75 research outputs found
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
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
Real-time Monitoring for the Next Core-Collapse Supernova in JUNO
Core-collapse supernova (CCSN) is one of the most energetic astrophysical
events in the Universe. The early and prompt detection of neutrinos before
(pre-SN) and during the SN burst is a unique opportunity to realize the
multi-messenger observation of the CCSN events. In this work, we describe the
monitoring concept and present the sensitivity of the system to the pre-SN and
SN neutrinos at the Jiangmen Underground Neutrino Observatory (JUNO), which is
a 20 kton liquid scintillator detector under construction in South China. The
real-time monitoring system is designed with both the prompt monitors on the
electronic board and online monitors at the data acquisition stage, in order to
ensure both the alert speed and alert coverage of progenitor stars. By assuming
a false alert rate of 1 per year, this monitoring system can be sensitive to
the pre-SN neutrinos up to the distance of about 1.6 (0.9) kpc and SN neutrinos
up to about 370 (360) kpc for a progenitor mass of 30 for the case
of normal (inverted) mass ordering. The pointing ability of the CCSN is
evaluated by using the accumulated event anisotropy of the inverse beta decay
interactions from pre-SN or SN neutrinos, which, along with the early alert,
can play important roles for the followup multi-messenger observations of the
next Galactic or nearby extragalactic CCSN.Comment: 24 pages, 9 figure
Performances de l'Ă©lectronique front-end du systĂšme des PMTs 3â dans l'expĂ©rience JUNO et Ă©tude de son impact sur les mesures de charge et de temps.
The observation of neutrino oscillations has led to questioning the Standard Model of particle physics, and precisely measuring the neutrino oscillation parameters and answering the question about the ordering of the neutrino mass states could provide the key to understanding other unsolved puzzles in both cosmology and particle physics. This is the objective of the Jiangmen Underground Neutrino Observatory (JUNO), a multi-purpose neutrino experiment expected to start taking data in 2024, which will detect reactor anti-neutrinos from two nearby nuclear power plants using a central detector containing 20 kton of liquid scintillator. The emitted photons will be observed by two large arrays of 20-inch (LPMTs) and 3-inch (SPMTs) photomultiplier tubes, the SPMT system having been designed to serve as a complementary array of photodetectors to the LPMT system. By mostly operating in a photon-counting mode, it will help calibrate the energy response of the LPMTs as well as help better understand the systematics of the system. Located underwater, its read out electronics consists in 128 SPMTs being connected to a single ABC front-end board hosting 8 16-channels CATIROC ASICs. Precise studies on the performances of this ABC board are presented in this thesis, including studies on pedestal measurements (0.05 photoelectron pedestalwidths), charge linearity and calibration (0.05% deviation to linear model), time resolution (about 0.25 ns),crosstalk (below 0.15%), as well as on test-benches combining all the SPMT electronics to date. The boardsâability to asynchronously auto-trigger on random SPE events with thresholds as low as 1/3 photoelectronis also demonstrated, and the processing of a PMT signal within the ABC board is studied with precise parametrizations of