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The convergence of large language model (LLM) technology and instructional laboratory has been vividly demonstrated through ChatGPT’s role as ‘agents-to-think-with’ in structuring new experiments with smartphone-based radiation measurement. Collaborating with instructors, ChatGPT can initiate creative ideas, facilitate laboratory design, and even draft comprehensive laboratory manuals encompassing theoretical backgrounds, experimental procedures, safety guidelines, and questions for students. Furthermore, engaging with ChatGPT prompts students to deeply grasp the applicability of radioactivity concepts across diverse scenarios, effectively fostering ideas for other laboratory setups or future research projects. Recognising both the advantageous applications and inherent risks of radioactivity, students are encouraged to comprehend safety protocols and ethical considerations, a knowledge crucially conveyed by ChatGPT to the broader public as well. By bridging the gap between scientific expertise and public comprehension, ChatGPT empowers individuals to engage with radioactivity in a responsible, informed, and socially conscious manner. [ABSTRACT FROM AUTHOR]

BaO-B2O3 glasses doped with different Er concentrations were synthesized by the meltquenching technique. The Er concentrations were 1, 5, 10, and 15%. All the synthesized samples were transparent and homogeneous and exhibited near-infrared scintillation. The 5% Er-doped sample showed the highest scintillation intensity among all the samples, and the lower detection limit of the X-ray dose rate with our setup was 0.06 Gy/h. [ABSTRACT FROM AUTHOR]

This research project envisions using a lunar observation platform to measure the full-wave (0.2~100 μm) and shortwave (0.2~4.3 μm) radiation of the Earth, achieving an accurate estimation of the overall radiation budget of the Earth. Based on the lunar platform, the system analyzes Earth's radiation characteristics and geometric attributes, as well as the sampling properties of observation times. Informed by these analyses, an Earth-facing optical radiation measurement system tailored to these specifications is designed. The optical system adopts an off-axis three-mirror configuration with a secondary image plane, incorporating a field stop at the primary image plane to effectively suppress solar stray light, scattered lunar surface light, and background radiation from the instrument itself, ensuring the satisfactory signal-to-noise ratio, detection sensitivity, and observation duration of the instrument. At the same time, stringent requirements are imposed for the surface treatments of instrument components and temperature control accuracy to further ensure accuracy. Simulation analyses confirm that the design satisfies requirements, achieving a measurement accuracy of better than 1% across the entire optical system. This Moon-based Earth-radiation measurement system, with capabilities for Earth-pointing tracking, radiation energy detection, and stray-light suppression, furnishes a more comprehensive dataset, helping to advance our understanding of the mechanisms driving global climate change [ABSTRACT FROM AUTHOR]

Dental consultations are highly frequented in the healt area. Several medical devices converge in these settings. The use of electrical energy generates electromagnetic fields that affect the environment. To control this, there are recommendations issued by the International Commission on Non-Ionizing Radiation Protection. Therefore, measurements of the existing magnetic field in the dental consultation area of the CUJAE hospital were conducted to verify if the environmental values are within permitted limits using an EMDEX gaussmeter. The results indicated that when the equipment is operational, values exceeding 120 mG are reached near the pedestal. Although these levels are below the recommended limits, it should be borne in mind the levels they reach, especially since there is only one dental chair located in this area. [ABSTRACT FROM AUTHOR]

We quantified the level of backscatter radiation generated from physicians' heads using a phantom. We also evaluated the shielding rate of the protective eyewear and optimal placement of the eye-dedicated dosimeter (skin surface or behind the Pb-eyewear). We performed diagnostic X-rays of two head phantoms: Styrofoam (negligible backscatter radiation) and anthropomorphic (included backscatter radiation). Radiophotoluminescence glass dosimeters were used to measure the eye-lens dose, with or without 0.07-mm Pb-equivalent protective eyewear. We used tube voltages of 50, 65 and 80 kV because the scattered radiation has a lower mean energy than the primary X-ray beam. The backscatter radiation accounted for 17.3–22.3% of the eye-lens dose, with the percentage increasing with increasing tube voltage. Furthermore, the shielding rate of the protective eyewear was overestimated, and the eye-lens dose was underestimated when the eye-dedicated dosimeter was placed behind the protective eyewear. We quantified the backscatter radiation generated from physicians' heads. To account for the effect of backscatter radiation, an anthropomorphic, rather than Styrofoam, phantom should be used. Close contact of the dosimeter with the skin surface is essential for accurate evaluation of backscatter radiation from physician's own heads. To assess the eye-lens dose accurately, the dosimeter should be placed near the eye. If the dosimeter is placed behind the lens of the protective eyewear, we recommend using a backscatter radiation calibration factor of 1.2–1.3. [ABSTRACT FROM AUTHOR]

