Status of the SNO+ Experiment Caden, E
Journal of physics. Conference series,
01/2020, Letnik:
1342, Številka:
1
Journal Article
Recenzirano
Odprti dostop
The SNO+ experiment is located at SNOLAB in Sudbury, Ontario, Canada. It will employ 780 tonnes of liquid scintillator loaded, in its initial phase, with 1.3 tonnes of130Te (0.5% by mass) for a ...low-background and high-isotope-mass search for neutrino-less double beta decay. SNO+ uses the acrylic vessel and PMT array of the SNO detector with several experimental upgrades and necessary adaptations to fill with liquid scintillator. The SNO+ technique can be scaled up with a future high loading Phase II, able to probe to the bottom of the inverted hierarchy parameter space for effective Majorana mass. Low backgrounds and a low energy threshold allow SNO+ to also have other physics topics in its program, including geo- and reactor neutrinos, supernova and solar neutrinos. This will describe the SNO+ approach for the double-beta decay program, the current status of the experiment and its sensitivity prospects.
A Revolutionary Look at Sleep Buxton, Caden E.C.; Kryger, Meir H.
Sleep health,
June 2023, 2023-06-00, 20230601, Letnik:
9, Številka:
3
Journal Article
Commissioning the SNO+ Detector Caden, E.; Coulter, I.
Journal of physics. Conference series,
09/2017, Letnik:
888, Številka:
1
Journal Article
Recenzirano
Odprti dostop
SNO+ is a multipurpose liquid scintillator neutrino experiment based at SNOLAB in Sudbury, Ontario, Canada. The experiment's main physics goal is a search for neutrinoless double beta decay in ...Tellurium-130, but SNO+ will also study low energy solar neutrinos, geo- and reactor-antineutrinos, among other topics. We are reusing much of the hardware from the original SNO experiment, but significant work has taken place to transform the heavy water detector into a liquid scintillator detector. We present upgrades and improvements to the read-out electronics and trigger system to handle the higher data rates expected by a scintillator experiment. We show the successful installation and testing of a hold-down rope net for the acrylic vessel to counter-act the buoyancy of organic liquid scintillator. We also describe the new scintillator process plant and cover gas systems that have been constructed to achieve the purification necessary to meet our physics goals. We are currently commissioning the experiment with ultra-pure water in preparation for filling with scintillator in early 2017 and present the current status of this work.
The Double Chooz experiment has determined the value of the neutrino oscillation parameter thetas sub(13)thetas13 from an analysis of inverse beta decay interactions with neutron capture on hydrogen. ...This analysis uses a three times larger fiducial volume than the standard Double Chooz assessment, which is restricted to a region doped with gadolinium (Gd), yielding an exposure of 113.1 GW-ton-years. The data sample used in this analysis is distinct from that of the Gd analysis, and the systematic uncertainties are also largely independent, with some exceptions, such as the reactor neutrino flux prediction. A combined rate- and energy-dependent fit finds sin22thetas13=0.097 plus or minus 0.034 (stat.) plus or minus 0.034 (syst.), excluding the no-oscillation hypothesis at 2.0 sigma . This result is consistent with previous measurements of sin22thetas13.
(ProQuest: ... denotes formulae and/or non-USASCII text omitted; see image) Abstract The Double Chooz experiment presents improved measurements of the neutrino mixing angle theta ^sub 13^ using the ...data collected in 467.90 live days from a detector positioned at an average distance of 1050 m from two reactor cores at the Chooz nuclear power plant. Several novel techniques have been developed to achieve significant reductions of the backgrounds and systematic uncertainties with respect to previous publications, whereas the efficiency of the ... signal has increased. The value of theta ^sub 13^ is measured to be sin^sup 2^2theta ^sub 13^=0.090^sub -0.029^^sup +0.032^ from a fit to the observed energy spectrum. Deviations from the reactor ... prediction observed above a prompt signal energy of 4 MeV and possible explanations are also reported. A consistent value of theta ^sub 13^ is obtained from a fit to the observed rate as a function of the reactor power independently of the spectrum shape and background estimation, demonstrating the robustness of the theta ^sub 13^ measurement despite the observed distortion. Figure not available: see fulltext.
The SNO+ detector operated initially as a water Cherenkov detector. The
implementation of a sealed covergas system midway through water data taking
resulted in a significant reduction in the activity ...of $^{222}$Rn daughters in
the detector and allowed the lowest background to the solar electron scattering
signal above 5 MeV achieved to date. This paper reports an updated SNO+ water
phase $^8$B solar neutrino analysis with a total livetime of 282.4 days and an
analysis threshold of 3.5 MeV. The $^8$B solar neutrino flux is found to be
$\left(2.32^{+0.18}_{-0.17}\text{(stat.)}^{+0.07}_{-0.05}\text{(syst.)}\right)\times10^{6}$
cm$^{-2}$s$^{-1}$ assuming no neutrino oscillations, or
$\left(5.36^{+0.41}_{-0.39}\text{(stat.)}^{+0.17}_{-0.16}\text{(syst.)}
\right)\times10^{6}$ cm$^{-2}$s$^{-1}$ assuming standard neutrino oscillation
parameters, in good agreement with both previous measurements and Standard
Solar Model Calculations. The electron recoil spectrum is presented above 3.5
MeV.
The SNO+ collaboration reports its first spectral analysis of long-baseline
reactor antineutrino oscillation using 114 tonne-years of data. Fitting the
neutrino oscillation probability to the ...observed energy spectrum yields
constraints on the neutrino mass-squared difference $\Delta m^2_{21}$. In the
ranges allowed by previous measurements, the best-fit $\Delta m^2_{21}$ is
(8.85$^{+1.10}_{-1.33}$) $\times$ 10$^{-5}$ eV$^2$. This measurement is
continuing in the next phases of SNO+ and is expected to surpass the present
global precision on $\Delta m^2_{21}$ with about three years of data.
The next core-collapse supernova in the Milky Way or its satellites will represent a once-in-a-generation opportunity to obtain detailed information about the explosion of a star and provide ...significant scientific insight for a variety of fields because of the extreme conditions found within. Supernovae in our galaxy are not only rare on a human timescale but also happen at unscheduled times, so it is crucial to be ready and use all available instruments to capture all possible information from the event. The first indication of a potential stellar explosion will be the arrival of a bright burst of neutrinos. Its observation by multiple detectors worldwide can provide an early warning for the subsequent electromagnetic fireworks, as well as signal to other detectors with significant backgrounds so they can store their recent data. The Supernova Early Warning System (SNEWS) has been operating as a simple coincidence between neutrino experiments in automated mode since 2005. In the current era of multi-messenger astronomy there are new opportunities for SNEWS to optimize sensitivity to science from the next Galactic supernova beyond the simple early alert. This document is the product of a workshop in June 2019 towards design of SNEWS 2.0, an upgraded SNEWS with enhanced capabilities exploiting the unique advantages of prompt neutrino detection to maximize the science gained from such a valuable event.
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