This paper presents the design and cryogenic electrical characterization of a voltage reference and a linear voltage regulator at temperatures between 6 K and 300 K. Both circuits are employed as test vehicles for the experimental performance evaluation of the 22 nm FDSOI MOS technology when used as platform for the development of cryogenic analog systems, whose role is relevant in Quantum Computing (QC) applications. Additionally, we report the impact that MOS transistor cryogenic phenomena have over these circuits and propose to take advantage of some of those phenomena in analog circuit design. In particular, we focus on the cryogenic threshold voltage $(V_{\text {th}})$ saturation, the transconductance $(g_{m})$ increase and the low frequency (LF) excess noise. Our experimental results indicate that the cryogenic $V_{\text {th}}$ saturation and the $g_{m}$ increase can be used as circuit design tools, while the LF excess noise is a performance handicap for cryogenic analog circuits.

The Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator detector designed to explore many topics in fundamental physics. In this study, the potential of searching for proton decay in the mode with JUNO is investigated. The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification. Moreover, the excellent energy resolution of JUNO permits suppression of the sizable background caused by other delayed signals. Based on these advantages, the detection efficiency for the proton decay via is 36.9% ± 4.9% with a background level of events after 10 years of data collection. The estimated sensitivity based on 200 kton-years of exposure is years, which is competitive with the current best limits on the proton lifetime in this channel and complements the use of different detection technologies.

Abstract The Serappis (SEarch for RAre PP-neutrinos In Scintillator) project aims at a precision measurement of the flux of solar pp neutrinos on the few-percent level. Such a measurement will be a relevant contribution to the study of solar neutrino oscillation parameters and a sensitive test of the equilibrium between solar energy output in neutrinos and electromagnetic radiation (solar luminosity constraint). The concept of Serappis relies on a small organic liquid scintillator detector ( $$\sim $$ ∼ 20 m $$^3$$ 3 ) with excellent energy resolution ( $$\sim $$ ∼ 2.5% at 1 MeV), low internal background and sufficient shielding from surrounding radioactivity. This can be achieved by a minor upgrade of the OSIRIS facility at the site of the JUNO neutrino experiment in southern China. To go substantially beyond current accuracy levels for the pp flux, an organic scintillator with ultra-low $$ {^{14}\hbox {C}}$$ 14 C levels (below $$10^{-18}$$ 10 - 18 ) is required. The existing OSIRIS detector and JUNO infrastructure will be instrumental in identifying suitable scintillator materials, offering a unique chance for a low-budget high-precision measurement of a fundamental property of our Sun that will be otherwise hard to access.

We characterized the thermal behavior of a 65 nm bulk CMOS transistor, by measuring the self-heating effect (SHE) as a function of bias condition. We demonstrated that at a base temperature of 6.5 K the channel temperature of the transistor can increase up to several tens of kelvins due to power dissipation. The thermal behavior of the transistor is determined not only by the thermal response of the transistor itself but also by the thermal properties of the surroundings, i.e., source, drain, bulk, and gate interfaces, metal contacts, and vias. On top of it, the thermal response is bias-dependent through bias dependence of power and self-heating. This information becomes relevant for proper design of integrated circuits for quantum computing or other cryogenic applications, where the circuitry requires to be operated at a stable cryogenic temperature.

We study damping signatures at the Jiangmen Underground Neutrino Observatory (JUNO), a medium-baseline reactor neutrino oscillation experiment. These damping signatures are motivated by various new physics models, including quantum decoherence, ν3 decay, neutrino absorption, and wave packet decoherence. The phenomenological effects of these models can be characterized by exponential damping factors at the probability level. We assess how well JUNO can constrain these damping parameters and how to disentangle these different damping signatures at JUNO. Compared to current experimental limits, JUNO can significantly improve the limits on τ3/m3 in the ν3 decay model, the width of the neutrino wave packet σx, and the intrinsic relative dispersion of neutrino momentum σrel.

