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Currently, no cost-effective and sustainable substitutes were developed for gel dosimeters. However, the properties of saluyot (Corchorus olitorius) may be integrated to improve the dose-response of the gel matrix. The study aimed to make a gel dosimeter using saluyot leaves. Specifically, this study aimed to describe the physical characteristics and assess the radiation detection capability of the fabricated saluyot gel dosimeter and to generate a dose-response curve using the ROI and R2 values. Saluyot leaves were sun-dried for 24 hours and powdered. The gel formulation consisted of gelatin (250 Bloom, Porcine) and finely powdered saluyot leaves which varied in the range of 4-9%, resulting in a mixture of 13% with 87% water for the final formulation. The gels were irradiated using a 6 MV photon beam by a LINAC. MRI was used as the imaging technique to scan for the dose distribution of the irradiated gel dosimeter. The images were subjected to post-analysis after scanning. The physical qualities of each dosimeter changed after irradiation, but the measured absorbed doses were in the range of the established limits. Based on the dose-response curvature and linearity, the 4% to 7% concentrations were the optimal range for an organic gel dosimeter. Lastly, this study showed that the ROI and stability were inversely related to the concentrations of powdered saluyot leaves. [ABSTRACT FROM AUTHOR]

The present study aims to measure background radiation of natural radioactivity (Dose rate, Annual Effective Dose, and Effective Long Cancer Risk) in thirty locations at different hospitals and government institutions in Karbala governorate. The results using the dosimeter are shown that the average value of (D), (AAED), and (ELCR) due to background radiation in the soil at 50 cm and 100 cm are 0.01 ± 0.008µSv/h, 0.089 ± 0.073 mSv/y, 0.036,0.017 ± 0.005µSv/h,0.152 ± 0.048 mSv/y and 0.061 respectively. The minimum and maximum values of the Dose rate at 50 cm are (0.005, 0.01µSv/h and 0.016,0.01µSv/h), while at 100 cm are (0.004 0.01µSv/h and 0.13 0.01µSv/h) respectively. The minimum and maximum values of AAED at 50 cm are (0.044 mSv/y and 0.14 mSv/y), while at 100 cm are (0.035 mSv/y and 1.139 mSv/y) respectively. The minimum and maximum values of ELCR at 50 cm are (0.018 and 0.056), and at the same time, at 100 cm are (0.014 and 0.445) respectively. All results are drawn by using a statistical program named SPSS version 26.0 and the GIS system. Therefore, the radiological hazard index and background radiation levels in most soil samples in the study region of Karbala, Iraq, do not threaten human health. [ABSTRACT FROM AUTHOR]

A thin film made from polyvinyl chloride (PVC) and methyl yellow (MY) was developed for potential application as a dosimeter for gamma irradiation. The PVC-MY film dosimeter was prepared by a simple solvent-casting method of the homogeneous solution containing PVC and MY. To investigate the potential application of the PVC-MY film as a dosimeter, the film was exposed to gamma radiation at absorbed doses of 0–20 kGy with a dose rate of 3.1 kGy/hour. The optical properties of the PVC-MY film were observed using a UV-Vis spectrophotometer in the wavelength range of 550–300 nm. The absorption spectra of different PVC-MY films revealed that the PVC-MY film has a maximum absorption at 419 nm and 527 nm. The absorption of the PVC-MY film at 419 nm decreased gradually as gamma-irradiation doses increased, while the film absorption at 527 nm increased as gamma-irradiation doses increased. The change in the absorption behavior of the PVC-MY film was also manifested in the change of the film color, where increasing radiation doses changed the film's color from yellow to red. The gamma dose-response curves of the PVC- MY film had a high correlative coefficient when described by a logarithmic function. These results demonstrated that PVC-MY film might potentially be a gamma-irradiation dosimeter in the dose range of 0–20 kGy. [ABSTRACT FROM AUTHOR]

Gypsum was commonly material required for many types of construction. Nowadays, many buildings/homes in the community have used this material. Gypsum contains hydrous sulfate of Calcium (CaSO4.2H2O). Calcium sulfate has widely used as a dosimeter due to its high TL sensitivity to radiation. Two types of gypsum that are widely used in Indonesia were investigated as possible dosimeters for emergency purposes. The other properties of gypsum such as crystal structure using X-ray Diffraction (XRD) and material composition using X-ray Fluorescence (XRF) were also investigated. The gypsum samples were grinded and packed to be irradiated using Cs-137 with dose variations 0.2, 0.5, 1.0, 2.0, 5.0, 7.5, 10.0 and 15.0 mGy. These samples were read using TLD Reader Harshaw 3500. The thermoluminescence (TL) responses were similar for both samples and it gives the linear response. Based on the study, gypsum was feasible to estimate exposure to the community during a nuclear emergency. [ABSTRACT FROM AUTHOR]