certain CATIROC ASIC features such as the trigger time and time walk, the deadtimesand the charge acceptance. This intricate knowledge of the SPMT electronics was additionally implemented in the JUNO simulation, and simulated events showed that the impact of the response of the SPMT system on physical studies involving the charge and time information was negligible before the response of the PMTs. This work has furthermore led to the qualification of the performances of the 25,600 SPMTs and of the 220 ABC front-end boards, which will pave the way for the exploitation of the JUNO physics data starting from 2024.Lâobservation du phĂ©nomĂšne dâoscillation des neutrinos a conduit Ă la remise en question du ModĂšle Standard de la physique des particules. Effectuer une mesure prĂ©cise de leurs paramĂštres dâoscillation, ainsi que rĂ©pondre Ă la question de la hiĂ©rarchie de leurs Ă©tats de masse, pourrait bien fournir des Ă©lĂ©ments de rĂ©ponse quant Ă dâautres Ă©nigmes non rĂ©solues en cosmologie et en physique des particules.Câest lâobjectif de lâobservatoire souterrain de neutrinos de Jiangmen (JUNO), une expĂ©rience polyvalente sur les neutrinos devant commencer Ă prendre des donnĂ©es en 2024, qui dĂ©tectera les anti-neutrinos de rĂ©acteurs de deux centrales nuclĂ©aires voisines Ă lâaide dâun dĂ©tecteur central contenant 20000 tonnes de scintillateur liquide. Les photons Ă©mis seront observĂ©s par deux grands rĂ©seaux de tubes photomultiplicateursde 20 pouces (LPMTs) et de 3 pouces (SPMTs), le systĂšme SPMT ayant Ă©tĂ© conçu pour servir de rĂ©seau complĂ©mentaire au systĂšme LPMT. Fonctionnant principalement dans un mode de comptage de photons, il permettra dâĂ©talonner la rĂ©ponse en Ă©nergie des LPMTs et de mieux comprendre les erreurs systĂ©matiques du systĂšme. EntreposĂ©e dans de lâeau, son Ă©lectronique de lecture consiste en 128 SPMTs connectĂ©s Ă une mĂȘme carte frontale ABC, hĂ©bergeant 8 ASICs CATIROC de 16 voies. Des Ă©tudes prĂ©cises menĂ©es sur les performances de cette carte ABC sont prĂ©sentĂ©es dans cette thĂšse, comprenant des Ă©tudes sur les mesures de piĂ©destaux (largeurs infĂ©rieures Ă 0,05 photoĂ©lectron), la linĂ©aritĂ© et lâĂ©talonnage en charge (dĂ©viation de 0,05% par rapport Ă un modĂšle linĂ©aire), la rĂ©solution temporelle (environ 0,25 ns), la diaphonie (infĂ©rieure Ă 0,15%), ainsi que sur des bancs de tests combinant toute lâĂ©lectronique du systĂšme SPMT Ă ce jour. La bonne capacitĂ© des cartes ABC Ă dĂ©clencher de maniĂšre asynchrone et alĂ©atoire sur des photoĂ©lectrons avec des seuils Ă 1/3 de photoĂ©lectron est Ă©galement dĂ©montrĂ©e, et le traitement dâun signal PM dans la carte ABC est Ă©tudiĂ© avec le paramĂ©trage prĂ©cis de certaines caractĂ©ristiques des ASICs CATIROC telles que le temps de dĂ©clenchement et le time walk, les temps morts et lâ acceptance en charge.Cette connaissance approfondie de lâĂ©lectronique SPMT a Ă©galement Ă©tĂ© implĂ©mentĂ©e dans la simulation JUNO et les Ă©vĂ©nements simulĂ©s ont montrĂ© que lâimpact de la rĂ©ponse du systĂšme SPMT sur des Ă©tudes physiques impliquant les informations de charge et de temps est nĂ©gligeable devant la rĂ©ponse des PMs. Ces travaux ont en outre abouti Ă la qualification des performances des 25600 SPMTs et des 220 cartes frontales ABC, ce qui ouvre la voie Ă lâexploitation des donnĂ©es de physique de JUNO Ă partir de 2024
Performances of the 3'' PMT front-end electronics in the JUNO experiment and study of its impact on charge and time measurements.
