Radiation Detection System Research Articles

Enhancing aerial mapping with gamma radiation detection: a study in UAE

This work presents a comprehensive study on the development of a sophisticated gamma radiation detection system based on a drone-mounted gamma scintillation detector tailored for aerial mapping and radiation surveillance, aimed at generating an environmental radioactivity map within the United Arab Emirates (UAE). The project incorporates careful assembly and calibration techniques that utilize four high-resolution crystals (two CeBr3 and two Lanthanum Bromochloride crystals) to optimize detection sensitivity. Additionally, the study examines the effectiveness of a VETO system in improving the signal-to-noise ratio and reducing background. The detector system employs modern front-end and back-end electronics to digitize the signal at the outset of signal processing. The detector will be installed on a drone to facilitate thorough and effective surveys.

Radiological hazard assessment of the soil in Daquq district, Kirkuk, Iraq

Abstract This investigation assessed the baseline levels of radioactivity in the soil of Daquq district, Iraq, using the GR-460 radiation detection system. 238U, 232Th, and 40K’s specific activities were measured and the hazard indices’ values determined. The average values of the absorbed dose, annual effective dose equivalent, annual gonadal equivalent dose, and lifetime cancer risk radiological risk factors were estimated. It is important to note that some of these results exceeded the global average levels. Various multivariate statistical techniques were employed to explore the relationships between the radioactive variables and identify potential correlations amongst them. Cluster analysis was utilized to identify clusters or groups of variables that shared similar characteristics. The study aimed to gain insights into the relationships between the radioactive variables and identify any correlations between them. These analyses provided valuable information regarding the associations and patterns within the data, thus contributing to an improved understanding of the radioactive variables and their potential implications.

Development of a silicon carbide radiation detection system and experimentation of the system performance

Silicon carbide (SiC) detectors have excellent radiation detection capabilities for various radiation particles, including high energy resolution, fast response times, and good radiation resistance. A SiC radiation detection system was developed to measure the neutron fluence rate and the γ-ray dose rate in high intensity radiation fields. The system was composed of two SiC detectors, a temperature monitor, two preamplifiers for each SiC detector, a data acquisition unit with two signal channels, three pairs of communication devices, and an application software to analyze and visualize the measurement data. The two SiC detectors were fabricated based on two kinds of 4H-SiC diodes and used to respectively respond to neutrons and γ-rays. Repeated experiments showed that the two SiC detectors of the system can respond to α-particles, neutrons, and γ-rays. To verify the performance of the SiC detection system, including the response linearity of the neutron fluence rate, the measurement range of the γ-ray dose rate, and the radiation resistance of the SiC radiation detectors, the system was tested in multiple neutron and γ-ray fields. The tests results show the system can measure the neutron fluence rate from 5.64 × 10 2 cm−2 s−1 to 1.03 × 10 5 cm−2 s−1 with excellent linearity response, and the γ-ray dose rate from 0.005 Gy/h to 20 Gy/h. Furthermore, the SiC detectors demonstrated good radiation resistance. The neutron and γ-ray radiation field can still be measured stably by the system after exposure to neutron fluence of 1.07 × 10 14 cm−2 and γ-ray dose of 3.52 × 10 4 Gy. This work is the preliminary research to continue the exploration how to measure the n/γ hybrid fields accurately using SiC detectors considering the different energy of neutrons.

A study on in-situ characterization technology development for clearance verification of radioactive waste from nuclear decommissioning

Although the clearance level of every radioactive nuclide was published by the IAEA to promote the recycling and reuse of decontaminated radioactive waste worldwide, technical and regulatory issues have always been raised around the application of the criteria. Therefore, several countries are developing in-situ characterization equipment or apparatus for on-site verification to check if the clearance criteria is met.In this study authors developed a pilot radiation detection and measurement system using in-situ characterization technology to solve the issues, which consists of a 3D scanning camera system and a built-in Monte Carlo simulation program. Measurement results show that MDA (Minimum Detectable Activity) of the current design was indisputably below the clearance level and built-in Monte Carlo simulation package closely predicts the measurements results with the error of less than 5%. This implicates that it can determine with enough margin whether the radioactivity level of decontaminated metallic components meets the clearance criteria at decommissioning site or not.Practically when we measure the radioactivity from gamma ray source mass attenuation always takes place during the photon transports through the medium. In fact, the reduction depends on the material, shapes, and radioactive sources. In this study the reduction factors were experimentally examined according to the influencing parameters and the results were saved as DCF (Density Correction Factor) in the data base. As expected, it turned out that the factor is somewhat affected by medium material and radioactive sources, but it is basically proportional to the distance of gamma ray passage.It is expected that upgraded design with more accurate and reliable instruments can make it easier for regulators to accept the application of the in-situ characterization technology on-site.