Linear accelerator (Linac) measurements for software Treatment Planning System (TPS) heaver have been carried out using a phantom slab. This study aims to examine and determine the proportion of deviations between the computerized treatment Planning System (TPS) and the output of the linear accelerator (Linac) machine using a slab phantom and to determine the Percentage Depth Dose (PDD) curve between the two. The dosimeter used in the measurement is the Wellhofer IC 70 Farmer ionization chamber detector which uses an IBA electrometer through a coaxial cable. Linear accelerator (Linac) output measurement results are calculated using TRS-398. The phantom was irradiated using 6 MV photon beam X-rays at a depth of 1.5 cm, 5 cm, 10 cm, and 15 cm with variations in field area of 5x5 cm2, 8x8 cm2, 10x10 cm2, and 15x15 cm2 for each depth. The Source Surface Distance (SSD) irradiation conditions were 100 cm, the dose depth was 10 g/cm2, the dose rate was 300 MU/min, the tumor dose was 100 cGy for software Treatment Planning System (TPS), and the administered dose was 100 MU for linear accelerator (Linac). Of the 16 data deviations between calculations on the computerized software Treatment Planning System (TPS) and the radiation output of the linear accelerator (Linac) machine as a whole, it shows that there is a balance with the proportion ranging from-4%-5%. Based on the results of the study obtained deviations that still meet the recommended tolerance value. [ABSTRACT FROM AUTHOR]

We analyzed dose rate data of space neutron and gamma radiation during several flight with various destinations, i.e. Jakarta – Kupang, Kupang – Jakarta, Jakarta – Pontianak, and Pontianak – Jakarta. Data were collected using personal radiation dosimeter (RadEye for neutron and Dosicard for gamma radiation) during flights from take off until landing at the destination airports. As expected, the higher the aircraft from sea level, the radiation received are higher also, but the behaviour of the neutron and gamma radiation are different. The neutron radiation received are more erratic compared with that of the gamma radiation. We found the correlation between the height of the aircraft and neutron and gamma radiation dose rates with correlation coeficient values of 0.89, 0.86, 0.90, 0.87 respectively for neutron radiation and 0.91, 0.95, 0.84, 0.88 respectively for gamma radiation. We found the empirical relations between latitude and dose rates of neutron and gamma radiation in the height of 35.000 feet from the sea level as Dn = −0.034 Lat + 1.036 for neutron dose rates and Dg = −0.027 Lat + 0.636 for gamma radiation dose rates. [ABSTRACT FROM AUTHOR]

In this study, Poly(O-toluidine)/Multi-Walled Carbon Nanotube/Polystyrene (POT/MWCNT/PS) films were prepared by casting and irradiated with different doses of gamma rays (0, 3, 5 kGy) at room temperature to manufacture a polymer gamma ray dosimeter. The effect of these rays on the physical properties of the samples was investigated in terms of their structure, morphology, optical, and electrical conductivity. The effect of irradiation on the morphology of the prepared films and their crystal structure was explored by scanning electron microscopy and X-ray diffraction. The electrical conductivity of unirradiated POT.MWCNT/PS films increased from 1.89×10−8 S/cm to 5.61×10−8 S/cm after exposure to 5 kGy dose gamma irradiation. The absorbance and transmittance spectra of POT.MWCNT/PS films were recorded. An analysis of these spectra shows that the optical transitions are an allowed direct transition and the irradiation increases the value of the optical energy gap. The above influences on the physical properties of POT.MWCNT/PS films due to gamma rays make them a candidate for use as a gamma ray detector. [ABSTRACT FROM AUTHOR]

OSL dosimeter as a passive radiation measuring dosimeter can be an option to replace radiation measurement instrument containing electronic circuit. In this study, dose response on environmental OSL (optically stimulated luminescence) dosimeters to industrial and medical at tube potential 80 kV X ray exposure and their linearity were tested. The effect of fading on reading repeatability after the OSL dosimeters stored were examined. Forty-eight OSL dosimeters were annealed and read to ensure that the dose information was reset to zero. Then they were packed using Al foil to prevent light exposure. The dosimeters are divided into 2 groups, namely 24 dosimeters for irradiation of industrial X ray and the rest for medical X ray. Each of them is divided into 6 groups consisting of 4 dosimeters each. The five groups were irradiated at 0.5 mSv, 1 mSv, 2.5 mSv, 5 mSv and 10 mSv at a distance of 200 cm with an additional filter of 0.59 mm Cu for industrial X ray and 0.3 mm Cu for medical X ray. While the rest consisting of 8 dosimeters were as control dosimeters. All dosimeters were read using the OSL microStar Reader. The result shows that the ratio of the measured dose to the exposure dose on industrial X ray is ≥0.89 for≥2.5 mSv exposure. It was different when it compared to the response with 1 mSv and 0.5 mSv exposure that the ratio is ≤0.61. Moreover, the smaller the dose of exposure, the deviation of the measured dose to the exposure dose is greater. Meanwhile, ratio measured dose to exposure dose in the medical X ray did not show a tendency as in the industrial X-ray exposure. Deviation of the measured dose to exposure dose in medical X ray is ≤22%. The fading effect of OSL dosimeter on the 12th day reading dose on industrial X ray was ≤6% while for medical X-ray showed a fading ≤7% on 14th day. It can be seen that the fading effect on the OSL dosimeter to X ray is relatively small. Linearity curve shows that the correlation between the measured dose to the exposure dose at industrial X-ray is linear with a correlation factor (R2)≥0.999. Meanwhile, linearity on medical X ray indicates R2 value≥0.997. The experiment showed that the relationship between measured dose to exposure dose on industrial and medical at tube potential 80 kV X ray was linier. After 2 weeks stored the fading effect of OSLD was relatively small. [ABSTRACT FROM AUTHOR]