Purpose: This work investigated the dosimetric accuracy of the intensity‐modulated bolus electron conformal therapy (IM‐BECT) planning and delivery process using the decimal ElectronRT (eRT) treatment planning system. Methods: An IM‐BECT treatment plan was designed using eRT for a cylindrical, anthropomorphic retromolar trigone phantom. Treatment planning involved specification of beam parameters and design of a variable thickness wax bolus and Passive Radiotherapy Intensity Modulator for Electrons (PRIME) device, which was comprised of 33 tungsten island blocks of discrete diameters from 0.158 to 0.223 cm (Intensity Reduction Factors from 0.937 to 0.875, respectively) inside a 10.1 × 6.7 cm2 copper cutout. For comparison of calculation accuracy, a BECT plan was generated by copying the IM‐BECT plan and removing the intensity modulation. For both plans, a 16 MeV electron beam was used with 104.7 cm source‐to‐surface distance to bolus. In‐phantom TLD‐100 measurements (N = 47) were compared with both eRT planned dose distributions, which used the pencil beam redefinition algorithm with modifications for passive electron intensity modulation (IM‐PBRA). Dose difference and distance to agreement (DTA) metrics were computed for each measurement point. Results: Comparison of measured dose distributions with planned dose distributions yielded dose differences (calculated minus measured) characterized by a mean and standard deviation of −0.36% ± 1.64% for the IM‐BECT plan, which was similar to −0.36% ± 1.90% for the BECT plan. All dose measurements were within 5% of the planned dose distribution, with both the BECT and IM‐BECT measurement sets having 46/47 (97.8%) points within 3% or within 3 mm of the respective treatment plans. Conclusions: It was found that the IM‐BECT treatment plan generated using eRT was sufficiently accurate for clinical use when compared to TLD measurements in a cylindrical, anthropomorphic phantom, and was similarly accurate to the BECT treatment plan in the same phantom. [ABSTRACT FROM AUTHOR]

Sufficient dose reduction may not be achieved if radioprotective curtains are folded. This study aimed to evaluate the scattered dose rate distribution and physician eye lens dose at different curtain lengths. Using an over-couch fluoroscopy system, dH*(10)/dt was measured using a survey meter 150 cm from the floor at 29 positions in the examination room when the curtain lengths were 0% (no curtain), 50%, 75%, and 100%. The absorbed dose rates in the air at the positions of endoscopist and assistant were calculated using a Monte Carlo simulation by varying the curtain length from 0 to 100%. The air kerma was measured by 10 min fluoroscopy using optically stimulated luminescence dosimeters at the eye surfaces of the endoscopist phantom and the outside and inside of the radioprotective goggles. At curtain lengths of 50%, 75%, and 100%, the ratios of dH*(10)/dt relative to 0% ranged from 80.8 to 104.1%, 10.5 to 61.0%, and 11.8 to 24.8%, respectively. In the simulation, the absorbed dose rates at the endoscopist's and assistant's positions changed rapidly between 55 and 75% and 65% and 80% of the curtain length, respectively. At the 0%, 50%, 75%, and 100% curtain lengths, the air kerma at the left eye surface of the endoscopist phantom was 237 ± 29, 271 ± 30, 37.7 ± 7.5, and 33.5 ± 6.1 μGy, respectively. Therefore, a curtain length of 75% or greater is required to achieve a sufficient eye lens dose reduction effect at the position of the endoscopist. [ABSTRACT FROM AUTHOR]