Lâobservation du phĂ©nomĂšne dâoscillation des neutrinos a conduit Ă la remise en question du ModĂšle Standard de la physique des particules. Effectuer une mesure prĂ©cise de leurs paramĂštres dâoscillation, ainsi que rĂ©pondre Ă la question de la hiĂ©rarchie de leurs Ă©tats de masse, pourrait bien fournir des Ă©lĂ©ments de rĂ©ponse quant Ă dâautres Ă©nigmes non rĂ©solues en cosmologie et en physique des particules.Câest lâobjectif de lâobservatoire souterrain de neutrinos de Jiangmen (JUNO), une expĂ©rience polyvalente sur les neutrinos devant commencer Ă prendre des donnĂ©es en 2024, qui dĂ©tectera les anti-neutrinos de rĂ©acteurs de deux centrales nuclĂ©aires voisines Ă lâaide dâun dĂ©tecteur central contenant 20000 tonnes de scintillateur liquide. Les photons Ă©mis seront observĂ©s par deux grands rĂ©seaux de tubes photomultiplicateursde 20 pouces (LPMTs) et de 3 pouces (SPMTs), le systĂšme SPMT ayant Ă©tĂ© conçu pour servir de rĂ©seau complĂ©mentaire au systĂšme LPMT. Fonctionnant principalement dans un mode de comptage de photons, il permettra dâĂ©talonner la rĂ©ponse en Ă©nergie des LPMTs et de mieux comprendre les erreurs systĂ©matiques du systĂšme. EntreposĂ©e dans de lâeau, son Ă©lectronique de lecture consiste en 128 SPMTs connectĂ©s Ă une mĂȘme carte frontale ABC, hĂ©bergeant 8 ASICs CATIROC de 16 voies. Des Ă©tudes prĂ©cises menĂ©es sur les performances de cette carte ABC sont prĂ©sentĂ©es dans cette thĂšse, comprenant des Ă©tudes sur les mesures de piĂ©destaux (largeurs infĂ©rieures Ă 0,05 photoĂ©lectron), la linĂ©aritĂ© et lâĂ©talonnage en charge (dĂ©viation de 0,05% par rapport Ă un modĂšle linĂ©aire), la rĂ©solution temporelle (environ 0,25 ns), la diaphonie (infĂ©rieure Ă 0,15%), ainsi que sur des bancs de tests combinant toute lâĂ©lectronique du systĂšme SPMT Ă ce jour. La bonne capacitĂ© des cartes ABC Ă dĂ©clencher de maniĂšre asynchrone et alĂ©atoire sur des photoĂ©lectrons avec des seuils Ă 1/3 de photoĂ©lectron est Ă©galement dĂ©montrĂ©e, et le traitement dâun signal PM dans la carte ABC est Ă©tudiĂ© avec le paramĂ©trage prĂ©cis de certaines caractĂ©ristiques des ASICs CATIROC telles que le temps de dĂ©clenchement et le time walk, les temps morts et lâ acceptance en charge.Cette connaissance approfondie de lâĂ©lectronique SPMT a Ă©galement Ă©tĂ© implĂ©mentĂ©e dans la simulation JUNO et les Ă©vĂ©nements simulĂ©s ont montrĂ© que lâimpact de la rĂ©ponse du systĂšme SPMT sur des Ă©tudes physiques impliquant les informations de charge et de temps est nĂ©gligeable devant la rĂ©ponse des PMs. Ces travaux ont en outre abouti Ă la qualification des performances des 25600 SPMTs et des 220 cartes frontales ABC, ce qui ouvre la voie Ă lâexploitation des donnĂ©es de physique de JUNO Ă partir de 2024.The observation of neutrino oscillations has led to questioning the Standard Model of particle physics, and precisely measuring the neutrino oscillation parameters and answering the question about the ordering of the neutrino mass states could provide the key to understanding other unsolved puzzles in both cosmology and particle physics. This is the objective of the Jiangmen Underground Neutrino Observatory (JUNO), a multi-purpose neutrino experiment expected to start taking data in 2024, which will detect reactor anti-neutrinos from two nearby nuclear power plants using a central detector containing 20 kton of liquid scintillator. The emitted photons will be observed by two large arrays of 20-inch (LPMTs) and 3-inch (SPMTs) photomultiplier tubes, the SPMT system having been designed to serve as a complementary array of photodetectors to the LPMT system. By mostly operating in a photon-counting mode, it will help calibrate the energy response of the LPMTs as well as help better understand the systematics of the system. Located underwater, its read out electronics consists in 128 SPMTs being connected to a single ABC front-end board hosting 8 16-channels CATIROC ASICs. Precise studies on the performances of this ABC board are presented in this thesis, including studies on pedestal measurements (0.05 photoelectron pedestalwidths), charge linearity and calibration (0.05% deviation to linear model), time resolution (about 0.25 ns),crosstalk (below 0.15%), as well as on test-benches combining all the SPMT electronics to date. The boardsâability to asynchronously auto-trigger on random SPE events with thresholds as low as 1/3 photoelectronis also demonstrated, and the processing of a PMT signal within the ABC board is studied with precise parametrizations of certain CATIROC ASIC features such as the trigger time and time walk, the deadtimesand the charge acceptance. This intricate knowledge of the SPMT electronics was additionally implemented in the JUNO simulation, and simulated events showed that the impact of the response of the SPMT system on physical studies involving the charge and time information was negligible before the response of the PMTs. This work has furthermore led to the qualification of the performances of the 25,600 SPMTs and of the 220 ABC front-end boards, which will pave the way for the exploitation of the JUNO physics data starting from 2024
Performances de l'Ă©lectronique front-end du systĂšme des PMTs 3â dans l'expĂ©rience JUNO et Ă©tude de son impact sur les mesures de charge et de temps.
