Synergies and Prospects for Early Resolution of the Neutrino Mass Ordering

The measurement of neutrino Mass Ordering (MO) is a fundamental element for the understanding of leptonic flavour sector of the Standard Model of Particle Physics. Its determination relies on the precise measurement of $\Delta m^2_{31}$ and $\Delta m^2_{32}$ using either neutrino vacuum oscillations, such as the ones studied by medium baseline reactor experiments, or matter effect modified oscillations such as those manifesting in long-baseline neutrino beams (LB$\nu$B) or atmospheric neutrino experiments. Despite existing MO indication today, a fully resolved MO measurement ($\geq$5$\sigma$) is most likely to await for the next generation of neutrino experiments: JUNO, whose stand-alone sensitivity is $\sim$3$\sigma$, or LB$\nu$B experiments (DUNE and Hyper-Kamiokande). Upcoming atmospheric neutrino experiments are also expected to provide precious information. In this work, we study the possible context for the earliest full MO resolution. A firm resolution is possible even before 2028, exploiting mainly vacuum oscillation, upon the combination of JUNO and the current generation of LB$\nu$B experiments (NOvA and T2K). This opportunity is possible thanks to a powerful synergy boosting the overall sensitivity where the sub-percent precision of $\Delta m^2_{32}$ by LB$\nu$B experiments is found to be the leading order term for the MO earliest discovery. We also found that the comparison between matter and vacuum driven oscillation results enables unique discovery potential for physics beyond the Standard Model.Comment: Entitled in arXiv:2008.11280v1 as "Earliest Resolution to the Neutrino Mass Ordering?

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$M_{\odot}$ 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

Empowering JUNO physics by means of an ancillary photodetection system

International audienceJUNO is a liquid scintillator detector currently under construction in the south of China. JUNO aims to detect the disappearance of reactor antineutrinos at an average baseline of 53 km, with the primary goal of determining the neutrino mass ordering and performing a sub-percent measurement of three of the neutrino oscillation parameters. This physics program is rooted in the detector’s unprecedented capability to detect 1345 photoelectrons (p.e)/MeV of deposited energy, yielding a 3% energy resolution at 1 MeV. The main photodetection system comprises 17,612 20-inch “large” photomultipliers (LPMTs), each of which experiences an illumination varying over two orders of magnitude. To help calibrating the LPMT response in such a demanding environment, JUNO will be instrumented with additional 25,600 custom-made 3" "small" photomultipliers (SPMTs). They will operate in photon-counting regime by detecting at most 1 PE per neutrino interaction, hence providing a complementary energy estimator with a novel dual calorimetry technique. In addition, the SPMT system is designed to provide a semi-independent measurement of the “solar” oscillation parameters, to aid the measurement of supernova neutrinos, to study the proton decay and to improve the muon track reconstruction, whose performance is pivotal for background rejection. Like the LPMTs, the SPMTs together with their power and readout systems, will have to operate under water for over 20 years, posing challenging constraints on the design, reliability and implementation of this major subsystem of JUNO. In this talk, we will present the innovative design of the JUNO SPMT system, its impact on physics, and the current status of SPMT production and testing

Vers la Détection des Neutrinos issus de l’Explosion des Supernovae à Effondrement de Coeur avec les système PMT 3 pouces du détecteur JUNO

