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$M_{\odot}$ 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

Développement et caractérisation d un ASIC de lecture de macro-cellule de photo-détecteurs de grande dimension

PMm est un projet financé pour 3 ans (2007-2010) par l Agence Nationale de la Recherche (ANR) dont le titre exact est Electronique innovante pour photo-détecteurs distribués en physique des particules et astroparticule . Le projet PMm propose de segmenter les grandes surfaces de photo-détection en macro modules de 16 PMTs de 12 (2x2 m ), connectés à une électronique innovante autonome qui fonctionne en déclenchement automatique et est installé proche des PMTs. Ce développement est rendu possible par les progrès de la microélectronique qui permettent d'intégrer la lecture et le traitement des signaux de tous ces photomultiplicateurs à l intérieur d un même circuit intégré (ASIC) baptisé PARISROC (Photomultiplier ARray Integrated in SiGe Read Out Chip) et seules les données numérisées sont ensuite expédiées par réseau vers le système de stockage des données en surface. Le circuit PARISROC, réalisé en technologie AMS SiGe 0.35 m, contient 16 voies totalement indépendantes correspondant aux 16 PMTs de chaque module. Chacune de ces voies permet la lecture de la charge du signal reçu ainsi que du temps associé. Le premier prototype du circuit PARISROC a une surface totale de 19 mm2. Il a été envoyé en fabrication en juin 2008 chez Austrian Micro-System (AMS) par l intermédiaire du centre de multi-projet CMP (à Grenoble), puis livré au laboratoire en décembre 2008. Les mesures effectuées sur l ASIC ont conduit à la réalisation d un second prototype. Des améliorations notables ont été apportées, en termes de bruit, de dynamique, de vitesse de lecture du chip (passage des horloges de 10 MHz à 40 MHz), de mesure de temps (améliorations de la TDC), de mesure de charge (améliorations du shaper lent). Envoyé en fabrication en novembre 2009 et reçu au laboratoire en février 2010, ce nouveau prototype PARISROC 2 a été testé en laboratoire et l analyse a montré un comportement général correct et la réalisation des modifications apportées.PMm is a project founded for three years by the French National Agency for Research (ANR) with the complete title: Innovative electronics for photo-detectors array used in high energy physics and astroparticles . The project proposes to segment the large surface of photo-detection in macro pixel consisting of an array of 16 PMTs of 12-inches (2*2 m ), connected to an autonomous front-end electronics which works in a triggerless data acquisition mode placed near the array. This is possible thanks to the microelectronics progress that allows to integrate the read out and the signal processing, of all the photomultipliers, in the same circuit (ASIC) named PARISROC (Photomultiplier ARray Integrated in SiGe Read Out Chip). The ASIC must send out only the digital data by network to the surface central data storage. The PARISROC Chip, made in AMS 0.35 m technology, integrates 16 independent channels for each PMTs of the array, providing charge and time measurements. The first prototype of PARISROC chip has a total surface of 19 mm . It has been sent for fabrication in June 2008 to AMS foundry (AustriaMicroSystems) through the CMP (Multi Project Center) and received in December 2008. The ASIC measurements have led to the realization of a second prototype. Important measurements were brought in terms of noise, dynamic range, read out frequency (from 10 MHz to 40 MHz), time measurements (TDC improvements) and charge measurements (Slow shaper improvements). Sent for fabrication in November 2009 and received in February 2010, this new prototype PARISROC 2 has been tested and the characterisation has shown a good overall behavior and the verification of the improvements.ORSAY-PARIS 11-BU Sciences (914712101) / SudocSudocFranceF

ALTIROC0, a 20 pico-second time resolution ASIC for the ATLAS High Granularity Timing Detector (HGTD)

International audienceALTIROC0 is an 8-channel ASIC prototype designed to readout 1x1 or 2x2 mm2 50 µm thick Low Gain Avalanche Diodes (LGAD) of the ATLAS High Granularity Timing Detector (HGTD). The targeted combined time resolution of the sensor and the readout electronics is 30 ps for one MIP. Each analog channel of the ASIC must exhibit an extremely low jitter to ensure this challenging time resolution, while keeping a low power consumption of 2 mW/channel. A “Time Over Threshold” and a “Constant Fraction Discriminator” architecture are integrated to correct for the time walk. Test bench measurements performed on the ASIC received in April 2017 are presented

