Characterization of a Nd-loaded organic liquid scintillator for neutrinoless double beta decay search of 150Nd with a 10-ton scale detector (original) (raw)
Review of Novel Approaches to Organic Liquid Scintillators in Neutrino Physics
Symmetry
Organic liquid scintillators have been used for decades in many neutrino physics experiments. They are particularly suited for the detection of low-energy neutrinos where energy and timing information is required. Organic liquid scintillators exhibit advantages such as high light yield, cost effectiveness, radio purity, and more. However, they also entail disadvantages, most prominently a lack of vertex resolution and particle identification. In recent years, various novel ideas have emerged to improve the performance of organic liquid scintillators. In this review, novel approaches to organic liquid scintillators in neutrino experiments as of 2022 are reviewed and their prospects and applications compared.
Development of a Gd loaded liquid scintillator for electron anti-neutrino spectroscopy
Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment, 1999
We report on the development and deployment of 11.3 tons of 0.1% Gd-loaded liquid scintillator used in the Palo Verde reactor neutrino oscillation experiment. We discuss the chemical composition, properties, and stability of the scintillator elaborating on the details of the scintillator preparation crucial for obtaining a good scintillator quality and stability.
Production and properties of the liquid scintillators used in the STEREO reactor neutrino experiment
Journal of Instrumentation, 2019
The electron antineutrino spectrum in the S reactor experiment (ILL Grenoble) is measured via the inverse beta decay signals in an organic liquid scintillator. The six target cells of the S detector are filled with about 1800 litres of Gd-loaded liquid scintillator optimised for the requirements of the experiment. These target cells are surrounded by similar cells containing liquid scintillator without the Gd-loading. The development and characteristics of these scintillators are reported. In particular, the transparency, light production and pulse shape discrimination capabilities of the organic liquids are discussed.
Journal of the Korean Physical Society, 2013
Various liquid scintillators are commonly used in neutrino experiments. If successful neutrino experiments are to be performed over several years, using stable solvents with the capability of mass production in the liquid scintillator is one of the key requirements. We investigate the various physical and optical properties, absorption, light transmission, light output, density, index of refraction, water content, etc., of the solvents used in neutrino detectors. In addition, safety for the environment and humans needs to be taken in consideration. In this paper, the preparation and the various characteristics of the solvents used for the liquid scintillator are summarized and reported.
Low energy neutrino detection with a compact water-based liquid scintillator detector
The European Physical Journal C
In this study, the conceptual design and physics simulations of a near-field Water-based Liquid Scintillator (WbLS) detector placed 100 m from the Akkuyu Nuclear Power Plant (ANPP), currently under construction and aiming at being Turkey’s first nuclear power plant, is presented. The ANPP is an excellent opportunity for neutrino studies and the development of an R &D program for neutrino detectors in Turkey. The Reactor Neutrino Experiments of Turkey (RNET) program includes a compact detector with a 2.5-ton volume of WbLS and a \sim ∼30∼ 30% photo-coverage, and the program is planned to be expanded with a medium-size 30-ton detector that will be an international testbed for WbLS and new detector technologies through low energy neutrino studies. In the following, the focus will be on the smaller∼30\sim ∼ 2.5 ton detector, instrumented with 8-in. high quantum efficiency PMTs and two layers of cosmic veto paddles, covering all sides of the detector, to track and veto cosmic partic...
Perspective liquid scintillators for spectrometry of neutron and gamma radiation
EPJ Web of Conferences, 2020
This paper presents some results of the development of two new scintillation detectors usable for the detection and spectrometry of neutron and photon components of the mixed field. It is a series of liquid organic scintillators containing carbon, hydrogen, nitrogen and oxygen. Elements of individual scintillator designs are arranged in various chemical bonds defining physical and chemical properties of the scintillators. These scintillators have advantageous useful properties. They are non-hygroscopic, not poisonous and are not sensitive to contact with the outside atmosphere and can be stored in conventional laboratory containers.
Optimization of the JUNO liquid scintillator composition using a Daya Bay antineutrino detector
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2021
To maximize the light yield of the liquid scintillator (LS) for the Jiangmen Underground Neutrino Observatory (JUNO), a 20 t LS sample was produced in a pilot plant at Daya Bay. The optical properties of the new LS in various compositions were studied by replacing the gadolinium-loaded LS in one antineutrino detector. The concentrations of the fluor, PPO, and the wavelength shifter, bis-MSB, were increased in 12 steps from 0.5 g/L and <0.01 mg/L to 4 g/L and 13 mg/L, respectively. The numbers of total detected photoelectrons suggest that, with the optically purified solvent, the bis-MSB concentration does not need to be more than 4 mg/L. To bridge the one order of magnitude in the detector size difference between Daya Bay and JUNO, the Daya Bay data were used to tune the parameters of a newly developed optical model. Then, the model and tuned parameters were used in the JUNO simulation. This enabled to determine the optimal composition for the JUNO LS: purified solvent LAB with 2.5 g/L PPO, and 1 to 4 mg/L bis-MSB.
