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Characterizing Quantum-Dot-Doped Liquid Scintillator for Applications to Neutrino Detectors  [PDF]
Lindley Winslow,Raspberry Simpson
Physics , 2012, DOI: 10.1088/1748-0221/7/07/P07010
Abstract: Liquid scintillator detectors are widely used in modern neutrino studies. The unique optical properties of semiconducting nanocrystals, known as quantum dots, offer intriguing possibilities for improving standard liquid scintillator, especially when combined with new photodetection technology. Quantum dots also provide a means to dope scintillator with candidate isotopes for neutrinoless double beta decay searches. In this work, the first studies of the scintillation properties of quantum-dot-doped liquid scintillator using both UV light and radioactive sources are presented.
Spectroscopic study of light scattering in linear alkylbenzene for liquid scintillator neutrino detectors  [PDF]
Xiang Zhou,Qian Liu,Junbo Han,Zhenyu Zhang,Xuan Zhang,Yayun Ding,Yangheng Zheng,Li Zhou,Jun Cao,Yifang Wang
Physics , 2015,
Abstract: We has set up a light scattering spectrometer to study the depolarization of light scattering in linear alkylbenzene. From the scattering spectra it can be unambiguously shown that the depolarized part of light scattering belongs to Rayleigh scattering. The additional depolarized Rayleigh scattering can make the effective transparency of linear alkylbenzene much better than it was expected. Therefore sufficient scintillation photons can transmit through the large liquid scintillator detector of JUNO. Our study is crucial to achieving the unprecedented energy resolution 3\%/$\sqrt{E\mathrm{(MeV)}}$ for JUNO experiment to determine the neutrino mass hierarchy. The spectroscopic method can also be used to judge the attribution of the depolarization of other organic solvents used in neutrino experiments.
Prompt directional detection of galactic supernova by combining large liquid scintillator neutrino detectors  [PDF]
V. Fischer,T. Chirac,T. Lasserre,C. Volpe,M. Cribier,M. Durero,J. Gaffiot,T. Houdy,A. Letourneau,G. Mention,M. Pequignot,V. Sibille,M. Vivier
Physics , 2015, DOI: 10.1088/1475-7516/2015/08/032
Abstract: Core-collapse supernovae produce an intense burst of electron antineutrinos in the few-tens-of-MeV range. Several Large Liquid Scintillator-based Detectors (LLSD) are currently operated worldwide, being very effective for low energy antineutrino detection through the Inverse Beta Decay (IBD) process. In this article, we develop a procedure for the prompt extraction of the supernova location by revisiting the details of IBD kinematics over the broad energy range of supernova neutrinos. Combining all current scintillator-based detector, we show that one can locate a canonical supernova at 10 kpc with an accuracy of 45 degrees (68% C.L.). After the addition of the next generation of scintillator-based detectors, the accuracy could reach 12 degrees (68% C.L.), therefore reaching the performances of the large water Cerenkov neutrino detectors. We also discuss a possible improvement of the SuperNova Early Warning System (SNEWS) inter-experiment network with the implementation of a directionality information in each experiment. Finally, we discuss the possibility to constrain the neutrino energy spectrum as well as the mass of the newly born neutron star with the LLSD data
Short-baseline Neutrino Oscillation Waves in Ultra-large Liquid Scintillator Detectors  [PDF]
Sanjib Kumar Agarwalla,J. M. Conrad,M. H. Shaevitz
Physics , 2011, DOI: 10.1007/JHEP12(2011)085
Abstract: Powerful new multi-kiloton liquid scintillator neutrino detectors, including NOvA and LENA, will come on-line within the next decade. When these are coupled with a modest-power decay-at-rest (DAR) neutrino source at short-baseline, these detectors can decisively address the recent ambiguous signals for neutrino oscillations at high Delta m^2. These detectors are > 50 m long, and so with a DAR beam, the characteristic oscillation wave will be apparent over the length of the detector, providing a powerful verification of the oscillation phenomena. LENA can simultaneously perform numubar to nuebar appearance and nue to nue disappearance searches with unprecedented sensitivity. NOvA is likely limited to nue disappearance given its present design, but also has excellent sensitivity in the high Delta m^2 region. For the appearance channel, LENA could provide a stringent test of the LSND and MiniBooNE signal regions at > 5 sigma with a reduced fiducial volume of 5 kt and a 10 kW neutrino source. In addition, the LENA and NOvA disappearance sensitivities in nue mode are complementary to the recent reactor anomaly indicating possible nuebar disappearance and would cover this possible oscillation signal at the 3 sigma level.
