Showing papers on "Scintillation published in 2020"

Highly efficient eco-friendly X-ray scintillators based on an organic manganese halide.

Abstract: Scintillation based X-ray detection has received great attention for its application in a wide range of areas from security to healthcare. Here, we report highly efficient X-ray scintillators with state-of-the-art performance based on an organic metal halide, ethylenebis-triphenylphosphonium manganese (II) bromide ((C38H34P2)MnBr4), which can be prepared using a facile solution growth method at room temperature to form inch sized single crystals. This zero-dimensional organic metal halide hybrid exhibits green emission peaked at 517 nm with a photoluminescence quantum efficiency of ~ 95%. Its X-ray scintillation properties are characterized with an excellent linear response to X-ray dose rate, a high light yield of ~ 80,000 photon MeV−1, and a low detection limit of 72.8 nGy s−1. X-ray imaging tests show that scintillators based on (C38H34P2)MnBr4 powders provide an excellent visualization tool for X-ray radiography, and high resolution flexible scintillators can be fabricated by blending (C38H34P2)MnBr4 powders with polydimethylsiloxane. Scintillation-based X-ray detection is promising for applications in various areas ranging from security to healthcare, and low-cost and eco-friendly scintillation materials would be beneficial. Here the authors report a facile solution growth of organic manganese halide for efficient X-ray scintillation.

Highly Stable Organic Antimony Halide Crystals for X-ray Scintillation

Abstract: Scintillators are utilized for X-ray detection in many important fields ranging from homeland security to health care. Developing low-cost, high-performance scintillation materials to address the i...

Two-dimensional halide perovskite as β-ray scintillator for nuclear radiation monitoring

Abstract: Ensuring nuclear safety has become of great significance as nuclear power is playing an increasingly important role in supplying worldwide electricity. β-ray monitoring is a crucial method, but commercial organic scintillators for β-ray detection suffer from high temperature failure and irradiation damage. Here, we report a type of β-ray scintillator with good thermotolerance and irradiation hardness based on a two-dimensional halide perovskite. Comprehensive composition engineering and doping are carried out with the rationale elaborated. Consequently, effective β-ray scintillation is obtained, the scintillator shows satisfactory thermal quenching and high decomposition temperature, no functionality decay or hysteresis is observed after an accumulated radiation dose of 10 kGy (dose rate 0.67 kGy h-1). Besides, the two-dimensional halide perovskite β-ray scintillator also overcomes the notorious intrinsic water instability, and benefits from low-cost aqueous synthesis along with superior waterproofness, thus paving the way towards practical application.

Lithium-doped two-dimensional perovskite scintillator for wide-range radiation detection

Abstract: Two-dimensional lead halide perovskites have demonstrated their potential as high-performance scintillators for X- and gamma-ray detection, while also being low-cost Here we adopt lithium chemical doping in two-dimensional phenethylammonium lead bromide (PEA)2PbBr4 perovskite crystals to improve the properties and add functionalities with other radiation detections Li doping is confirmed by X-ray photoemission spectroscopy and the scintillation mechanisms are explored via temperature dependent X-ray and thermoluminescence measurements Our 1:1 Li-doped (PEA)2PbBr4 demonstrates a fast decay time of 11 ns (80%), a clear photopeak with an energy resolution of 124%, and a scintillation yield of 11,000 photons per MeV under 662 keV gamma-ray radiation Additionally, our Li-doped crystal shows a clear alpha particle/gamma-ray discrimination and promising thermal neutron detection through 6Li enrichment X-ray imaging pictures with (PEA)2PbBr4 are also presented All results demonstrate the potential of Li-doped (PEA)2PbBr4 as a versatile scintillator covering a wide radiation energy range for various applications Two-dimensional lead halide perovskites have shown great potential as X- and γ-ray scintillators due to their high light yield, fast decay rate, and low fabrication cost Here, their versatility is expanded by achieving, via Li-doping, α-particle/γ-ray discrimination and thermal neutron detection