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2007
The use of multiple, identical liquid scintillator (LS) detectors at distances between 0.1 and 2 km from a nuclear reactor has the potential to detect antineutrino oscillations and to measure the value of the unknown neutrino-mixing angle y 13. The nuclear reaction of interest in the LS is the inverse b-decay reaction on protons, with the coincidence tag between the emitted prompt positron and the delayed neutron-capture providing a clear signature of the antineutrino capture. The neutron-capture signal is greatly enhanced by loading gadolinium into the LS, because of the large (n, g) cross-sections of the Gd isotopes (49,000 barns for natural abundance Gd), and the 8MeVofemittedgrays.WehavedevelopedproceduresatBNLtosynthesizehigh−qualityGd−loadedLS(Gd−LS)inasimplified,consistent,andreproducibleway,usingthemethodofpH−controlled,solvent−solventextraction.ThisGd−LShaslongattenuationlength(415m),highlightoutput(8 MeV of emitted grays. We have developed procedures at BNL to synthesize high-quality Gd-loaded LS (Gd-LS) in a simplified, consistent, and reproducible way, using the method of pH-controlled, solvent-solvent extraction. This Gd-LS has long attenuation length (415 m), highlight output (8MeVofemittedgrays.WehavedevelopedproceduresatBNLtosynthesizehigh−qualityGd−loadedLS(Gd−LS)inasimplified,consistent,andreproducibleway,usingthemethodofpH−controlled,solvent−solventextraction.ThisGd−LShaslongattenuationlength(415m),highlightoutput(90% of pseudocumene), and long-term stability (41.5 years to date). The preparation and characteristics of this Gd-LS are discussed in this paper.
Radiochemistry, 2007
A comparison was made of the properties of solvents meeting the requirements posed on Gd-loaded organic liquid scintillators (transparency, light output, compatibility with the structural materials of the detector). The optical properties of the solvents were examined in relation to various factors (purity of the initial reagents, concentrations of Gd and scintillation additives). Extraction of Gd with C 4 3C 8 carboxylic acids was examined. The composition of the extractable Gd complexes with 2-methylvaleric and 2-ethylhexanoic acids, GdR 3. 3HR. mH 2 O (where m = 132, depending on the solvents used), was determined. The solubility of water in 2-ethylhexanoic and 2-methylvaleric acids was examined. Scintillators based on Gd 2-methylvalerates have better parameters than those based on the other carboxylic acids tested. The instability of the optical properties of the Gd carboxylate solutions is presumably due to the presence of water in the scintillator. Possible methods of water removal from the organic phase were discussed.
A step toward CNO solar neutrino detection in liquid scintillators
Physics Letters B, 2011
The detection of CNO solar neutrinos in ultrapure liquid scintillator detectors is limited by the background produced by Bismuth-210 nuclei that undergo β-decay to Polonium-210 with a lifetime of ∼ 7 days. Polonium-210 nuclei are unstable and decay with a lifetime equal to ∼ 200 days emitting α particles that can be also detected. In this letter, we show that the Bi-210 background can be determined by looking at the time evolution of α−decay rate of Po-210, provided that α particle detection efficiency is stable over the data acquisition period and external sources of Po-210 are negligible. A sufficient accuracy can be obtained in a relatively short time. As an example, if the initial Po-210 event rate is ∼ 2000 cpd/100ton or lower, a Borexino-like detector could start discerning CNO neutrino signal from Bi-210 background in ∆t ∼ 1yr.
Study of phenylxylylethane (PXE) as scintillator for low energy neutrino experiments
Nuclear Instruments & Methods in Physics Research Section a-Accelerators Spectrometers Detectors and Associated Equipment, 2008
We report on the study of a new liquid scintillator target for neutrino interactions in the framework of the research and development program of the Borexino solar neutrino experiment. The scintillator consists of 1,2-dimethyl-4-(1-phenylethyl)-benzene (phenylo-xylylethane, PXE) as solvent and 1,4-diphenylbenzene (para-Terphenyl, p-Tp) as primary and 1,4-bis(2-methylstyryl)benzene (bis-MSB) as secondary solute. The density close to that of water and the high flash point makes it an attractive option for large scintillation detectors in general. The study focused on optical properties, radioactive trace impurities and novel purification techniques of the scintillator. Attenuation lengths of the scintillator mixture of 12 m at 430 nm were achieved after purification with an alumina column. A radiocarbon isotopic ratio of 14 C= 12 C ¼ 9:1 Â 10 À18 has been measured in the scintillator. Initial trace impurities, e.g. 238 U at 3:2 Â 10 À14 g=g could be purified to levels below 1 Â 10 À17 g=g by silica gel solid column purification. r
Novel technique for ultra-sensitive determination of trace elements in organic scintillators
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2003
A technique based on neutron activation has been developed for an extremely high sensitivity analysis of trace elements in organic materials. Organic materials are sealed in plastic or high purity quartz and irradiated at the HFIR and MITR. The most volatile materials such as liquid scintillator (LS) are first preconcentrated by clean vacuum evaporation. Activities of interest are separated from side activities by acid digestion and ion exchange. The technique has been applied to study the liquid scintillator used in the KamLAND neutrino experiment. Detection limits of <2.4×10 −15 g 40 K/g LS, <5.5×10 −15 g Th/g LS, and <8×10 −15 g U/g LS have been achieved.
