Scintillator Modules Research Articles

NuSD: A Geant4 based simulation framework for segmented anti-neutrino detectors

NuSD: Neutrino Segmented Detector is a Geant4-based user application that simulates inverse beta decay events in a variety of segmented scintillation detectors developed by different international collaborations. This simulation framework uses a combination of cross-programs and libraries including Geant4, ROOT and CLHEP developed and used by the high energy physics community. It will enable the neutrino physics community to simulate and study neutrino interactions within different detector concepts using a single program. In addition to neutrino simulations in segmented detectors, this program can also be used for various research projects utilizing scintillation detectors for different physics applications. Program summaryProgram title: NuSDCPC Library link to program files:https://doi.org/10.17632/7vgfhxbzdv.1Licensing provisions: GNU General Public License 3Programming language: C++External routines/libraries: Geant4, CLHEP, ROOT, CMAKENature of problem: Considerable effort has been spent on small anti-neutrino detectors for various purposes by different collaborations around the globe, but there is not an interactive and user-friendly joint-simulation framework.Solution method: To fulfill the need in the field, we developed a simulation framework to combine various segmented detector technologies. This package code will be open to public to let people simulate and test different detector concepts easily. Here, we categorized segmented anti-neutrino detectors as homogeneous and inhomogeneous detectors. Homogeneous detectors consist of PROSPECT, NULAT, and HSP type detectors. Inhomogeneous detectors consist of PANDA type detectors with single scintillator modules. CHANDLER, SOLID and SWEANY detector types are characterized as composite scintillator modules.

A portable cosmic ray detector for school education

This article describes the design, assembly and characterization of a portable cosmic ray detector, developed by the INSULAB group and suitable for teaching activities aimed at high school students. It consists of a compact aluminum suitcase containing three plastic scintillator modules coupled to photomultipliers, readout by a custom compact electronics chain and powered by a power bank. The modules operate in coincidence and the system records the arrival time of each particle and the time over threshold of the signal of each scintillator module. The data are acquired and processed by a Raspberry PI connected to a touch screen display for online monitoring. The procedure implemented for the determination of the detector efficiency is reported, along with the results of the measurements of the cosmic ray rate as a function of the altitude and the zenith angle, performed in the laboratory and in different locations outdoors.

Design, upgrade and characterization of the silicon photomultiplier front-end for the AMIGA detector at the Pierre Auger Observatory

AMIGA (Auger Muons and Infill for the Ground Array) is an upgrade of the Pierre Auger Observatory to complement the study of ultra-high-energy cosmic rays (UHECR) by measuring the muon content of extensive air showers (EAS). It consists of an array of 61 water Cherenkov detectors on a denser spacing in combination with underground scintillation detectors used for muon density measurement. Each detector is composed of three scintillation modules, with 10 m2 detection area per module, buried at 2.3 m depth, resulting in a total detection area of 30 m2. Silicon photomultiplier sensors (SiPM) measure the amount of scintillation light generated by charged particles traversing the modules. In this paper, the design of the front-end electronics to process the signals of those SiPMs and test results from the laboratory and from the Pierre Auger Observatory are described. Compared to our previous prototype, the new electronics shows a higher performance, higher efficiency and lower power consumption, and it has a new acquisition system with increased dynamic range that allows measurements closer to the shower core. The new acquisition system is based on the measurement of the total charge signal that the muonic component of the cosmic ray shower generates in the detector.

