Measurements of Scintillation Light Yield Non-proportionality in NaI(Tl) Detector

2021 ◽  
Author(s):  
Md. Shahinur Rahman ◽  
Wayne D. Hutchison ◽  
Lindsey Bignell ◽  
Gregory Lane ◽  
Lei Wang ◽  
...  
Keyword(s):  
Dark Matter ◽  
Liquid Scintillator ◽  
Light Yield ◽  
Recoil Energy ◽  
Detector Response ◽  
Scintillation Light ◽  
Coincidence Technique ◽  
Background Rejection ◽  
Ionization Density ◽  
Background Events

Abstract The SABRE (Sodium-iodide with Active Background Rejection) experiment consists of 50 kg of ultrapure NaI(Tl) crystal contained within a 10.5 ton liquid scintillator (LS) veto detector, and will search for dark matter interactions in the inner NaI(Tl) detector. The relative scintillation light yield in NaI(Tl) scintillator for different incident particle energies is not constant and is important for characterizing the detector response. The relative scintillation light yield in two different NaI(Tl) scintillators was measured with a 10 µCi 137Cs radioactive source using the Compton coincidence technique (CCT) for scattering angles 30? - 135? using electron energies ranging from 60 to 500 keVee, and these measurements are compared to the previously published results. Light yield was proportional within 3.5% at energies between 60 and 500 keVee, but non-proportionality increases drastically below 60 keVee which might be due to the non-uniform ionization density and multiple Compton scattering background events in the scintillator. An improved experimental setup with ultrapure NaI(Tl) scintillator and proper coincidence timing of radioactive events could allow scintillation light yield measurement at lower electron recoil energy. The obtained light yield non-proportionality results will be useful for the SABRE dark matter detector experiment.

scholarly journals The WArP Experiment: A Double-Phase Argon Detector for Dark Matter Searches

2014 ◽  
Vol 2014 ◽  
pp. 1-17 ◽  
Author(s):  
Andrea Zani
Keyword(s):  
Dark Matter ◽  
Gas Phase ◽  
Detector Response ◽  
Background Rejection ◽  
Double Phase ◽  
Previous Decade ◽  
Nuclear Recoils ◽  
Dark Matter Detection ◽  
Matter Detection

Cryogenic noble liquids emerged in the previous decade as one of the best media to perform WIMP dark matter searches, in particular due to the possibility to scale detector volumes to multiton sizes. The WArP experiment was then developed as one of the first to implement the idea of coupling Argon in liquid and gas phase, in order to discriminateβ/γ-interactions from nuclear recoils and then achieve reliable background rejection. Since its construction, other projects spawned, employing Argon and Xenon and following its steps. The WArP 100l detector was assembled in 2008 at the Gran Sasso National Laboratories (LNGS), as the final step of a years-long R&D programme, aimed at characterising the technology of Argon in double phase for dark matter detection. Though it never actually performed a physics run, a technical run was taken in 2011, to characterise the detector response.

scholarly journals JUNO sensitivity to low energy atmospheric neutrino spectra

2021 ◽  
Vol 81 (10) ◽  
Author(s):  
Angel Abusleme ◽  
Thomas Adam ◽  
Shakeel Ahmad ◽  
Rizwan Ahmed ◽  
Sebastiano Aiello ◽  
...  
Keyword(s):  
Liquid Scintillator ◽  
Detection System ◽  
Atmospheric Neutrino ◽  
Light Yield ◽  
Theoretical Models ◽  
Neutrino Energy ◽  
Low Energy ◽  
Atmospheric Neutrinos ◽  
Scintillation Light ◽  
Light Pattern

AbstractAtmospheric 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.