The reduction in the effective dose of evacuated injured persons through contaminated areas of nuclear accidents is an essential emergency services requirement. In this context, there appeared a need to develop a dose-optimised route finding method for firefighting rescue vehicles, which includes the development of a real-time decision support measurement and evaluation system. This determines and visualises the radiation exposure of possible routes in a tested area. The system inside and outside of the vehicle measures the ambient dose equivalent rate, the gamma spectra, and also the airborne radioactive aerosol and iodine levels. The method uses gamma radiation measuring NaI(Tl) scintillation detectors mounted on the outside of the vehicle, to determine the dose rate inside the vehicle using the previously recorded attenuation conversation function, while continuously collecting the air through a filter and using an alpha, beta, and gamma radiation measuring NaI(Tl)+ PVT + ZnS(Ag) scintillator to determine the activity concentration in the air, using these measured values to determine the effective dose for all routes and all kinds of vehicles. The energy-dependent shielding effect of the vehicle, the filtering efficiency of the collective protection equipment, and the vehicle's speed and travel time were taken into account. The results were validated by using gamma point sources with different activity and energy levels. The measurement results under real conditions and available real accident data used in our simulations for three different vehicles and pedestrians proved the applicability of the system. During a nuclear accident based on our model calculations, the inhalation of radioactive aerosols causes a dose almost an order of magnitude higher than the external gamma radiation caused by the fallout contamination. The selection of the appropriate vehicle and its route is determined by the spectrum that can be measured at the accident site but especially by the radioactive aerosol concentration in the air that can be measured in the area. In the case of radiation measuring detectors, the shielding effect of the carrier vehicle must be taken into account, especially in the case of heavy shielding vehicles. The method provides an excellent opportunity to reduce the damage to the health of accident victims and first responders during rescue operations. [ABSTRACT FROM AUTHOR]

The outdoor gamma dose rate was measured in 540 locations in southern regions (Ramanathapuram, Virudhunagar, Tirunelveli, and Thoothukudi) of Tamil Nadu, India. The measured dose rates vary from 35 to 335 nSv/h (mean 89 nSv/h). The observed mean dose rate (89 nSv/h) is 2.3 times higher than the national (India) average of 39 nSv/h (56 nGy/h) and 2.1 times higher than the world average of 41 nSv/h (59 nGy/h). Annual Effective Dose (AED) calculated varies from 0.04 to 0.41 mSv/y (mean 0.11 mSv/y). The mean AED (0.11 mSv/y) is 1.6 times higher than the world average annual effective dose of 0.07 mSv/y. 30% of the locations have higher AED values due to the higher radiation in that locations. The present study reveals that the Tirunelveli district of the southern Tamilnadu region has higher gamma radiation than the other four districts of this region and is due to the topography of coastal and mountainous areas in Tirunelveli. The higher gamma radiation dose in the study area is due to the radionuclides present in the mountainous region's rocks and the coastal regions' soils. The radiological maps were used for spatial interpretation of the outdoor gamma dose rate in the study area. The radiological cancer risk assessment reveals that the Tirunelveli district has a higher risk due to the higher background gamma radiation. [ABSTRACT FROM AUTHOR]

Na2O-ZnO-TeO2-B2O3 (NZTB) glasses doped with Tm (0.1, 0.5, 1, and 2%) were synthesized by a conventional melt quenching technique, and their photoluminescence and scintillation properties were investigated. Some emission peaks due to the electronic transitions of Tm3+ appeared upon ultraviolet light and X-ray irradiation. Decay times were valid as the 4f-4f transitions of Tm3+. A 1% Tm-doped NZTB glass showed a full absorption peak under 241Am a-ray irradiation, and the light yield was estimated to be 51 photons/5.5 MeV-a when the peak channel was compared with a photoabsorption peak of 137Cs γ-rays measured with a Ce-doped Gd2SiO5 sample. [ABSTRACT FROM AUTHOR]

Undoped and Ce-doped Tb4O7-Al2O3 glasses without glass network-former oxides were synthesized by the containerless method. The X-ray diffraction measurement indicated that the synthesized glass samples were amorphous. In diffuse transmission spectra, the undoped sample showed absorption due to Tb4+, and the reduction of Tb4+ to Tb3+ was observed in Ce-doped samples. In X-ray-induced scintillation spectra, the Ce-doped samples showed luminescence due to the 4f-4f transitions of Tb3+. This result indicated that CeCl3 acted as a reducer and enhanced the luminescence due to Tb3+. In addition, the Ce-doped samples suppressed the thermally stimulated luminescence glow peaks at the low-temperature region. [ABSTRACT FROM AUTHOR]

0.1% BaCl2:Ce and BaCl2:Eu transparent ceramics were synthesized by the spark plasma sintering method, and the optical and dosimetric properties of BaCl2:Ce and BaCl2:Eu were compared. BaCl2:Ce and BaCl2:Eu transparent ceramics showed photoluminescence (PL) and optically stimulated luminescence (OSL) peaks at around 380 nm due to the 5d-4f transition of Ce3+ and Eu2+. The PL quantum yields of BaCl2:Ce and BaCl2:Eu transparent ceramics were 3.8 and 25.6%, respectively. The PL decay times of BaCl2:Ce and BaCl2:Eu were 21 and 400 ns, respectively. In OSL dose responses, the BaCl2:Eu sample showed better OSL intensity than BaCl2:Ce, and the OSL signal was detectable from 0.01 mGy. In terms of detection sensitivity, this value was comparable to those of some commercially available materials. [ABSTRACT FROM AUTHOR]

