Measurements Of Radiation Research Articles

Radiation exposure in augmented fluoroscopic bronchoscopy procedures: a comprehensive analysis for patients and physicians

Cancer is a major health challenge and causes millions of deaths worldwide each year, and the incidence of lung cancer has increased. Augmented fluoroscopic bronchoscopy (AFB) procedures, which combine bronchoscopy and fluoroscopy, are crucial for diagnosing and treating lung cancer. However, fluoroscopy exposes patients and physicians to radiation, and therefore, the procedure requires careful monitoring. The National Council on Radiation Protection and Measurement and the International Commission on Radiological Protection have emphasised the importance of monitoring patient doses and ensuring occupational radiation safety. The present study evaluated radiation doses during AFB procedures, focusing on patient skin doses, the effective dose, and the personal dose equivalent to the eye lens for physicians. Skin doses were measured using thermoluminescent dosimeters. Peak skin doses were observed on the sides of the patients’ arms, particularly on the side closest to the x-ray tube. Differences in the procedures and experience of physicians between the two hospitals involved in this study were investigated. AFB procedures were conducted more efficiently at Hospital A than at Hospital B, resulting in lower effective doses. Cone-beam computed tomography (CT) contributes significantly to patient effective doses because it has higher radiographic parameters. Despite their higher radiographic parameters, AFB procedures resulted in smaller skin doses than did image-guided interventional and CT fluoroscopy procedures. The effective doses differed between the two hospitals of this study due to workflow differences, with cone-beam CT playing a dominant role. No significant differences in left and right eye Hp (3) values were observed between the hospitals. For both hospitals, the Hp (3) values were below the recommended limits, indicating that radiation monitoring may not be required for AFB procedures. This study provides insights into radiation exposure during AFB procedures, concerning radiation dosimetry, and safety for patients and physicians.

Low-level Arctic clouds: a blind zone in our knowledge of the radiation budget

Abstract. Quantifying the role of clouds in the earth's radiation budget is essential for improving our understanding of the drivers and feedback mechanisms of climate change. This holds in particular for the Arctic, the region currently undergoing the most rapid changes. This region, however, also poses significant challenges to remote-sensing retrievals of clouds and radiative fluxes, introducing large uncertainties in current climate data records. In particular, low-level stratiform clouds are common in the Arctic but are, due to their low altitude, challenging to observe and characterize with remote-sensing techniques. The availability of reliable ground-based observations as reference is thus of high importance. In the present study, radiative transfer simulations using state-of-the-art ground-based remote sensing of clouds are contrasted with surface radiative flux measurements to assess their ability to constrain the cloud radiative effect. Cloud radar, lidar, and microwave radiometer observations from the PS106 cruise in the Arctic marginal sea ice zone in summer 2017 were used to derive cloud micro- and macrophysical properties by means of the instrument synergy approach of Cloudnet. Closure of surface radiative fluxes can only be achieved by a realistic representation of the low-level liquid-containing clouds in the radiative transfer simulations. The original, most likely erroneous, representation of these low-level clouds in the radiative transfer simulations led to errors in the cloud radiative effect of 54 W m−2. In total, the proposed method could be applied to 11 % of the observations. For the data, where the proposed method was utilized, the average relative error decreased from 109 % to 37 % for the simulated solar and from 18 % to 2.5 % for the simulated terrestrial downward radiative fluxes at the surface. The present study highlights the importance of jointly improving retrievals for low-level liquid-containing clouds which are frequently encountered in the high Arctic, together with observational capabilities both in terms of cloud remote sensing and radiative flux observations. Concrete suggestions for achieving these goals are provided.