The Jiangmen Underground Neutrino Observatory (JUNO) is a 20 kton liquid scintillator detector in a laboratory at 700-m underground. An excellent energy resolution and a large fiducial volume offer exciting opportunities for addressing many important topics in neutrino and astro-particle physics. With six years of data, the neutrino mass ordering can be determined at a 3-4 sigma significance and the neutrino oscillation parameters sin(2 )theta(12), Delta m(21)(2), and vertical bar Delta m(32)(2)vertical bar can be measured to a precision of 0.6% or better, by detecting reactor antineutrinos from the Taishan and Yangjiang nuclear power plants. With ten years of data, neutrinos from all past core-collapse supernovae could be observed at a 3 sigma significance; a lower limit of the proton lifetime, 8.34 x 10(33) years (90% C.L.), can be set by searching for p -> (nu) over barK(+); detection of solar neutrinos would shed new light on the solar metallicity problem and examine the vacuum-matter transition region. A typical core-collapse supernova at a distance of 10 kpc would lead to similar to 5000 inverse-beta-decay events and similar to 2000 (300) all-flavor neutrino-proton (electron) elastic scattering events in JUNO. Geo-neutrinos can be detected with a rate of similar to 400 events per year. Construction of the detector is very challenging. In this review, we summarize the final design of the JUNO detector and the key R&D achievements, following the Conceptual Design Report in 2015 (Djurcic et al., 2015). All 20-inch PMTS have been procured and tested. The average photon detection efficiency is 28.9% for the 15,000 MCP PMTS and 28.1% for the 5000 dynode PMTS, higher than the JUNO requirement of 27%. Together with the >20 m attenuation length of the liquid scintillator achieved in a 20-ton pilot purification test and the >96% transparency of the acrylic panel, we expect a yield of 1345 photoelectrons per MeV and an effective relative energy resolution of 3.02%/root E(MeV) in simulations (Abusleme et al., 2021). To maintain the high performance, the underwater electronics is designed to have a loss rate <0.5% in six years. With degassing membranes and a micro-bubble system, the radon concentration in the 35 kton water pool could be lowered to <10 mBq/m(3). Acrylic panels of radiopurity <0.5 ppt U/Th for the 35.4-m diameter liquid scintillator vessel are produced with a dedicated production line. The 20 kton liquid scintillator will be purified onsite with Alumina filtration, distillation, water extraction, and gas stripping. Together with other low background handling, singles in the fiducial volume can be controlled to similar to 10 Hz. The JUNO experiment also features a double calorimeter system with 25,600 3-inch PMTS, a liquid scintillator testing facility OSIRIS, and a near detector TAO. (C) 2021 Elsevier B.V. All rights reserved.

Abstract The OSIRIS detector is a subsystem of the liquid scintillator filling chain of the JUNO reactor neutrino experiment. Its purpose is to validate the radiopurity of the scintillator to assure that all components of the JUNO scintillator system work to specifications and only neutrino-grade scintillator is filled into the JUNO Central Detector. The aspired sensitivity level of $$10^{-16}\hbox { g/g}$$ 10 - 16 g/g of $$^{238}\hbox {U}$$ 238 U and $$^{232}\hbox {Th}$$ 232 Th requires a large ( $$\sim 20\,\hbox {m}^3$$ ∼ 20 m 3 ) detection volume and ultralow background levels. The present paper reports on the design and major components of the OSIRIS detector, the detector simulation as well as the measuring strategies foreseen and the sensitivity levels to U/Th that can be reached in this setup.

Abstract Atmospheric neutrinos are one of the most relevant natural neutrino sources that can be exploited to infer properties about cosmic rays and neutrino oscillations. The Jiangmen Underground Neutrino Observatory (JUNO) experiment, a 20 kton liquid scintillator detector with excellent energy resolution is currently under construction in China. JUNO will be able to detect several atmospheric neutrinos per day given the large volume. A study on the JUNO detection and reconstruction capabilities of atmospheric $$\nu _e$$ ν e and $$\nu _\mu $$ ν μ fluxes is presented in this paper. In this study, a sample of atmospheric neutrino Monte Carlo events has been generated, starting from theoretical models, and then processed by the detector simulation. The excellent timing resolution of the 3” PMT light detection system of JUNO detector and the much higher light yield for scintillation over Cherenkov allow to measure the time structure of the scintillation light with very high precision. Since $$\nu _e$$ ν e and $$\nu _\mu $$ ν μ interactions produce a slightly different light pattern, the different time evolution of light allows to discriminate the flavor of primary neutrinos. A probabilistic unfolding method has been used, in order to infer the primary neutrino energy spectrum from the detector experimental observables. The simulated spectrum has been reconstructed between 100 MeV and 10 GeV, showing a great potential of the detector in the atmospheric low energy region.