One-Dimensional All-Inorganic K2CuBr3 with Violet Emission as Efficient X‑ray Scintillators

Abstract: Lead halide perovskites have shown great X-ray scintillation properties One big challenge is to find nontoxic replacements for practical applications Moreover, the scintillator should contain les

A solution-processed zero-dimensional all-inorganic perovskite scintillator for high resolution gamma-ray spectroscopy detection

Abstract: Low dimensional scintillators have been successfully and widely applied in the radiation-detection community for home security, scientific research, and imaging. We have grown zero-dimensional Cs4PbBr6 materials with CsPbBr3 nanocrystals embedded by using a solution-growth method at low temperature. We have demonstrated the scintillation properties of these 0D nanoscintillators with high luminescence quantum efficiency for green light. In addition, we have successfully achieved pulse height spectra with this 0D perovskite material, which has been demonstrated with fast decay time (<10 ns), high energy resolution (3.0 ± 0.1%, 59.5 keV from 241Am), high light yield (64 000 photons per MeV) and long term stability under various atmospheres (moisture, radiation). These results are much better than those of the most widely used commercial products such as NaI(Tl). It also demonstrates that this 0D all-inorganic material can be employed as a scintillator for ionization radiation applications such as X-ray imaging and spectroscopy applications.

Bright and fast scintillations of an inorganic halide perovskite CsPbBr 3 crystal at cryogenic temperatures

Abstract: Highly efficient scintillation crystals with short decay times are indispensable for improving the performance of numerous detection and imaging instruments that use- X-rays, gamma-quanta, ionising particles or neutrons. Halide perovskites emerged recently as very promising materials for detection of ionising radiation that motivated further exploration of the materials. In this work, we report on excellent scintillation properties of CsPbBr3 crystals when cooled to cryogenic temperatures. The temperature dependence of luminescence spectra, decay kinetics and light yield under excitation with X-rays and α-particles was investigated. It is shown that the observed changes of spectral and kinetic characteristics of the crystal with temperature can be consistently explained by radiative decay of free excitons, bound and trapped excitons as well as electron-hole pairs originating from their disintegration. It has been found that the crystal exhibits a fast decay time constant of 1 ns at 7 K. The scintillation light yield of CsPbBr3 at 7 K is assessed to be 50,000 ± 10,000 ph/MeV at excitation with 12 keV X-rays and 109,000 ± 22,000 ph/MeV at excitation with α-particles of 241Am. This finding places CsPbBr3 in an excellent position for the development of a new generation of cryogenic, efficient scintillation detectors with nanosecond response time, marking a step-change in opportunities for scintillator-based applications.

Optimisation of monolithic nanocomposite and transparent ceramic scintillation detectors for positron emission tomography.

Abstract: High-resolution arrays of discrete monocrystalline scintillators used for gamma photon coincidence detection in PET are costly and complex to fabricate, and exhibit intrinsically non-uniform sensitivity with respect to emission angle. Nanocomposites and transparent ceramics are two alternative classes of scintillator materials which can be formed into large monolithic structures, and which, when coupled to optical photodetector arrays, may offer a pathway to low cost, high-sensitivity, high-resolution PET. However, due to their high optical attenuation and scattering relative to monocrystalline scintillators, these materials exhibit an inherent trade-off between detection sensitivity and the number of scintillation photons which reach the optical photodetectors. In this work, a method for optimising scintillator thickness to maximise the probability of locating the point of interaction of 511 keV photons in a monolithic scintillator within a specified error bound is proposed and evaluated for five nanocomposite materials (LaBr3:Ce-polystyrene, Gd2O3-polyvinyl toluene, LaF3:Ce-polystyrene, LaF3:Ce-oleic acid and YAG:Ce-polystyrene) and four ceramics (GAGG:Ce, GLuGAG:Ce, GYGAG:Ce and LuAG:Pr). LaF3:Ce-polystyrene and GLuGAG:Ce were the best-performing nanocomposite and ceramic materials, respectively, with maximum sensitivities of 48.8% and 67.8% for 5 mm localisation accuracy with scintillator thicknesses of 42.6 mm and 27.5 mm, respectively.

