Prototype Detector Research Articles

Performance evaluation of a 71Ga(n,γ)72Ga reaction-based epithermal neutron flux detector at an AB-BNCT device

The 71Ga(n,γ)72Ga reaction-based epithermal neutron flux detectors are novel instruments developed to measure the epithermal neutron flux of boron neutron capture therapy (BNCT) treatment beams. In this study, a spherical epithermal neutron flux detector using 71Ga(n,γ)72Ga reaction was prototyped. The performance of the detector was experimentally evaluated at an accelerator-based BNCT (AB-BNCT) device developed by Lanzhou University, China. Based on the experimental results and related analysis, we demonstrated that the detector is a reliable tool for the quality assurance of BNCT treatment beams.

Scintillation and cherenkov photon counting detectors with analog silicon photomultipliers for TOF-PET

Objective. Standard signal processing approaches for scintillation detectors in positron emission tomography (PET) derive accurate estimates for 511 keV photon time of interaction and energy imparted to the detection media from aggregate characteristics of electronic pulse shapes. The ultimate realization of a scintillation detector for PET is one that provides a unique timestamp and position for each detected scintillation photon. Detectors with these capabilities enable advanced concepts for three-dimensional (3D) position and time of interaction estimation with methods that exploit the spatiotemporal arrival time kinetics of individual scintillation photons. Approach. In this work, we show that taking into consideration the temporal photon emission density of a scintillator, the channel density of an analog silicon photomultiplier (SiPM) array, and employing fast electronic readout with digital signal processing, a detector that counts and timestamps scintillation photons can be realized. To demonstrate this approach, a prototype detector was constructed, comprising multichannel electronic readout for a bismuth germanate (BGO) scintillator coupled to an SiPM array. Main Results. In proof-of-concept measurements with this detector, we were able to count and provide unique timestamps for 66% of all optical photons, where the remaining 34% (two-or-more-photon pulses) are also independently counted, but each photon bunch shares a common timestamp. We show this detector concept can implement 3D positioning of 511 keV photon interactions and thereby enable corrections for time of interaction estimators. The detector achieved 17.6% energy resolution at 511 keV and 237 ± 10 ps full-width-at-half-maximum coincidence time resolution (CTR) (fast spectral component) versus a reference detector. We outline the methodology, readout, and approach for achieving this detector capability in first-ever, proof-of-concept measurements for scintillation photon counting detector with analog silicon photomultipliers. Significance. The presented detector concept is a promising design for large area, high sensitivity TOF-PET detector modules that can implement advanced event positioning and time of interaction estimators, which could push state-of-the-art performance.

Application of thin boron deposit by electrophoresis as neutron detectors

Abstract Detecting nuclear radiation presents a distinctive challenge, particularly with neutrons, which are neutral particles. The method of direct detection involves the utilization of a converter material, acting as an intermediary. Boron plays a pivotal role in this process, reacting with thermal neutrons to generate alpha particles and lithium, with a notable energy release of 2.314 MeV during the 10B (n,α) 7Li reaction. This facilitates effective identification and measurement of neutrons in radiation detection systems. The paths of the particles α (for E = 1.474 MeV) and Li (for E Li = 0.842 MeV). The active medium of the nuclear detector, typically a gas, undergoes ionization by these highly charged particles, or they form ion pairs that are subsequently collected by electrodes to produce the signal at the detector’s output. Various deposit methods can be used for this purpose, electrophoresis offers a distinct advantage in terms of both simplicity and precision. This study details the utilization of the electrophoresis technique for the deposition of boron on the tube walls of prototype detectors developed within our laboratory.