Validation of Photon Collimation Techniques for Monolithic PET Detector Calibration

Monolithic-based positron emission tomography (PET) detectors have become an attractive alternative to traditional pixelated scintillator modules. One of the main limiting factors to further expand the use of the monolithic approach in commercial PET scanners is the requirement of more complex calibration setups than for their pixelated counterparts. These calibration procedures are usually based on hardware-collimation methods in which a physically collimated beam source is moved across the front face of the scintillator. These procedures require the use of manifold hardware setups and are time consuming, especially when dealing with systems composed of many detector modules. To reduce the mechanical complexity and long acquisition times required to obtain calibration datasets when using monolithic-based detectors, we have validated in this work the recently proposed method of using software-collimated calibration data for monolithic PET detectors. software-collimated methods require less hardware, are easier to implement, and have the potential to be used in an assembled PET scanner. We are evaluating a defined bias estimator and the overall detector spatial resolution using data obtained with the two different collimation techniques. Results showed bias behavior and spatial resolution discrepancies as small as 4.9% between the two datasets for a monolithic crystal with dimensions of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$50 \times 50 \times 8$ </tex-math></inline-formula> mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> . These results demonstrate that software-collimated data in combination with accurate positioning algorithms promises to be competitive against traditional hardware-collimation procedures. Finally, we have explored and confirmed the use of software-collimated data for the calibration step using two procedures, the PC3 method (calibrated data is shown) and Voronoi diagrams.

Diseño, mejora y caracterización del front-end con fotomultiplicadores de silicio para los detectores de AMIGA del Observatorio Pierre Auger

AMIGA (Auger Muons and Infill for the Ground Array) es una mejora del Observatorio Pierre Auger con el objetivo de complementar el estudio de los rayos cósmicos de ultra alta energía (UHECR) mediante la medición del contenido muónico de las cascadas atmosféricas extensas (EAS). Éste consiste en un arreglo de 61 detectores de agua de efecto Cherenkov ubicado en un espacio más denso en combinación con detectores de centelleo enterrados bajo tierra utilizados para la medición de densidad de muones. Cada detector esta compuesto por tres módulos centelladores, con un área de detección de 10 m2 por módulo, enterrados a 2.3 m de profundidad, resultando un área total de detección de 30 m2. Fotomultiplicadores de silicio (SiPM) miden la cantidad de luz de centelleo generada por las partículas cargadas que atraviesan los módulos. En este trabajo, el diseño de la electrónica del front-end para procesar las señales de esos SiPMs, y los resultados de pruebas realizadas en el laboratorio como también en el sitio del Observatorio Pierre Auger son descriptos. Comparado con el diseño anterior, esta nueva electrónica muestra un mayor rendimiento, una mayor eficiencia y un menor consumo de potencia, e incluye además, un nuevo sistema de adquisición con un rango dinámico ampliado que permite realizar mediciones cercanas al núcleo de la lluvia. El nuevo sistema de adquisición esta basado en la medición de la carga total que la componente muónica de la lluvia cósmica genera en el detector.

A low cost hybrid detection system of high energy air showers

We report on the design and the expected performance of a low cost hybrid air shower detection system suitable for operation as an autonomous unit in strong electromagnetic noise environments. The system consists of three particle detectors (scintillator modules) and one or more RF antennas. The particle detector units are used to detect air showers and to supply the trigger to the RF Data acquisition electronics. The hardware of the detector as well as the expected performance in detecting and reconstructing the angular direction for the shower axis is presented. Calibration data are used to trim the simulation parameters and to investigate the response to high energy (E > 1015 eV) extensive air showers.

Nuclear reactor monitoring with gadolinium-loaded plastic scintillator modules

In this study, simulation-based design and optimization studies of a gadolinium-loaded segmented plastic scintillator detector are presented for monitoring applications of nuclear reactors in Turkey using antineutrinos. For the first time in the literature, a multivariate analysis technique is introduced to suppress cosmic background for such a reactor antineutrino detector.

Charge identification performance of a [formula omitted]E-TOF detector prototype for the FOOT experiment

FOOT (FragmentatiOn On Target) is an applied nuclear physics experiment aimed at measuring the production cross sections of fragments for energies, beams and targets relevant in particle therapy and radioprotection in space. The ΔE-TOF detector will measure the energy deposited by the fragments in a wall of plastic scintillators and the time of flight with respect to a start detector. These two quantities allow to determine the charge Z of the fragment. In this work, we summarize the charge identification procedure of a detector prototype with two scintillator modules.