ENVIRONMENTAL CONDITION MEASUREMENT SYSTEM WITH A MINI WEATHER STATION USING ESP32

Weather conditions are important to know because they have an impact on various human activities, such as agriculture, infrastructure, hydrology, and more. Several factors affect the weather, including wind speed, temperature, and air humidity. However, in this study, a mini weather station was designed to provide information not only on wind speed, temperature, and humidity but also on solar radiation. The research employed several sensors, including the DHT11, anemometer, and pyranometer. The research results indicate that the DHT11 error indoors is 1.4%, but it increases to 9% outdoors. The pyranometer shows a 3.62% error from direct solar radiation measurements. However, the wind speed sensor is still unstable, suggesting the need for improvement in future research.

Non-linear QED approach for betatron radiation in a laser wakefield accelerator

Laser plasma-based accelerators provide an excellent source of collimated, bright, and adequately coherent betatron-type x-ray pulses with potential applications in science and industry. So far the laser plasma-based betatron radiation has been described within the concept of classical Liénard–Wiechert potentials incorporated in particle-in-cell simulations, a computing power-demanding approach, especially for the case of multi-petawatt lasers. In this work, we describe the laser plasma-based generation of betatron radiation at the most fundamental level of quantum mechanics. In our approach, photon emission from the relativistic electrons in the plasma bubble is described within a nonlinear quantum electrodynamics (QED) framework. The reported QED-based betatron radiation results are in excellent agreement with similar results using Liénard–Wiechert potentials, as well as in very good agreement with betatron radiation measurements, obtained with multi-10-TW lasers interacting with He and multielectron N_2 gas targets. Furthermore, our QED approach results in a dramatic reduction of the computational runtime demands, making it a favorable tool for designing betatron radiation experiments, especially in multi-petawatt laser facilities.

A novel analytical method to calibrate cylindrical side-hole type sodium iodide scintillation detectors

Geometrical and absolute efficiencies play a significant role in the calibration of radioactivity measuring systems, which are regularly complicated. A novel analytical method of efficiency calibration is proposed for cylindrical side-hole type sodium iodide scintillation detectors. Cylindrical side-hole type sodium iodide scintillation detectors have a cylindrical side-hole passing perpendicularly on the sodium iodide crystal axis, which is gathered in the aluminum cover. This detector is a setup for low-level gamma radiation measurement, because of the close 4π solid angle correlated with it, this setup is convenient when low-energy radiation requires efficient detection. Also, the 4π gamma-ray counting is an established way for direct activity measurements and is remarkably well suited for radionuclides with complex gamma-ray spectra. This novel approach depends on the calculation of two primary factors, the photon path length inside the detector active material, and the solid angle, delimited by the radiation source-detector system. In addition, the attenuation of photons by the sodium iodide crystal covering substance is also included by determining the photon path length through this substance. The novel analytical approach calculates the total and geometrical efficiencies of this kind of detector. In comparison, the differences with the published data in the literature indicate that the current approach is favorable in the efficiency measurement of the cylindrical side-hole type sodium iodide scintillation detectors.

THz SASE FEL at PITZ: lasing at a wavelength of 100 μm

Development of an accelerator-based tunable THz source prototype for pump-probe experiments at the European XFEL is ongoing at the Photo Injector Test facility at DESY in Zeuthen (PITZ). The proof-of-principle experiments on the THz SASE FEL are performed utilizing the LCLS-I undulator (on loan from SLAC) installed in the PITZ beamline. The first lasing at a center wavelength of 100 μm was observed in the summer of 2022. The lasing of the narrowband THz source was achieved using an electron beam with an energy of ∼17 MeV and a bunch charge up to several nC. Optimization of beam transport and matching resulted in the measurement of THz radiation with a pulse energy of tens of μJ, measured with pyroelectric detectors. The THz FEL gain curves were measured by means of specially designed short coils along the undulator. The results of the first characterization of the THz source at PITZ will be presented.