Flexible Single Microwire X-Ray Detector with Ultrahigh Sensitivity for Portable Radiation Detection System.

Sensitive, flexible, and low false alarm rate X-ray detector is crucial for medical diagnosis, industrial inspection, and scientific research. However, most semiconductors for X-ray detectors are susceptible to interference from ambient light, and their high thickness hinders their application in wearable electronics. Herein, a flexible visible-blind and ultraviolet-blind X-ray detector based on Indium-doped Gallium oxide (Ga2O3:In) single microwire is prepared. Joint experiment-theory characterizations reveal that the Ga2O3:In microwire possess a high crystal quality, large band gap, and satisfactory stability, and reliability. On this basis, an extraordinary sensitivity of 5.9×105µCGyair -1cm-2 and a low detection limit of 67.4nGyairs-1 are achieved based on the prepared Ag/Ga2O3:In/Ag device, which has outstanding operation stability and excellent high temperature stability. Taking advantage of the flexible properties of the single microwire, a portable X-ray detection system is demonstrated that shows the potential to adapt to flexible and lightweight formats. The proposed X-ray detection system enables real-time monitor for X-rays, which can be displayed on the user interface. More importantly, it has excellent resistance to natural light interference, showing a low false alarm rate. This work provides a feasible method for exploring high-performance flexible integrated micro/nano X-ray detection devices.

Impurity-enhanced core valence luminescence via Zn-doping in cesium magnesium chlorides

Scintillators with faster timing capabilities are currently in high demand for use in radiation detection systems in the fields of nuclear and medical physics. The limited number of suitable materials that meet the performance criteria of next generation detection systems presents an opportunity for discovery of new fast scintillator materials. In this work, the effects of doping several ultrafast core-valence luminescent (CVL) scintillators with divalent Zn is explored. Three compounds are investigated – CsMgCl3, Cs2MgCl4, and Cs3MgCl5 – and single crystals of each doped with 5 mol% Zn are grown via the Bridgman method. Additionally, mixing across the full range of concentrations (from 0 % to 100 % Zn) is explored in the Cs2Mg1-xZnxCl4 and Cs3Mg1-xZnxCl5 systems. For low concentrations of Zn, light yields of all three compounds are enhanced (by up to ∼60 %) compared to the pure crystals, achieving what we believe to be the brightest known CVL, CsMgCl3:Zn 5 % (3400 ± 170 ph/MeV light yield). More importantly, Zn doping does not affect the ultrafast timing properties, with each composition maintaining a single-component decay time around 1–3 ns. A sub-100 ps coincidence time resolution (CTR) is also achieved with CsMgCl3:Zn 5 %. The results of this work reveal a new avenue towards obtaining brighter CVL materials, which could open up possibilities for more advanced ultrafast scintillators to be discovered moving forward.

Modeling of N and P-Type of Coaxial Ge Detectors Using MCNPX and the Effect of Dead Layer Variation on Its Response Function

Abstract This study assessed the response function of a p-type and n-type coaxial high-purity germanium (HPGe) detector via Monte Carlo N-Particle eXtended (MCNPX). MCNPX was employed to model the Coaxial Ge detectors, and for a precise simulation, the dimensions of the dead layer of germanium crystals were added. The dead layer was separated into front and lateral surfaces, and the thickness of each dead layer was modeled. In this work, the simulated detectors have been performed at different energy lines using a radioactive source Eu-152 to study the response function of each with dead layer variations for the front dead layer and study the range of relative deviation of the Monte Carlo simulation outputs from the manufactured declared data. The results proved that the n-type coaxial HPGe detector is more sensitive to the dead layer change than the p-type with a thick change of 0.01 mm. This research has significant effects on the efficiencies of the radiation detection systems in the energy range ∼ (120–1410) keV.

Simulation of Readout Electronics for Nuclear Radiation Detector Using MATLAB Program

A computer program was developed using the MATLAB programming language to simulate the electronics readout for a radiation detector system. The function of each stage of this system is described by a mathematical model in the Laplace domain. The electrical signals have been shown and analyzed at two main outputs of the system. They are described according to their related circuit parameters. The obtained results of the simulation can be used to achieve a best design of the concerned circuits and to provide appropriate details about the system operation. Validation of the simulated signals by comparison with available experimental results has been achieved.

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.

Decay rate changes in radioactive gamma emission as affected by 18 MeV proton cyclotron

Previous efforts to investigate changes in the decay constants of radioactive nuclides discovered that solar flares can temporarily alter radioactive decay rates. Thus, discerning whether external factors affect radioactive decay rates is vital for understanding nuclear processes. This study sought to explore the effect of neutrinos on radioactive nuclei by constructing a gamma radiation detection system that employs a radioactive source in front of a neutrino emission system. Responding to cyclotron operations, each of the four detection systems registered gamma count rate decreases. The results of this study confirm that rises in neutrino flux affected the decay rates of the examined radioactive nuclides. Here we provide significant evidence that neutrinos affect the radioactive decay process. Neutrino detection is challenging due to the minuscule absorption in a stable nucleus. However, the study found a greater probability of radionuclides interaction with the neutrino.