Design and construction of the MicroBooNE Cosmic Ray Tagger system

The MicroBooNE detector utilizes a liquid argon time projection chamber (LArTPC) with an 85 t active mass to study neutrino interactions along the Booster Neutrino Beam (BNB) at Fermilab. With a deployment location near ground level, the detector records many cosmic muon tracks in each beam-related detector trigger that can be misidentified as signals of interest. To reduce these cosmogenic backgrounds, we have designed and constructed a TPC-external Cosmic Ray Tagger (CRT) . This sub-system was developed by the Laboratory for High Energy Physics (LHEP), Albert Einstein center for fundamental physics, University of Bern. The system utilizes plastic scintillation modules to provide precise time and position information for TPC-traversing particles. Successful matching of TPC tracks and CRT data will allow us to reduce cosmogenic background and better characterize the light collection system and LArTPC data using cosmic muons. In this paper we describe the design and installation of the MicroBooNE CRT system and provide an overview of a series of tests done to verify the proper operation of the system and its components during installation, commissioning, and physics data-taking.

Status of PANDA and Japanese reactors

We are developing the Plastic Anti-Neutrino Detector Array (PANDA) to measure the reactor antineutrinos for the nuclear safeguard application. We completed construction of the PANDA100, which consists of 100 plastic scintillator modules, in August, 2016. After a study using background radiation in the laboratory at Kitasato University in Tokyo, we carried out a measurement of γ-ray bursts under the thunderclouds at Mt. Norikura in Gifu, Japan employing the PANDA100. As the results, we found three burst candidates in the data of 38 days. The original purpose of the PANDA project is to measure antineutrinos from a Japanese commercial reactor. We joined the Japanese reactor monitoring community arranged by University of Fukui group. In this community, we share the information about Japanese reactor activities and developement of a new monitoring tool. We are also preparing for a reactor monitoring with the PANDA100 when Japanese reactors resumed operation.

Scalable gamma-ray camera for wide-area search based on silicon photomultipliers array.

Portable coded-aperture imaging systems based on scintillators and semiconductors have found use in a variety of radiological applications. For stand-off detection of weakly emitting materials, large volume detectors can facilitate the rapid localization of emitting materials. We describe a scalable coded-aperture imaging system based on 5.02 × 5.02 cm2 CsI(Tl) scintillator modules, each partitioned into 4 × 4 × 20 mm3 pixels that are optically coupled to 12 × 12 pixel silicon photo-multiplier (SiPM) arrays. The 144 pixels per module are read-out with a resistor-based charge-division circuit that reduces the readout outputs from 144 to four signals per module, from which the interaction position and total deposited energy can be extracted. All 144 CsI(Tl) pixels are readily distinguishable with an average energy resolution, at 662 keV, of 13.7% FWHM, a peak-to-valley ratio of 8.2, and a peak-to-Compton ratio of 2.9. The detector module is composed of a SiPM array coupled with a 2 cm thick scintillator and modified uniformly redundant array mask. For the image reconstruction, cross correlation and maximum likelihood expectation maximization methods are used. The system shows a field of view of 45° and an angular resolution of 4.7° FWHM.

The design of the JUNO veto system

The Jiangmen Underground Neutrino Observatory (JUNO) is a multipurpose 20 kton liquid scintillator detector. The detector will be built in a 700 m deep underground laboratory, and its primary physics goal will be to determine the neutrino mass hierarchy. Due to the low background requirement of the experiment, a multi-veto system for cosmic muon detection and background reduction is designed. The volume outside the central detector is filled with pure water and equipped with 2000 MCP-PMTs (20 inches) to form a water Cherenkov detector for muon tagging. A Top Tracker system will be built by re-using the Target Tracker plastic scintillator modules of the OPERA experiment and will cover half of the top area. This will provide valuable information for cosmic muon induced 9Li/8He study.