Engineering of a new single-crystal multi-ionic fast and high-light-yield scintillation material (Gd0.5–Y0.5)3Al2Ga3O12:Ce,Mg

Abstract: A single crystal scintillation material (Gd0.5–Y0.5)3Al2Ga3O12 (GYAGG) doped with Ce and codoped with Mg at a small concentration was grown by the Czochralski technique and studied for its scintillation properties for the first time. The Czochralski technique enabled this multi-ionic garnet to be produced from a melt in a single crystal form and allowed the problems of codoping peculiar to this material in a ceramic form to be solved. Due to codoping, the scintillation kinetics of a single crystal is shorter than that of GYAGG ceramics produced before. The scintillation properties of GYAGG were found to be superior to those of the solely Ce-doped or Mg-codoped Gd3Al2Ga3O12 crystal. The light yield of GYAGG:Ce,Mg was found to be 52 000 ph MeV−1, the coefficient of the light yield temperature dependence in the temperature range 20–100 °C was equal to 0.37%/°C, and the scintillation decay time constant was 50 ns.

Multimodal Non-Contact Luminescence Thermometry with Cr-Doped Oxides.

Abstract: Luminescence methods for non-contact temperature monitoring have evolved through improvements of hardware and sensor materials. Future advances in this field rely on the development of multimodal sensing capabilities of temperature probes and extend the temperature range across which they operate. The family of Cr-doped oxides appears particularly promising and we review their luminescence characteristics in light of their application in non-contact measurements of temperature over the 5-300 K range. Multimodal sensing utilizes the intensity ratio of emission lines, their wavelength shift, and the scintillation decay time constant. We carried out systematic studies of the temperature-induced changes in the luminescence of the Cr3+-doped oxides Al2O3, Ga2O3, Y3Al5O12, and YAlO3. The mechanism responsible for the temperature-dependent luminescence characteristic is discussed in terms of relevant models. It is shown that the thermally-induced processes of particle exchange, governing the dynamics of Cr3+ ion excited state populations, require low activation energy. This then translates into tangible changes of a luminescence parameter with temperature. We compare different schemes of temperature sensing and demonstrate that Ga2O3-Cr is a promising material for non-contact measurements at cryogenic temperatures. A temperature resolution better than ±1 K can be achieved by monitoring the luminescence intensity ratio (40-140 K) and decay time constant (80-300 K range).

Disentangling ionospheric refraction and diffraction effects in GNSS raw phase through fast iterative filtering technique

Abstract: We contribute to the debate on the identification of phase scintillation induced by the ionosphere on the global navigation satellite system (GNSS) by introducing a phase detrending method able to provide realistic values of the phase scintillation index at high latitude. It is based on the fast iterative filtering signal decomposition technique, which is a recently developed fast implementation of the well-established adaptive local iterative filtering algorithm. FIF has been conceived to decompose nonstationary signals efficiently and provide a discrete set of oscillating functions, each of them having its frequency. It overcomes most of the problems that arise when using traditional time–frequency analysis techniques and relies on a consolidated mathematical basis since its a priori convergence and stability have been proved. By relying on the capability of FIF to efficiently identify the frequencies embedded in the GNSS raw phase, we define a method based on the FIF-derived spectral features to identify the proper cutoff frequency for phase detrending. To test such a method, we analyze the data acquired from GPS and Galileo signals over Antarctica during the September 2017 storm by the ionospheric scintillation monitor receiver (ISMR) located in Concordia Station (75.10° S, 123.33° E). Different cases of diffraction and refraction effects are provided, showing the capability of the method in deriving a more accurate determination of the $$\sigma_{\phi }$$ index. We found values of cutoff frequency in the range of 0.73–0.83 Hz, providing further evidence of the inadequacy of the choice of 0.1 Hz, which is often used when dealing with ionospheric scintillation monitoring at high latitudes.