The observation of neutrino oscillations has led to questioning the Standard Model of particle physics, and precisely measuring the neutrino oscillation parameters and answering the question about the ordering of the neutrino mass states could provide the key to understanding other unsolved puzzles in both cosmology and particle physics. This is the objective of the Jiangmen Underground Neutrino Observatory (JUNO), a multi-purpose neutrino experiment expected to start taking data in 2024, which will detect reactor anti-neutrinos from two nearby nuclear power plants using a central detector containing 20 kton of liquid scintillator. The emitted photons will be observed by two large arrays of 20-inch (LPMTs) and 3-inch (SPMTs) photomultiplier tubes, the SPMT system having been designed to serve as a complementary array of photodetectors to the LPMT system. By mostly operating in a photon-counting mode, it will help calibrate the energy response of the LPMTs as well as help better understand the systematics of the system. Located underwater, its read out electronics consists in 128 SPMTs being connected to a single ABC front-end board hosting 8 16-channels CATIROC ASICs. Precise studies on the performances of this ABC board are presented in this thesis, including studies on pedestal measurements (0.05 photoelectron pedestalwidths), charge linearity and calibration (0.05% deviation to linear model), time resolution (about 0.25 ns),crosstalk (below 0.15%), as well as on test-benches combining all the SPMT electronics to date. The boardsâability to asynchronously auto-trigger on random SPE events with thresholds as low as 1/3 photoelectronis also demonstrated, and the processing of a PMT signal within the ABC board is studied with precise parametrizations of certain CATIROC ASIC features such as the trigger time and time walk, the deadtimesand the charge acceptance. This intricate knowledge of the SPMT electronics was additionally implemented in the JUNO simulation, and simulated events showed that the impact of the response of the SPMT system on physical studies involving the charge and time information was negligible before the response of the PMTs. This work has furthermore led to the qualification of the performances of the 25,600 SPMTs and of the 220 ABC front-end boards, which will pave the way for the exploitation of the JUNO physics data starting from 2024.Lâobservation du phĂ©nomĂšne dâoscillation des neutrinos a conduit Ă la remise en question du ModĂšle Standard de la physique des particules. Effectuer une mesure prĂ©cise de leurs paramĂštres dâoscillation, ainsi que rĂ©pondre Ă la question de la hiĂ©rarchie de leurs Ă©tats de masse, pourrait bien fournir des Ă©lĂ©ments de rĂ©ponse quant Ă dâautres Ă©nigmes non rĂ©solues en cosmologie et en physique des particules.Câest lâobjectif de lâobservatoire souterrain de neutrinos de Jiangmen (JUNO), une expĂ©rience polyvalente sur les neutrinos devant commencer Ă prendre des donnĂ©es en 2024, qui dĂ©tectera les anti-neutrinos de rĂ©acteurs de deux centrales nuclĂ©aires voisines Ă lâaide dâun dĂ©tecteur central contenant 20000 tonnes de scintillateur liquide. Les photons Ă©mis seront observĂ©s par deux grands rĂ©seaux de tubes photomultiplicateursde 20 pouces (LPMTs) et de 3 pouces (SPMTs), le systĂšme SPMT ayant Ă©tĂ© conçu pour servir de rĂ©seau complĂ©mentaire au systĂšme LPMT. Fonctionnant principalement dans un mode de comptage de photons, il permettra dâĂ©talonner la rĂ©ponse en Ă©nergie des LPMTs et de mieux comprendre les erreurs systĂ©matiques du systĂšme. EntreposĂ©e dans de lâeau, son Ă©lectronique de lecture consiste en 128 SPMTs connectĂ©s Ă