Abstract JUNO is a massive liquid scintillator detector with a primary scientific goal of determining the neutrino mass ordering by studying the oscillated anti-neutrino flux coming from two nuclear power plants at 53 km distance. The expected signal anti-neutrino interaction rate is only 60 counts per day (cpd), therefore a careful control of the background sources due to radioactivity is critical. In particular, natural radioactivity present in all materials and in the environment represents a serious issue that could impair the sensitivity of the experiment if appropriate countermeasures were not foreseen. In this paper we discuss the background reduction strategies undertaken by the JUNO collaboration to reduce at minimum the impact of natural radioactivity. We describe our efforts for an optimized experimental design, a careful material screening and accurate detector production handling, and a constant control of the expected results through a meticulous Monte Carlo simulation program. We show that all these actions should allow us to keep the background count rate safely below the target value of 10 Hz (i.e. ∼1 cpd accidental background) in the default fiducial volume, above an energy threshold of 0.7 MeV.

Future universal quantum computers solving problems of practical relevance are expected to require at least 10(6) qubits, which is a massive scale-up from the present numbers of less than 50 qubits operated together. Out of the different types of qubits, solid state qubits are considered to be viable candidates for this scale-up, but interfacing to and controlling such a large number of qubits is a complex challenge that has not been solved yet. One possibility to address this challenge is to use qubit control circuits located close to the qubits at cryogenic temperatures. In this work we evaluate the feasibility of this idea, taking as a reference the physical requirements of a two-electron spin qubit and the specifications of a standard 65 nmcomplementary metal-oxide-semiconductor process. Using principles and flows from electrical systems engineering we provide realistic estimates of the footprint and of the power consumption of a complete control-circuit architecture. Our results show that with further research it is possible to provide scalable electrical control in the vicinity of the qubit, with our concept.

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.

The Jiangmen Underground Neutrino Observatory (JUNO) is a multi-purpose experiment with the neutrino mass hierarchy determination as main objective. The signal detection is based on a 20 kt liquid scintillator surrounded by photomultipliers (PMTs) that are read out with electronics close to them. A highly integrated analog to digital conversion unit with low power and large dynamic range is developed in 65 nm CMOS to be integrated into the PMT housing. Due to the inaccessibility of the electronics, low failure rate has to be achieved. A rigorous production test strategy is developed and presented here to increase the test coverage and effectively eliminate the expected failure rate in the experiment's runtime. This work also gives an overview of the features and some recent measurement results from the second generation of the readout chip.

The Jiangmen Underground Neutrino Observatory (JUNO) is a multi-purpose underground experiment based on a 20,000 ton liquid scintillator with the one main objective to determine the neutrino mass hierarchy. The signal detection is performed by photomultipliers with directly attached readout electronics. The central component for the digitization process is a receiver chip with a low power and large dynamic range analog to digital conversion unit. The concept and design of the included data processing unit and regulation circuit are presented.