Analysis of Free Space Optics Link Performance Considering the Effect of Different Weather Conditions and Modulation Formats for Terrestrial Communication

Abstract: Abstract Free space optics (FSO) links provide an effectual and efficient way of transmission of data throughout free channels due to its higher bandwidth and inbuilt capability of security. In this research analysis, the FSO link is evaluated on the basis of Q value for different modulation formats and weather conditions. Gamma–Gamma and log-normal scintillation models have been analyzed for different index of refraction in terms of Q factor versus a range of a proposed FSO link. Attenuation increases during the occurrence of different fog conditions, and there might be complete link failure in the case of dense fog and for some of the cloud conditions.

Mitigation of ionospheric scintillation effects on GNSS precise point positioning (PPP) at low latitudes

Abstract: Global navigation satellite systems (GNSS) underpin a number of modern life activities, including applications demanding positioning accuracy at the level of centimetres, such as precision agriculture, offshore operations and mining, to name a few. Precise point positioning (PPP) exploits the precision of the GNSS signal carrier phase measurements and may be used to provide the high accuracy positioning needed by these applications. The Earth’s ionosphere is critical in PPP due to its high variability and to disturbances such as scintillation, which can affect the satellite signals propagation and thereby degrade the positioning accuracy, especially at low latitudes, where severe scintillation frequently occurs. This manuscript presents results from a case study carried out at two low latitude stations in Brazil, where a dedicated technique is successfully applied to mitigate the scintillation effects on PPP. The proposed scintillation mitigation technique improves the least square stochastic model used for position computation by assigning satellite and epoch specific weights based on the signal tracking error variances. The study demonstrates that improvements in the 3D positioning error of around 62–75% can be achieved when applying this technique under strong scintillation conditions. The significance of the results lies in the fact that this technique can be incorporated in PPP to achieve the required high accuracy in real time and thus improve the reliability of GNSS positioning in support of high accuracy demanding applications.

Spatial power spectrum of natural water turbulence with any average temperature, salinity concentration and light wavelength

Abstract: The power spectrum of water optical turbulence is shown to vary with its average temperature ⟨T⟩ and average salinity concentration ⟨S⟩, as well as with light wavelength λ. This study explores such variations for ⟨T⟩∈[0∘C,30∘C], ⟨S⟩∈[0ppt,40ppt] covering most of the possible natural water conditions within the Earth's boundary layer and for visible electromagnetic spectrum, λ∈[400nm,700nm]. For illustration of the effects of these parameters on propagating light, we apply the developed power spectrum model for estimation of the scintillation index of a plane wave (the Rytov variance) and the threshold between weak and strong turbulence regimes.

Assessing LoRa for Satellite-to-Earth Communications Considering the Impact of Ionospheric Scintillation

Abstract: Since the appearance of 5G, Internet of Things (IoT) has gained an increased interest, with multiple technologies emerging and converging to cover different user needs. One of the biggest challenges today is to have global IoT coverage, ensuring seamless communication with IoT devices placed in rural and even remote areas. Satellite constellations, and in particular CubeSats orbiting in Low Earth Orbit, can provide a solution to these challenges. Out of the technologies available, LoRa (Long Range) has a great potential for implementation in space-to-Earth satellite communications. As the space-to-Earth channel is different with respect to the conventional Earth-to-Earth one, it is important to asses the capabilities of LoRa in this new environment. This paper presents a study of different LoRa device configurations to identify the constrains for each one and determine which one is better for particular mission requirements. Also, the effect of ionospheric scintillation is assessed with a SDR-based (Software-Defined Radio) test set-up that evaluates the performance of this technology against with Humprey's ionospheric scintillation model. This phenomena produces deep signal intensity fadings and phase fluctuations in equatorial regions, and mainly phase fluctuations in high latitudes. The obtained metrics are the received power and the packet delivery ratio as a function of the intensity scintillation index, and show the robustness of the LoRa modulation in these new environments.