Relationship of precipitation intensity in the form of snow with atmospheric electricity and radiothermal radiation of the snow cover

Remote radiophysical methods using artificial satellites of the Earth allow to determine physical and chemical parameters of the atmosphere. For this purpose, calibration subsatellite measurements are necessary. One of the natural phenomena to be studied is precipitation in the form of snow. This paper presents the results of ground-based measurements of radio-thermal radiation of snow cover at two wavelengths 0.88 cm and 1.35 cm, as well as the results of measurements of the variation of the vertical component of the surface atmospheric electric field strength during snowfall. The measurements were made near the ice-water phase transition temperature. The research site is located in the city of Chita (Russian Federation). A strong influence of air temperature on the measured values, especially at the ice-water phase transition temperature, was found.

RAD01: Development of a NUMTEK RAD01 Low-Cost, Portable Digital Gamma Radiation Detector

Additive manufacturing and open-source affordable instruction provide equal opportunities. Therefore, it is possible to quickly, compactly, and cheaply make expensive, scarce, and large devices in the previous century. The Geiger-Muller tube is used for the primary sensing component proposed and incorporates digital signal processing to ensure accurate and reliable measurement of gamma radiation. The performance of the developed detector is evaluated through experimental testing and comparisons with commercially available radiation detection devices. The results demonstrate the detector's ability to provide precise and consistent measurements while remaining cost-effective. Moreover, its portability and user-friendly interface make it suitable for various applications, including environmental monitoring, nuclear safety, personal radiation exposure assessment, and, most importantly, educational purposes. This low-cost portable digital gamma radiation detector contributes to the field of radiation detection by presenting an accessible solution that addresses the financial limitations associated with conventional gamma radiation detectors.

Transient measurement of near-field thermal radiation between macroscopic objects.

The involvement of evanescent waves in the near-field regime could greatly enhance spontaneous thermal radiation, offering a unique opportunity to study nanoscale photon-phonon interaction. However, accurately characterizing this subtle phenomenon is very challenging. This paper proposes a transient all-optical method for rapidly characterizing near-field radiative heat transfer (NFRHT) between macroscopic objects, using the first law of thermodynamics. Significantly, a full measurement at a fixed gap distance is completed within tens of seconds. By simplifying the configuration, the transient all-optical method achieves high measurement accuracy and reliable reproducibility. The proposed method can effectively analyze the NFRHT in various material systems, including SiO2, SiC, and Si, which involve different phonon or plasmon polaritons. Experimental observations demonstrate significant super-Planckian radiation, which arises from the near-field coupling of bounded surface modes. Furthermore, the method achieves excellent agreement with theory, with a minimal discrepancy of less than 2.7% across a wide temperature range. This wireless method could accurately characterize the NFRHT for objects with different sizes or optical properties, enabling the exploration of both fundamental interests and practical applications.

Optimisation of the performance of a prototype instrument for measuring solar irradiation using artificial neural network

Accurate measurement of solar radiation is essential for understanding climate patterns, assessing solar energy potential, and predicting weather conditions. Over the years, solar radiation measuring instruments such as pyranometers and solarimeters have been used to achieve this objective. However, the high cost of these standard instruments makes the technology less accessible, especially to students and academic researchers in low-to-middle-income countries. A low-cost prototype solarimeter has been developed that operates using a mini solar PV panel and a microcontroller. During testing, it was found that as temperature increased the instrument had significant accuracy deviations. As such, this study seeks to optimise the performance of the prototype solarimeter using Artificial Neural Networks (ANNs), a powerful data-driven machine learning tool for optimisation. Solar radiation data was simultaneously collected using the prototype solarimeter and a standard solarimeter. Corresponding ambient temperature was also recorded for each solar radiation measurement. The data was used to train the ANN model to learn data patterns and to predict accurate solar radiation in spite of the ambient temperature. Results of the study revealed that temperature has a negative correlation (–0.7381) with accuracy, such that an increase in temperature reduces the accuracy of the prototype solarimeter. Increased temperature caused an accuracy deviation of about 27.16 %. The ANN model successfully predicts accurate solar radiation measurement with an R-squared of 0.974, RMSE of 49.24 W/m2, and an accuracy of 86.32 % which represents a 13.39 % improvement in the performance of the prototype solarimeter. This study's novelty stands in its attempt to use machine learning to address the temperature sensitivity of a PV-based solar irradiance instrument. The results revealed here exposes the potency of deep learning models for optimising engineering systems.