Pr-doped (Lu1− x , Y x )2Si2O7 (x = 0.25, 0.5, and 0.75) crystals were synthesized by the floating zone method. Emission peaks due to 5d–4f transitions of Pr3+ were observed at 300 nm under excitation of both UV light and X-rays. Scintillation decay times of 19–22 ns were obtained, and they originated from the 5d–4f transitions of Pr3+. Afterglow levels became high from 64.7 to 541 ppm as the Y-admixed concentration increased. The light yields were estimated to be 560–700 photons MeV−1 by comparing the channels of photoabsorption peaks from the pulse height spectra of 137Cs γ -rays measured using prepared crystals and commercial Gd2SiO5 reference. [ABSTRACT FROM AUTHOR]

Abstract Introduction Despite the development of DOSIRIS™, an eye lens dosimeter, the characteristics of DOSIRIS™ in the area of radiotherapy have not been investigated. The purpose of this study was to evaluate the basic characteristics of the 3‐mm dose equivalent measuring instrument DOSIRIS™ in radiotherapy. Methods Dose linearity and energy dependence were evaluated for the irradiation system based on the calibration method of the monitor dosimeter. The angle dependence was measured by irradiating from a total of 18 directions. Interdevice variation was repeated three times by simultaneously irradiating five dosimeters. The measurement accuracy was based on the absorbed dose measured by the monitor dosimeter of the radiotherapy equipment. Absorbed doses were converted to 3‐mm dose equivalents and compared with DOSIRIS™ measurements. Results Dose linearity was evaluated using the determination coefficient (R2) R2 = 0.9998 and 0.9996 at 6 and 10 MV, respectively. For energy dependence, although the therapeutic photons evaluated in this study had higher energies than in the previous studies and had a continuous spectrum, the response was equivalent to 0.2–1.25 MeV, well below the IEC 62387 limits. The maximum error at all angles was 15% (angle of 140°) and the coefficient of variation at all angles was 4.70%, which satisfies the standard of the thermoluminescent dosimeter measuring instrument. Accuracy of measurement was determined in terms of the measurement errors for DOSIRIS™ (3.2% and 4.3% at 6 and 10 MV, respectively,) using the 3‐mm dose equivalent obtained from the theoretical value as a reference. The DOSIRIS™ measurements met the IEC standard which defines the measurement error of ±30% of the irradiance value in IEC 62387. Conclusions We found that the characteristics of the 3‐mm dose equivalent dosimeter in a high‐energy radiation satisfy the IEC standards and have the same measurement accuracy as diagnostic areas such as Interventional Radiology.

In this study, a high sampling rate data acquisition system with the ability to provide timestamp, pulse shape information, and waveform simultaneously under a sub megahertz pulse counting rate was developed for radiation diagnostics for magnetic confinement nuclear fusion plasma research. The testing of the data acquisition system under the high pulse counting rate condition using real signals was performed in an accelerator-based deuterium-deuterium fusion neutron source (Fast Neutron Source) at the Japan Atomic Energy Agency. We found that the pulse counts acquired by the system linearly increased up to 6 × 105 cps, and the count loss at 106 cps was estimated to be ~10%. The data acquisition system was applied to deuterium-deuterium neutron profile diagnostics in the deuterium gas operation of a helical-type magnetic confinement plasma device, called the Large Helical Device, to observe the radial profile of neutron emissivity for the first time in a three-dimensional magnetic confinement fusion device. Time-resolved measurements of the deuterium-deuterium fusion emission profile were performed. The experimentally observed radial neutron emission profile was consistent with numerical predictions based on the orbit-following models using experimental data. The data acquisition system was shown to have the desired performance. [ABSTRACT FROM AUTHOR]

We use fast silicon detectors and the fast sampling method originally developed for high energy physics for two applications: cosmic ray measurements in collaboration with NASA and dose measurements during flash beam cancer treatment. The cosmic ray measurement will benefit from the fast sampling method to measure the Bragg peak where the particle stops in the silicon detector and the dose measurement is performed by counting the number of particles that enter the detector. [ABSTRACT FROM AUTHOR]

