Radioactive Detection Research Articles

Northern Blotting: Protocols for Radioactive and Nonradioactive Detection of RNA.

Northern blotting is a common technique in RNA biology, allowing to detect and quantify RNAs of interest following separation by gel electrophoresis, transfer to a membrane, and hybridization of specific anti-complementary labelled probes. In this chapter, we describe our protocol for efficient RNA extraction from yeast, separation on agarose gel, and capillary transfer to a membrane. We provide two different methods for strand-specific detection of several types of RNAs using oligonucleotide probes, the first using radioactive 32P-labelled probes, the second based on nonradioactive digoxigenin-labelled probes.

Bayesian non-parametric modeling by mixture of Kibble-Pólya tree to detect Low-Activity uranium contamination

Accurate detection of low-level radioactivity is critical for decommissioning projects in nuclear facilities, particularly in the design of radiation monitoring systems with a low false alarm rate. Utilizing a non-parametric Bayesian continuous probability distribution enables reliable mapping of potential contamination. Our method introduces a statistical test based on a Pólya tree prior, applied to radiation detection. The detection efficiency of this proposed Bayesian test is quantified using receiver-operating characteristic (ROC) curves and compared to a Bayesian test based on the Kibble bivariate gamma distribution developed for the same purpose. The results demonstrate that the new Bayesian test generally outperforms the previous method in terms of detection performance under very low signal-to-noise ratios, with improvements ranging from 3% to 28% against both stationary and non-stationary radiological backgrounds, respectively. This superiority is further reaffirmed through comparisons with alternative Bayesian and frequentist hypothesis tests, with gains estimated at 52% and 4%, respectively.

Observation of atmospheric millimeter-wave discharges at 94 GHz and comparison with other microwave and millimeter-wave frequencies

This report describes an investigation by experimentation to elucidate atmospheric discharge plasma induced using a 50 kW millimeter-wave beam at 94 GHz. Millimeter-wave discharge plasma is useful for an ultraviolet light source, radioactive material detection, chemical decomposition, and beamed energy propulsion (BEP). The gyrotron used in this study is the “UT-94” with a frequency of 94 GHz and an output power of 100 kW, which was developed at the University of Tokyo specifically for BEP research. The 94 GHz frequency is promising for atmospheric energy beaming because of its low atmospheric attenuation, small beam divergence, and existing utilization track records in the atmosphere. This study experimentally investigated the relationship between the incident beam power density and propagation velocity of an ionization-wave front, which is particularly critical to thrust performance. In addition, the plasma structures were also clarified at 94 GHz and compared with other microwave and millimeter-wave frequencies, such as 28 GHz and those higher than 100 GHz. As a result, finer microscopic structure in the H–k plane was observed than those reported in earlier studies. Furthermore, we found a clear relation between structures and propagation velocities in terms of the electric field concentration of the incoming electromagnetic-waves.

Advanced radiation detector design for applications in food safety and national security

We describe a new concept for a radiation detector based on extruded scintillator technology and commercially available solid-state photo-detectors. The detector is simple in construction, robust, very efficient, cost-effective and easily scalable in size from tens of cm2 to tens of m2. We describe two possible applications: flagging radioactive food contamination and detection of illicit radioactive materials, such as those potentially used in a dirty bomb.

Alpibectir: Early Qualitative and Quantitative Metabolic Profiling from a First-Time-in-Human Study by Combining 19F-NMR (Nuclear Magnetic Resonance), 1H-NMR, and High-Resolution Mass Spectrometric Analyses.