Calibration Strategy of the JUNO-TAO Experiment

The Taishan Antineutrino Observatory (JUNO-TAO, or TAO) is a satellite detector for the Jiangmen Underground Neutrino Observatory (JUNO). Located near the Taishan reactor, TAO independently measures the reactor's antineutrino energy spectrum with unprecedented energy resolution. To achieve this goal, energy response must be well calibrated. Using the Automated Calibration Unit (ACU) and the Cable Loop System (CLS) of TAO, multiple radioactive sources are deployed to various positions in the detector to perform a precise calibration of energy response. The non-linear energy response can be controlled within 0.6% with different energy points of these radioactive sources. It can be further improved by using $^{12}\rm B$ decay signals produced by cosmic muons. Through the energy non-uniformity calibration, residual non-uniformity is less than 0.2%. The energy resolution degradation and energy bias caused by the residual non-uniformity can be controlled within 0.05% and 0.3%, respectively. In addition, the stability of other detector parameters, such as the gain of each silicon photo-multiplier, can be monitored with a special ultraviolet LED calibration system

Calibration Strategy of the JUNO-TAO Experiment

The Taishan Antineutrino Observatory (JUNO-TAO, or TAO) is a satellite detector for the Jiangmen Underground Neutrino Observatory (JUNO). Located near the Taishan reactor, TAO independently measures the reactor's antineutrino energy spectrum with unprecedented energy resolution. To achieve this goal, energy response must be well calibrated. Using the Automated Calibration Unit (ACU) and the Cable Loop System (CLS) of TAO, multiple radioactive sources are deployed to various positions in the detector to perform a precise calibration of energy response. The non-linear energy response can be controlled within 0.6% with different energy points of these radioactive sources. It can be further improved by using $^{12}\rm B$ decay signals produced by cosmic muons. Through the energy non-uniformity calibration, residual non-uniformity is less than 0.2%. The energy resolution degradation and energy bias caused by the residual non-uniformity can be controlled within 0.05% and 0.3%, respectively. In addition, the stability of other detector parameters, such as the gain of each silicon photo-multiplier, can be monitored with a special ultraviolet LED calibration system

Calibration Strategy of the JUNO-TAO Experiment

The Taishan Antineutrino Observatory (JUNO-TAO, or TAO) is a satellite detector for the Jiangmen Underground Neutrino Observatory (JUNO). Located near the Taishan reactor, TAO independently measures the reactor's antineutrino energy spectrum with unprecedented energy resolution. To achieve this goal, energy response must be well calibrated. Using the Automated Calibration Unit (ACU) and the Cable Loop System (CLS) of TAO, multiple radioactive sources are deployed to various positions in the detector to perform a precise calibration of energy response. The non-linear energy response can be controlled within 0.6% with different energy points of these radioactive sources. It can be further improved by using $^{12}\rm B$ decay signals produced by cosmic muons. Through the energy non-uniformity calibration, residual non-uniformity is less than 0.2%. The energy resolution degradation and energy bias caused by the residual non-uniformity can be controlled within 0.05% and 0.3%, respectively. In addition, the stability of other detector parameters, such as the gain of each silicon photo-multiplier, can be monitored with a special ultraviolet LED calibration system

Calibration strategy of the JUNO-TAO experiment

The Taishan Antineutrino Observatory (TAO or JUNO-TAO) is a satellite experiment of the Jiangmen Underground Neutrino Observatory (JUNO). Located near a reactor of the Taishan Nuclear Power Plant, TAO will measure the reactor antineutrino energy spectrum with an unprecedented energy resolution of < 2% at 1 MeV. Energy calibration is critical to achieve such a high energy resolution. Using the Automated Calibration Unit (ACU) and the Cable Loop System (CLS), multiple radioactive sources are deployed to various positions in the TAO detector for energy calibration. The residual non-uniformity can be controlled within 0.2%. The energy resolution degradation and energy bias caused by the residual non-uniformity can be controlled within 0.05% and 0.3%, respectively. The uncertainty of the non-linear energy response can be controlled within 0.6% with the radioactive sources of various energies, and could be further improved with cosmogenic 12B which is produced by the interaction of cosmic muon in the liquid scintillator. The stability of other detector parameters, e.g., the gain of each Silicon Photo multiplier, will be monitored with an ultraviolet LED calibration system