Core-Collapse Supernovae (CCSN) are gigantic explosions that occur when a massive star comes to death. Thirty-five years ago, for the first time, two dozens of neutrinos from a CCSN (SN1987A) were detected, marking the beginning of a new era in the study of CCSN. JUNO is a 20 kton liquid scintillator (LS) detector currently under construction in China. Two photomultiplier tube (PMT) systems, the first one made of #18,000 20-inch PMTs and the second one made of #26,000 3-inch PMTs, will collect the light produced by the neutrino interactions in the LS. JUNO primary objectives are to determine the neutrino mass ordering and to precisely measure three oscillation parameters. Thanks to its huge detection volume, JUNO is also expected to detect a burst of a few hundreds to a few thousands of neutrinos from the next galactic CCSN. The present thesis focuses on various aspects of the detection of CCSN neutrino using the 3-inch PMT system of JUNO. Based on simulation data, the rate capabilities of the system are assessed, the events vertex and energy reconstruction algorithms developed as well as an analysis for energy spectra reconstruction are presented.Les supernovae à effondrement de coeur (SNEC) sont des explosions gigantesques qui se produisent à la fin de la vie d’une étoile massive. Il y a trente-cinq ans, pour la première fois, deux douzaines de neutrinos provenant d’une SNEC (SN1987A) ont été détectés, marquant le début d’une nouvelle air dans l’études des SNEC. JUNO est un détecteur à liquide scintillant (LS) actuellement en construction en Chine. Deux systèmes de tubes photomultiplicateurs (PMT), le premier constitué de #18,000 PMT de 20 pouces et le second constitué de #26,000 PMT de 3 pouces, collecteront la lumière produite par les interactions des neutrinos avec le LS. Les objectives primaires de JUNO sont de déterminer l’ordre des masses des neutrinos et de mesurer précisément trois paramètres d’oscillation. Grâce à son immense volume de détection, JUNO devrait également détecter une salve de quelques centaines à quelques milliers de neutrinos provenant de la prochaine SNEC galactique. Cette thèse se concentre sur divers aspects de la détection des neutrinos des SNEC avec le système PMT 3 pouces de JUNO. Basé sur des données de simulation, les performances de lecture du système sont évaluées, les algorithmes de reconstruction de la position et de l’énergie des évènements dévelopés ainsi qu’une analyse pour la reconstruction des spèctres en énergie sont présentés

Vers la Détection des Neutrinos issus de l’Explosion des Supernovae à Effondrement de Coeur avec les système PMT 3 pouces du détecteur JUNO

Les supernovae à effondrement de coeur (SNEC) sont des explosions gigantesques qui se produisent à la fin de la vie d’une étoile massive. Il y a trente-cinq ans, pour la première fois, deux douzaines de neutrinos provenant d’une SNEC (SN1987A) ont été détectés, marquant le début d’une nouvelle air dans l’études des SNEC. JUNO est un détecteur à liquide scintillant (LS) actuellement en construction en Chine. Deux systèmes de tubes photomultiplicateurs (PMT), le premier constitué de #18,000 PMT de 20 pouces et le second constitué de #26,000 PMT de 3 pouces, collecteront la lumière produite par les interactions des neutrinos avec le LS. Les objectives primaires de JUNO sont de déterminer l’ordre des masses des neutrinos et de mesurer précisément trois paramètres d’oscillation. Grâce à son immense volume de détection, JUNO devrait également détecter une salve de quelques centaines à quelques milliers de neutrinos provenant de la prochaine SNEC galactique. Cette thèse se concentre sur divers aspects de la détection des neutrinos des SNEC avec le système PMT 3 pouces de JUNO. Basé sur des données de simulation, les performances de lecture du système sont évaluées, les algorithmes de reconstruction de la position et de l’énergie des évènements dévelopés ainsi qu’une analyse pour la reconstruction des spèctres en énergie sont présentés.Core-Collapse Supernovae (CCSN) are gigantic explosions that occur when a massive star comes to death. Thirty-five years ago, for the first time, two dozens of neutrinos from a CCSN (SN1987A) were detected, marking the beginning of a new era in the study of CCSN. JUNO is a 20 kton liquid scintillator (LS) detector currently under construction in China. Two photomultiplier tube (PMT) systems, the first one made of #18,000 20-inch PMTs and the second one made of #26,000 3-inch PMTs, will collect the light produced by the neutrino interactions in the LS. JUNO primary objectives are to determine the neutrino mass ordering and to precisely measure three oscillation parameters. Thanks to its huge detection volume, JUNO is also expected to detect a burst of a few hundreds to a few thousands of neutrinos from the next galactic CCSN. The present thesis focuses on various aspects of the detection of CCSN neutrino using the 3-inch PMT system of JUNO. Based on simulation data, the rate capabilities of the system are assessed, the events vertex and energy reconstruction algorithms developed as well as an analysis for energy spectra reconstruction are presented