Radiation dosimeters are essential in dose measurement in radiation therapy. Dosimetry in radiation therapy is based on determination of absorbed dose to water in a radiation beam quality (DW,Q). When dose is measured in a detector, the conversion of radiation dose from detector to water relies on several correction factors. Recently, chlorophyll dosimeter has been proposed in radiation therapy. This study aims the application of Monte Carlo (MC) simulation technique to determine the correction factors for chlorophyll based chemical dosimeter. BEAMnrc code of the EGSnrc MC simulation toolkit has been utilised to simulate a 6 MV photon beam from Elekta VersaHD medical linear accelerator (linac). Accuracy of the MC model has been validated by gamma analysis of measured and MC calculated beam data. The DOSXYZnrc code has been used to simulate the water phantom and the chlorophyll dosimeter inside it. The non-water equivalence of the dosimeter correction factor (fw,chl), wall correction factor (Pwall) and volume averaging correction factors (Pv) have been calculated. The MC calculated and measured data has been found to be within 2 % dose difference and 2 mm distance to agreement criteria of gamma. The values of correction factors: fw,chl = 0.969, Pwall = 0.995 and Pv = 0.999 have been obtained. The largest correction comes from non-water equivalence of the dosimeter followed by polypropylene wall and volume averaging respectively. These correction factors can be utilised for determination of Dw,Q from dose to chlorophyll (Dchl). [ABSTRACT FROM AUTHOR]

EBT3 radiochromics film is a dosimeter commonly used in radiation oncology because it has properties equivalent to tissue or water, high spatial resolution, low dependence on energy and dose. Consequently, the accuracy and precision during the dose reading procedure of the EBT3 must be excellent accomplished during radiation therapy treatment. The objective was to evaluate the dosimetry of the EBT3 radiochromic using the transmission and reflection mode scanning method for radiation therapy. This study used an EBT3 radiochromic film with a size of 2.5×3 cm² and irradiated with 6 MV photons and 6, 8, 10, 12, and 15 MeV electrons. The EBT3 film irradiation process used a surface axis distance (SAD) of 100 cm, solid water phantom for the scattering medium, and an irradiation field of 10×10 cm². Each EBT3 film was irradiated using prescribed energy at doses of 0, 100, 200, 300, 400, 500, 600, and 700 cGy. The digitalization process of EBT3 film used an Epson V850 Pro flatbed with a resolution of 72 dpi, 48-bit RGB, no correction color, using reflection and transmission modes. The pixel value reading of the EBT3 film used Image-J to obtain a calibrating curve for EBT3 film in each photon and electron energy range. The results showed that the transmission mode had a higher accuracy than the reflection mode for all dose and energy ranges, while the reflection mode had a higher sensitivity than the transmission mode. [ABSTRACT FROM AUTHOR]

Radiation dosimetry using EPR is one of the most accurate and reliable techniques for passively evaluating radiation doses and is characterized by its non-destructive readout. In this manuscript, cystine is proposed as a radiation dosimeter using EPR. Cystine, a sulfur-containing amino acid, was studied from the EPR spectroscopy point of view, where its unirradiated and 1kGy gamma-irradiated samples spectra were recorded and analyzed. Samples were exposed to radiation doses ranging from 10 Gy to 1000 Gy. A direct and uniform relationship was found between the intensity of the peak-to-peak amplitude of the radiation-induced EPR signals and the received radiation dose. On the other hand, tissue equivalency over a wide range of photon energies was investigated. Furthermore, the time dependence of the radiation-induced radicals has been traced over 35 days which revealed that the decay behavior of the cystine radical EPR spectrum is predictable and shows reasonable stability enabling its use as a transfer dosimeter. [ABSTRACT FROM AUTHOR]

The present study measured the dose rate to the background radiation of soil samples collected from all Najaf districts at Al-Najaf governorate, Iraq using portable radiation dosimeter type Inspector Exp. made in the USA. Also, annual average effective dose (AAED) and excess lifetime cancer risk (ELCR) were determined as well as all results were drawn by the GIS(ArcGIS 10.7.1.) technique. The results show that the average values with stander error for dose rate (µSv/h), AAED (mSv/y), and ELCR×10−3 were 0.121±0.004, 1.06±0.03, and 3.73±0.12, respectively. The background radiation from soil samples was determined for each district indicate that the Najaf city can be regarded as having normal levels of background radiation which suggests that it does not pose any health hazards or radiological effects for the inhabitant of the study area. [ABSTRACT FROM AUTHOR]