une mĂȘme carte frontale ABC, hĂ©bergeant 8 ASICs CATIROC de 16 voies. Des Ă©tudes prĂ©cises menĂ©es sur les performances de cette carte ABC sont prĂ©sentĂ©es dans cette thĂšse, comprenant des Ă©tudes sur les mesures de piĂ©destaux (largeurs infĂ©rieures Ă 0,05 photoĂ©lectron), la linĂ©aritĂ© et lâĂ©talonnage en charge (dĂ©viation de 0,05% par rapport Ă un modĂšle linĂ©aire), la rĂ©solution temporelle (environ 0,25 ns), la diaphonie (infĂ©rieure Ă 0,15%), ainsi que sur des bancs de tests combinant toute lâĂ©lectronique du systĂšme SPMT Ă ce jour. La bonne capacitĂ© des cartes ABC Ă dĂ©clencher de maniĂšre asynchrone et alĂ©atoire sur des photoĂ©lectrons avec des seuils Ă 1/3 de photoĂ©lectron est Ă©galement dĂ©montrĂ©e, et le traitement dâun signal PM dans la carte ABC est Ă©tudiĂ© avec le paramĂ©trage prĂ©cis de certaines caractĂ©ristiques des ASICs CATIROC telles que le temps de dĂ©clenchement et le time walk, les temps morts et lâ acceptance en charge.Cette connaissance approfondie de lâĂ©lectronique SPMT a Ă©galement Ă©tĂ© implĂ©mentĂ©e dans la simulation JUNO et les Ă©vĂ©nements simulĂ©s ont montrĂ© que lâimpact de la rĂ©ponse du systĂšme SPMT sur des Ă©tudes physiques impliquant les informations de charge et de temps est nĂ©gligeable devant la rĂ©ponse des PMs. Ces travaux ont en outre abouti Ă la qualification des performances des 25600 SPMTs et des 220 cartes frontales ABC, ce qui ouvre la voie Ă lâexploitation des donnĂ©es de physique de JUNO Ă partir de 2024
Sexual communication in the termite Prorhinotermes simplex (Isoptera, Rhinotermitidae) mediated by a pheromone from female tergal glands
We studied the post-flight behavior and sex attraction in imagoes of the termite Prorhinotermes simplex (Rhinotermitidae, Prorhinotermitinae). Pairing is mediated by the secretion from tergal glands, exposed by females in a calling posture and highly attractive to males. Analysis of extracts of these glands by means of gas chromatography with electroantennographic detection indicated a chromatographic area corresponding to an intense physiological response of males. The retention characteristics of this area proved to be identical with those of (3Z,6Z,8E)-dodeca-3,6,8-trien-1-ol. Electroantennographic and behavioral assays revealed that units of picograms of the compound represent a stimulus qualitatively and quantitatively equivalent to one female tergal gland. Thus, we hypothesize that (3Z,6Z,8E)-dodeca-3,6,8-trien-1-ol is a major component of the female sex pheromone in P. simplex. © 2009 BirkhÀuser Verlag, Basel/Switzerland.SCOPUS: ar.jinfo:eu-repo/semantics/publishe
CATIROC: an integrated chip for neutrino experiments using photomultiplier tubes
An ASIC (Application Specific Integrated Chip) named CATIROC (Charge And Time Integrated Read Out Chip) has been developed for the next-generation neutrino experiments using a large number of photomultiplier tubes (PMTs). Each CATIROC provides the time and the charge measurements for 16 configurable input channels operating in auto-trigger mode. Originally designed for the light emission in water Cherenkov detectors, we show in this paper that its use can be extended to liquid-scintillator based experiments. The âŒÂ 26000 3-inch PMTs of the JUNO experiment, under construction in China, is a case in point. This paper describes the features of CATIROC with a special attention to the most critical points for its application to the time profile of the light emission in liquid scintillators. The achieved performances in both charge and time measurements can be inputs for future high-precision experiments making use of PMTs or other photo-sensitive detectors
- âŠ