Alpibectir (also known as BVL-GSK098 and GSK3729098) is a new chemical entity (NCE) with a novel mechanism for the treatment of tuberculosis. The disposition of alpibectir was determined in subjects from a first-time-in-human trial after a single oral dose of 40 mg and after 7 days repeat dosing at 30 mg. Here we present a combined approach of 19F-NMR (nuclear magnetic resonance), 1H-NMR, and high-resolution mass spectrometry (HRMS) to confidently determine the human metabolic fate of alpibectir. Utilizing multiple sites of fluorination in the molecule, it was possible to fractionate human urine and plasma to confidently detect and quantify the metabolite responses using 19F-NMR. Qualitative detection and structural characterization of F-containing NMR fractions were performed using complementary high-resolution ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) analyses to further add confidence to the metabolite responses in these fractions. Subsequent 1H-NMR then provided unequivocal standard-free structural confirmation for key metabolites, which would not be possible with conventional radioactivity detection and LC-MS/MS techniques. Alpibectir was shown to undergo extensive hydrolysis of the central amide moiety, where the resultant N-dealkylated amine and trifluorobutyric acid products were detected initially by unbiased 19F-NMR detection along with major downstream biotransformations to form a carbamoyl glucuronide conjugate and trifluoroacetic acid, respectively. Parallel UHPLC-MS/MS analyses provided confirmatory or additional structural characterization only where relevant. These concerted data allowed for the qualitative metabolic profile and quantitative determination of drug-related material (DRM) in urine and plasma, along with the percentage of dose excreted in urine, to be reported in a comprehensive, efficient, and data-led manner. SIGNIFICANCE STATEMENT: Combining the selectivity of 19F-NMR (nuclear magnetic resonance) for unfractionated samples as first-intent, data-led sample fractionation prior to 19F-NMR and structure-rich 1H-NMR detection, along with the sensitivity of high-resolution ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS), a novel alternative for time-efficient detection and quantification of drug-related material (DRM) in human without use of radiolabeled drug is reported. This allowed more complete data rationalization of human metabolism, permitting early risk assessment and progression of the development of antitubercular agent, alpibectir.

Design of the sparrow search algorithm (SSA) for airborne radioactive hotspot detection

In the context of using aircraft as a pivotal tool for detecting radioactive hotspots, the acquisition of radioactivity data was conducted through a CeBr3 scintillation crystal detector mounted on a helicopter. However, challenges arose, including managing extensive data volumes, computationally demanding tasks, and susceptibility to local optima issues. To address these challenges and leverage the benefits of the Sparrow Search Algorithm (SSA) in global optimization and convergence speed, an improved SSA was devised. This improved version integrated SSA principles with the intricacies of searching for radioactive hotspots. The algorithm employed a matrix segmentation method to process data matrices derived from measured data, aiming to enhance efficiency and accuracy. An empirical analysis was conducted, performing 100 iterations on an experimental matrix to scrutinize the impact of matrix segmentation. Computation times and results were compared across different segmentation levels, confirming the favorable algorithmic outcomes of the method. The practical viability and convergence stability of the algorithm were further assessed using genuine measured data, with segmented matrices generated for evaluation. Remarkably, a comparison between computational outcomes and manually identified data reaffirmed the algorithm's reliability in effectively detecting radioactive hotspots.

Application of unmanned aerial vehicles in emergency radiation monitoring

The paper is based on experiments within a project to prepare tutorial tasks on a training centre for testing radiation detectors fixed on unmanned aerial vehicles (UAVs) and in unmanned ground vehicles. The paper reports on a small UAV with NaI(Tl) 2“ x 2” detector for radiation monitoring in an emergency event and for radioactive source chasing and detection. The paper is focused on some special cases with the possibility to determine local air kerma rates and the activities of point sources. The detector was calibrated for air kerma rates from 5 nGy h−1 to 20 μGy h−1. The verified model of the NaI(Tl) 2″ x 2″ detector including the electronic module assembled on a UAV was designed in a Monte Carlo simulation. The model was used for calculating the air kerma rates at various altitudes above the ground both for a natural background and for selected point sources. The response functions for 137Cs, 131I, 192Ir, 60Co and 99Mo point sources were calculated by the Monte Carlo simulation to estimate their activities. Experiments were carried out with an NaI(Tl) 2“ x 2” detector fixed on a Robodrone UAV and flying over 60Co and 137Cs point sources over the airfield area and the local air kerma rates and the activities of the point sources were calculated with the AGAMA post-processing program. In addition, the response functions for 137Cs distributed uniformly on the surface were calculated by Monte Carlo simulation for future emergency purposes. The detection limits of selected man-made nuclides (point sources) were calculated.