Эмнэлгийн рентген төхөөрөмжийн цацрагийн хамгаалалтын тооцоолол

In this study, we performed radiation shielding calculations for the diagnostic X-ray equipment at Rekha Med Hospital. The lead thickness required for radiation protection, as determined by the methodology outlined in the National Council on Radiation Protection and Measurements (NCRP) Report No. 147, was approximately 2 mm. Air kerma measurements were taken outside the X-ray room to validate the shielding effectiveness with a 2 mm thick lead barrier installed along the walls. The results confirmed that the air kerma dose did not exceed the regulatory dose limit of 0.5 mSv/H in uncontrolled areas, indicating sufficient shielding.

Uncertainties in Field Spectroscopy: Operator and Setup Induced Effects on Spectral Radiance Measurements

Uncertainties in Field Spectroscopy: Operator and Setup Induced Effects on Spectral Radiance Measurements

The CELESTA CubeSat In-Flight Radiation Measurements and their Comparison with Ground Facilities Predictions

The CELESTA CubeSat In-Flight Radiation Measurements and their Comparison with Ground Facilities Predictions

Wearable Ultrasound System Using Low-Voltage Time Delay Spectrometry for Dynamic Tissue Imaging.

Wearable ultrasound is emerging as a new paradigm of real-time imaging in freely moving humans and has wide applications from cardiovascular health monitoring to human gesture recognition. However, current wearable ultrasound devices have typically employed pulse-echo imaging which requires high excitation voltages and sampling rates, posing safety risks, and requiring specialized hardware. Our objective was to develop and evaluate a wearable ultrasound system based on time delay spectrometry (TDS) that utilizes low-voltage excitation and significantly simplified instrumentation. We developed a TDS-based ultrasound system that utilizes continuous, frequency-modulated sweeps at low excitation voltages. By mixing the transmit and receive signals, the system digitizes the ultrasound signal at audio frequency (kHz) sampling rates. Wearable ultrasound transducers were developed, and the system was characterized in terms of imaging performance, acoustic output, thermal characteristics, and applications in musculoskeletal imaging. The prototype TDS system is capable of imaging up to 6cm of depth with signal-to-noise ratio of up to 42dB at a spatial resolution of 0.33mm. Acoustic and thermal radiation measurements were within clinically safe limits for continuous ultrasound imaging. We demonstrated the ability to use a 4-channel wearable system for dynamic imaging of muscle activity. We developed a wearable ultrasound imaging system using TDS to mitigate challenges with pulse echo-based wearable ultrasound imaging systems. Our device is capable of high-resolution, dynamic imaging of deep-seated tissue structures and is safe for long-term use. This work paves the way for low-voltage wearable ultrasound imaging devices with significantly reduced hardware complexity.

Case study of a bore wind-ramp event from lidar measurements and HRRR simulations over ARM Southern Great Plains

The rapid change of wind speed and direction on 21 August 2017 is studied using Doppler lidar measurements at five sites of the Atmospheric Radiation Measurement (ARM) Southern Great Plains (SGP) facility in north-central Oklahoma. The Doppler lidar data were investigated along with meteorological variables such as temperature, humidity, and turbulence available from the large suite of instrumentation deployed at the SGP Central Facility (C1) during the Land-Atmosphere Feedback Experiment in August 2017. Lidar measurements at five sites, separated by 55–70 km, allowed us to document the development and evolution of the wind flow over the SGP area, examine synoptic conditions to understand the mechanism that leads to the ramp event, and estimate the ability of the High-Resolution Rapid Refresh model to reproduce this event. The flow feature in question is an atmospheric bore, a small-scale phenomenon that is challenging to represent in models, that was generated by a thunderstorm outflow northwest of the ARM SGP area. The small-scale nature of bores, its impact on power generation, and the modeling challenges associated with representing bores are discussed in this paper. The results also provide information about model errors between sites of different surface and vegetation types.

