO 20-inch PMT readout electronics Cerrone, Vanessa; von Sturm, Katharina; Bergnoli, Antonio ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
August 2023, 2023-08-00, Volume:
1053
Journal Article
Peer reviewed
Open access
The Jiangmen Underground Neutrino Observatory (JUNO) is a large neutrino detector currently under construction in China. JUNO aims to determine the neutrino mass ordering and to perform leading ...measurements detecting terrestrial and astrophysical neutrinos over a wide energy range, spanning from 200 keV to several GeV. Given the ambitious physics goals of JUNO, its readout electronics has to meet specific requirements, which motivated the thorough characterization described in this manuscript. The time synchronization among the electronics modules was found to exceed by few ns the theoretical expectation, as a consequence of the non-optimal data taking conditions. However, the system showed an excellent stability over long data taking periods, ensuring that any time offset could be calibrated out at the beginning of the data taking.
The maximal deviation from a linear charge response was found to be 1.1% for the high gain ADC and 0.8% for the low gain ADC. In a JUNO-like environment, i.e 40 m underwater, the recorded FPGA temperature complied with the reliability standards of JUNO.
The Jiangmen Underground Neutrino Observatory (JUNO) is a large neutrino detector currently under construction in China. Thanks to the tight requirements on its optical and radio-purity properties, ...it will be able to perform leading measurements detecting terrestrial and astrophysical neutrinos in a wide energy range from tens of keV to hundreds of MeV. A key requirement for the success of the experiment is an unprecedented 3% energy resolution, guaranteed by its large active mass (20 ktons) and the use of more than 20,000 20-inch photo-multiplier tubes (PMTs) acquired by high-speed, high-resolution sampling electronics located very close to the PMTs. As the Front-End and Read-Out electronics is expected to continuously run underwater for 30 years, a reliable readout acquisition system capable of handling the timestamped data stream coming from the Large-PMTs and permitting to simultaneously monitor and operate remotely the inaccessible electronics had to be developed. In this contribution, the firmware and hardware implementation of the IPbus based readout protocol will be presented, together with the performances measured on final modules during the mass production of the electronics.
The JUNO experiment Top Tracker Aleem, Abid; Alexandros, Tsagkarakis; Auguste, Didier ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
12/2023, Volume:
1057
Journal Article
Peer reviewed
Open access
The main task of the Top Tracker detector of the neutrino reactor experiment Jiangmen Underground Neutrino Observatory (JUNO) is to reconstruct and extrapolate atmospheric muon tracks down to the ...central detector. This muon tracker will help to evaluate the contribution of the cosmogenic background to the signal. The Top Tracker is located above JUNO’s water Cherenkov Detector and Central Detector, covering about 60% of the surface above them. The JUNO Top Tracker is constituted by the decommissioned OPERA experiment Target Tracker modules. The technology used consists in walls of two planes of plastic scintillator strips, one per transverse direction. Wavelength shifting fibres collect the light signal emitted by the scintillator strips and guide it to both ends where it is read by multianode photomultiplier tubes. Compared to the OPERA Target Tracker, the JUNO Top Tracker uses new electronics able to cope with the high rate produced by the high rock radioactivity compared to the one in Gran Sasso underground laboratory. This paper will present the new electronics and mechanical structure developed for the Top Tracker of JUNO along with its expected performance based on the current detector simulation.
The ongoing upgrade campaign at the INFN National Laboratories of Legnaro, required to accommodate the selective production of exotic species (SPES) facility, demands for a new beam diagnostic system ...that outperforms the legacy versabus module eurocard-based current and beam position monitor. The beam diagnostic is an essential component without whom the operator would blindly attempt to setup all accelerator parameters in order to transport the beam from the source to the target experiment. This paper provides a complete overview of the diagnostic data readout chain inclusive of custom hardware solutions, signal processing, and data management. Each diagnostic point, installed along the beam pipe, consists of a Faraday cup and a beam profile monitor. The front-end electronics is based on a custom general purpose motherboard endowed with an field programmable gate array that handles the data sampling, data filtering, and data buffering and with a computer on module that runs an EPICS input-output controller application and bridges the beam diagnostic information to the control network for remote visualization. The custom hardware platform at the heart of the diagnostic system is able to perform real-time tasks and allows for hardware standardization and modularity, then being the base for embedding the control of several different appliances in our accelerators complex. A precise beam current and position measurement is required by the SPES project that foresees a radioactive ion beam in a wide range of intensities and energies. The prototypes of the new electronics have shown good performance improvements and the beam current resolution has been extended to a few pA.
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