In this study, an environmental dose response of OSL dosimeter to 137Cs gamma photon irradiation and its acceptability according to the criteria in General Safety Guide No. GSG-7 were examined as well as the linearity correlation between the measured dose to its exposed dose. Thirty two OSL dosimeters were annealed and then read to confirm that the dose information was already reset into zero. The dosimeters were divided into 8 groups that each of them consists of 4 OSL dosimeters. Each group was irradiated with gamma radiation at 0.1 mSv, 0.25 mSv, 1 mSv, 2.5 mSv, 3 mSv, 5 mSv and 10 mSv at a distance of 200 cm from the source without an absorber. All dosimeters were read using the OSL microStar Reader. The result of the analysis using the trumpet curve equation provides the acceptable value for the exposed dose at ε 0.5 mSv. Linearity analysis for the exposed dose of 0.5 mSv to 10 mSv shows a linear trend with a correlation factor (R2) of 0.999 and a linear equation of Y = 1.061 X - 0.222. The measured dose to 137Cs gamma photon irradiation was responded if exposed dose as more than 0.222 mSv. [ABSTRACT FROM AUTHOR]

As a portable calibration media, acoustic comparison coupler has been designed, and therefore, it is intended to be applied for acoustic instrument calibration such as sound level meter and noise dosimeter. In addition, its performance has been discussed in the previous paper, where the result is acceptable to be used further. However, the calibration result using this prototype has not been identified yet. In this work, testing of the sound level meter according to the international standard IEC 61672 has been implemented using this acoustic calibration media by the two methods that consist of substitution method and direct comparison method. Therefore, the frequency weighting was chosen as the representative parameter. In addition, the result shows that the deviation of calibration result between these methods is slight for the aforementioned parameter. [ABSTRACT FROM AUTHOR]

The calibration of noise dosimeter based on a percentage of noise dose exposure has been conducted in Laboratory of Acoustics and Vibration, Sub-directorate of National Measurement Standards for Acoustics and Vibration, National Standardization Agency of Indonesia (SNSU-BSN). The aim of this work is, therefore, to realize calibration of noise dosimeter of the aforementioned parameter using two methods at the frequencies of 125 Hz, 250 Hz, 500 Hz, 1000 Hz, 2000 Hz, 4000 Hz, and 8000 Hz. The first method is carried out by comparing the measurand between the reference and DUT (device under test) by a substitution technique. Meanwhile, for the second method, the main parameter indicated by the two instruments will be compared directly. The determined parameter is a percentage of noise dose exposure that can be calculated from sound pressure levels (SPL) of 104 dB, and 114 dB respectively at the specific duration time. In the first method, the maximum deviation was found at the frequency of 4000 Hz and 8000 Hz that whose value is 2.3 % for the horizontal position, and 2.2 % belongs to the vertical position. Meanwhile, for the second method, the maximum deviation of percentage dose is obtained about 4.3 % and 4.1 % for the two positions respectively. In addition, these methods are necessary to be validated using the absolute method that was recently under research. [ABSTRACT FROM AUTHOR]

Radiation applications today are widely encountered, one of which is in the medical field. In working, workers are required to pay attention to the dose that must be considered not to exceed the dose limit value. To monitor the dose, TLD can be used as a radiation dosimeter. However, in practice, it cannot be denied that mistakes can occur in dosimeter use. The study aimed to analyze the effect of the TLD chip position on the dose-response of the 3D printed head phantom. The 3D printed head phantom is printed similarly to the human head in which it is equipped with an artificial brain and artificial Cerebro Spinal Fluid (CSF). This study used TLD-700H. The TLD-700H was irradiated with a 137Cesium irradiator. The error value of Hp(3) dose can be achieved in the range of 1 to 14% against the ideal TLD position and 2 to 18% on the 3D printed head phantom to the ideal TLD position of CIRS CT Dose Phantom. [ABSTRACT FROM AUTHOR]

The main problem of radiation therapy is damage to normal tissues. One of the ways to solve this problem is radiomodification using cerium oxide nanoparticles (CONP's). The protective effect of CONP's can be measured with ferrous sulfate dosimeter (FSD). The dose modifying factors for tissue equivalent solution of FSD with CONP's in concentration 0.5 mg/ml irradiated by bremsstrahlung of 9 MeV electron beam were calculated. The addition of nanoparticles led to significant reduction in adsorbed dose. [ABSTRACT FROM AUTHOR]

This paper presents the results of the energy and angular dependence calculations and experimental verification of the military dosimetric device DP-86 probe. This device was designed to measure the gamma radiation dose rate of nuclear weapons fall out, that means the fission products mixture. The beta emission can also be roughly estimated. Based on these results was calculated the time dependence of the device response to nuclear weapon fallout. [ABSTRACT FROM AUTHOR]