Introduction: Despite the development of DOSIRIS™, an eye lens dosimeter, the characteristics of DOSIRIS™ in the area of radiotherapy have not been investigated. The purpose of this study was to evaluate the basic characteristics of the 3‐mm dose equivalent measuring instrument DOSIRIS™ in radiotherapy. Methods: Dose linearity and energy dependence were evaluated for the irradiation system based on the calibration method of the monitor dosimeter. The angle dependence was measured by irradiating from a total of 18 directions. Interdevice variation was repeated three times by simultaneously irradiating five dosimeters. The measurement accuracy was based on the absorbed dose measured by the monitor dosimeter of the radiotherapy equipment. Absorbed doses were converted to 3‐mm dose equivalents and compared with DOSIRIS™ measurements. Results: Dose linearity was evaluated using the determination coefficient (R2) R2 = 0.9998 and 0.9996 at 6 and 10 MV, respectively. For energy dependence, although the therapeutic photons evaluated in this study had higher energies than in the previous studies and had a continuous spectrum, the response was equivalent to 0.2–1.25 MeV, well below the IEC 62387 limits. The maximum error at all angles was 15% (angle of 140°) and the coefficient of variation at all angles was 4.70%, which satisfies the standard of the thermoluminescent dosimeter measuring instrument. Accuracy of measurement was determined in terms of the measurement errors for DOSIRIS™ (3.2% and 4.3% at 6 and 10 MV, respectively,) using the 3‐mm dose equivalent obtained from the theoretical value as a reference. The DOSIRIS™ measurements met the IEC standard which defines the measurement error of ±30% of the irradiance value in IEC 62387. Conclusions: We found that the characteristics of the 3‐mm dose equivalent dosimeter in a high‐energy radiation satisfy the IEC standards and have the same measurement accuracy as diagnostic areas such as Interventional Radiology. [ABSTRACT FROM AUTHOR]

In this study, Ag2O–Cs2O–CaO–Al2O3–P2O5 glasses with different Ag concentrations (0, 0.1, 0.3, 1.0, and 3.0 mol.%) were made by the melt-quenching method. The photoluminescence (PL) properties, the radio-photoluminescence (RPL) phenomenon, and the spatial resolution of X-ray imaging based on RPL were studied to aim for the X-ray imaging application. The RPL phenomenon was observed as an appearance of a new PL emission at around 620 nm after X-ray irradiation. According to the shape of the PL spectrum and lifetime (13.1–16.7 ns), the luminescence was confirmed to be due to Ag2+. In addition, the 3.0% Ag-doped sample had the highest emission intensity of Ag2+. From the X-ray imaging resolution test, the 3.0% Ag-doped sample showed a spatial resolution of at least 10.0 LP mm−1. [ABSTRACT FROM AUTHOR]

We synthesized 20Lu2O3-30Ga2O3-50SiO2 glasses doped with various concentrations of Sn using a floating zone furnace equipped with Xe arc lamps. The samples showed a luminescence band around 450 nm in both photoluminescence (PL) and scintillation spectra. The origin of the luminescence was ascribed to the T1-S0 transition of Sn2+ on the basis of the luminescence wavelength and PL decay time constant. The highest scintillation intensity and PL quantum yield were observed from the 1% Sn-doped sample. The afterglow level tended to decrease with increasing Sn doping, and the afterglow levels of the 1 and 3% Sn-doped samples were comparable to that of the conventional Tl-doped CsI scintillator. The optimal concentration of Sn for the glass was estimated to be 1%. [ABSTRACT FROM AUTHOR]

In this study, we developed a neutron time-of-flight (nTOF) measurement system for a 1.7-MV tandem proton accelerator with a target covered with 300-nm-thick lithium (Li) layer. With implementation of beam chopping module after its ion source, the accelerator is configured to operate in pulsed-beam mode with a pulse width

Undoped and various concentrations of Nd-doped Ca 3 TaGa 3 Si 2 O 14 (CTGS) single crystals were fabricated via the floating zone technique. The luminescence and radiation response characteristics were investigated. A broad intrinsic luminescence was observed at 300–600 nm. Sharp luminescence appeared at 900, 1060, and 1300 nm in Nd-doped samples and they originated from 4f–4f transitions of Nd3+. Photoluminescence quantum yields were calculated to be 44.7, 94.1, 87.4, and 75.5% in 0.1, 0.5, 1, and 2% Nd-doped samples, respectively when monitored at near-infrared (NIR) ranges. Linear responses between dose-rate and scintillation outputs in NIR regions were confirmed in Nd-doped samples. The 0.5% Nd-doped CTGS achieved a detection limit of 1 mGy/h. • Nd-doped Ca 3 TaGa 3 Si 2 O 14 single crystals were successfully grown via the floating zone method. • VUV–visible light excited luminescence and scintillation properties under X-rays were investigated. • A quantum yield of the 0.5% Nd-doped Ca 3 TaGa 3 Si 2 O 14 was 94.1% when monitored at near-infrared ranges. • The best lower detection limit in prepared samples was 1 mGy/h obtained by the 0.5% Nd-doped Ca 3 TaGa 3 Si 2 O 14. [ABSTRACT FROM AUTHOR]