How to observe 8B solar neutrinos in liquid scintillator detectors  [PDF]
A. Ianni,D. Montanino,F. L. Villante
Physics , 2005, DOI: 10.1016/j.physletb.2005.08.122
Abstract: We show that liquid organic scintillator detectors (e.g., KamLAND and Borexino) can measure the 8B solar neutrino flux by means of the nu_e charged current interaction with the 13C nuclei naturally contained in the scintillators. The neutrino events can be identified by exploiting the time and space coincidence with the subsequent decay of the produced 13N nuclei. We perform a detailed analysis of the background in KamLAND, Borexino and in a possible liquid scintillator detector at SNOLab, showing that the 8B solar neutrino signal can be extracted with a reasonable uncertainty in a few years of data taking. KamLAND should be able to extract about 18 solar neutrino events from the already collected data. Prospects for gigantic scintillator detectors (such as LENA) are also studied.
Phenylxylylethane (PXE): a high-density, high-flashpoint organic liquid scintillator for applications in low-energy particle and astrophysics experiments  [PDF]
Borexino Collaboration
Physics , 2004,
Abstract: 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 (phenyl-o-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 radio carbon isotopic ratio of C-14/C-12 = 9.1 * 10^{-18}$ has been measured in the scintillator. Initial trace impurities, e.g. U-238 at 3.2 * 10^{-14} g/g could be purified to levels below 10^{-17} g/g by silica gel solid column purification.
New Power to Measure Supernova $ν_e$ with Large Liquid Scintillator Detectors  [PDF]
Ranjan Laha,John F. Beacom,Sanjib Kumar Agarwalla
Physics , 2014,
Abstract: We examine the prospects for detecting supernova $\nu_e$ in JUNO, RENO-50, LENA, or other approved or proposed large liquid scintillator detectors. The main detection channels for supernova $\nu_e$ in a liquid scintillator are its elastic scattering with electrons and its charged-current interaction with the $^{12}$C nucleus. In existing scintillator detectors, the numbers of events from these interactions are too small to be very useful. However, at the 20-kton scale planned for the new detectors, these channels become powerful tools for probing the $\nu_e$ emission. We find that the $\nu_e$ spectrum can be well measured, to better than $\sim 40\%$ precision for the total energy and better than $\sim 25\%$ precision for the average energy. This is adequate to distinguish even close average energies, e.g., 11 MeV and 14 MeV, which will test the predictions of supernova models. In addition, it will help set constraints on neutrino mixing effects in supernovae by testing non-thermal spectra. Without such large liquid scintillator detectors (or Super-Kamiokande with added gadolinium, which has similar capabilities), supernova $\nu_e$ will be measured poorly, holding back progress on understanding supernovae, neutrinos, and possible new physics.