Development of a radioactive substance detection system integrating a Compton camera and a LiDAR camera with a hexapod robot

Herein, a system for locating radioactive substances using a hexapod robot equipped with a Compton camera and light detection and ranging (LiDAR) camera was developed and its performance was evaluated at FUGEN, a nuclear facility owned by the Japan Atomic Energy Agency. During the evaluation test, the system visualized and identified the radioactive hotspot, wherein radioactive substances accumulated due to 60Co. This was achieved by projecting images of the radioactive substances acquired using the Compton camera onto a three-dimensional model of the work environment obtained using the LiDAR camera. Furthermore, the results of dose-rate measurements related to the work area obtained using a survey meter confirmed that the identified radioactive hotspot exhibited a dose rate that was one order of magnitude higher than that exhibited by the surrounding area.

Exploring radiological contamination among the same moving objects based on a fusion between radioactive detectors and surveillance cameras

Exploring radiological contamination among the same moving objects based on a fusion between radioactive detectors and surveillance cameras

Iodine Gas Detection System Using Color Sensor

Iodine can exist in the form of radioactive and non-radioactive states. Radioactive Iodine-131 (I-131) has been utilized in nuclear facilities. Due to its ability to be absorbed by the thyroid gland, I-131 is used for therapy in thyroid cancer cases. Contrary to the benefit, Iodine is a volatile material that becomes a health problem if humans inhale more than a certain dose under a certain period. Thus, to prevent overexposure to Iodine, all Iodine-related facilities must equip their facilities with Iodine detection systems. The most common radioactive detection system uses an expensive Na(Tl), and HPGe detector. So, this study will build a low-cost iodine detection system by means of a low-cost color-based sensor utilizing the color property of the Iodine gasses. This finding showed that the color sensor will detect the Iodine gas leaks in the air in a range of 0 - 100 ppm, resulting in a pink-dark purple color. This finding showed that the sensor could detect low concentrations of Iodine gas in particular areas very well. Since the good resolution of this detection system, it will be promising to be applied in a real-time iodine gasses detection system.

Dual-functional metal-organic frameworks-based hydrogel micromotor for uranium detection and removal

Self-propelled micro/nanomotors have attracted great attention for environmental remediation, however, their use for radioactive waste detection and removal has not been addressed. Engineered micromotors that are able to combine fast detection and highly adsorptive capability are promising tools for radioactive waste management but remain challenging. Herein, we design self-propelled micromotors based on zeolite imidazolate framework (ZIF-8)-hydrogel composites via inverse emulsion polymerization and show their potential for efficient uranium detection and removal. The incorporation of magnetic ferroferric oxide nanoparticles enables the magnetic recycling and actuation of the single micromotors as well as formation of swarms of worm-like or tank-treading structure. Benefited from the enhanced motion, the micromotors show fast and high-capacity uranium adsorption (747.3 mg g−1), as well as fast uranium detection based on fluorescence quenching. DFT calculation confirms the strong binding between carboxyl groups and uranyl ions. The combination of poly(acrylic acid-co-acrylamide) with ZIF-8 greatly enhances the fluorescence of the micromotor, facilitating the high-resolution fluorescence detection. A low detection limit of 250 ppb is reached by the micromotors. Such self-propelled micromotors provide a new strategy for the design of smart materials in remediation of radioactive wastewater.

Steps Toward Optimizing HPGE Detector Efficiency in the Context of Low-Level Radioactivity Detection

"Different empirical and theoretical methods are used to precisely determine radionuclide activity concentrations. This study used Monte Carlo simulation MCNP5 code and EFFTRAN software (Efficiency Transfer) to determine the HPGe detector Full-Energy Peak (FEP) efficiency. A set of point sources (133Ba, 152Eu, 137Cs, 60Co, and 22Na) fixed on the top of the standard geometry plastic container were measured in order to obtain the calibration curve. Because of the importance of chemical composition parameters, the detector behavior due to different matrices was investigated. Experimental verification of the calibration was obtained using IAEA-TEL-2021-03 quality control water sample spiked with 152Eu and 133Ba, and the results were compared with reported results. A set of Certified Standard Reference samples were used for method validation. The obtained results were compared with the experimental results. The comparison clarified the advantages and disadvantages of both methods and their precision to demonstrate and suitable method for matrix types."