Interventional cardiology and radiology workers are exposed with occupational radiation. Radiation workers must use not only personal dosimeter; but also eye lens dosimeter in order to maintain the dose that does not exceed the dose limit value set by Nuclear Energy Regulatory Agency (Bapeten) which is 20 mSv a year with no single year exceeding 50 mSv. In order to provide a reliable with affordable price dosimeter, a new eye lens dosimeter was developed at NuklindoLab using TLD-900 (CaSO4:Dy) disc for measurement of dose in term of Hp(3). The type testing including homogeneity test, linearity of dose response, angular dependence test, and determining detection threshold were done after the irradiation carried out in Secondary Standard Dosimetry Laboratory (SSDL) Agensi Nuklear Malaysia. The method of the irradiation was based on ISO 4037-3 and the reference of the type testing was based on ISO 12794. The coefficient of variance (CV) value from homogeneity test results 4.8%, the linearity test result R2 values vary from 0.998 to 0.999, the angular dependence result ranges from 0% to 19% with average value 12.9%, and the detection threshold of SOCA dosimeter value was 0.35 mSv. [ABSTRACT FROM AUTHOR]

This paper presents the result of the development of a small-sized X-ray intensity sensor. For a large number of X-ray dosimetry tasks, it is not necessary to use expensive dosimeters to estimate the radiation dose. The developed intensity sensor allows to qualitatively evaluate the dose of radiation absorbed in the object, while having small dimensions and cost. The work describes the internal structure of the sensor, its design. The method of conducting the study using the device is presented, as well as additional possibilities of using the sensor are described. [ABSTRACT FROM AUTHOR]

We present results of the development of two personal dosimetry devices, called 4-FRD and Koph/Shin, based on thermoluminescent dosimeters. 4-FRD uses TLD-100 and different filters, while Koph/Shin uses a TLD-100/TLD-300 combination. These devices were calibrated for 15-1250 keV photons (4-FRD) and 15-65 keV (Koph/Shin), in terms of air kerma. 4-FRD was able to determine Effective Dose (E) with ∼33% relative expanded uncertainty (k=2), while Koph/Shin determined E with ∼16% relative expanded uncertainty. Both fulfilled ICRP recommendations for personal dosimetry devices in terms of uncertainty. [ABSTRACT FROM AUTHOR]

Introduction: Accurate radiation dose measurements at non-target tissues in external beam radiation oncology treatments has become a relevant issue in modern clinical practice. In these cases, low doses out-of-the-treatment-field (OTF) were considered those less than 20% of the prescribed dose beyond 1 cm from field edge defined by jaws. In this work we compare dosimetric response of the optically stimulated luminescence dosimeter OSLD nanoDot versus ionization chamber (IC) and treatment planning system (TPS) Modular Integrated Radiotherapy System (MIRS) v.5.1 and Eclipse (AAA) in cases of water phantom, anthropomorphic phantom CIRS and in vivo tests on points OTF in IMRT with compensator filters. Method: I) in a water tank phantom using 6 MV photon beam (Varian Clinac iX). Exposures were carried out with open field and adding a scatter element (cerrobend compensator filter) at 2.5, 4.5 and 6.5 cm from field edge. II) in anthropomorphic thorax CIRS phantom for an IMRT plan with compensator filters, measurements were made at 4 cm OTF. III) in IMRT plans for 20 intracavitary in vivo dosimetry (IVD) measurements were carried out (on average 9 cm distance OTF). Dosimeters were placed in the oral cavity and rectum. Results: I) In water phantom, OSL response closely followed the IC measured dose: absolute difference of 2.6% in open field and 4.4% with presence of scatter element up to 6.5 cm OTF. Absolute differences showed that both TPS MIRS and Eclipse underestimated doses up to 55.7% and 39.4% respectively in presence of scatter elements up to 6.5 cm from field edge. II) In anthropomorphic phantom, in terms of absolute differences, OSL measured dose followed IC up to 3%. TPS MIRS underestimated doses up to 34.5%. III) intracavitary in vivo dosimetry measurements for OSL and TPS MIRS showed absolute difference dose underestimation up to 42%. Conclusions: Different experiments showed a reliable response of OSL nanoDot versus IC. Both TPS MIRS and Eclipse (AAA) show limitations to determine and to model OTF dose with differences up to 55.7%. Multiple tests has shown OSLD nanoDot with a correct and adequate low dose calibration curve is a viable detector to measure OTF dose since there is no need for correction factors for spectral changes as suggested by Bordy et al. It is important to continue researching dosimetry in anatomical regions at OTF low doses due to probable long-term biological effects. [ABSTRACT FROM AUTHOR]

Mean Glandular Dose (MGD) is obtained from air kerma measurements, compressed breast characteristics, and beam quality, usually using an ionization chamber (IC). We have developed a system called M3D to evaluate MGD using thermoluminescent dosimetry. The system consists of two PMMA phantoms, one to obtain the radiological techniques for different breast thicknesses and the other to measure air kerma and half-value-layer. In this work, we have redesigned the first phantom to have a variable thickness, and we have evaluated two alternative methods for the use of thermoluminescent dosimeters to measure the required kerma and half-value-layer: use of TLD-100 and Al foils, or a combination of TLD-100/ TLD-300. In the second method, the TLD-300 glow curve shape was analyzed as a vector and was used to determine beam quality. Results showed that the kerma measured by both methods were equivalent to the use of an IC. Typical MGD uncertainties were about 14% and 35% for the two methods, respectively, and these figures rule out the use of the TLD-100/TLD-300 combination for this application. We have concluded that the newly designed M3D system is an option to determine MGD for different breast thicknesses. [ABSTRACT FROM AUTHOR]