Electronics design for a muon imaging system using triangular plastic scintillators with WLS fiber readouts

Muon imaging technology has developed rapidly over the past decades with extensive applications. In many cases, plastic scintillator detectors are preferred because of their high cost performance, ease of processing and robustness in harsh environments. To reduce imaging time and improve imaging quality, detectors tend to have large areas and high position resolutions. The challenge to the electronics for such detectors is to maintain the scale of electronics acceptable while improving the high position resolution of the detector. In this paper, the basic detector unit is a triangular strip of plastic scintillator, each embedded with two wavelength-shifting (WLS) fibers read out by the silicon photomultipliers (SiPMs). Since the hit position of muon on the detector is determined by the splitting ratio of the scintillation light on two adjacent scintillator strips, it is necessary the readout electronics has high linearity and low noise. The possibility of the electronics channel multiplexing on the same detector plane is fully explored so that four WLS fibers can be read out by one SiPM realizing 2:1 readout channel compression. Furthermore, since multiple electronics modules are connected by a daisy chain structure, the electronics system is very scalable with its data acquisition system (DAQ) independent of detector size. In addition to detailing the position encoding readout scheme, the design of electronics module and the DAQ system, the electronics system has been implemented and applied to a prototype detector for performance evaluation. Using scintillator strips with 11 mm pitch size, the position resolution of the detector reaches 1.49 mm, which demonstrates that the designed electronics is suitable for the new detector structure, and the combination of the two has a good application prospect in muon imaging.

First experimental evaluation of count-rate performance for micrometre resolution deep silicon detector

Objective. An ultra-fine-pitch deep silicon detector has been developed for clinical photon-counting computed tomography (CT). With a small pixel size of 14 × 650 μm2, it has shown potential to reach micrometre spatial resolution in previous simulation studies. A detector prototype with such geometry has been manufactured, and we report on the first experimental evaluation of its count-rate performance. Approach. The measurement was carried out at MAX IV synchrotron laboratory with 35 keV monochromatic x-rays. By inserting tungsten attenuators of 50, 75, 100, 150, 200, 225, 325 μ m-thicknesses into the beam, the response of the detector to fluence rates from 3.3 × 107 to 1.3 × 1011 mm−2 s−1 was characterized. Main results. The measurement result showed that the detector exhibited count rate linearity up to 6.66 × 108 mm−2 s−1 with 13% count loss and was still functional at count rate up to 2.9 × 1010 mm−2 s−1. A semi-nonparalyzable dead-time model was fitted to the count-rate behaviour of the detector, showing great agreement with the measured data, with an estimated nonparalyzable dead time of 2.9 ns. Significance. This is the first experimental evaluation of the count-rate performance for a deep silicon detector with such small pixel geometry. The results suggest that this type of detector shows the potential to be used at fluence rates encountered in clinical CT with little count loss due to pile-up.

Preliminary Characterization of an Active CMOS Pad Detector for Tracking and Dosimetry in HDR Brachytherapy.

We assessed the accuracy of a prototype radiation detector with a built in CMOS amplifier for use in dosimetry for high dose rate brachytherapy. The detectors were fabricated on two substrates of epitaxial high resistivity silicon. The radiation detection performance of prototypes has been tested by ion beam induced charge (IBIC) microscopy using a 5.5 MeV alpha particle microbeam. We also carried out the HDR Ir-192 radiation source tracking at different depths and angular dose dependence in a water equivalent phantom. The detectors show sensitivities spanning from (5.8 ± 0.021) × 10-8 to (3.6 ± 0.14) × 10-8 nC Gy-1 mCi-1 mm-2. The depth variation of the dose is within 5% with that calculated by TG-43. Higher discrepancies are recorded for 2 mm and 7 mm depths due to the scattering of secondary particles and the perturbation of the radiation field induced in the ceramic/golden package. Dwell positions and dwell time are reconstructed within ±1 mm and 20 ms, respectively. The prototype detectors provide an unprecedented sensitivity thanks to its monolithic amplification stage. Future investigation of this technology will include the optimisation of the packaging technique.