Szintillationseigenschaften von Anthracen- und Naphthalinkristallen beim Beschuß mit energiereichen α-Teilchen, Deuteronen und Elektronen bei tiefen Temperaturen*

1964 ◽  
Vol 19 (6) ◽  
pp. 756-767 ◽  
Author(s):  
Werner F. Kienzle
Keyword(s):  
Lattice Thermal Conductivity ◽  
Light Yield ◽  
Particle Impact ◽  
Crystal Temperature ◽  
Scintillation Light ◽  
Temperature Range ◽  
Ionization Density ◽  
Complicated Manner ◽  
Limiting Value ◽  
Α Particles

The scintillation response of anthracene crystals has been investigated with 7.0 MeV a particles within the temperature range 1.5°K < T < 300°K and with 46 MeV α particles and 24 MeV deuterons within the temperature range 11°K < T < 300°K. With decreasing crystal temperature the scintillation light yield increases towards a temperature independent but still angularly dependent limiting value reached at about 4 CK.The angular dependence of the scintillation light yield shows a so far unknown sharp peak at particle impact directions nearly paralel to the (a, b) plane. The peak changes with crystal temperature and ionization density in a complicated manner and disappears below 10°K.For 0.6 MeV β particles the scintillation light yield has been investigated within the temperature range 11°K < T < 300°K. It increases with decreasing temperature less steeply than the α-light yield, i. e. the α/β yield ratio increases as the crystal temperature decreases. From this it is concluded that the quenching of excitations within an ionization column is a function of the crystal temperature. Similar results have been obtained with single crystals of naphthalene.A possible relation between the scintillation anisotropy and the anisotropy of the lattice thermal conductivity has been examined.

scholarly journals Characterization of water-based liquid scintillator for Cherenkov and scintillation separation

2020 ◽  
Vol 80 (9) ◽  
Author(s):  
J. Caravaca ◽  
B. J. Land ◽  
M. Yeh ◽  
G. D. Orebi Gann
Keyword(s):  
Large Scale ◽  
Liquid Scintillator ◽  
Light Yield ◽  
Time Profile ◽  
Pure Liquid ◽  
Scintillation Light ◽  
Linear Alkylbenzene ◽  
Water Based ◽  
Measured Time ◽  
Simple Extrapolation

AbstractThis paper presents measurements of the scintillation light yield and time profile for a number of concentrations of water-based liquid scintillator, formulated from linear alkylbenzene (LAB) and 2,5-diphenyloxazole (PPO). We find that the scintillation light yield is linear with the concentration of liquid scintillator in water between 1 and 10% with a slope of $$127.9\pm 17.0$$ 127.9 ± 17.0 ph/MeV/concentration and an intercept value of $$108.3\pm 51.0$$ 108.3 ± 51.0 ph/MeV, the latter being illustrative of non-linearities with concentration at values less than 1%. This is larger than expected from a simple extrapolation of the pure liquid scintillator light yield. The measured time profiles are consistently faster than that of pure liquid scintillator, with rise times less than 250 ps and prompt decay constants in the range of 2.1–2.85 ns. Additionally, the separation between Cherenkov and scintillation light is quantified using cosmic muons in the CHESS experiment for each formulation, demonstrating an improvement in separation at the centimeter scale. Finally, we briefly discuss the prospects for large-scale detectors.

scholarly journals Performance of Water-Based Liquid Scintillator: An Independent Analysis

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
D. Beznosko ◽  
A. Batyrkhanov ◽  
A. Duspayev ◽  
A. Iakovlev ◽  
M. Yessenov
Keyword(s):  
Liquid Scintillator ◽  
National Laboratory ◽  
Light Yield ◽  
Brookhaven National Laboratory ◽  
Pure Liquid ◽  
Scintillation Light ◽  
Detection Techniques ◽  
Measurement Analysis ◽  
Water Based ◽  
Large Water

The water-based liquid scintillator (WbLS) is a new material currently under development. It is based on the idea of dissolving the organic scintillator in water using special surfactants. This material strives to achieve the novel detection techniques by combining the Cerenkov rings and scintillation light, as well as the total cost reduction compared to pure liquid scintillator (LS). The independent light yield measurement analysis for the light yield measurements using three different proton beam energies (210 MeV, 475 MeV, and 2000 MeV) for water, two different WbLS formulations (0.4% and 0.99%), and pure LS conducted at Brookhaven National Laboratory, USA, is presented. The results show that a goal of ~100 optical photons/MeV, indicated by the simulation to be an optimal light yield for observing both the Cerenkov ring and the scintillation light from the proton decay in a large water detector, has been achieved.

