57 research outputs found
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TAO Conceptual Design Report: A Precision Measurement of the Reactor Antineutrino Spectrum with Sub-percent Energy Resolution
The Taishan Antineutrino Observatory (TAO, also known as JUNO-TAO) is a
satellite experiment of the Jiangmen Underground Neutrino Observatory (JUNO). A
ton-level liquid scintillator detector will be placed at about 30 m from a core
of the Taishan Nuclear Power Plant. The reactor antineutrino spectrum will be
measured with sub-percent energy resolution, to provide a reference spectrum
for future reactor neutrino experiments, and to provide a benchmark measurement
to test nuclear databases. A spherical acrylic vessel containing 2.8 ton
gadolinium-doped liquid scintillator will be viewed by 10 m^2 Silicon
Photomultipliers (SiPMs) of >50% photon detection efficiency with almost full
coverage. The photoelectron yield is about 4500 per MeV, an order higher than
any existing large-scale liquid scintillator detectors. The detector operates
at -50 degree C to lower the dark noise of SiPMs to an acceptable level. The
detector will measure about 2000 reactor antineutrinos per day, and is designed
to be well shielded from cosmogenic backgrounds and ambient radioactivities to
have about 10% background-to-signal ratio. The experiment is expected to start
operation in 2022
Potential of Core-Collapse Supernova Neutrino Detection at JUNO
JUNO is an underground neutrino observatory under construction in Jiangmen, China. It uses 20kton liquid scintillator as target, which enables it to detect supernova burst neutrinos of a large statistics for the next galactic core-collapse supernova (CCSN) and also pre-supernova neutrinos from the nearby CCSN progenitors. All flavors of supernova burst neutrinos can be detected by JUNO via several interaction channels, including inverse beta decay, elastic scattering on electron and proton, interactions on C12 nuclei, etc. This retains the possibility for JUNO to reconstruct the energy spectra of supernova burst neutrinos of all flavors. The real time monitoring systems based on FPGA and DAQ are under development in JUNO, which allow prompt alert and trigger-less data acquisition of CCSN events. The alert performances of both monitoring systems have been thoroughly studied using simulations. Moreover, once a CCSN is tagged, the system can give fast characterizations, such as directionality and light curve
Detection of the Diffuse Supernova Neutrino Background with JUNO
As an underground multi-purpose neutrino detector with 20 kton liquid scintillator, Jiangmen Underground Neutrino Observatory (JUNO) is competitive with and complementary to the water-Cherenkov detectors on the search for the diffuse supernova neutrino background (DSNB). Typical supernova models predict 2-4 events per year within the optimal observation window in the JUNO detector. The dominant background is from the neutral-current (NC) interaction of atmospheric neutrinos with 12C nuclei, which surpasses the DSNB by more than one order of magnitude. We evaluated the systematic uncertainty of NC background from the spread of a variety of data-driven models and further developed a method to determine NC background within 15\% with {\it{in}} {\it{situ}} measurements after ten years of running. Besides, the NC-like backgrounds can be effectively suppressed by the intrinsic pulse-shape discrimination (PSD) capabilities of liquid scintillators. In this talk, I will present in detail the improvements on NC background uncertainty evaluation, PSD discriminator development, and finally, the potential of DSNB sensitivity in JUNO
Potential for a precision measurement of solar neutrinos in the Serappis Experiment
The Serappis (SEarch for RAre PP-neutrinos In Scintillator) project aims at a precision measurement of the flux of solar neutrinos on the few-percent level. Such a measurement will be a relevant contribution to the study of solar neutrino oscillation parameters and a sensitive test of the solar luminosity constraint. The concept of Serappis relies on a small organic liquid scintillator detector (20 m) with excellent energy resolution (2.5 % at 1 MeV), low internal background and sufficient shielding from surrounding radioactivity. This can be achieved by a minor upgrade of the OSIRIS facility at the site of the JUNO neutrino experiment in southern China. To go substantially beyond current accuracy levels for the flux, an organic scintillator with ultra-low C levels (below ) is required. The existing OSIRIS detector and JUNO infrastructure will be instrumental in identifying suitable scintillator materials, offering a unique chance for a low-budget high-precision measurement of a fundamental property of our Sun that will be otherwise hard to access
Potential for a precision measurement of solar pp neutrinos in the Serappis experiment
The Serappis (SEarch for RAre PP-neutrinos In Scintillator) project aims at a precision measurement of the flux of solar pp neutrinos on the few-percent level. Such a measurement will be a relevant contribution to the study of solar neutrino oscillation parameters and a sensitive test of the equilibrium between solar energy output in neutrinos and electromagnetic radiation (solar luminosity constraint). The concept of Serappis relies on a small organic liquid scintillator detector (∼20 m) with excellent energy resolution (∼2.5% at 1 MeV), low internal background and sufficient shielding from surrounding radioactivity. This can be achieved by a minor upgrade of the OSIRIS facility at the site of the JUNO neutrino experiment in southern China. To go substantially beyond current accuracy levels for the pp flux, an organic scintillator with ultra-low C levels (below 10) is required. The existing OSIRIS detector andJUNO infrastructure will be instrumental in identifying suitable scintillator materials, offering a unique chance for a low-budget high-precision measurement of a fundamental property of our Sun that will be otherwise hard to access