In this study, we developed Ce:GAGG ceramic scintillators (containing 5 × 5 × 2 mm3 Ce:GAGG single crystals) encapsulated by different light reflectors, namely, Teflon (400 μm), an enhanced specular reflector film (65 μm), and a titanium dioxide (TiO 2) reflector with different thicknesses and measured their γ-ray spectra under irradiation by a 137Cs radioactive source. The reflectance of a 100-μm-thick (optimal thickness) TiO 2 layer demonstrated higher reflectance than other the TiO 2 reflectors of other thicknesses, and resulted in a high light-collection efficiency. To assess the temperature dependence of the reflectors, the samples were heated up to 300 °C in air. The measured reflectance decreased with increasing temperature, and the color of the reflector's surface changed. The observed variations in the surface morphology, measured by scanning electron microscopy, corresponded to the determined reflectance of the TiO 2 layer. Upon heating above 200 °C in air, the TiO 2 layer decomposed into other oxides, with a simultaneous increase in its surface porosity. By contrast, the Ce:GAGG single-crystal sample heated at 300 °C in vacuum showed only a negligible color variation, retained 80.3% of its initial reflectance, and exhibited an energy resolution of 12.8%. This result suggests oxidation as the potential cause of performance degradation. In addition, a TiO 2 layer covered with a heat-resistant epoxy isolated reflections from air, thus exhibiting a performance comparable to that of the without-epoxy sample. This result confirmed that a passivation layer may allow the use of reflectors at high temperatures. The results obtained in this study suggest that a TiO 2 layer can be used as a long-wavelength reflector in oxide and other types of scintillators for efficient radiation detection in harsh environments, including air-free environments, such as in aerospace, under vacuum conditions or in the presence of a protective passivation layer. • Compatibility of TiO 2 reflectors with Ce:GAGG in harsh environments studied. • Reflectance decreased with increasing temperature; optimal TiO 2 thickness: 100 μm. • Above 200 °C in air, the TiO 2 layer decomposed, and its surface porosity increased. • Vacuum-heated reflector retained 80.3 % of its initial reflectance at 300 °C. • Scintillator with vacuum-heated reflector showed a 12.8 % energy resolution. [ABSTRACT FROM AUTHOR]

Standardized radiation measurements can be simulated by various numerical or analytical approaches. In this article, a transfer function method is proposed for a fast and accurate antenna voltage prediction. Assuming that the interference source can be characterized as a linear Norton equivalent current source, its internal admittances and source currents are determined from measurements made with a vector network analyzer and an oscilloscope. The setup of the radiation measurement is described as a transfer function using its scattering parameters. A system of equations is set up with the multiport theory and solved for the antenna voltage, which is fed into a spectrum analyzer model. The result is compared to a measurement in a fully anechoic chamber. The method is extended to interference sources with stochastic signals, and, in the course of this, an approach for the estimation of the radiation measurement is developed. A dc motor is used as an application example. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this work is to evaluate the Standard Imaging Exradin W2 plastic scintillation detector (W2) for use in the types of fields used for stereotactic radiosurgery. Methods: Prior to testing the W2 in small fields, the W2 was evaluated in standard large field conditions to ensure good detector performance. These tests included energy dependence, short‐term repeatability, dose‐response linearity, angular dependence, temperature dependence, and dose rate dependence. Next, scan settings and calibration of the W2 were optimized to ensure high quality data acquisition. Profiles of small fields shaped by cones and multi‐leaf collimator (MLCs) were measured using the W2 and IBA RAZOR diode in a scanning water tank. Output factors for cones (4–17.5 mm) and MLC fields (1, 2, 3 cm) were acquired with both detectors. Finally, the dose at isocenter for seven radiosurgery plans was measured with the W2 detector. Results: W2 exhibited acceptable warm‐up behavior, short‐term reproducibility, axial angular dependence, dose‐rate linearity, and dose linearity. The detector exhibits a dependence upon energy, polar angle, and temperature. Scanning measurements taken with the W2 and RAZOR were in good agreement, with full‐width half‐maximum and penumbra widths agreeing to within 0.1 mm. The output factors measured by the W2 and RAZOR exhibited a maximum difference of 1.8%. For the seven point‐dose measurements of radiosurgery plans, the W2 agreed well with our treatment planning system with a maximum deviation of 2.2%. The Čerenkov light ratio calibration method did not significantly impact the measurement of relative profiles, output factors, or point dose measurements. Conclusion: The W2 demonstrated dosimetric characteristics that are suitable for radiosurgery field measurements. The detector agreed well with the RAZOR diode for output factors and scanned profiles and showed good agreement with the treatment planning system in measurements of clinical treatment plans. [ABSTRACT FROM AUTHOR]