Fluorescence decay-time constants in organic liquid scintillators
Review of Scientific Instruments, 2009
The fluorescence decay-time constants have been measured for several scintillator mixtures based on phenyl-o-xylylethane (PXE) and linear alkylbenzene (LAB) solvents. The resulting values are of relevance for the physics performance of the proposed large-volume liquid scintillator detector LENA (Low Energy Neutrino Astronomy). In particular, the impact of the measured values to the search for proton decay via p → K + ν is evaluated in this work.
A Step toward CNO solar neutrinos detection in liquid scintillators, Phys.Lett. B701
2011
The detection of CNO solar neutrinos in ultrapure liquid scintillator detectors is limited by the back-ground produced by Bismuth-210 nuclei that undergo β-decay to Polonium-210 with a lifetime of ∼ 7 days. Polonium-210 nuclei are unstable and decay with a lifetime equal to ∼ 200 days emitting α particles that can be also detected. In this letter, we show that the Bi-210 background can be determined by looking at the time evolution of α−decay rate of Po-210, provided that α particle detection efficiency is stable over the data acquisition period and external sources of Po-210 are negligible. A sufficient accuracy can be obtained in a relatively short time. As an example, if the initial Po-210 event rate is ∼ 2000 cpd/100ton or lower, a Borexino-like detector could start discerning CNO neutrino signal from Bi-210 background in ∆t ∼ 1yr. 1 ar
Review of Liquid Scintillators (Technology and Challenges)
Technolology and Instrumentation in Particle Physics TIPP2023, 2023
I review the mechanism of scintillation in organic and noble liquids. I also review the latest progress and future challenges. I was not able to upload the video lecture but a link is provided. Readers are encouraged to listen to the video.
Liquid scintillation detectors for high energy neutrinos
Progress in Particle and Nuclear Physics, 2010
Large liquid scintillation detectors have been generally used for low energy neutrino measurements, in the MeV energy region. We describe the potential employment of large detectors (>1 kiloton) for studies of higher energy neutrino interactions, such as cosmic rays and long baseline experiments. When considering the physics potential of new large instruments the possibility of doing useful measurements with higher energy neutrino interactions has been overlooked. Here we take into account Fermat's principle, which states that the first light to reach each PMT will follow the shortest path between that PMT and the point of origin. We describe the geometry of this process, and the resulting wavefront, which we call the ''Fermat surface'', and discuss methods of using this surface to extract directional track information and particle identification. This capability may be demonstrated in the new long baseline neutrino beam from Jaeri accelerator to the KamLAND detector in Japan. Other exciting applications include the use of Hanohano as a movable long baseline detector in this same beam, and LENA in Europe for future long baseline neutrino beams from CERN. Also, this methodology opens up the question as to whether a large liquid scintillator detector should be given consideration for use in a future long baseline experiment from Fermilab to the DUSEL underground laboratory at Homestake.
Novel opaque scintillator for neutrino detection
Journal of Instrumentation, 2019
There is rising interest in organic scintillators with low scattering length for future neutrino detectors. Therefore, a new scintillator system was developed based on admixtures of paraffin wax in linear alkyl benzene. The transparency and viscosity of this gel-like material can be tuned by temperature adjustment. Whereas it is a colorless transparent liquid at temperatures around 40 • C, it has a milky wax structure below 20 • C. The production and properties of such a scintillator as well as its advantages compared to transparent liquids are described.
Reactor neutrino experiments with a large liquid scintillator detector
Journal of High Energy Physics, 2007
We discuss several new ideas for reactor neutrino oscillation experiments with a Large Liquid Scintillator Detector. We consider two different scenarios for a measurement of the small mixing angle θ 13 with a mobileν e source: a nuclear-powered ship, such as a submarine or an icebreaker, and a land-based scenario with a mobile reactor. The former setup can achieve a sensitivity to sin 2 2θ 13 0.004 at the 90% confidence level, while the latter performs only slightly better than Double Chooz. Furthermore, we study the precision that can be achieved for the solar parameters, sin 2 2θ 12 and ∆m 2 21 , with a mobile reactor and with a conventional power station. With the mobile reactor, a precision slightly better than from current global fit data is possible, while with a power reactor, the accuracy can be reduced to less than 1%. Such a precision is crucial for testing theoretical models, e.g. quark-lepton complementarity.
The liquid scintillator neutrino detector and LAMPF neutrino source
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 1997
A search for neutrino oscillations of the typeνµ →νe has been conducted at the Los Alamos Meson Physics Facility usingνµ from muon decay at rest. Evidence for this transition has been reported previously. This paper discusses in detail the experimental setup, detector operation and neutrino source, including aspects relevant to oscillation searches in the muon decay-at-rest and pion decay in flight channels.