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

Research on Population Spatialization Method Based on PMST-SRCNN

How to improve the accuracy of population spatialization by using downscaling technology has always been a difficult issue in academic research. The population spatialization model constructed from the global or local perspective alone has its own limitations that cannot capture the local and global characteristics of the population distribution. Based on the counties of Chongqing municipality in 2010, this paper uses the two steps of “removing-rough” rasterizationof partitioned multivariate statistical regression and the “getting-accuracy” of super-resolution convolutional neural network to construct a coupling model of population spatialization to complete global and local Feature learning and compare and analyze with other four schemes. The results show that the mean square error and root mean square error of the coupled model of partitioned multivariate statistical regression and super-resolution convolutional neural network are the lowest, especially in densely populated areas. Studies have shown that although super-resolution convolutional neural network has a good ability to downscale learning, it still does not reflect the heterogeneity of population spatial patterns well, and the coupling of multilevel global feature learning models and super-resolution convolutional neural network models can make up for this to a certain extent

Sensitivity Improvement and Determination of Rydberg Atom-Based Microwave Sensor

We present a theoretical and experimental investigation of the improvement and determination of the sensitivity of Rydberg atom-based microwave RF sensor. An optical Bloch equation has been set up based on the configuration that two-color cascading lasers exciting atom to highly Rydberg state and a microwave RF coupling this Rydberg state to its adjacent neighbor. The numerical simulation shows that the sensitivity of the atomic RF sensor is correlated with the amplitude strengths of the applied two lasers and the RF itself. It also depends on the frequency detuning of the coupling laser, which induces an asymmetrically optical splitting. The coupling laser frequency fixing at the shoulder of the stronger one is more favorable for a higher sensitivity. Accordingly, we perform an experimental demonstration for the optimization of all these parameters and the sensitivity is improved to 12.50(04) nVcm−1·Hz−1/2

Sensitivity Improvement and Determination of Rydberg Atom-Based Microwave Sensor

We present a theoretical and experimental investigation of the improvement and determination of the sensitivity of Rydberg atom-based microwave RF sensor. An optical Bloch equation has been set up based on the configuration that two-color cascading lasers exciting atom to highly Rydberg state and a microwave RF coupling this Rydberg state to its adjacent neighbor. The numerical simulation shows that the sensitivity of the atomic RF sensor is correlated with the amplitude strengths of the applied two lasers and the RF itself. It also depends on the frequency detuning of the coupling laser, which induces an asymmetrically optical splitting. The coupling laser frequency fixing at the shoulder of the stronger one is more favorable for a higher sensitivity. Accordingly, we perform an experimental demonstration for the optimization of all these parameters and the sensitivity is improved to 12.50(04) nVcm−1·Hz−1/2

Influence of Cooking Pollutant Diffusion Regularity by High-Rise Residential Inner-Courtyard Forms in Wuhan

In China’s typical high-density cities, in order to meet the residential needs, a Chinese characteristic and typical high-rise residence with multiple flats sharing one staircase has been created. Due to the Chinese cooking methods, such as frying and stir-frying, the middle flats’ kitchens of these high-rise residences are easily exposed to cooking pollutants, which endanger people’s health. As the outdoor transition space directly adjacent to the kitchens of the middle flats, the inner-courtyards in high-rise residences make the cooking pollutants easier to be diffused. Therefore, the inner-courtyard form has a significant impact on the ventilation and diffusion of cooking pollutants. In this study, with the method of measurement and CFD simulation, the relationship between cooking pollutants diffusion in the kitchens of the middle flats and the flow field in inner-courtyards was analyzed, and the impact of different inner-courtyard forms on cooking pollutants diffusion distribution in high-rise residential under natural ventilation was discussed. The results show that different inner-courtyard forms have different effects on the diffusion of cooking pollutants: the enclosed courtyards will greatly increase the cross-contamination between the kitchen and the adjacent space; increasing the openness of the courtyard will not enhance the diffusion level of pollutants, but has a negative effect; compared with centralized courtyards, symmetrical courtyards have a better echo with the kitchen in the layout, which is more conducive to the diffusion of cooking pollutants

A motion characteristics modeled angular position sensor by nonlinear transfer of differential capacitance for miniaturized scanning mirrors

Abstract In this paper, an angular position sensor (APS) designed for a resonant miniaturized scanning mirror (M-SM) is presented. The APS operates based on the principle of differential variable capacitance, significantly expanding the detectable bandwidth from a few hertz to several kilohertz. By modeling the motion characteristics, the sampling rates of the biaxial scanning angles are 1473.6 times and 539.4 times higher than those of conventional sensors. Initially, the motion characteristics model is presented as a simple harmonic motion, converting sampled capacitance into continuous capacitance. Subsequently, the nonparallel state of the M-SM and sensor is transformed into a parallel state through the space coordinate system transformation. Furthermore, a 2D nonlinear angle transfer function is developed to convert the differential capacitance into an angle, thereby mitigating the nonlinear errors resulting from large angles. Achieving an accuracy better than 0.014°, the measuring range expands from ±0.5729° (±10 mrad) to ±5.026° ( ± 87 mrad). Additionally, the capturing mode and tracking mode are proposed to monitor real-time angular changes of the M-SM with an accuracy of 0.017°. High-precision APSs have enhanced beam pointing accuracy and resolution and can thereby be used to advance the development of laser components, including light detection and ranging (LiDAR)

Guide to rational membrane selection for oily wastewater treatment by membrane distillation

Membrane wetting and fouling are two major challenges in membrane distillation (MD), especially when the feed has components with low surface tension. A series of membranes with different wettability were developed herein to provide rational guidelines for membrane selection to treat these wastewaters. The membranes with different wettability, and Janus membranes composing of same hydrophilic surface but different substrates (hydrophobicity, superhydrophobicity, superomniphobicity), were made by electrospinning and modifications. It was found that when the feeds had anionic and cationic surfactants, the superhydrophobic and superomniphobic modifications improved their anti-fouling/wetting properties. However, both membranes were rapidly wetted when the feeds had nonionic surfactant Tween-20. The Janus membranes could not delay membrane fouling/wetting when treating the feeds with free surfactants. It even worsened membrane performance as the hydrophilic layer absorbed the surfactants and accelerated membrane fouling/wetting. Regarding the emulsified oily wastewaters, the hydrophilic layer on Janus membranes did show obvious improvement in their anti-fouling/wetting abilities. The underwater hydrophobic layer formed a protective layer and impeded oil contact with the underlying substrate, but the choice of the substrate still needed attention. The superomniphobic substrate showed the most excellent stability as it could reject surfactants even if some managed to pass through.This work was supported by Nankai University & Cangzhou Bohai New Area Institute of Green Chemical Engineering Fund (20220142), National Natural Science Foundation of China (21906086), National One Thousand Talents Foreign Experts Program of the Ministry of Science and Technology of China and Tianjin Government (040-BE044741, 040-C021801601)