Purpose: This study aimed to quantitatively evaluate the range uncertainties that arise from daily cone-beam CT (CBCT) images for proton dose calculation compared to CT using a measurement-based technique. Methods: For head and thorax phantoms, wedge-shaped intensity-modulated proton therapy (IMPT) treatment plans were created such that the gradient of the wedge intersected and was measured with a 2D ion chamber array. The measured 2D dose distributions were compared with 2D dose planes extracted from the dose distributions using the IMPT plan calculated on CT and CBCT. Treatment plans of a thymoma cancer patient treated with breath-hold (BH) IMPT were recalculated on 28 CBCTs and 9 CTs, and the resulting dose distributions were compared. Results: The range uncertainties for the head phantom were determined to be 1.2% with CBCT, compared to 0.5% for CT, whereas the range uncertainties for the thorax phantom were 2.1% with CBCT, compared to 0.8% for CT. The doses calculated on CBCT and CT were similar with similar anatomy changes. For the thymoma patient, the primary source of anatomy change was the BH uncertainty, which could be up to 8 mm in the superior–inferior (SI) direction. Conclusion: We developed a measurement-based range uncertainty evaluation method with high sensitivity and used it to validate the accuracy of CBCT-based range and dose calculation. Our study demonstrated that the CBCT-based dose calculation could be used for daily dose validation in selected proton patients. [ABSTRACT FROM AUTHOR]

PurposeThis study aimed to quantitatively evaluate the range uncertainties that arise from daily cone-beam CT (CBCT) images for proton dose calculation compared to CT using a measurement-based technique.MethodsFor head and thorax phantoms, wedge-shaped intensity-modulated proton therapy (IMPT) treatment plans were created such that the gradient of the wedge intersected and was measured with a 2D ion chamber array. The measured 2D dose distributions were compared with 2D dose planes extracted from the dose distributions using the IMPT plan calculated on CT and CBCT. Treatment plans of a thymoma cancer patient treated with breath-hold (BH) IMPT were recalculated on 28 CBCTs and 9 CTs, and the resulting dose distributions were compared.ResultsThe range uncertainties for the head phantom were determined to be 1.2% with CBCT, compared to 0.5% for CT, whereas the range uncertainties for the thorax phantom were 2.1% with CBCT, compared to 0.8% for CT. The doses calculated on CBCT and CT were similar with similar anatomy changes. For the thymoma patient, the primary source of anatomy change was the BH uncertainty, which could be up to 8 mm in the superior–inferior (SI) direction.ConclusionWe developed a measurement-based range uncertainty evaluation method with high sensitivity and used it to validate the accuracy of CBCT-based range and dose calculation. Our study demonstrated that the CBCT-based dose calculation could be used for daily dose validation in selected proton patients.

With significant upgrades over the last decade, the Department of Energy's Atmospheric Radiation Measurement (ARM) radar network now features multiple scanning dual-polarization Doppler radars to exploit polarimetric, multifrequency, and multi-Doppler [...]

Even the best-instrumented supersite cannot observe the atmosphere sufficiently to infer everything researchers want to know. In particular, researchers continue to struggle to connect localized observations to scales relevant for [...]