Muon counting using silicon photomultipliers in the AMIGA detector of the Pierre Auger observatory

AMIGA (Auger Muons and Infill for the Ground Array) is an upgrade of the Pierre Auger Observatory designed to extend its energy range of detection and to directly measure the muon content of the cosmic ray primary particle showers. The array will be formed by an infill of surface water-Cherenkov detectors associated with buried scintillation counters employed for muon counting. Each counter is composed of three scintillation modules, with a 10 m2 detection area per module. In this paper, a new generation of detectors, replacing the current multi-pixel photomultiplier tube (PMT) with silicon photo sensors (aka. SiPMs), is proposed. The selection of the new device and its front-end electronics is explained. A method to calibrate the counting system that ensures the performance of the detector is detailed. This method has the advantage of being able to be carried out in a remote place such as the one where the detectors are deployed. High efficiency results, i.e. 98% efficiency for the highest tested overvoltage, combined with a low probability of accidental counting (∼2%), show a promising performance for this new system.

A Novel Cosmic Ray Tagger System for Liquid Argon TPC Neutrino Detectors

The Fermilab Short Baseline Neutrino (SBN) program aims to observe and reconstruct thousands of neutrino-argon interactions with its three detectors (SBND, MicroBooNE, and ICARUS-T600), using their hundred-ton scale Liquid Argon Time Projection Chambers to perform a rich physics analysis program, in particular focused on the search for sterile neutrinos. Given the relatively shallow depth of the detectors, the continuous flux of cosmic ray particles crossing their volumes introduces a constant background which can be falsely identified as part of the event of interest. Here we present the Cosmic Ray Tagger (CRT) system, a novel technique to tag and identify these crossing particles using scintillation modules which measure their time and coordinates relative to the internal events to the neutrino detector, with the intent of mitigating their effect in the event tracking reconstruction.

The design of the TASD (totally active scintillator detector) prototype

Totally active and magnetic segmented scintillation neutrino detectors are developed for the nextgeneration accelerator neutrino experiments. Such detectors will incorporate scintillation modules with scintillation counters that form X and Y planes. A single counter is a 7 × 10 × 90 mm3 scintillation bar with gluedin wavelength-shifting fibers and micropixel avalanche photodiodes. The results of measurements of the parameters of these detectors are presented.

Digital electronics for the Pierre Auger Observatory AMIGA muon counters

The ``Auger Muons and Infill for the Ground Array'' (AMIGA) project provides direct muon counting capacity to the Pierre Auger Observatory and extends its energy detection range down to 0.3 EeV. It currently consists of 61 detector pairs (a Cherenkov surface detector and a buried muon counter) distributed over a 23.5 km2 area on a 750 m triangular grid. Each counter relies on segmented scintillator modules storing a logical train of `0's and `1's on each scintillator segment at a given time slot. Muon counter data is sampled and stored at 320 MHz allowing both the detection of single photoelectrons and the implementation of an offline trigger designed to mitigate multi-pixel PMT crosstalk and dark rate undesired effects. Acquisition is carried out by the digital electronics built around a low power Cyclone III FPGA. This paper presents the digital electronics design, internal and external synchronization schemes, hardware tests, and first results from the Observatory.

AMIGA at the Auger observatory: the telecommunications system

AMIGA is an extension of the Pierre Auger Observatory that will consist of 85 detector pairs, each one composed of a surface water-Cherenkov detector and a buried muon counter. Each muon counter has an area of 30 square meters and is made of scintillator strips, with doped optical fibers glued to them, which guide the light to 64 pixel photomultiplier tubes. The detector pairs are arranged at 433 m and 750 m array spacings. In this paper we present the telecommunications system designed to connect the muon counters with the central data processing system at the observatory campus in Malarg"ue. The telecommunications system consists of a point-to-multipoint radio link designed to connect the 85 muon counters or subscribers to two coordinators located at the Coihueco fluorescence detector building. The link provides TCP/IP remote access to the scintillator modules through router boards installed on each of the surface detectors of AMIGA. This setup provides a flexible LAN configuration for each muon counter connected to a WAN that links all the data generated by the muon counters and the surface detectors to the Central Data Acquisition System, or CDAS, at the observatory campus. We present the design parameters, the proposed telecommunications solution and the laboratory and field tests proposed to guarantee its functioning for the whole data traffic generated between each surface detector and muon counter in the AMIGA array and the CDAS.

