29 research outputs found
Model Independent Approach of the JUNO B Solar Neutrino Program
No full textInternational audienceThe physics potential of detecting B solar neutrinos is exploited at the Jiangmen Underground Neutrino Observatory (JUNO), in a model independent manner by using three distinct channels of the charged-current (CC), neutral-current (NC) and elastic scattering (ES) interactions. Due to the largest-ever mass of C nuclei in the liquid-scintillator detectors and the potential low background level, B solar neutrinos would be observable in the CC and NC interactions on C for the first time. By virtue of optimized event selections and muon veto strategies, backgrounds from the accidental coincidence, muon-induced isotopes, and external backgrounds can be greatly suppressed. Excellent signal-to-background ratios can be achieved in the CC, NC and ES channels to guarantee the B solar neutrino observation. From the sensitivity studies performed in this work, we show that one can reach the precision levels of 5%, 8% and 20% for the B neutrino flux, , and , respectively, using ten years of JUNO data. It would be unique and helpful to probe the details of both solar physics and neutrino physics. In addition, when combined with SNO, the world-best precision of 3% is expected for the B neutrino flux measurement
Charge reconstruction in large-area photomultipliers
No full textThe International School for Advanced Studies (SISSA), find out more
The International School for Advanced Studies (SISSA), find out more
Charge reconstruction in large-area photomultipliers
M. Grassi1,2, M. Montuschi3,4, M. Baldoncini3,4, F. Mantovani3,4, B. Ricci3,4, G. Andronico5, V. Antonelli1,11, M. Bellato7, E. Bernieri8,9, A. Brigatti1,11Show full author list
Published 6 February 2018 • © 2018 IOP Publishing Ltd and Sissa Medialab
Journal of Instrumentation, Volume 13, February 2018 Citation M. Grassi et al 2018 JINST 13 P02008
Download Article PDF
References
95 Total downloads
2
2 total citations on Dimensions.
Article has an altmetric score of 1
Turn on MathJax
Get permission to re-use this article
Share this article
Share this content via email
Share on Facebook (opens new window)
Share on Twitter (opens new window)
Share on Mendeley (opens new window)
Article information
Abstract
Large-area PhotoMultiplier Tubes (PMT) allow to efficiently instrument Liquid Scintillator (LS) neutrino detectors, where large target masses are pivotal to compensate for neutrinos' extremely elusive nature. Depending on the detector light yield, several scintillation photons stemming from the same neutrino interaction are likely to hit a single PMT in a few tens/hundreds of nanoseconds, resulting in several photoelectrons (PEs) to pile-up at the PMT anode. In such scenario, the signal generated by each PE is entangled to the others, and an accurate PMT charge reconstruction becomes challenging. This manuscript describes an experimental method able to address the PMT charge reconstruction in the case of large PE pile-up, providing an unbiased charge estimator at the permille level up to 15 detected PEs. The method is based on a signal filtering technique (Wiener filter) which suppresses the noise due to both PMT and readout electronics, and on a Fourier-based deconvolution able to minimize the influence of signal distortions—such as an overshoot. The analysis of simulated PMT waveforms shows that the slope of a linear regression modeling the relation between reconstructed and true charge values improves from 0.769 ± 0.001 (without deconvolution) to 0.989 ± 0.001 (with deconvolution), where unitary slope implies perfect reconstruction. A C++ implementation of the charge reconstruction algorithm is available online at [1]
Mass testing of the JUNO experiment 20-inch PMTs readout electronics
No full textThe 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%
JUNO Sensitivity on Proton Decay Searches
No full textThe Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid
scintillator detector designed to explore many topics in fundamental physics.