Radioactive source localization using a mobile radiation detection system featuring informed path-based decisions

Radioactive source localization using a mobile radiation detection system featuring informed path-based decisions

Real-time radiation monitoring of high energy 1.2-GeV synchrotron accelerator using experimental physics and industrial control system

The high energy 1.2-GeV electron accelerator facility’s radiation detection and monitoring system (RDMS) has greatly evolved to be the effective backbone of real-time radiation monitoring for the new light source 3-GeV synchrotron facility. Experimental Physics and Industrial Control System (EPICS), ethernet hardware connections (Optic fibers), and Web-based software interfaces make up the new RDMS framework, built on well-liked network technology. The problems of monitoring i.e., a lot of manpower, poor monitoring accuracy, and inability to monitor continuously in the high radiation dose are eliminated. EPICS, composed of an Input/Output Controller (IOC) and Client Workstations which can communicate with a Local Area Network (LAN), were applied for remote control and radiation measurement. EPICS has been able to transport and store massive amounts of data for large-scale systems with a wide range and high accuracy. The monitoring data were sent to the server through the optic fibers network system, which is more advantages such as no distance restrictions, low attenuation of the signal, faster responding times, and particularly electromagnetic resistance. The data can be accessed anywhere from client monitors with graphical user interfaces. This system is successfully developed and tested for the high energy 1.2-GeV electron accelerator. The RDMS is useful for radiation safety to monitor the radiation dose level during machine operation to protect occupational workers and the public from radiation hazards.

A new detector concept based on the prompt gamma radiation analysis for In vivo boron monitoring in BNCT.

The problem of boron concentration monitoring during the boron neutron capture therapy (BNCT) therapy is one of the main challenges of this type of radiotherapy and is directly related to the nature of the interaction of neutrons with mater. Among the available in vivo methods of boron monitoring positron emission tomography seems to be very promising but it requires a new boron carrier with a β+ emitter, which is not yet clinically available. An alternative solution may be the prompt gamma radiation analysis (PGRA) based on the secondary radiation emitted in the interaction of neutrons with the patient's tissues. This method requires, however, compact gamma radiation detection systems sustaining high counting rates and characterized by very good energy resolution. In this contribution, we present state-of-the-art solutions for monitoring in BNCT based on PGRA. Moreover, we describe a new concept of such a system based on position-sensitive scintillator detectors equipped with an anti-Compton shield and data analysis supported with modern artificial intelligence algorithms.

Electronic Noise in Semiconductor-Based Radiation Detection Systems: A Comprehensive Analysis With a Unified Approach

Electronic Noise in Semiconductor-Based Radiation Detection Systems: A Comprehensive Analysis With a Unified Approach

Non-iterative pulse tail extrapolation algorithms for correcting nuclear pulse pile-up

Radiation detection systems working at high count rates suffer from the overlapping of their output electric pulses, known as pulse pile-up phenomenon, resulting in spectrum distortion and degradation of the energy resolution. Pulse tail extrapolation is a pile-up correction method which tries to restore the shifted baseline of a piled-up pulse by extrapolating the overlapped part of its preceding pulse. This needs a mathematical model which is almost always nonlinear, fitted usually by a nonlinear least squares (NLS) technique. NLS is an iterative, potentially time-consuming method.The main idea of the present study is to replace the NLS technique by an integration-based non-iterative method (NIM) for pulse tail extrapolation by an exponential model. The idea of linear extrapolation, as another non-iterative method, is also investigated. Analysis of experimental data of a NaI(Tl) radiation detector shows that the proposed non-iterative method is able to provide a corrected spectrum quite similar with the NLS method, with a dramatically reduced computation time and complexity of the algorithm. The linear extrapolation approach suffers from a poor energy resolution and throughput rate in comparison with NIM and NLS techniques, but provides the shortest computation time.

CERN Super Proton Synchrotron Radiation Environment and Related Radiation Hardness Assurance Implications

The Super Proton Synchrotron (SPS) is the second largest accelerator at CERN where protons are accelerated between 16 GeV/c and 450 GeV/c. Beam losses, leading to the mixed-field radiation of up to MGy magnitude, pose a threat to the reliability of the electronic equipment and polymer materials located in the tunnel and its vicinity. Particularly in the arc sectors, where both main magnets and radiation sensors are periodically arranged, the Total Ionizing Dose (TID) is of concern for the front-end electronics of A Logarithmic Position System (ALPS). The SPS is equipped with multiple radiation detection systems such as Beam Loss Monitors (BLM), RadMons, and as of 2021, the Distributed Optical Fibre Radiation Sensing (DOFRS), that combined all together provide a very comprehensive picture of both the TID spatial distribution and its time evolution. Within this study, the overview of measured 2021 and 2022 TID levels is presented, together with the demonstration of capabilities offered by the different radiation monitors. The DOFRS, supported by the passive Radio-Photo Luminescence (RPL) dosimeter measurements, is used to assess the TID values directly at the electronic racks, which turned out to be reaching several tens of Gy per year, potentially affecting the ALPS lifetime.