Introduction: In vivo dosimetry (IVD) is the tool that has been shown to be suitable for verification and improvement on the accuracy of dose delivery and to prevent accidents during radiotherapy treatment. OSLD nanoDot complies with the characteristics to perform intracavitary IVD: being small-sized, they show little or no dependence on variables such as temperature, dose rate, field size, among others. The goal of this work is to define confidence and action levels for intracavitary IVD in intensity modulated radiotherapy (IMRT) at high dose gradient regions (HDGR). Method: OSLD nanoDot were prepared following the TG-191 AAPM international guideline. Commissioning test: OSLD response at HDGR in the penumbra region of an open field with a dedicated acrylic phantom was evaluated and compared with an ionization chamber. Geometrical uncertainties were evaluated as i) dosimeter location at planar digital images, ii) internal anatomical movements, iii) construction and placement of compensator filters and iv) mechanical indicators of the linear accelerator such as gantry, telemeter, laser, among others. Dosimetric impact was evaluated by relative difference considering calculated dose at distant points ±5 mm on anteroposterior direction at HDGR at rectum as organ at risk (OAR) in prostate cancer treatments. In vivo dosimetry test: a small ergonomic silicone device contained two dosimeters and they were placed on 23 patients. Patients gave their consent to participate in this statistical study. Geometrical coordinates of the dosimeters location were acquired by anteroposterior and lateral planar digital images. Coordinates were imported to the treatment planning system Modular Integrated Radiotherapy System (MIRS) v.5.1 (Nuclemed S.A., Argentina) and dose was determined at these points. Results: OSLD response followed with good agreement ionization chamber response over the entire penumbra region and the maximum distance to agreement (DTA) is 1.2 mm. Total geometrical uncertainty was ±5 mm. On the basis of intracavitary IVD, confidence (CL) and action levels (AL) were defined for HDGR. CL was ±19.2% and AL was ±37.1%. Conclusion: Geometrical uncertainty analysis associated to IMRT and intracavitary IVD has excellent correspondence to action level defined. With the correct characterization of the OSLD nanoDot, this detector becomes a good option for its implementation in intracavitary IVD at HDGR. [ABSTRACT FROM AUTHOR]

Tabletop and compact fusion sources are in much demand because of their efficiency in producing mono- energetic particles that find application in various societal usages. Inertial Electrostatic Confinement Fusion (IECF) based source, in particular, stands as one of the vital sources for producing neutrons, protons, X-rays, etc. The most promising applications of the device include neutron activation analyses (NAA), neutron radiography, medical isotope production, explosive detection, etc. IECF is basically a fusion concept wherein the lighter fuel ions (deuterium, tritium) are trapped in a converging electrostatic field inside a cylindrical or spherical geometry. A cylindrical IECF device is in operation at our center and it has been emitting a copious amount of 2.45 MeV DD fusion neutrons. The device primarily consists of a cylindrical wire grid electrode assembly housed inside a cylindrical vacuum chamber, a gas insertion system, a high voltage feedthrough, and a high voltage power supply of negative polarity. On the application of a high negative potential of few tens of kV (∼ 80 kV) to the inner grid of the device, the energetic ions overcome the coulomb barrier force and thus fuse together to produce neutrons of the order 106 n s−1. The emitted neutrons from the device are characterized by employing various detectors such as neutron area monitor, He-3 proportional counter, bubble dosimeters etc. The neutrons emitted from the device were utilized for the detection of explosive. The detailed results are discussed in the paper. [ABSTRACT FROM AUTHOR]

A PET-CT procedure has many steps that contribute to the occupational radiation exposure of a nuclear medicine staff. Most of them are well studied, measured, and documented except for the radiation emission of an actual PET acquisition. This study aims to fill that knowledge gap. We measure the estimated whole-body radiation exposure to nuclear medicine staff during a PET acquisition of a routine whole-body PET-CT procedure by electronic pocket dosimeters for 1 month at a distance of 1.0, 1.5, 2.0, and 3.0 m from the center of the PET-CT machine. PET acquisition radiation emission measurements of 159 subjects (83 M, 76 F) who underwent whole-body PET-CT were included in the study. Average radiation emission rate at 1.0, 1.5, 2.0, and 3.0 m from the center of the PET-CT machine were; 6.94 0.85, 0.14 0.60, 0.99 1.38 and 0.02 0.22 µSv/hr respectively. In our study, based on subject's weight, emission rates follow the general rule in radiation emission, the heavier the subject, the higher the radiation. Among the different types of malignancy evaluated by PET-CT, lymphoma exhibited the highest emission rate at 5.4 µSv/hr, followed by thyroid and lung cancer at 4.48 and 4.26 µSv/hr, respectively (p ¡ 0.001). The estimated annual radiation emission from a PET acquisition was 3.98 (1.0 m), 0.08 (1.5 m), 0.58 (2.0 m) and 0.01 (3.0 m) mSv/yr. Computed annual whole-body occupational dose rate are the following 9.74 (1.0 m), 5.84 (1.5 m), 6.34 (2.0 m), 5.77 (3.0 m) mSv/yr, respectively, which are below the regulatory limit (p <0.001). Computed annual radiation emission from a PET acquisition of a whole-body PET-CT procedure, was relatively low. Incorporating this data to other radiation-emitting PET-CT steps, annual occupational radiation exposure estimate to the nuclear medicine staff will not exceed regulatory limit. Lymphoma showed the highest radiation emission rates among the different types of malignancy but data is inconclusive. [ABSTRACT FROM AUTHOR]