The next-generation liquid-scintillator neutrino observatory LENA  [PDF]
Michael Wurm,John F. Beacom,Leonid B. Bezrukov,Daniel Bick,Johannes Blümer,Sandhya Choubey,Christian Ciemniak,Davide D'Angelo,Basudeb Dasgupta,Amol Dighe,Grigorij Domogatsky,Steve Dye,Sergey Eliseev,Timo Enqvist,Alexey Erykalov,Franz von Feilitzsch,Gianni Fiorentini,Tobias Fischer,Marianne G?ger-Neff,Peter Grabmayr,Caren Hagner,Dominikus Hellgartner,Johannes Hissa,Shunsaku Horiuchi,Hans-Thomas Janka,Claude Jaupart,Josef Jochum,Tuomo Kalliokoski,Pasi Kuusiniemi,Tobias Lachenmaier,Ionel Lazanu,John G. Learned,Timo Lewke,Paolo Lombardi,Sebastian Lorenz,Bayarto Lubsandorzhiev,Livia Ludhova,Kai Loo,Jukka Maalampi,Fabio Mantovani,Michela Marafini,Jelena Maricic,Teresa Marrodán Undagoitia,William F. McDonough,Lino Miramonti,Alessandro Mirizzi,Quirin Meindl,Olga Mena,Randolph M?llenberg,Rolf Nahnhauer,Dmitry Nesterenko,Yuri N. Novikov,Guido Nuijten,Lothar Oberauer,Sandip Pakvasa,Sergio Palomares-Ruiz,Marco Pallavicini,Silvia Pascoli,Thomas Patzak,Juha Peltoniemi,Walter Potzel,Tomi R?ih?,Georg G. Raffelt,Gioacchino Ranucci,Soebur Razzaque,Kari Rummukainen,Juho Sarkamo,Valerij Sinev,Christian Spiering,Achim Stahl,Felicitas Thorne,Marc Tippmann,Alessandra Tonazzo,Wladyslaw H. Trzaska,John D. Vergados,Christopher Wiebusch,Jürgen Winter
Physics , 2011, DOI: 10.1016/j.astropartphys.2012.02.011
Abstract: We propose the liquid-scintillator detector LENA (Low Energy Neutrino Astronomy) as a next-generation neutrino observatory on the scale of 50 kt. The outstanding successes of the Borexino and KamLAND experiments demonstrate the large potential of liquid-scintillator detectors in low-energy neutrino physics. LENA's physics objectives comprise the observation of astrophysical and terrestrial neutrino sources as well as the investigation of neutrino oscillations. In the GeV energy range, the search for proton decay and long-baseline neutrino oscillation experiments complement the low-energy program. Based on the considerable expertise present in European and international research groups, the technical design is sufficiently mature to allow for an early start of detector realization.
ecCNO Solar Neutrinos: A Challenge for Gigantic Ultra-Pure Liquid Scintillator Detectors  [PDF]
F. L. Villante
Physics , 2014, DOI: 10.1016/j.physletb.2015.01.043
Abstract: Neutrinos produced in the Sun by electron capture reactions on $^{13}{\rm N}$, $^{15}{\rm O}$ and $^{17}{\rm F}$, to which we refer as ecCNO neutrinos, are not usually considered in solar neutrino analysis since the expected fluxes are extremely low. The experimental determination of this sub-dominant component of the solar neutrino flux is very difficult but could be rewarding since it provides a determination of the metallic content of the solar core and, moreover, probes the solar neutrino survival probability in the transition region at $E_\nu\sim 2.5\,{\rm MeV}$. In this letter, we suggest that this difficult measure could be at reach for future gigantic ultra-pure liquid scintillator detectors, such as LENA.
Antineutrino Geophysics with Liquid Scintillator Detectors  [PDF]
Casey G. Rothschild,Mark C. Chen,Frank P. Calaprice
Physics , 1997, DOI: 10.1029/98GL50667
Abstract: Detecting the antineutrinos emitted by the decay of radioactive elements in the mantle and crust could provide a direct measurement of the total abundance of uranium and thorium in the Earth. In calculating the antineutrino flux at specific sites, the local geology of the crust and the background from the world's nuclear power reactors are important considerations. Employing a global crustal map, with type and thickness data, and using recent estimates of the uranium and thorium distribution in the Earth, we calculate the antineutrino event rate for two new neutrino detectors. We show that spectral features allow terrestrial antineutrino events to be identified above reactor antineutrino backgrounds and that the uranium and thorium contributions can be separately determined.
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