Depth of Interaction Estimation in a Preclinical PET Scanner Equipped with Monolithic Crystals Coupled to SiPMs Using a Deep Neural Network

Abstract: The scintillation light distribution produced by photodetectors in positron emission tomography (PET) provides the depth of interaction (DOI) information required for high-resolution imaging. The goal of positioning techniques is to reverse the photodetector signal’s pattern map to the coordinates of the incident photon energy position. By considering the DOI information, monolithic crystals offer good spatial, energy, and timing resolution along with high sensitivity. In this work, a supervised deep neural network was used for the approximation of DOI and to assess through Monte Carlo (MC) simulations the performance on a small-animal PET scanner consisting of ten 50 × 50 × 10 mm3 continuous Lutetium-Yttrium Oxyorthosilicate doped with Cerium (LYSO: Ce) crystals and 12 × 12 silicon photomultiplier (SiPM) arrays. The scintillation position was predicted by a multilayer perceptron neural network with 256 units and 4 layers whose inputs were the number of fired pixels on the SiPM plane and the total deposited energy. A GEANT4 MC code was used to generate training and test datasets by altering the photons’ incident position, energy, and direction, as well as readout of the photodetector output. The calculated spatial resolutions in the X-Y plane and along the Z-axis were 0.96 and 1.02 mm, respectively. Our results demonstrated that using a multilayer perceptron (MLP)-based positioning algorithm in the detector modules, constituting the PET scanner, enhances the spatial resolution by approximately 18% while the absolute sensitivity remains constant. The proposed algorithm proved its ability to predict the DOI for depth under 7 mm with an error below 8.7%.

Improving system performance by using adaptive optics and aperture averaging for laser communications in oceanic turbulence.

Abstract: We theoretically investigate the effectiveness of adaptive optics correction for Gaussian beams affected by oceanic turbulence. Action of an idealized adaptive optics system is modeled as a perfect removal of a certain number of Zernike modes from the aberrated wavefront. We focused on direct detection systems and we used the aperture-averaged scintillation as the main metric to evaluate optical system performances. We found that, similar to laser beam propagation in atmospheric turbulence, adaptive optics is very effective in improving the performance of laser communication links if an optimum aperture size is used. For the specific cases we analyzed in this study, scintillation was reduced by a factor of ∼7 when 15 modes were removed and when the aperture size of the transceiver was large enough to capture 4-5 speckles of the oceanic turbulence-affected beam.

Extending light WIMP searches to single scintillation photons in LUX

Abstract: We present a novel analysis technique for liquid xenon time projection chambers that allows for a lower threshold by relying on events with a prompt scintillation signal consisting of single detected photons. The energy threshold of the LUX dark matter experiment is primarily determined by the smallest scintillation response detectable, which previously required a twofold coincidence signal in its photomultiplier arrays, enforced in data analysis. The technique presented here exploits the double photoelectron emission effect observed in some photomultiplier models at vacuum ultraviolet wavelengths. We demonstrate this analysis using an electron recoil calibration dataset and place new constraints on the spin-independent scattering cross section of weakly interacting massive particles (WIMPs) down to 2.5 GeV/c2 WIMP mass using the 2013 LUX dataset. This new technique is promising to enhance light WIMP and astrophysical neutrino searches in next-generation liquid xenon experiments.