Efficient Methods to Detect Atmospheric Concentration with Low Signal to Noise Ratio on a Sensor Network

Accidental or malicious releases of materials into the air can occur surreptitiously and lead to low concentrations involving very limited changes in the atmospheric background noise. This may result in signal variations on sensors placed in the environment characterized by a low signal-to-noise ratio (SNR). In this work, we aim to provide a selection of efficient online detection methods adapted to low signal to noise ratio (SNR). These methods take into consideration signals that are monitored by a subset of a network of sensors and for a limited period of time. We show that it is possible to detect with a very reasonable false alarm rate only knowing the statistics of the background noise. Derived from the Cumulative Sum (CUSUM), the methods presented and tested here are generalizations to multivariate time series considering space and time sparsity of the exposure of the network of sensors. We show that the methods previously presented in a Gaussian context can easily be extended to a Poisson model which is consistent with particle counting sensors like those used in the frame of radioactivity detection. We demonstrate the validity of the different methods on toy example and then prove its interest on data from the twin experiment of a fictitious radioactive release in an urban area.

P-254 - LC/MS coupled to radioactive detection for the chemical characterization of radiopharmaceuticals: identification of multiple intermediates en route to [99mTc]Tc-sestamibi

P-254 - LC/MS coupled to radioactive detection for the chemical characterization of radiopharmaceuticals: identification of multiple intermediates en route to [99mTc]Tc-sestamibi

Design and implementation of a virtual nuclear pulse signal generator

This paper presents a virtual nuclear pulse signal generator. The pulse generator can be used in specific scenarios such as calibration and maintenance of nuclear detection systems, validation of nuclear signal processing algorithms, and nuclear physics teaching experiments, as a substitute for real radioactive sources and detectors to generate nuclear pulse signals. This helps to avoid exposing experimental personnel to radiation hazards. The pulse generator is capable of generating specific nuclear pulse signals according to experimental requirements, and these signals has the same physical characteristics as real nuclear pulse signals, including amplitude distribution, time and amplitude randomness. In the pulse generator, we conducted theoretical analysis of the radioactive source and detector, and established a model library for both, to obtain crucial parameters of the nuclear pulse signals. The pulse generator is built on a hardware framework with field-programmable gate array (FPGA) as the core, utilizing these key parameters to generate signals with realistic physical characteristics of nuclear pulse signals, including amplitude and time characteristics. The counting rate of the output nuclear pulse signals can be adjusted by configuring the hardware parameters of the pulse generator.

Non-radioactive electron capture detector based on soft X-ray ionization for gas chromatography - A possible replacement for radioactive detectors

In this paper, we present a new electron capture detector based on a compact X-ray tube (X-ECD) for electron generation by soft X-ray radiation instead of using a radioactive source. ECDs are commonly used in many laboratories as standard GC detectors since their invention in the 1950s, especially for highly sensitive detection of halogenated substances, pesticides or other environmental pollutants. However, due to unsatisfactory alternatives, many ECDs are still used with radioactive β-emitters, which is difficult and expensive in most applications today due to legal restrictions. The new X-ECD contains a small X-ray tube for generating free electrons by ionizing the carrier gas like in radioactive ECDs. Thus, no additional dopants or special gases are required. The X-ECD has limits of detection in the pptv range and shows linearity over a wide concentration range. Furthermore, the used X-ray tube shows good long-term stability. So far, we have operated the X-ray tube continuously for about one year without notable degradation. However, in case of future degradation, the X-ECD can still be operated with the same sensitivity by simple adjusting the set point current in constant current mode. This makes calibration robust against possible degradation of the X-ray tube. In combination with a conventional gas chromatograph, the X-ECD is able to detect halogenated hydrocarbons and even low volatile pesticides without any peak distortion such as tailing. Thereby a minimum detectability in the upper fg/µL range for Lindane was reached, which is similar when compared to radioactive ECDs.

Novel production method for traceable surface sources by aluminium functionalisation

Accurate detection of low-level radioactivity is critical in decommissioning. However, commercial sources used for calibration lack representativeness due to their flat surface. The objective of this work is to produce flexible and large area surface sources for alpha and beta emitters by functionalising aluminium foil. Functionalisation strategies were developed to provide these sources. The manganese oxide coated sample shows the highest fixation yield for 241Am: (70.0 ± 2.6)% and conforms to ISO 8769 for uniformity (92%).