Vers la Détection des Neutrinos issus de l’Explosion des Supernovae à Effondrement de Coeur avec les système PMT 3 pouces du détecteur JUNO

Core-Collapse Supernovae (CCSN) are gigantic explosions that occur when a massive star comes to death. Thirty-five years ago, for the first time, two dozens of neutrinos from a CCSN (SN1987A) were detected, marking the beginning of a new era in the study of CCSN. JUNO is a 20 kton liquid scintillator (LS) detector currently under construction in China. Two photomultiplier tube (PMT) systems, the first one made of #18,000 20-inch PMTs and the second one made of #26,000 3-inch PMTs, will collect the light produced by the neutrino interactions in the LS. JUNO primary objectives are to determine the neutrino mass ordering and to precisely measure three oscillation parameters. Thanks to its huge detection volume, JUNO is also expected to detect a burst of a few hundreds to a few thousands of neutrinos from the next galactic CCSN. The present thesis focuses on various aspects of the detection of CCSN neutrino using the 3-inch PMT system of JUNO. Based on simulation data, the rate capabilities of the system are assessed, the events vertex and energy reconstruction algorithms developed as well as an analysis for energy spectra reconstruction are presented.Les supernovae à effondrement de coeur (SNEC) sont des explosions gigantesques qui se produisent à la fin de la vie d’une étoile massive. Il y a trente-cinq ans, pour la première fois, deux douzaines de neutrinos provenant d’une SNEC (SN1987A) ont été détectés, marquant le début d’une nouvelle air dans l’études des SNEC. JUNO est un détecteur à liquide scintillant (LS) actuellement en construction en Chine. Deux systèmes de tubes photomultiplicateurs (PMT), le premier constitué de #18,000 PMT de 20 pouces et le second constitué de #26,000 PMT de 3 pouces, collecteront la lumière produite par les interactions des neutrinos avec le LS. Les objectives primaires de JUNO sont de déterminer l’ordre des masses des neutrinos et de mesurer précisément trois paramètres d’oscillation. Grâce à son immense volume de détection, JUNO devrait également détecter une salve de quelques centaines à quelques milliers de neutrinos provenant de la prochaine SNEC galactique. Cette thèse se concentre sur divers aspects de la détection des neutrinos des SNEC avec le système PMT 3 pouces de JUNO. Basé sur des données de simulation, les performances de lecture du système sont évaluées, les algorithmes de reconstruction de la position et de l’énergie des évènements dévelopés ainsi qu’une analyse pour la reconstruction des spèctres en énergie sont présentés

Vers la Détection des Neutrinos issus de l’Explosion des Supernovae à Effondrement de Coeur avec les système PMT 3 pouces du détecteur JUNO