Measurement of the scintillation and ionization response of liquid xenon at MeV energies in the EXO-200 experiment

Abstract: Liquid xenon (LXe) is employed in a number of current and future detectors for rare event searches. We use the EXO-200 experimental data to measure the absolute scintillation and ionization yields generated by γ interactions from Th228 (2615 keV), Ra226 (1764 keV), and Co60 (1332 keV and 1173 keV) calibration sources, over a range of electric fields. The W value that defines the recombination-independent energy scale is measured to be 11.5±0.5 (syst.) ±0.1 (stat.) eV. These data are also used to measure the recombination fluctuations in the number of electrons and photons produced by the calibration sources at the MeV scale, which deviate from extrapolations of lower-energy data. Additionally, a semiempirical model for the energy resolution of the detector is developed, which is used to constrain the recombination efficiency, i.e., the fraction of recombined electrons that result in the emission of a detectable photon. Detailed measurements of the absolute charge and light yields for MeV-scale electron recoils are important for predicting the performance of future neutrinoless double β-decay detectors.

Slow fluors for effective separation of Cherenkov light in liquid scintillators

Abstract: The timing and spectral characteristics of four highly efficient, slow fluors are presented for liquid scintillator solutions using linear alkylbenzene (LAB) as the primary solvent. The mixtures exhibit high light yields, but with rise times of several ns or more and decay times on the order of tens of ns. Consequently, such liquid scintillator mixtures can be used for effective separation of Cherenkov and scintillation components based on timing in large scale liquid scintillation detectors. Such a separation, showing high light yield and directional information, is demonstrated here on a bench-top scale for electrons with energies extending below 1 MeV. This could have significant consequences for the future development of such detectors for measurements of solar neutrinos and neutrinoless double beta decay (0 ν β β ) as well as providing good directional information for elastic scattering events from supernovae neutrinos and reactor anti-neutrinos, amongst others.

Scintillation index and BER performance for optical wave propagation in anisotropic underwater turbulence under the effect of eddy diffusivity ratio

Abstract: Underwater optical communication has been a promising technology but is severely affected by underwater turbulence due to the resulting fluctuations in the index of refraction. In this paper, a revised spatial power spectrum model is obtained that considers the refraction index to be a function of the eddy diffusivity ratio, assuming the underwater turbulence is anisotropic. The scintillation indices for both plane and spherical waves that propagate in underwater turbulence are derived based on this model. Thereafter, the performance of an optical communication system, i.e., the outage probability and bit error rate, with the associated aperture averaging effect is considered. The simulation results demonstrate that temperature-induced and salinity-induced turbulence have distinct influences on the scintillation index and consequently result in different system performances. In addition, the variation in the eddy diffusivity ratio in some intervals induces more complicated results for underwater optical communication. Moreover, the effect of the receiver aperture diameter on the aperture averaging factor is presented in anisotropic underwater turbulence. Such an effect is more obvious in the plane wave case than in the spherical wave case. These results can find potential application in the engineering design of optical communication systems in an underwater environment.

Photonic-Crystal Scintillators: Molding the Flow of Light to Enhance X-Ray and γ-Ray Detection

Abstract: Scintillators are central for detection of γ-ray, x-ray, and high energy particles in various applications, all seeking higher scintillation yield and rate. However, these are limited by the intrinsic isotropy of spontaneous emission of the scintillation light and its inefficient outcoupling. We propose a new design methodology for scintillators that exploits the Purcell effect to enhance their light emission. As examples, we show 1D photonic crystals from scintillator materials that achieve directional emission and fivefold enhancement in the number of detectable photons per excitation.

Luminescence and scintillation properties of (C6H5(CH2)2NH3)2(Ba,Pb)Br4 with self-organized bi-dimensional quantum-well structures

Abstract: (C6H5(CH2)4NH3)2Ba x Pb1−x Br4 (x = 0, 0.1, 0.25 and 0.5) crystals were prepared by the solvent diffusion method to evaluate the scintillation properties. The samples exhibit photoluminescence and scintillation with a sharp emission peaking around 440 nm due to excitons, and the decay time is dominantly several nanoseconds. The pulse height spectrum under 137Cs gamma-ray irradiation demonstrates that the scintillation light yields of (C6H5(CH2)2NH3)2Ba0.25Pb0.75Br4 and (C6H5(CH2)2NH3)2Ba0.5Pb0.5Br4 crystals are approximately 19 000 ph MeV−1.