In this study, we constructed an image reader system for two-dimensional radiation dosimetry based on radiophotoluminescence (RPL). The reader system mainly consists of a Peltier-cooled CMOS camera and an LED excitation source, as well as control units, and it offers an arbitrary excitation wavelength (e.g., 365, 405, 460, 530, and 630 nm) and a wide spectral detection range (200-1000 nm) to be used for a wide range of prototype image detectors having different spectral features. Using the developed system, we were able to successfully obtain X-ray projection images recorded on a commercial RPL detector [Ag-doped phosphate glass (Ag-PG) plate] as well as custom-made prototypes of flexible imaging plates (IPs). Furthermore, the reader system is applicable not only for RPL imaging but also for conventional optically stimulated luminescence (OSL) imaging, which was demonstrated by using a commercial IP for medical diagnosis. [ABSTRACT FROM AUTHOR]

We use fast silicon detectors and the fast sampling method originally developed for high energy physics for two applications: cosmic ray measurements in collaboration with NASA and dose measurements during flash beam cancer treatment. The cosmic ray measurement will benefit from the fast sampling method to measure the Bragg peak where the particle stops in the silicon detector and the dose measurement is performed by counting the number of particles that enter the detector.

A rotating shadow-band spectroradiometer system is a powerful tool for surveying light in an environment. It can provide the following spectral components of the solar irradiance without using any traditional solar tracking tool: direct normal irradiance (spDNI), diffuse horizontal irradiance (spDHI), and global horizontal irradiance (spGHI). Both irradiances, spDNI and spDHI, are derived from the combination of spGHI observations at different shadow-band positions. The shadow-band system induces basic errors caused by the imperfect corrections of the diffuse irradiance shadowed by band. To restrict the basic errors to < 2 %, the band slant-angle should be < 72° for a usual operating condition of the MS-700 spectroradiometer manufactured by EKO Instruments Co., Ltd., with the MB-20 shadow-band system for MS-700. The errors in the spDNI and spDHI estimation are evaluated quantitatively by using realistic models that consider instrumental and atmospheric conditions. Estimates of spDNI can result in optical depth errors. The relative error in this estimation is described by using a correction coefficient Cfwd defined by the ratio of the true diffuse irradiance simulated by the shadowed irradiance to the approximate value observed. The value of Cfwd depends on the magnitude of the aerosol optical depth as well as the aerosol type. This error analysis should help in improving the accuracy of this system of measurements. [ABSTRACT FROM AUTHOR]

CaSiO3 crystals doped with 0.5%, 1.0% and 2.0% Ce were developed using the floating zone method, and the scintillation and thermally-stimulated luminescence (TSL) properties were evaluated. Under X-ray irradiation, the emission peaks due to the 5dâ€"4f transitions of Ce3+ appeared at 360 nm in all the samples. Under 241Am 5.5 MeV α -ray irradiation, a clear full-energy peak appeared in all the samples, and the light yield of the 2.0% Ce doped-sample was 1040 ph/5.5 MeV- α. As a TSL dosimeter, the samples were very sensitive to X-rays and showed a good linear response from 0.1 to 1000 mGy, which was equivalent to the measurable sensitivity of commercial dosimeters for personal dose monitoring. [ABSTRACT FROM AUTHOR]

In this study, we present a preprocess method using radiation energy intervals on a gamma-ray spectrum based on a deep learning algorithm to achieve real-time radionuclide identification. Data preprocessing is performed by classifying energy intervals, distinctly corresponding to pulse amplitudes of each radiation measurement system. Since the energy intervals are distinguished with noise, backscatter area, Compton edge, and photopeaks depending on radionuclides, raw data are sorted in each interval in preprocessed dataset using a deep learning algorithm. Using60Co,137Cs, and the energy interval preprocessing, the multi-source identification shows 100% accuracy in 2000 measured data compared with 70% accuracy for those without the preprocessing method. The measured time is 72 s for 2000 test data, dramatically reduced from the conventional data collection time of 60 min for 100 000 data. The proposed approach reduces the minimum number of data to identify radionuclides before visualizing the spectrum. With the preprocess method, radionuclide identification is completed in tens of seconds, applicable for low radiation activity areas such as decommissioning reactor sites. [ABSTRACT FROM AUTHOR]

Thermally stimulated luminescence (TSL), optically stimulated luminescence (OSL), and radio-photoluminescence (RPL) are radiation-induced luminescence phenomena, and they are widely used for radiation dosimetry today. Despite their successful applications, the R&D of conventional and new phosphor materials is still actively performed in a wide range of research fields from basic science to application. Although these phenomena are considered to be different, they share common physical processes such as the generation, trapping, and transfer of electronic charges. In order to have a deeper look into these phenomena, it is important to comprehensively characterize those of a single material. For this, we have constructed a prototype TSL/OSL/RPL automated and integrated measurement system (TORAIMS), and then the system performance has been studied. The system offers automated and integrated measurement of several different TSL, OSL, and RPL properties, and it is also designed to cover many different phosphor materials having a wide variety of spectroscopic properties. [ABSTRACT FROM AUTHOR]