A systematic study on complementary metal-oxide semiconductor technology (CMOS) and Internet of Things (IOT) for radioactive leakage detection in nuclear plant

Although nuclear power plants produce about 20% of India's power, the risk posed by radioactive leakage is considerable. Radiation leakage detection devices must be installed in all nuclear power plants to ensure that avoidable catastrophes never occur again and that the loss of human life is prevented. A safe atmosphere for inhabitants and workers may be ensured by keeping a consistent radiation level in all applications that use radioactive material. Complementary Metal-Oxide Semiconductor technology, or CMOS, uses complementary and symmetrical MOSFETS for logic-based functions in various applications, such as analog circuits (CMOS sensors). The Internet of Things (IoT) extends the power of the Internet beyond computing devices to a multitude of other things, processes, and environments. The main objective of this paper is to find a better and more creative solution for radioactive leakage detection techniques over present-day techniques. In this paper, the Authors aim to integrate CMOS and IOT applications for radioactive leakage detection methods on an industrial level. Within this paper, we have given brief descriptions of CMOS and IoT with their types, functions, methodology, and applications. CMOS is considered to be the most sophisticated and precise technology that can be employed to measure radiation leaks of all types (alpha rays, beta rays, gamma rays, and neutrons). With the help of IOT, massive disasters can be averted using complex alert systems. A well-coordinated combination of the two technologies has the potential to vastly increase leak detection potential and consistency. The study's major goal is to develop new and improved technology for detecting released radiation in the industry in order to obtain real-time information about the material leaked, as well as the location of the leak and the quantity of leakage that occurred, in order to reduce the danger of a natural catastrophe.

Prussian blue nanoparticles–mediated sensing and removal of 137Cs

Prussian blue nanoparticles (PBNPs) with controlled nano-geometry were synthesized from a single precursor (potassium hexacyanoferrate) in the presence of three different reagents, namely, polyethylenimine (PEI), tetrahydrofuran (THF)/H2O2, and 2-(3,4-epoxycyclohexyl)-ethyl-trimethoxysilane (EETMS)/cyclohexanone, which enabled the controlled nucleation and stabilization of PBNPs of variable plasmonic activities for selective sensing and removal of cesium radionuclides. The results of this study show the sensing and removal of cesium ions based on the nano-geometry, magnetic behavior, and fluorescence quenching ability of PBNPs as a function of the cesium ion concentration for the first time. A similar process was used to synthetically incorporate PBNPs in mesoporous silica with potential use for the selective adsorption of 137Cs, followed by the detection of radioactivity. The distribution coefficient (Kd) for adsorption of the cesium nuclide 137Cs was calculated to be 3.2 × 104 mL/g−1, displaying both Langmuir and Freundlich adsorption isotherms. The plasmonic activity of PBNPs has enabled fluorometric sensing of cesium ions; regulating the spatial control between the functional PBNPs and fluorescence probe molecules is a promising approach for PBNP-enhanced fluorescence and fluorescence resonance energy transfer–based cesium ion sensing. Similarly, PBNPs display superparamagnetic behavior; these magnetic properties were observed to be linearly dependent on the cesium ion concentration.

An extendable optical fibre probe survey meter for naturally occurring radioactive material (NORM) and other weak emitters

We have developed a radioluminescence-based survey meter for use in industries in which there is involvement in naturally occurring radioactive material (NORM), also in support of those needing to detect other weak emitters of radiation. The functionality of the system confronts particular shortcomings of the handheld survey meters that are currently being made use of. The device couples a LYSO:Ce scintillator with a photodetector via a polymer optical fibre waveguide, allowing for "intrinsically safe" inspection within pipework, separators, valves and other such component pieces. The small-diameter optical fibre probe is electrically passive, immune to electromagnetic interference, and chemically inert. The readout circuit is entirely incorporated within a handheld casing housing a silicon photomultiplier (SiPM) detection circuit and a microprocessor circuit connected to an LCD display. A 15 m long flexible PMMA optical fibre waveguide is butt coupled to an ABS plastic probe that retains the LYSO:Ce scintillator. Initial tests have included the use of lab-based mixed gamma-ray sources, measurements being made in concert with a reference conventional GM survey-meter. Characterization, via NORM sources at a decontamination facility, has shown useful sensitivity, covering the dose-rate range 0.10- to 28 µSv h−1 (R-squared 0.966), extending to 80 µSv/h as demonstrated in use of a Cs-137 source. The system is shown to provide an effective tool for detection of radioactivity within hard to access locations, in particular for sources emitting at low radiation levels, down to values that approach background.