scholarly journals Xenon-1T excess as a possible signal of a sub-GeV hidden sector dark matter

2021 ◽  
Vol 2021 (2) ◽  
Author(s):  
Amin Aboubrahim ◽  
Michael Klasen ◽  
Pran Nath
Keyword(s):  
Dark Matter ◽  
Particle Physics ◽  
Small Mass ◽  
Big Bang ◽  
Mass Splitting ◽  
Recoil Energy ◽  
Dirac Fermions ◽  
Dark Sector ◽  
Dark Photon ◽  
Physics Model

Abstract We present a particle physics model to explain the observed enhancement in the Xenon-1T data at an electron recoil energy of 2.5 keV. The model is based on a U(1) extension of the Standard Model where the dark sector consists of two essentially mass degenerate Dirac fermions in the sub-GeV region with a small mass splitting interacting with a dark photon. The dark photon is unstable and decays before the big bang nucleosynthesis, which leads to the dark matter constituted of two essentially mass degenerate Dirac fermions. The Xenon-1T excess is computed via the inelastic exothermic scattering of the heavier dark fermion from a bound electron in xenon to the lighter dark fermion producing the observed excess events in the recoil electron energy. The model can be tested with further data from Xenon-1T and in future experiments such as SuperCDMS.

scholarly journals Exothermic dark matter for XENON1T excess

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Hyun Min Lee
Keyword(s):  
Dark Matter ◽  
Mass Difference ◽  
Mass Splitting ◽  
Effective Theory ◽  
Recoil Energy ◽  
Detector Resolution ◽  
Atomic Excitation ◽  
Microscopic Models ◽  
Electron Recoil ◽  
Two Component

Abstract Motivated by the recent excess in the electron recoil from XENON1T experiment, we consider the possibility of exothermic dark matter, which is composed of two states with mass splitting. The heavier state down-scatters off the electron into the lighter state, making an appropriate recoil energy required for the Xenon excess even for the standard Maxwellian velocity distribution of dark matter. Accordingly, we determine the mass difference between two component states of dark matter to the peak electron recoil energy at about 2.5 keV up to the detector resolution, accounting for the recoil events over ER = 2 − 3 keV, which are most significant. We include the effects of the phase-space enhancement and the atomic excitation factor to calculate the required scattering cross section for the Xenon excess. We discuss the implications of dark matter interactions in the effective theory for exothermic dark matter and a massive Z′ mediator and provide microscopic models realizing the required dark matter and electron couplings to Z′.

Szintillationslichtausbeuten anorganischer und organischer Kristalle für energiereiche Deuteronen, α-Teilchen und Elektronen

1966 ◽  
Vol 21 (7) ◽  
pp. 1075-1080
Author(s):  
W. Schött ◽  
A. Flammersfeld
Keyword(s):  
Electronic Circuit ◽  
Pulse Height ◽  
Light Yield ◽  
Organic Crystals ◽  
Height Ratio ◽  
Scintillation Light ◽  
Time Constants ◽  
Inverse Effect ◽  
Short Time ◽  
Α Particles

The scintillation light yield S of three anorganic [NaJ (Tl), KJ (Tl), CsJ (Tl)], of two organic (p-terphenyl, anthracene) crystals, and of plastic NE 102 by bombardement with deuterons in the energy range from 10,0—27,5 MeV, α-particles from 8,0—55,0 MeV, and electrons has been measured. The time constants of the electronic circuit have been chosen to τ1 = 0,5 sec and τ2 = 2,0 µsec. The pulse-height ratios SD/Sβ and Sα/Sβ are slightly different for the two time constants. The anorganic crystals have a higher pulse-height ratio for the short time constant, whereas the organic crystals and plastic show the inverse effect.

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