16 research outputs found

    A Novel Manufacturing Process for Glass THGEMs and First Characterisation in an Optical Gaseous Argon TPC

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    This paper details a novel, patent pending, abrasive machining manufacturing process for the formation of sub-millimetre holes in THGEMs, with the intended application in gaseous and dual-phase TPCs. Abrasive machining favours a non-ductile substrate such as glasses or ceramics. This innovative manufacturing process allows for unprecedented versatility in THGEM substrates, electrodes, and hole geometry and pattern. Consequently, THGEMs produced via abrasive machining can be tailored for specific properties, for example: high stiffness, low total thickness variation, radiopurity, moisture absorption/outgassing and/or carbonisation resistance. This paper specifically focuses on three glass substrate THGEMs (G-THGEMs) made from Schott Borofloat 33 and Fused Silica. Circular and hexagonal hole shapes are also investigated. The G-THGEM electrodes are made from Indium Tin Oxide (ITO), with a resistivity of 150 ő©\Omega/Sq. All G-THGEMs were characterised in an optical (EMCCD) readout GArTPC, and compared to a traditionally manufactured FR4 THGEM, with their charging and secondary scintillation (S2) light production behaviour analysed

    On the measurement of optical scattering and studies of background rejection in the SNO+ detector

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    SNO&amp;plus; is a liquid scintillator experiment designed to study a wide range of neutrino-related physics goals, such as solar neutrinos, reactor and geo-neutrinos, and neutrinoless double beta decay. The success of the experiment depends in part on the ability to accurately characterise the detector's optical properties, and also develop effective methods to suppress contributions from unwanted backgrounds. This thesis presents one of the central calibration systems which will be used to make measurements of the detector's optical scattering properties. The hardware and its integration into the wider detector will be discussed. A simplifed analysis of simulated water data is also presented, in order to show that the scattering properties can be accurately measured. The reconstruction of photons' scattering position, length and angles can be achieved to a high degree of accuracy, with a small reconstruction bias and resolution in comparison to the scale of the detector itself. This thesis also presents a study into the rejection of two important radioactive backgrounds that will be encountered during the scintillator phases of SNO&amp;plus;: the (212Bi &amp;plus; 212Po) and (214Bi &amp;plus; 214Po) beta-alpha chains, where both components of each chain occur within a single detector trigger window, creating what is known as a BiPo pileup event. Two methods have been considered: one using a comparison between the cumulative time residual distributions of BiPo pileup and double-beta signal events, and the other using a log-likelihood difference method. Both methods perform extremely well, with the first being capable of rejecting &amp;GT; 95&amp;percnt; of BiPo pileup events for a 1&amp;percnt; loss of signal, and the second rejecting &amp;GT; 97&amp;percnt; of backgrounds for the same signal loss.</p

    Review of Liquid Argon Detector Technologies in the Neutrino Sector

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    Liquid Argon (LAr) is one of the most widely used scintillators in particle detection, due to its low cost, high availability and excellent scintillation properties. A large number of experiments in the neutrino sector are based around using LAr in one or more Time Projection Chambers (TPCs), leading to high resolution three-dimensional particle reconstruction. In this paper, we review and summarise a number of these Liquid Argon Time Projection Chamber (LArTPC) experiments, and briefly describe the specific technologies that they currently employ. This includes single phase LAr experiments (ICARUS T600, MicroBooNE, SBND, LArIAT, DUNE-SP, ProtoDUNE-SP, ArgonCube and Vertical Drift) and dual phase LAr experiments (DUNE-DP, WA105, ProtoDUNE-DP and ARIADNE). We also discuss some new avenues of research in the field of LArTPC readout, which show potential for wide-scale use in the near future.Comment: 59 pages, 54 figure

    Development of high performance pervaporation desalination membranes: A brief review

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    Water scarcity rises as the level of water pollution continues to increase with the progress of urbanization, industrialization and exponential growth of population. Therefore, saline water of the sea should also be made suitable rather than river water to meet the huge global demand of clean and safe drinking water. Pervaporation (PV) desalination, among many purification and separation processes, is a promising technology to reduce the crisis of global drinking water supply. From this perspective, the key success of PV desalination relies on its remarkable salt rejection from highly saline water with appropriate flux to obtain fresh water by using a suitable membrane. In this review we aim to provide a comprehensive assessment of PV desalination membrane materials, transport phenomena, the advantages of the process over comparable technologies (e.g., fractional distillation, membrane distillation, reverse osmosis) and the advantages of crosslinking during the preparation of composite membranes. This review further highlights the advantages of inorganic ceramic substrates as a support of composite membranes and the use of hydrophilic polymers as active layer for preparing stable and robust crosslinked PV desalination membranes.(c) 2022 Institution of Chemical Engineers. Published by Elsevier Ltd. All rights reserved

    Highly-parallelized simulation of a pixelated LArTPC on a GPU

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    The rapid development of general-purpose computing on graphics processing units (GPGPU) is allowing the implementation of highly-parallelized Monte Carlo simulation chains for particle physics experiments. This technique is particularly suitable for the simulation of a pixelated charge readout for time projection chambers, given the large number of channels that this technology employs. Here we present the first implementation of a full microphysical simulator of a liquid argon time projection chamber (LArTPC) equipped with light readout and pixelated charge readout, developed for the DUNE Near Detector. The software is implemented with an end-to-end set of GPU-optimized algorithms. The algorithms have been written in Python and translated into CUDA kernels using Numba, a just-in-time compiler for a subset of Python and NumPy instructions. The GPU implementation achieves a speed up of four orders of magnitude compared with the equivalent CPU version. The simulation of the current induced on 10310^3 pixels takes around 1 ms on the GPU, compared with approximately 10 s on the CPU. The results of the simulation are compared against data from a pixel-readout LArTPC prototype

    The DUNE Far Detector Vertical Drift Technology, Technical Design Report

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    DUNE is an international experiment dedicated to addressing some of the questions at the forefront of particle physics and astrophysics, including the mystifying preponderance of matter over antimatter in the early universe. The dual-site experiment will employ an intense neutrino beam focused on a near and a far detector as it aims to determine the neutrino mass hierarchy and to make high-precision measurements of the PMNS matrix parameters, including the CP-violating phase. It will also stand ready to observe supernova neutrino bursts, and seeks to observe nucleon decay as a signature of a grand unified theory underlying the standard model. The DUNE far detector implements liquid argon time-projection chamber (LArTPC) technology, and combines the many tens-of-kiloton fiducial mass necessary for rare event searches with the sub-centimeter spatial resolution required to image those events with high precision. The addition of a photon detection system enhances physics capabilities for all DUNE physics drivers and opens prospects for further physics explorations. Given its size, the far detector will be implemented as a set of modules, with LArTPC designs that differ from one another as newer technologies arise. In the vertical drift LArTPC design, a horizontal cathode bisects the detector, creating two stacked drift volumes in which ionization charges drift towards anodes at either the top or bottom. The anodes are composed of perforated PCB layers with conductive strips, enabling reconstruction in 3D. Light-trap-style photon detection modules are placed both on the cryostat's side walls and on the central cathode where they are optically powered. This Technical Design Report describes in detail the technical implementations of each subsystem of this LArTPC that, together with the other far detector modules and the near detector, will enable DUNE to achieve its physics goals