Characterization of the energy response of a LYSO+SiPM detector module for E//B NPA using [formula omitted] and hydrogen ions

This article presents a novel application of the lutetium-yttrium oxyorthosilicate (LYSO) scintillator in a newly constructed neutral particle analyzer with a parallel electric and magnetic fields structure (E//B NPA). The LYSO scintillator, coupled to the silicon photomultiplier (SiPM) without a reflector, serves as the detector module in the E//B NPA. The LYSO+SiPM configuration offers numerous advantages for the NPA application, including high efficiencies, compact size, low voltage operation, and exceptional resistance to magnetic fields. The performance of a prototype detector module was studied using a radioactive source in conjunction with the 50 kV electron cyclotron resonance (ECR) ion source platform. The crosstalk of optical photons from adjacent detector modules was examined with two detectors, and it was determined to be negligible. The high-energy α spectra exhibited a distinctive two-shoulder structure, which arises from α particles impinging on different positions of the LYSO crystal surface. This observation was further investigated through Geant4 simulations. The detector module was found to have a low-energy limit of 10 keV for hydrogen ions. In the comprehensive measurements, linear energy responses were observed for α particles and hydrogen ions within the error bars. The relative light yield of α and hydrogen ions exhibited a different trend compared to that of γ rays or electrons, providing valuable insights for the study of non-proportionality of light yield for light ions in the LYSO scintillator.

Internet of Things (IoT) Based Temperature and Humidity Detector Prototype in the UHAMKA Data Center Room

Internet of Things (IoT) is a concept where an object or entity is imbued with technology such as sensors and software, aiming to communicate, control, connect, and exchange data with other devices as long as they remain connected to the internet. In this research, the developed IoT is employed to monitor and control the conditions of a data center space. The research methodology follows the system development life cycle, utilizing the Blynk application and a modified Arduino Uno with the esp8266 microcontroller, relay, and DHT-22 sensor for real-time temperature and humidity detection. The IoT development's outcomes were tested through black box and white box approaches. The research results demonstrate that the IoT network prototype functions effectively, enhancing the performance of the data center space. Temperature measurements were acquired from the DHT22 sensor, and alternative temperature measurements were taken without utilizing the DHT22 sensor, instead using a tool known as a thermometer, revealing measurement errors. Based on the calculation of the average percentage of temperature error on the DHT22 sensor, it can be concluded that the temperature error rate reaches 0.051%, while for humidity it reaches 0.064%, with an average delay time of 6.542 ms. Additionally, users have convenient access through both a website and mobile platform for seamless monitoring.

Multi-tile zinc-oxide-based radiation-hard fast scintillation counter for relativistic heavy-ion beam diagnostics: prototype design and test

This contribution summarizes the design and performance test of a prototype radiation-hard fast scintillation detector based on the indium-doped zinc oxide ceramic scintillator, ZnO(In). The prototype detector has been developed for use as a beam diagnostics tool for high-energy beam lines of the SIS18 synchrotron at the GSI Helmholtz Center for Heavy Ion Research GmbH. The new detector consists of multiple ZnO(In) scintillating ceramics tiles stacked on the front and back sides of a borosilicate light guide. The performance of the detector was tested in comparison to a standard plastic scintillation detector with 300 MeV/u energy 40Ar, 197Au, 208Pb, and 238U ion beams. The investigated prototype exhibits 100% counting efficiency and radiation hardness of a few orders of magnitude higher than the standard plastic scintillation counter. Therefore, it provides an improved beam diagnostics tool for relativistic heavy-ion beam measurements.

Prototype of Flexible Digital X-ray Imaging Detector

Prototype of Flexible Digital X-ray Imaging Detector

Structural and Physical Properties of Two Distinct 2D Lead Halides with Intercalated Cu(II).

Transition metal cation intercalation between the layers of two-dimensional (2D) metal halides is an underexplored research area. In this work we focus on the synthesis and physical property characterizations of two layered hybrid lead halides: a new compound [Cu(O2C-CH2-NH2)2]Pb2Br4 and the previously reported [Cu(O2C-(CH2)3-NH3)2]PbBr4. These compounds exhibit 2D layered crystal structures with incorporated Cu2+ between the metal halide layers, which is achieved by combining Cu(II) and lead bromide with suitable amino acid precursors. The resultant [Cu(O2C-(CH2)3-NH3)2]PbBr4 adopts a 2D layered perovskite structure, whereas the new compound [Cu(O2C-CH2-NH2)2]Pb2Br4 crystallizes with a new structure type based on edge-sharing dodecahedral PbBr5O3 building blocks. [Cu(O2C-CH2-NH2)2]Pb2Br4 is a semiconductor with a bandgap of 3.25 eV. It shows anisotropic charge transport properties with a semiconductor resistivity of 1.44×1010 Ω·cm (measured along the a-axis) and 2.17×1010 Ω·cm (along the bc-plane), respectively. The fabricated prototype detector based on this material showed response to soft low-energy X-rays at 8 keV with a detector sensitivity of 1462.7 μCGy-1cm-2, indicating its potential application for ionizing radiation detection. These encouraging results are discussed together with the results from density functional theory calculations, optical, magnetic, and thermal property characterization experiments.