A Low-Power, Portable Radiation Detection System for High Count Rate, Long-Term Monitoring

A Low-Power, Portable Radiation Detection System for High Count Rate, Long-Term Monitoring

High Accuracy Solar Diffuser BRDF Measurement for On-Board Calibration in the Solar Reflective Band

In the solar reflective band, an on-board calibration method based on a solar diffuser (SD) can realize full aperture, full field of view, and end-to-end absolute radiometric calibration of optical remote sensors. The SD’s bidirectional reflectance distribution function (BRDF) is a key parameter that affects the accuracy of the on-board calibration. High-accuracy measurement of the SD BRDF is required in the laboratory before launch. Due to the uncertainty of the goniometer system, polarization effects, and other factors, the measurement uncertainty of the SD BRDF at large incident angles is much higher than that at a 0° incident zenith angle and 45° reflection zenith angle. In this paper, an absolute BRDF measurement facility is reported. The goniometric system consists of a high-brightness integrating sphere as a radiation source, a six-axis robot arm, and a large rotation stage. The measurement wavelength range was from 350 nm to 2400 nm. An improved data processing method based on the reciprocity theorem was proposed to reduce the measurement uncertainty of the SD BRDF at large incident angles. At an incident zenith angle of 75°, the improved data processing method reduced the measurement uncertainty of the SD BRDF by 52% at 410 nm to 480 nm, by 70% at 480 nm to 1000 nm, and by 20% at other bands compared to the absolute measurement method. The influence of the radiation source, goniometer system, detection system, and other factors on the measurement uncertainty are analyzed in this paper. The results show that the measurement uncertainty (coverage factor k = 2) of the SD BRDF was better than 1.04% at 350 nm to 410 nm, 0.60% at 410 nm to 480 nm, 0.43% at 480 nm to 1000 nm, and 0.86% at 1000 nm to 2400 nm.

Evaluation of the effectiveness of radiation detection systems in measurement of equivalent dose rate for nuclear reactor workers

This paper introduces a practical study to evaluate and analyze the effectiveness of radiation detection systems used to measure the equivalent dose of the workers involved in Gemstones (Topaz) colour treatment process at Egypt Second Research Reactor (ETRR-2). Typically, thermoluminescence dosimeters (TLDs) are used to record the accumulated radiation dose equivalent to the periodic assessment of the health and safety of reactor workers. The accuracy of using TLDs has been evaluated in the International Atomic Energy Agency's Radiological Dosimetry Laboratory as they can be used in various nuclear environments such as nuclear reactors. This paper proposes the use of a gas-filled radiation detector, a Geiger-Muller (GM) tube, to assess the intervention of workers in handling Topaz irradiation boxes and preparing them for regular irradiation at the reactor. A comparison was made between the TLDs and the GM tube detectors and the difference in their readings and their dependence on the radiation dose rate were assessed. The difference in sub-linearity phenomena of both detectors and its effect on the GM tube values and the effect on the operator's performance to complete the filling and preparing Topaz boxes for irradiation were investigated. The difference in recording dose for both the TLD and the GM tube was taken into account based on the equation shown.

Cosmic Muon Rates and Neutron Background in a Backpack Radiation Detection System

Radiation detection systems for security applications are often equipped with neutron sensors and required to promptly respond with an alarm if the neutron flux exceeds the background level. As the ambient neutron flux is essentially caused by cosmic radiation, this background could be evaluated by assessing the rate of muons crossing the gamma-ray detector which is comprised in such systems anyway. A study performed with a commercial Backpack Radiation Detection System (BRD) demonstrates the feasibility of this approach, supposed the gamma spectrometer is capable of discriminating muon signals from energetic events caused by the gamma-ray cascades following neutron captures. This requires a dynamic range exceeding the usual 3-4 MeV. The instrument used provided standard spectroscopy up to 10 MeV and facilitated charge-loss compensated spectroscopy up to 1 GeV, which allowed a separate assessment of normal gamma events (< 3 MeV), neutron-capture gamma events (3-7 MeV), and muon events (> 10 MeV). In this case, the rate of neutron-capture gamma events can be used as a neutron indicator on its own, while the muon rate signals the ambient neutron background level.