Mass testing of the JUNO experiment 20-inch PMTs readout electronics

The Jiangmen Underground Neutrino Observatory (JUNO) is a multi-purpose, large size, liquid scintillator experiment under construction in China. JUNO will perform leading measurements detecting neutrinos from different sources (reactor, terrestrial and astrophysical neutrinos) covering a wide energy range (from 200 keV to several GeV). This paper focuses on the design and development of a test protocol for the 20-inch PMT underwater readout electronics, performed in parallel to the mass production line. In a time period of about ten months, a total number of 6950 electronic boards were tested with an acceptance yield of 99.1%

Implementation and performances of the IPbus protocol for the JUNO Large-PMT readout electronics

The Jiangmen Underground Neutrino Observatory (JUNO) is a large neutrino detector currently under construction in China. Thanks to the tight requirements on its optical and radio-purity properties, it will be able to perform leading measurements detecting terrestrial and astrophysical neutrinos in a wide energy range from tens of keV to hundreds of MeV. A key requirement for the success of the experiment is an unprecedented 3% energy resolution, guaranteed by its large active mass (20 kton) and the use of more than 20,000 20-inch photo-multiplier tubes (PMTs) acquired by high-speed, high-resolution sampling electronics located very close to the PMTs. As the Front-End and Read-Out electronics is expected to continuously run underwater for 30 years, a reliable readout acquisition system capable of handling the timestamped data stream coming from the Large-PMTs and permitting to simultaneously monitor and operate remotely the inaccessible electronics had to be developed. In this contribution, the firmware and hardware implementation of the IPbus based readout protocol will be presented, together with the performances measured on final modules during the mass production of the electronics

Validation and integration tests of the JUNO 20-inch PMTs readout electronics

The Jiangmen Underground Neutrino Observatory (JUNO) is a large neutrino detector currently under construction in China. JUNO will be able to study the neutrino mass ordering and to perform leading measurements detecting terrestrial and astrophysical neutrinos in a wide energy range, spanning from 200 keV to several GeV. Given the ambitious physics goals of JUNO, the electronic system has to meet specific tight requirements, and a thorough characterization is required. The present paper describes the tests performed on the readout modules to measure their performances.Comment: 20 pages, 13 figure

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

PbS Colloidal Quantum Dot Near Infrared Photoconductors: DC and Noise Characterization

High sensitivity photodetectors based on PbS colloidal quantum dots have been demonstrated by several research groups in the last years with performance comparable to commercial IIIâ\u80\u93V semiconductor devices. Nevertheless, investigation of the noise performance of such new photodetectors is still lacking. Here we report on the characterization of PbS colloidal quantum dot near infrared photoconductors including a preliminary analysis of noise power spectra. Devices have been characterized focusing on the low frequency regime (up to 10 kHz) investigating the noise dependence on the voltage bias

Multisensor device for emergency recognition in smart building environment

In case of serious environmental disasters, such as floods, landslides and earthquakes, the first activity that an emergency management system must carry out is the detection, recognition and report of anomalous events. In order to be able to automatically perform these actions, it is necessary to have an efficient sensor network within the building. By means of a wellorganized and high-performance sensor network, data from the field are acquired and processed to produce usable information at a high level. The Building Management System (BMS) therefore has information available on the occurrence of an anomalous event, whether caused by natural or intentional causes. The purpose of our work is to design and implement a cost-effective sensorized device, managed by an ATmega microcontroller and equipped with a Wi-Fi module for easier integration, able to detect and report potentially dangerous situations within a building. In particular, fires, floods, gas leaks and earthquakes were considered. Thanks to the integration of simple data analysis and data fusion algorithms, the platform is able to recognize and report the occurrence of emergency events within a buildin

High Sensitivity Flame Sensor Based on PbS Colloidal Quantum Dots

Flame sensing and early fire detection are primary features in modern security and surveillance systems. Optical detection systems are widely developed and offer the highest sensitivity and selectivity but they are still expensive and show a high power budget. Here we propose a low-cost, low-power flame detector based on PbS colloidal quantum dots. We show detector operation with a 21 nW total power dissipation and the ability to detect the flame of a candle at 20 m with a 5 dB signal to noise ratio (SNR)

High Responsivity Fire Detectors Based on PbS Colloidal Quantum Dot Photoconductors

In this letter, we report on high responsivity fire detectors based on PbS colloidal quantum dots photoconductors. The devices operate in the near infrared and are equipped with a visible light silicon filter for wavelength selectivity. Devices are fabricated by a simple, low cost, and silicon compatible process based on drop casting of a ligand exchanged solution of PbS nanoparticles. The photodetectors exhibit responsivity as high as 20 A/W at 1-V bias. We exploit the combination of their high responsivity and spectral response for the development of a novel fire detector able to detect a small flame at a distance exceeding 15 m in ambient illumination

PbS colloidal quantum dot visible-blind photodetector for early indoor fire detection

We report on a novel optical fire detector based on a PbS colloidal quantum dot photodetector. The sensor is realized with a simple, cost effective, drop casting technique. The photodetector is characterized in terms of its electrical characteristics, responsivity, and specific detectivity to monochromatic light. We demonstrate effective indoor fire detection at a distance exceeding 20 m with a 120° field of view. We also show a twofold improvement of the detector signal to noise ratio exploiting a short focal lens