IONISE: An Ionospheric Observational Network for Irregularity and Scintillation in East and Southeast Asia

Abstract: An Ionospheric Observational Network for Irregularity and Scintillation in East and Southeast Asia (IONISE) is developed to identify and study the short‐term and fine‐scale ionospheric variations over China. The IONISE network mainly includes three crossed chains of Beidou geostationary satellite total electron content (TEC)/scintillation receivers along 110°E, 23°N, and 40°N respectively, multistatic portable digital ionosondes and bistatic very high‐frequency radars. Based on the IONISE observations, we report some preliminary results of ionospheric disturbances and irregularities, including (1) initially generated and zonally drifting equatorial plasma bubbles and related scintillations, (2) traveling ionospheric disturbances from middle to low latitudes, (3) drift of strong sporadic E structures over a wide area of more than 1,000 km, (4) fine‐scale ionospheric perturbation and regional TEC gradient, and (5) general features of ionospheric response to geomagnetic storms. Possible mechanisms responsible for these ionospheric phenomena are discussed. The IONISE provides new data set for investigation on ionospheric disturbances of various scales in a broad region with dense observations along specific latitude/longitude. Plain Language Summary There are various types of ionospheric variations under different triggering conditions. To reveal possible sources responsible for short‐term variability of ionosphere, trace the occurrence and movements of ionospheric irregularities and associated scintillations along the same longitude/latitude, and capture ionospheric disturbances of various scales over China, an Ionospheric Observational Network for Irregularity and Scintillation in East and Southeast Asia (IONISE), which consists of multiple types of instruments including Beidou geostationary (BD‐GEO) total electron content (TEC)/scintillation receiver, portable digital ionosonde (PDI), and very high‐frequency (VHF) radar, is developed. The BD‐GEO TEC/scintillation measurements continuously made at the dense array of fixed ionospheric pierce points can track ionospheric disturbances of various scales along the same longitude/latitude, making it possible for investigation of different types of ionospheric disturbances. The Doppler velocity measurements by PDI are sensitive to ionospheric perturbations with weak amplitude which may be difficult to be detected from the general parameters such as F layer peak or virtual height derived from ionosonde observation. The spatially separated VHF radars with imaging capability of field aligned irregularities (FAIs) may capture the fine‐scale evolution of FAIs. The preliminary results presented in this paper demonstrate the capability by IONISE for ionospheric disturbances of various scales such as equatorial plasma bubbles, traveling ionospheric disturbances, strong sporadic E structure, fine‐scale ionospheric perturbation, regional TEC gradient, and ionospheric response to geomagnetic storms. It is expected that new observations from the IONISE will help to achieve a better understanding on the potential mechanisms for the multiscale ionospheric disturbances.

Spectral Photon Sorting For Large-Scale Cherenkov and Scintillation Detectors

Abstract: We describe here measurements with a new device, the ``dichroicon,'' a Winston-style light concentrator built out of dichroic reflectors, which could allow large-scale neutrino detectors to sort photons by wavelength with small overall light loss. Photon sorting would benefit large-scale water or ice Cherenkov detectors such as Hyper-Kamiokande or IceCube by providing a measure of dispersion, which, in turn, could allow improved position reconstruction and timing. For scintillator detectors like JUNO and upgrades to $\mathrm{SNO}+$ or KamLAND-ZEN or to water-based liquid scintillator detectors like Theia, dichroicons would provide effective discrimination between Cherenkov and scintillation light, allowing them to operate as true hybrid detectors. We include measurements with a prototype dichroicon using first a Cherenkov source to show that spectral photon sorting works as expected. We then present measurements of two different linear-alkyl-benzene-based liquid scintillator sources and demonstrate discrimination between Cherenkov and scintillation light. On the benchtop, we can identify Cherenkov light with better than 90% purity while maintaining a high collection efficiency for the scintillation light. First results from simulations of a large-scale detector are also presented.