Status of DUNE Offline Computing

We summarize the status of Deep Underground Neutrino Experiment (DUNE) Offline Software and Computing program. We describe plans for the computing infrastructure needed to acquire, catalog, reconstruct, simulate and analyze the data from the DUNE experiment and its prototypes in pursuit of the experiment’s physics goals of precision measurements of neutrino oscillation parameters, detection of astrophysical neutrinos, measurement of neutrino interaction properties and searches for physics beyond the Standard Model. In contrast to traditional HEP computational problems, DUNE’s Liquid Argon Time Projection Chamber data consist of simple but very large (many GB) data objects which share many characteristics with astrophysical images. We have successfully reconstructed and simulated data from 4% prototype detector runs at CERN. The data volume from the full DUNE detector, when it starts commissioning late in this decade will present memory management challenges in conventional processing but significant opportunities to use advances in machine learning and pattern recognition as a frontier user of High Performance Computing facilities capable of massively parallel processing. Our goal is to develop infrastructure resources that are flexible and accessible enough to support creative software solutions as HEP computing evolves.

Residual gas noises in vacuum of optical interferometer for ground-based gravitational wave detection

Gravitational waves (GWs) are ripples in spacetime caused by most violent and energetic processes in the universe, such as the rapid motion of massive celestial bodies. The GWs carry energy when they propagate through the universe. The detection of GWs holds significance for advancing human understanding of the nature and driving scientific and technological progress. The continual upgrading and optimizing of GW detectors offer novel avenues for cosmic measurements. However, ground-based GW detectors based on a large interferometer necessitate addressing various noises which are harmful to the sensitivity of the GW detectors. Among these noises, the noise from residual gas in the light beam of the interferometer is a crucial factor to affect the sensitivity. Consequently, it is necessary to establish a vacuum system to shield the laser interferometer from the effects of gas flow. This paper focuses on China’s third-generation ground-based GWs detector, conducting theoretical analysis of the influence of residual gas noise on both a 20-meter arm-length prototype and a full-scale device with a 10-kilometer arm-length. In this paper, a theoretical model for the residual gas particles passing through the laser beam is established and the effect on the beam phase is analyzed. The theoretical simulations are performed to discover the relations between the residual gas noise and significant parameters such as gas pressure of the vacuum system, temperature, mass of residual gas particles, polarization rate of the residual gas, and the curvature radius of the test mass. The simulations indicate that when the residual gas pressure is below 2×10<sup>–6</sup> Pa, the GW detector can achieve the enough sensitivity, 10<sup>–24</sup> Hz<sup>–1/2</sup>, in a frequency range from 10 to 10<sup>3</sup> Hz. The findings of this research offer crucial theoretical insights for designing and constructing the vacuum systems in future third-generation GWs detector prototypes and full-scale devices.

Design of the data acquisition system for the HERD transition radiation detector prototype

Design of the data acquisition system for the HERD transition radiation detector prototype

Design Prototype Detector of Temperature, Humidity, and Air Quality using Sensors, Microcontrollers, Solar Cells, and IoT

Design Prototype Detector of Temperature, Humidity, and Air Quality using Sensors, Microcontrollers, Solar Cells, and IoT

Designing Prototype of Volume Detector for Medical Oxygen Cylinder Using NodeMCU ESP8266