Extension of the dynamic range of large photocathode PMTs for a UHECR detector

Ground arrays for UHECR shower detection based on traditional counters, water Cerenkov tanks or scintillator modules, are unavoidably limited by the saturation suffered by the counters nearest to the shower axis. Reducing to a negligible level the amount of events recorded with saturated counters should be mandatory in a future UHECR ground array. The use of the signals extracted from the internal dynodes of the used photomultipliers can offer an elegant and inexpensive way to increase the dynamic range of such detectors. The viability of this technique has been explored studying in laboratory the performances of a sample of 3 Hamamatsu R5912-MOD photomultipliers. Exploiting the signal from the fifth dynode, a linear response up to an equivalent anodic peak current larger than 1A (at gain G = 2 ⋅ 10 5 ) has been measured for all the studied PMTs. The feasibility of this technique in the frame of a new ground array for UHECR studies should be verified with a larger sample of photomultipliers.

The influence of electron multiplication and internal X-ray fluorescence on the performance of a scintillator-based gamma camera

When considering the ‘standard’ gamma-camera, one might picture an array of photo-multiplier tubes or a similar array of small-area detectors. This array of imaging detectors would be attached to a corresponding array of scintillator modules (or a solid layer of scintillator) in order to give a high detection efficiency in the energy region of interest, usually 8–140keV. Over recent years, developments of gamma-cameras capable of achieving much higher spatial resolutions have led to a new range of systems based on Charge-Coupled Devices with some form of signal multiplication between the scintillator and the CCD in order for one to distinguish the light output from the scintillator above the CCD noise. The use of an Electron-Multiplying Charge-Coupled Device (EM-CCD) incorporates the gain process within the CCD through a form of ‘impact ionisation’, however, the gain process introduces an ‘excess noise factor’ due to the probabilistic nature of impact ionisation and this additional noise consequently has an impact on the spatial and spectral resolution of the detector. Internal fluorescence in the scintillator, producing K-shell X-ray fluorescence photons that can be detected alongside the incident gamma-rays, also has a major impact on the imaging capabilities of gamma-cameras. This impact varies dramatically from the low spatial resolution to high spatial resolution camera system. Through a process of simulation and experimental testing focussed on the high spatial resolution (EM-CCD based) variant, the factors affecting the performance of gamma-camera systems are discussed and the results lead to important conclusions to be considered for the development of future systems. This paper presents a study into the influence of the EM-CCD gain process and the internal X-ray fluorescence in the scintillator on the performance of scintillator-based gamma cameras (CCD-based or otherwise), making use of Monte Carlo simulations to demonstrate the aspects involved, their influence on the imaging system and the hypotheses previously discussed in experimental studies.

AMIGA at the Auger Observatory: the scintillator module testing system

AMIGA is an extension of the Pierre Auger Observatory thatwill consist of 85 detector pairs each one composed of a surfacewater-Cherenkov detector and a buried muon counter. Each muoncounter has an area of 30 m2 and is made of scintillator stripswith doped optical fibers glued to them, which guide the light to64 pixels photomultiplier tubes. The detector pairs are arranged at433 m and 750 m array spacings. In this paper we present the testing and initialcalibration system for the scintillator modules that constituteeach muon counter of AMIGA. The scintillator modules are testedwith a “scanner” that consists of an x−y positioning systemthat moves a 5 mCi 137Cs radioactive source over the moduletaking data at fixed locations. The scanner both tests the modulefor possible fabrication defects and stores the light-attenuationcurve parameters. A complete scanning process of a 64 stripscintillator module has been performed and results are presented. Also,attenuation curves obtained with scanner and with background muons arecompared with satisfactory results.