Calibration method of relative spectral response function of indirect imaging spectrometer

In imaging spectrometers, area array detectors are usually used as photoelectric conversion devices, but the inconsistency of the spectral response among pixels can distort the collected target spectra. To improve the spectral radiometric accuracy of imaging spectrometers, calibrating and correcting the inconsistency of the spectral response among pixels is essential. The signal received by each pixel of area array detector of the indirect imaging spectrometer is usually the superposition of the target multi-spectral radiation signals or full-spectral radiation signals. Therefore, its relative spectral radiometric calibration requires measuring the spectral response of each pixel at different wavelengths on the array detector. Under the ideal conditions, the response values of each pixel in the area array detector are different, so the indirect imaging spectrometer cannot simply calibrate the relative spectral response (RSR) function between pixels by using the method of “monochromator + integrating sphere”. In this work, taking the interferometric imaging spectrometer for example, we analyze the influence of the inconsistency of the RSR among pixels on the target spectral radiation measurement accuracy, and propose a system-level RSR function measurement method for the indirect imaging spectrometer based on the Fourier transform modulation calibration source. In addition, we establish a mathematical model for calibrating the RSR function,and provide guidelines for selecting calibration system parameters such as light source, spectral resolution, and OPD sampling interval. The simulation results show that under the ideal noise-free condition, the 1% spectral response inconsistency among pixels results in a relative error of 1.02% to the recovered spectra. After RSR correction, the relative error of the recovered spectra of different rows decreases to 0.08%. Furthermore, in this work we simulate and analyse the influence of spectral signal-to-noise ratio on the calibration accuracy of the RSR function, and point out that increasing the brightness of the calibration light source, extending exposure time, and combining multi-frame interferograms can enhance RSR function calibration accuracy in practical applications. The research result can provide a theoretical basis for realizing the relative spectral radiometric calibration of indirect imaging spectrometer, which is of great significance in promoting quantitative spectral remote sensing.

Distribution of Electromagnetic Radiation on Television

Electromagnetic radiation on television has been analyzed. The aim is to create a radiation distribution pattern and compare the electromagnetic radiation of Tube television and LED television. In this study, radiation measurements using an electromagnetic radiation sensor. Radiation exposure dose measurements were carried out at 25 measurement points in the television room, namely 5 points each on the track and 1 point in the center of the radiation source. The data processing method uses Scilab to create radiation distribution patterns. The results of data processing showed that the largest radiation exposure dose was on line C (in front of television) for 60 minutes. The radiation value of Tube television is greater than the radiation value of LED television. The isodose contour shows the radiation exposure dose value of 0 at a distance of 2.5 m from the TV, which is the safe limit for watching.

Radiation measurements in dentistry

When patients undergo X-ray examinations, millions of photons pass through their bodies. In dental radiography, the part of the head that receives the greatest dose is the skin in the area where the X-rays enter, including brain, salivary gland and thyroid. The effective usage of radiation in dental practice has been studied for many years and several guidelines have been proposed. While not high doses of radiation are associated with dental radiography in the field of using radiation in dentistry practice it is the most important to provide periodical radiation measurements for radiographs used in dental clinics, to measure such main X-rays specifications, as Kilovoltage Peak (kVp), Dose/Exposure, Dose/Exposure Rate, Exposure Time – Radiographic Modes, Elapsed Time – Fluoro Modes, Average Pulse Rate – Pulsed Fluoro, Average Pulse Width – Pulsed Fluoro and Half-value Layer HVL. Besides these parameters of mAs spesifications da DoseMate specifications also must be measured. Quality control of radiological devices is very important. So, we plan periodical radiation measurements in more than 50 dental clinics in Georgia and hope that results of these measurements will be successful, encouraging. After the measurements, the results will be known to all stakeholders. We will also talk about them in our next publications.