In this paper, the potential on searching for proton decay in 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 to
suppress the sizable background caused by other delayed signals. Based on these
advantages, the detection efficiency for the proton decay via is 36.9% with a background level of 0.2 events after 10 years of data
taking. The estimated sensitivity based on 200 kton-years exposure is years, competitive with the current best limits on the proton
lifetime in this channel.Comment: 14 pages, 12 figures, an author adde
Quadrupole collectivity in <sup>42</sup>Ca from low-energy Coulomb excitation with AGATA
No full textA Coulomb-excitation experiment to study electromagnetic properties of 42Ca was performed using a 170-MeV calcium beam from the TANDEM XPU facility at INFN Laboratori Nazionali di Legnaro. γ rays from excited states in 42Ca were measured with the AGATA spectrometer. The magnitudes and relative signs of ten E2 matrix elements coupling six low-lying states in 42Ca, including the diagonal E2 matrix elements of 2+1 and 2+2 states, were determined using the least-squares code gosia. The obtained set of reduced E2 matrix elements was analyzed using the quadrupole sum rule method and yielded overall quadrupole deformation for 0+1,2 and 2+1,2 states, as well as triaxiality for 0+1,2 states, establishing the coexistence of a weakly deformed ground-state band and highly deformed slightly triaxial sideband in 42Ca. The experimental results were compared with the state-of-the-art large-scale shell-model and beyond-mean-field calculations, which reproduce well the general picture of shape coexistence in 42Ca
JUNO Sensitivity to Invisible Decay Modes of Neutrons
No full textInternational audienceWe explore the bound neutrons decay into invisible particles (e.g., or ) in the JUNO liquid scintillator detector. The invisible decay includes two decay modes: and . The invisible decays of -shell neutrons in will leave a highly excited residual nucleus. Subsequently, some de-excitation modes of the excited residual nuclei can produce a time- and space-correlated triple coincidence signal in the JUNO detector. Based on a full Monte Carlo simulation informed with the latest available data, we estimate all backgrounds, including inverse beta decay events of the reactor antineutrino , natural radioactivity, cosmogenic isotopes and neutral current interactions of atmospheric neutrinos. Pulse shape discrimination and multivariate analysis techniques are employed to further suppress backgrounds. With two years of exposure, JUNO is expected to give an order of magnitude improvement compared to the current best limits. After 10 years of data taking, the JUNO expected sensitivities at a 90% confidence level are and
Theological controversy in the seventh century concerning activities and wills in Christ
No full textThe primary purpose of the thesis is to fill the existing gaps in our understanding of various theological and political aspects of the controversy that took place in both Eastern and Western parts of the Roman Empire in the seventh century, the main theological point of which was wether Christ had one or two energeiai and wills. Before coming to any conclusions on this subject, I shall investigate the preliminary forms of Monenergism and Monothelitism i.e., belief in a single energeia and will of Christ, which were incorporated in the major Christological systems developed by Apollinarius of Laodicea, Theodore of Mopsuestia, and Severus of Antioch (chapters 1-3).Against this background, it becomes obvious that the Chalcedonian Monenergism and later Monothelitism emerged from the movement of neo- Chalcedonianism. It was an attempt by the political and ecclesiastical authorities to achieve a theological compromise with various non-Chalcedonian groups, mainly Severian, but also 'Nestorian'. Their ultimate goal was to reconcile these groups with the Catholic Church of the Empire (chapter 4). However, this project of reconciliation on the basis of the single-energeia formula was contested by the representatives of the same neo-Chalcedonian tradition and consequently condemned at the Councils of Lateran (649) and Constantinople (680/681). Thus, the same neo-Chalcedonian tradition produced two self-sufficient and antagonistic doctrines. A major concern of the thesis is to expose and compare systematically their doctrinal content per se and in the wider context of the principles of neo-Chalcedonianism (chapter 5)
Validation and integration tests of the JUNO 20-inch PMTs readout electronics
No full textThe 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
Implementation and performances of the IPbus protocol for the JUNO Large-PMT readout electronics
No full textThe 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
JUNO Sensitivity to Invisible Decay Modes of Neutrons
No full textWe explore the bound neutrons decay into invisible particles (e.g., or ) in the JUNO liquid scintillator detector. The invisible decay includes two decay modes: and . The invisible decays of -shell neutrons in will leave a highly excited residual nucleus. Subsequently, some de-excitation modes of the excited residual nuclei can produce a time- and space-correlated triple coincidence signal in the JUNO detector. Based on a full Monte Carlo simulation informed with the latest available data, we estimate all backgrounds, including inverse beta decay events of the reactor antineutrino , natural radioactivity, cosmogenic isotopes and neutral current interactions of atmospheric neutrinos. Pulse shape discrimination and multivariate analysis techniques are employed to further suppress backgrounds. With two years of exposure, JUNO is expected to give an order of magnitude improvement compared to the current best limits. After 10 years of data taking, the JUNO expected sensitivities at a 90% confidence level are and