The Jiangmen Underground Neutrino Observatory (JUNO), a 20 kton multipurpose underground liquid scintillator detector, was proposed with the determination of the neutrino mass hierarchy (MH) as a primary physics goal. The excellent energy resolution and the large fiducial volume anticipated for the JUNO detector offer exciting opportunities for addressing many important topics in neutrino and astro-particle physics. In this document, we present the physics motivations and the anticipated performance of the JUNO detector for various proposed measurements. Following an introduction summarizing the current status and open issues in neutrino physics, we discuss how the detection of antineutrinos generated by a cluster of nuclear power plants allows the determination of the neutrino MH at a 3-4 sigma significance with six years of running of JUNO. The measurement of antineutrino spectrum with excellent energy resolution will also lead to the precise determination of the neutrino oscillation parameters sin(2) theta(12), Delta m(21)(2), and vertical bar Delta m(ee)(2)vertical bar to an accuracy of better than 1%, which will play a crucial role in the future unitarity test of the MNSP matrix. The JUNO detector is capable of observing not only antineutrinos from the power plants, but also neutrinos/antineutrinos from terrestrial and extra-terrestrial sources, including supernova burst neutrinos, diffuse supernova neutrino background, geoneutrinos, atmospheric neutrinos, and solar neutrinos. As a result of JUNO's large size, excellent energy resolution, and vertex reconstruction capability, interesting new data on these topics can be collected. For example, a neutrino burst from a typical core-collapse supernova at a distance of 10 kpc would lead to similar to 5000 inverse-beta-decay events and similar to 2000 all-flavor neutrino-proton ES events in JUNO, which are of crucial importance for understanding the mechanism of supernova explosion and for exploring novel phenomena such as collective neutrino oscillations. Detection of neutrinos from all past core-collapse supernova explosions in the visible universe with JUNO would further provide valuable information on the cosmic star-formation rate and the average core-collapse neutrino energy spectrum. Antineutrinos originating from the radioactive decay of uranium and thorium in the Earth can be detected in JUNO with a rate of similar to 400 events per year, significantly improving the statistics of existing geoneutrino event samples. Atmospheric neutrino events collected in JUNO can provide independent inputs for determining the MH and the octant of the theta(23) mixing angle. Detection of the Be-7 and B-8 solar neutrino events at JUNO would shed new light on the solar metallicity problem and examine the transition region between the vacuum and matter dominated neutrino oscillations. Regarding light sterile neutrino topics, sterile neutrinos with 10-(5) eV(2) < Delta m(41)(2) < 10(-2) and a sufficiently large mixing angle theta(14) could be identified through a precise measurement of the reactor antineutrino energy spectrum. Meanwhile, JUNO can also provide us excellent opportunities to test the eV-scale sterile neutrino hypothesis, using either the radioactive neutrino sources or a cyclotron-produced neutrino beam. The JUNO detector is also sensitive to several other beyondthe-standard-model physics.Examples include the search for proton decay via the p -> K++ <(v)over bar> decay channel, search for neutrinos resulting from dark-matter annihilation in the Sun, search for violation of Lorentz invariance via the sidereal modulation of the reactor neutrino event rate, and search for the effects of non-standard interactions. The proposed construction of the JUNO detector will provide a unique facility to address many outstanding crucial questions in particle and astrophysics in a timely and cost-effective fashion. It holds the great potential for further advancing our quest to understanding the fundamental properties of neutrinos, one of the building blocks of our Universe.

A new ATLAS pixel chip FE-I4 is being developed for use in upgraded LHC luminosity environments, including the near-term Insertable B-Layer (IBL) upgrade. FE-I4 is designed in a 130 nm CMOS technology, presenting advantages in terms of radiation tolerance and digital logic density compared to the 0.25 mu m CMOS technology used for the current ATLAS pixel IC, FE-I3. The FE-I4 architecture is based on an array of 80 x 336 pixels, each 50 x 250 mu m(2), consisting of analog and digital sections.In the summer 2010, a first full scale prototype FE-I4A was submitted for an engineering run. This IC features the full scale pixel array as well as the complex periphery of the future full-size FE-I4. The FE-I4A contains also various extra test features which should prove very useful for the chip characterization, but deviate from the needs for standard operation of the final FE-I4 for IBL. In this paper, focus will be brought to the various features implemented in the FE-I4A submission, while also underlining the main differences between the FE-I4A IC and the final FE-I4 as envisioned for IBL. (C) 2010 Elsevier B.V. All rights reserved.

With the high hit rate foreseen for the innermost layers at an upgraded LHC, the current ATLAS Front-End pixel chip FE-I3 [1] would start being inefficient. The main source of inefficiency comes from the copying mechanism of the pixel hits from the pixel array to the end of column buffers. A new ATLAS pixel chip FE-I4 is being developed in a 130 nm technology for use both in the framework of the Insertable B-Layer (IBL) project and for the outer layers of Super-LHC. FE-I4 is made of 80x336 pixels and features a reduced pixel size of 50x250 mu m(2). In the current design, a new digital architecture is introduced in which hit memories are distributed across the entire pixel array and the pixels organized in regions. In this paper, the digital architecture of FE-I4 is presented as well as the complete data flow.

A flexible multimode receiver architecture for software defined radio systems with focus on GSM, WCDMA and CDMA systems has been designed in a 120 nm CMOS technology. The receiver consists of a wideband coilless common gate LNA2 with gain switches and a high linearity down-converter with current interface between mixer and baseband-filter. The LO signal of a 8 GHz VCO and divider with ratio 4 respectively 8 covers the whole receiver frequency range. The receiver consumes 32 mA at 1.5 V supply voltage