Potential for a precision measurement of solar neutrinos in the Serappis Experiment
The Serappis (SEarch for RAre PP-neutrinos In Scintillator) project aims at a precision measurement of the flux of solar neutrinos on the few-percent level. Such a measurement will be a relevant contribution to the study of solar neutrino oscillation parameters and a sensitive test of the solar luminosity constraint. The concept of Serappis relies on a small organic liquid scintillator detector (20 m) with excellent energy resolution (2.5 % at 1 MeV), low internal background and sufficient shielding from surrounding radioactivity. This can be achieved by a minor upgrade of the OSIRIS facility at the site of the JUNO neutrino experiment in southern China. To go substantially beyond current accuracy levels for the flux, an organic scintillator with ultra-low C levels (below ) is required. The existing OSIRIS detector and JUNO infrastructure will be instrumental in identifying suitable scintillator materials, offering a unique chance for a low-budget high-precision measurement of a fundamental property of our Sun that will be otherwise hard to access
Recommended from our members
TAO Conceptual Design Report: A Precision Measurement of the Reactor Antineutrino Spectrum with Sub-percent Energy Resolution
The Taishan Antineutrino Observatory (TAO, also known as JUNO-TAO) is a
satellite experiment of the Jiangmen Underground Neutrino Observatory (JUNO). A
ton-level liquid scintillator detector will be placed at about 30 m from a core
of the Taishan Nuclear Power Plant. The reactor antineutrino spectrum will be
measured with sub-percent energy resolution, to provide a reference spectrum
for future reactor neutrino experiments, and to provide a benchmark measurement
to test nuclear databases. A spherical acrylic vessel containing 2.8 ton
gadolinium-doped liquid scintillator will be viewed by 10 m^2 Silicon
Photomultipliers (SiPMs) of >50% photon detection efficiency with almost full
coverage. The photoelectron yield is about 4500 per MeV, an order higher than
any existing large-scale liquid scintillator detectors. The detector operates
at -50 degree C to lower the dark noise of SiPMs to an acceptable level. The
detector will measure about 2000 reactor antineutrinos per day, and is designed
to be well shielded from cosmogenic backgrounds and ambient radioactivities to
have about 10% background-to-signal ratio. The experiment is expected to start
operation in 2022
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The Design and Sensitivity of JUNO's scintillator radiopurity pre-detector OSIRIS
The OSIRIS detector is a subsystem of the liquid scintillator fillling chain
of the JUNO reactor neutrino experiment. Its purpose is to validate the
radiopurity of the scintillator to assure that all components of the JUNO
scintillator system work to specifications and only neutrino-grade scintillator
is filled into the JUNO Central Detector. The aspired sensitivity level of
g/g of U and Th requires a large (20 m)
detection volume and ultralow background levels. The present paper reports on
the design and major components of the OSIRIS detector, the detector simulation
as well as the measuring strategies foreseen and the sensitivity levels to U/Th
that can be reached in this setup
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JUNO Physics and Detector
The Jiangmen Underground Neutrino Observatory (JUNO) is a 20 kton LS detector
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 6 years of data, the neutrino mass
ordering can be determined at 3-4 sigma and three oscillation parameters can be
measured to a precision of 0.6% or better by detecting reactor antineutrinos.
With 10 years of data, DSNB could be observed at 3-sigma; a lower limit of the
proton lifetime of 8.34e33 years (90% C.L.) can be set by searching for
p->nu_bar K^+; detection of solar neutrinos would shed new light on the solar
metallicity problem and examine the vacuum-matter transition region. A
core-collapse supernova at 10 kpc would lead to ~5000 IBD and ~2000 (300)
all-flavor neutrino-proton (electron) scattering events. Geo-neutrinos can be
detected with a rate of ~400 events/year. We also summarize the final design of
the JUNO detector and the key R&D achievements. All 20-inch PMTs have been
tested. The average photon detection efficiency is 28.9% for the 15,000 MCP
PMTs and 28.1% for the 5,000 dynode PMTs, higher than the JUNO requirement of
27%. Together with the >20 m attenuation length of LS, we expect a yield of
1345 p.e. per MeV and an effective energy resolution of 3.02%/\sqrt{E (MeV)}$
in simulations. The underwater electronics is designed to have a loss rate
<0.5% in 6 years. With degassing membranes and a micro-bubble system, the radon
concentration in the 35-kton water pool could be lowered to <10 mBq/m^3.
Acrylic panels of radiopurity <0.5 ppt U/Th are produced. The 20-kton LS will
be purified onsite. Singles in the fiducial volume can be controlled to ~10 Hz.
The JUNO experiment also features a double calorimeter system with 25,600
3-inch PMTs, a LS testing facility OSIRIS, and a near detector TAO
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