Soda-lime glass was examined as a dosimeter for substantial gamma (y) radiation doses by estimating the changes affected as a result in the range of 320-800 nm in optical absorbance at room temperature. Observation concluded that absorbance expanded with the expanding gamma doses absorbed. Dynamics of morphology and the optical aspect of irradiation glasses were examined by utilizing absorption spectra and relaxation spectroscopy. UV-Vis spectroscopy was used to record optical absorption spectra. According to the spectra of optical absorption, optical band gap, the cutoff wavelength, refractive record, and Urbach energy were resolved and identified with the auxiliary variations in the glass frameworks by various gamma dosages. In the blooming exploratory setup, a 532 nm CW laser was utilized as an excitation source. The experimental results showed that the thermal diffusivity value of Soda-lime glass increases when the gamma (γ) radiation doses increased. [ABSTRACT FROM AUTHOR]

Silica-based optical fibres present significant benefits when incorporated in severe locations related to radiation restrictions. Typically, microelectronic devices were effected by high doses radiation or having low sensitivity for low radiation doses which could affect the obtained readings, while optical fibres had high sensitivity towards these ranges. When the optical fibres exposed to radiation; the radiation will modify the fibre characteristics through generation the point defects of fibre core and cladding material. The formation of the point defects affects the amplitude and kinetic of Radiation-Induced Absorption (RIA) and Radiation- Induced Emission (RIE). In this work a modified cladding optical fibre sensor for low radiation detection had been submitted. This was achieved through etched single mode fibres to different diameters (60 and 50) µm. Then coated with germanium to produce modified cladding fibres. The modified region had been exposed to different UV irradiation energies which considered as low radiation source. The optical properties of the fibre and sensing performance had been investigated. A decreasing of intensity and shifting towards the long wavelengths had been obtained for the different stages of manufacturing sensors (standard, etched, and modified cladding fibres). This behaviour was more clear with fibres of less diameter. Different energies of UV irradiation (0-40) µJ had been applied to modified cladding fibres with different diameters (60 and 50) µm. As the energy of UV irradiation increases, the light intensity decreases due to larger attenuation growth in the irradiated sensor fibres. The RIA decreases spatially due to the role of Ge dopant in governing the fibre response to radiation and the nature of defects involved in the absorptions process. [ABSTRACT FROM AUTHOR]

Indoor environments contribute to gamma radiation in the general population. The aims of the present study were to investigate average gamma radiation doses in the indoor dwellings. Also to compare indoor dose measured with personal exposure. Hence accumulated indoor gamma dose were evaluated around a prospective Uranium mining area of Gogi village, Yadgir district, North Karnataka, India. A passive measurement technique was adopted for the measurement of dose in the present study i.e. using thermoluminescent dosimeter (TLD). Also an active measurement was carried out in order to compare with the passive results using RadEye personal radiation dosimeter. The dwellings selected are at a 5 km radius from the Uranium mining area. A TLD is employed in the dwelling at about 2m above the ground level and 30cm away from any wall or surface. A total of 100 dwellings were selected for the study during the month January to April, 2013. The average annual effective dose estimated for TLD in Gogi region was found to be 0.69 mSv y-1 and 0.49 mSv y- 1 for RadEye survey meter. The dose rate is higher for RCC than other type of dwellings. [ABSTRACT FROM AUTHOR]

The quenching of sensitivity of non-gaseous dosimeters exposed to charged particles was studied, in particular with reference to gel dosimeters and gafchromic EBT3 films. The studies were focused to dosimetry for Hadron Therapy and boron neutron capture therapy (BNCT). A correction coefficient can be more easily determined for BNCT dosimetry, while it is complex to correct the dosimeter response in the case of charged particle beams for Hadron Therapy. A proposed method for correcting the measured images is in continuous development. [ABSTRACT FROM AUTHOR]

Carbon doped alumina (Al2O3:C) finds widespread use being a highly sensitive Optically Stimulated Dosimeter(OSL) phosphor. The enhanced sensitivity of this material is correlated with the number of anion vacancies produced during its synthesis. There have been a few studies which attempt to unravel the mechanism of this enhancement by looking at the effects of Al/O vacancy/substitution by C atoms. In this work, we find that there is a preferred inter-defect separation when producing two Al/O vacancies. The defect formation energies and density of states are also computed. [ABSTRACT FROM AUTHOR]