Core-Collapse Supernovae (CCSN) are gigantic explosions that occur when a massive star comes to death. Thirty-five years ago, for the first time, two dozens of neutrinos from a CCSN (SN1987A) were detected, marking the beginning of a new era in the study of CCSN. JUNO is a 20 kton liquid scintillator (LS) detector currently under construction in China. Two photomultiplier tube (PMT) systems, the first one made of #18,000 20-inch PMTs and the second one made of #26,000 3-inch PMTs, will collect the light produced by the neutrino interactions in the LS. JUNO primary objectives are to determine the neutrino mass ordering and to precisely measure three oscillation parameters. Thanks to its huge detection volume, JUNO is also expected to detect a burst of a few hundreds to a few thousands of neutrinos from the next galactic CCSN. The present thesis focuses on various aspects of the detection of CCSN neutrino using the 3-inch PMT system of JUNO. Based on simulation data, the rate capabilities of the system are assessed, the events vertex and energy reconstruction algorithms developed as well as an analysis for energy spectra reconstruction are presented.Les supernovae à effondrement de coeur (SNEC) sont des explosions gigantesques qui se produisent à la fin de la vie d’une étoile massive. Il y a trente-cinq ans, pour la première fois, deux douzaines de neutrinos provenant d’une SNEC (SN1987A) ont été détectés, marquant le début d’une nouvelle air dans l’études des SNEC. JUNO est un détecteur à liquide scintillant (LS) actuellement en construction en Chine. Deux systèmes de tubes photomultiplicateurs (PMT), le premier constitué de #18,000 PMT de 20 pouces et le second constitué de #26,000 PMT de 3 pouces, collecteront la lumière produite par les interactions des neutrinos avec le LS. Les objectives primaires de JUNO sont de déterminer l’ordre des masses des neutrinos et de mesurer précisément trois paramètres d’oscillation. Grâce à son immense volume de détection, JUNO devrait également détecter une salve de quelques centaines à quelques milliers de neutrinos provenant de la prochaine SNEC galactique. Cette thèse se concentre sur divers aspects de la détection des neutrinos des SNEC avec le système PMT 3 pouces de JUNO. Basé sur des données de simulation, les performances de lecture du système sont évaluées, les algorithmes de reconstruction de la position et de l’énergie des évènements dévelopés ainsi qu’une analyse pour la reconstruction des spèctres en énergie sont présentés

A methodology for performing sensitivity analysis in dynamic fuel cycle simulation studies applied to a PWR fleet simulated with the CLASS tool

Fuel cycle simulators are used worldwide to provide scientific assessment to fuel cycle future strategies. Those tools help understanding the fuel cycle physics and determining the most impacting drivers at the cycle scale. A standard scenario calculation is usually based on a set of operational assumptions, such as reactor Burn-Up, deployment history, cooling time, etc. Scenario output is then the evolution of isotopes mass in the facilities that composes the nuclear fleet. The increase of computing capacities and the use of neutron data fast predictors provide new opportunities in nuclear scenario studies. Indeed, a very high number of calculations is possible, which allows testing a high number of operational assumptions combinations. The global sensitivity analysis (GSA) formalism is specifically well adapted for this kind of problem. In this new framework, a scenario study is based on the sampling of operational data, which become input variables. A first result of a scenario study is the highlight of relations between operational input data and outputs. Input variable subspace that satisfy optimization criteria on an output, such as plutonium incineration or stabilization, can also be determined. In this paper, a focus is made on the methodology based on GSA. This innovative methodology is presented and applied to a simple fleet simulation composed of a PWR-UOx fuel and a PWR-MOx fuel. Calculations are done with the fuel cycle simulator CLASS developed by the CNRS/IN2P3 in collaboration with IRSN. The design of experiment is built from five fuel cycle input sampled variables. Sensitivity indices have been calculated on plutonium and minor actinide (MA) production. It shows that the PWR-UOx Burn-Up and the fraction of PWR-MOx fuel are the most important input variables that explain the plutonium production. For the MA production, main drivers depend strongly on isotopes. Sensitivity analysis also reveals input variable subspace responsible of simulation crash, what led to an important improvement of the model algorithms. An equilibrium condition on the plutonium mass in the stockpile used for building MOx fuel has been applied. The solution is represented as a subspace in the PWR-UOx Burn-Up and PWR-MOx fraction input space. For instance, achieving a plutonium equilibrium in a stockpile fed by a PWR-UOx that operates at 40 GWd/t requires a PWR-MOx fraction between 9 and 14%. This study also provides data related to plutonium incineration induced by the utilization of the MOx