The COVID-19 pandemic posed significant challenges to the healthcare sector, particularly due to the imbalance between patient numbers and available medical staff, resulting in difficulties during emergencies. One such challenge was the prompt replacement of oxygen cylinders. Leveraging Internet of Things (IoT) technology, we developed a prototype oxygen cylinder volume detector aimed at providing early notifications to healthcare professionals. This prototype incorporates the NodeMCU ESP8266, equipped with an Infrared (IR) Obstacle Sensor. The sensor communicates with a relay to activate an MP3 module, delivering audible alerts. Furthermore, the NodeMCU ESP8266 system integrates CTBot to send text notifications through the Telegram application to the nearest healthcare personnel. Visual alerts are also provided through red LED lights attached to the cylinders, indicating which oxygen cylinder is approaching depletion. Comprehensive testing validated the proper functionality of all system components. This innovative oxygen cylinder detector prototype is designed to streamline healthcare worker and nurse workflows by offering quicker access to accurate information regarding the status of medical oxygen cylinders. Not only does this enhance patient care efficiency, but it also ensuring the availability of oxygen is crucial for critical patients.

Correction to: Building of a ton-scale liquid argon prototype detector

Correction to: Building of a ton-scale liquid argon prototype detector

Study of MAPS silicon detector prototypes for the ALICE Inner Tracking System upgrade

The ALICE experiment, which is located at the Large Hadron Collider (LHC) at CERN, has planned an upgrade of the Inner Tracking System (ITS), called ITS3, which will be installed during the LHC Long Shutdown 3, in 2026–2028. The cornerstone of the upgrade is a new 65 nm CMOS pixel chip, produced using Monolithic Active Pixel Sensor (MAPS) technology and the stitching technology to extend the chip length to 26 cm. The produced chips will be bent and they will replace the three innermost layers of the existing detector with new ultra-light, truly cylindrical layers. The ITS3 will improve tracking performance, especially at low transverse momentum, thanks to better track impact-parameter resolution, improved by a factor two with respect to the present ITS in LHC Run 3. In addition, the detector will be closer to the interaction point and will have a much lower material budget, of 0.05% X0/layer. This proceedings paper presents the final configuration and structure of the ITS3, the challenges related to its design and construction, and the results of the current R&D program on the sensor design and characterization. Finally, it also reports the results of beam tests preformed at CERN, where an analog pixel test chip (APTS Source Follower) was investigated in terms of detection efficiency.

High-pressure xenon gas time projection chamber with scalable design and its performance around the Q value of 136Xe double-beta decay

Abstract We have been developing a high-pressure xenon gas time projection chamber (TPC) called AXEL (A Xenon ElectroLuminescence detector) to search for neutrinoless double-beta (0νββ) decay of 136Xe. The unique feature of this TPC is the electroluminescence light collection cell (ELCC), the part designed to detect ionization electrons. The ELCC is composed of multiple units, and one unit covers 48.5 cm2. A 180 L size prototype detector with 12 units, 672 channels, of the ELCC was constructed and operated with 7.6 bar natural xenon gas to evaluate the performance of the detector around a Q value of 136Xe 0νββ. The obtained FWHM energy resolution is $0.73 \pm 0.11\%$ at 1836 keV. This corresponds to $0.60 \pm 0.03\%$ to $0.70 \pm 0.21\%$ of the energy resolution at a Q value of 136Xe 0νββ. This result shows the scalability of the AXEL detector with the ELCC while maintaining a high energy resolution. Factors determining the energy resolution were quantitatively evaluated and the result indicates that further improvement is feasible. Reconstructed track images show distinctive structures at the endpoints of electron tracks, which will be an important feature in distinguishing 0νββ signals from gamma-ray backgrounds.

Status and prospects of the PandaX-III experiment

The PandaX-III experiment searches for neutrinoless double beta decay of 136Xe with a high-pressure xenon gaseous time projection chamber (TPC). Thermal-bonding Micromegas modules are used for charge collection. Benefitting from the excellent energy resolution and imaging capability, the background rate can be significantly suppressed through the topological information of events. The technology is successfully demonstrated by a prototype detector. The final detector has been constructed. In this paper, we will report the status of the PandaX-III experiment, including the construction and commissioning of the final detector, and the Micromegas-based TPC performance test in the prototype detector.