Carbon doped alumina (Al2O3:C) finds widespread use being a highly sensitive Optically Stimulated Dosimeter(OSL) phosphor. The enhanced sensitivity of this material is correlated with the number of anion vacancies produced during its synthesis. There have been a few studies which attempt to unravel the mechanism of this enhancement by looking at the effects of Al/O vacancy/substitution by C atoms. In this work, we find that there is a preferred inter-defect separation when producing two Al/O vacancies. The defect formation energies and density of states are also computed. [ABSTRACT FROM AUTHOR]

The glow curve of the CaF2:Tm thermoluminescent dosimeter (TLD-300) has the remarkable property of showing sensitivity to the energy of the radiation field. Careful analyses of the TLD-300 glow curve enable to determine the effective energy of the incident low- and intermediate-energy X ray photons, with a typical accuracy of 1 keV. The effect is consequence of different efficiencies for the high- and low-temperature peaks as a function of the secondary spectrum ionization density. Since the TLD-300 dosimeters have parallelepiped shape (3.2 × 3.2 × 0.89 mm³) and the spectra incident on its different sides do suffer a distinctive spectral hardening as they traverse the dosimeter, we have investigated the dependence of the emitted light and the glow curve shape on the beam direction of incidence with respect to the dosimeter geometrical shape. We have exposed dosimeters to photon spectra with effective energies between 15 and 60 keV (mammography and computed tomography, CT, beams) and studied the integrated TL response and the glow curve, for irradiations in air (essentially uni-directional) and inside phantoms (with an important multi-directional component from scattered radiation). Two limit cases were investigated: beam incidence on the main face (3.2 × 3.2 mm²) and incidence on a side face (3.2 × 0.89 mm²). A rigorous glow curve deconvolution process was applied to obtain 7 peaks, following our laboratory protocol. The observations with CT beams were interpreted by Monte Carlo simulations. Results showed that for irradiation in air, the ratio of integrated thermoluminescent response after side- and main-face exposures was about 0.3 at mammography energies (15 - 17 keV effective energy) and about 0.8 at CT energies (45 - 58 keV effective energy). These ratios became 0.6 - 0.7 and 0.9 - 1.0, respectively, inside plastic phantoms appropriate for each clinical modality. The glow curve analysis showed that, both for mammography and CT energies inside a phantom, there is no statistically significant difference between the effective energies obtained after main- and side-face exposures. We have concluded that exposure of TLD-300 inside phantoms can determine the radiation field effective energy for beams which are similar to those in this study, independent of the dosimeter orientation with respect to the primary beam. [ABSTRACT FROM AUTHOR]

In this study we investigate the performance of a new commercial 2D diode array SRS MapCHECKTM for its clinical use. The performance of the SRS MapCHECKTM was evaluated using wedge profiles compared with EBT3 radiochromic film measurements and with the profiles obtained from the treatment planning system. The results show a good correspondence between the two dosimeters. The absolute dosimetric evaluation for an end to end test with EBT3 film and PinPoint 3D ionization chamber was performed and the results showed local percentage differences less than 1.1% in both cases. Ten intracranial radiosurgery treatment plans were irradiated with all fields composite at 0° and the measured dose distributions were compared with the calculated ones. The average for gamma index result of (2%/1.5mm) was 97.21%. The SRS MapCHECKTM offers the dosimetric characteristics required in relative and absolute dosimetry for the verification of intracranial radiosurgery treatments (in restricted collapsed test of gantry at 0°). [ABSTRACT FROM AUTHOR]

Cosmic rays represent not only a significant health risk to the crew of spacecraft and aircraft but also a fundamental phenomenon of basic research on the origin and composition of the universe. High-energy atmospheric physics is a newly opened research domain which focuses on research of terrestrial gamma-ray flashes that can measurably contribute to the aircraft-crew irradiation according to the preliminary computer simulations. High-mountain observatories are suitable places for both the continual monitoring of cosmic radiation and the detection of ionizing radiation generated by lightning. Liulin Mobile Dosimetry Unit (MDU) is a silicon diode based radiation dosimeter developed by the team of Tsvetan Dachev at the Bulgarian Academy of Sciences, initially for the MIR space station. It is widely used as an instrument for radiation monitoring on board aircraft, on high altitude observatories as well as for example for ion fragmentation studies. The AIRDOS dosimeter is an open source device for measurement in low intensity mixed ionising radiation fields. In its aircraft version, it houses silicon PIN diode as a radiation detector, an electronics for conversion of the signal to the pulse-height spectra, Global Positioning System (GPS) module, memory card and batteries for one-month monitoring. The hardware design of AIRDOS is built on the Open Hardware modular platform MLAB, the firmware is written in Open Software platform Processing. Full documentation is freely available. Two AIRDOS devices have been installed at Basic Environmental Observtory (BEO) Moussala in December 2017, complementing the radiation and environment monitoring instruments already available, including the Liulin MDU. Preliminary results of comparative measurements of radiation environment at BEO Moussala using the AIRDOS units and Liulin MDU will be presented. The results from BEO Moussala will be compared with data acquired on board aircraft. [ABSTRACT FROM AUTHOR]