METHODS FOR IMPROVING THE DRG-05M DOSIMETER IN BRACHYTHERAPY

Relevance: The article discusses one of the ways to improve the DRG-05M dosimeter in brachytherapy by using new components and technologies in an improved scheme, which includes more accurate sensors, advanced signal processing techniques, efficient power cells, and other solutions. The application of such advanced components and technologies in the framework of DRG-05M dosimeter modernization is a new and original contribution to the field of dosimetry. The scientific novelty of the work is the improvement of the existing circuitry, namely, the improvement of the DRG-05M dosimeter’s electrical circuitry based on the analysis of its shortcomings. This includes replacing components, optimizing circuit structure, eliminating noise and interference, and improving the stability and accuracy of measurements.
 The study aimed to improve the DRG-05M dosimeter to provide more accurate and reliable radiation measurements in brachytherapy.
 Methods: The paper analyses the existing components and their use in the electrical circuit to improve the measurement accuracy of the DRG-05M dosimeter, offers a new electrical circuit based on the collected data and requirements, considering the optimal location of components, their characteristics, performed calculations, and modeled circuit operation. This scientific research was carried out within the framework of the PCF scientific program “Metrological support of dosimetric measurements in contact radiation therapy,” IRN BR12967832.
 Results: We have selected the components for improving the DRG-05M dosimeter:photomultiplier tube (PMT), analog-digital converter (ADC), indication unit, and power supply. The proposed changes to improve the DRG-05M dosimeter shall result in a very compact scintillation-type dosimeter. Its size and weight shall be reduced by at least 3 times; the accuracy and speed of measurement will increase, and the lifetime of the instrument shall improve.
 Conclusion: Improvement of the dosimeter in brachytherapy is an important task to ensure the accuracy and reliability of measurement in treating cancer. Using components such as PMT, calibration source, battery charger, and microcontroller KR572PV5 can significantly improve the operation of the DRG-05M dosimeter and increase the accuracy of radiation dose measurement in brachytherapy.

Evaluation and performance comparison of different models for global solar radiation forecasting: a case study on five cities

AbstractRecently, solar energy has emerged as the most promising renewable energy source to meet the world’s energy demands. However, to harness the potential of solar energy, accurate data on solar radiation are crucial. It is considered the first step in assessing solar resources for various applications and achieving energy sustainability goals. Due to the unavailability of solar radiation measurements in many parts of the world, several models have been developed to predict global solar radiation (GSR) at these locations. Thus, this study aims to evaluate the proficiency of several GSR models at five new locations and determine the most suitable one for GSR prediction. The study has further developed solar radiation models for these new locations, as well as general ones for the entire region, which does not have any GSR models despite the existence of many planned solar energy facilities in this area. Additionally, the study investigates the effect of changing the length of the validation dataset on models’ performance and accuracy, as well as assesses the introduced models’ generalization capability. To achieve these objectives, the observed data of GSR for approximately 37 years at studied locations are used to develop and validate the proposed models. The study’s findings reveal that Model 1 provides the best performance at all locations, with accuracy, coefficient of determination ($$R^{2}$$ R 2 ), ranging from 95 to 98%, except for the coastal location, where it is from 91 to 95%. The remaining performance indicators of the best models, such as RMSE, MABE, MAPE, and $$r$$ r , are good, and their values range from 0.7863 to 1.9097 (MJ m−2 day−1), from 0.6430 to 1.7060 (MJ m−2 day−1), from 3.4319 to 10.0890 (%), and from 0.9914 to 0.9981, respectively. The length of the validation dataset has a slight effect on the models’ performance, ranging from about 1% to 2%. Therefore, Model 1 is the recommended solar radiation model, which can provide precise and rapid estimates of global solar radiation. This approach could be used in the design and performance evaluation of many solar applications. The primary benefit of this approach in the current investigation is that temperature data are continuously and effortlessly recorded for various purposes.