Light emission in radiation detectors can increase due to nanoparticles presence. OSL detectors based on Brazilian natural CaF2 with silver nanoparticles (Nps-Ag/CaF2) were produced. It was observed an enhancement of OSL intensity from CaF2 detectors with Nps-Ag.
BNCT, optical fiber-based neutron detector, moderator-based neutron energy spectrometer
FNTDs (Fluorescence Nuclear Track Detector) exposed to fast neutrons were analyzed by acquiring a stack of images using a 2D-galvo FNTD reader. These stacks of images were processed to reconstruct the 3D recoil proton trajectories, providing ultimately an effective delta electron signal filtering and offering additional information on the exposure conditions.
We report plastic scintillators containing organic phosphors with aggregation-induced emission (AIE) properties. The optimum phosphor concentration was investigated upon changing the concentration of the phosphor. All of the as-prepared samples emitted scintillation light. Interestingly, the photoelectric peaks of the pulse height spectra were confirmed in the samples to which a large amount of phosphor were added.
The development of modern heavy-ion accelerators is associated with an increase in beam intensity.
Accordingly, with high-intensity heavy-ion beams, the actual problem is beam diagnostics by non-destructive methods, because using of contact methods for beam diagnostics is impossible due to the high power of the beam.
The beam diagnostics by non-destructive methods can be implemented on the basis of radiation detection resulting from the interaction of a heavy ion beam with accelerator construction materials.
Chips of CaSiO3 have been produced for ion accelerated detection.
Irradiations with 290 MeV/n Carbon and 160 MeV proton.
TL response, after irradiation, presented two prominent peaks at 120 °C and 270 °C.
Doses from proton and carbon ions were compared with gamma doses from Cs(137) source.
A low cost multi-sample integrated thermo luminescence/optically stimulated luminescence (TL/OSL) reader (MS-ITOR) has been developed for various application. This reader system can handle 36 aliquots at a time. Apart from measuring the TL and OSL the reader has in-built irradiation and optical bleaching facilities.
Different concentrations of Eu doped LiMgAlF6 samples were synthesized by the spark plasma sintering method. Eu-doped LiMgAlF6 showed an intense thermally stimulated luminescence (TSL).
An instrument has been designed to image the recently identified Stokes-shifted IR-photoluminescence emission for routine measurements on large rock slices. Using samples of K-feldspar, appropriate routine measurement protocols were established and demonstrated.
Novel semiconductor devices for real-time sub-mm resolution dosimetry were developed.
This paper presents a new automatic algorithm for TL Glow Curve (GC) categorization. Possible irregular GCs can be automatically identified by this new procedure. The presented algorithm can be routinely used for quality control measures in individual monitoring services.
The precise energy measurement of an a particle using a silicon semiconductor detector (SSD) is very important to identify whether the a particle is emitted through the decay chain of superheavy elements (SHEs) with atomic numbers Z>103. The measurement of the total kinetic energy (TKE) of fission fragments generated through the decay of SHEs is also reliable because a high TKE indicates that fission occurred from a very heavy nucleus. It is necessary to evaluate the dead-layer thickness of the SSD to correct the measured energy to the initial energy of an a particle or the TKE of the fission fragment. To evaluate the dead-layer thicknesses of SSDs, energy spectra were first investigated using 241Am by irradiating a-rays at incident angles of 0, 25, and 45° for three types of SSD. The dead-layer thicknesses of the SSDs were deduced by comparing the peak shifts related to the incident angle of 0° with those obtained by a computer simulation using the particle and heavy ion transport code system (PHITS).
The effect of the body size on the detection efficiency of a newly developed thyroid monitor was estimated by Monte Carlo simulations using several voxel phantoms. The discrepancy from the efficiency in calibration was found to be 30 % at the maximum.
We studied a new effective energy measurement method using stacked thermoluminescence dosimeters (TLDs). We were able to obtain the decay curves through analyzing the relationship between the absorber depth and the absorbed dose, because the stacked small TLD plates have two functions as an absorber and a dosimeter. Given the importance of calculating the effective energies, the further study of this method would be of value to the field of radiation exposure dose management.
In this study, Tb3+- or Dy3+-doped CaO–Al2O3–B2O3 glasses were prepared with nB, 10B, and 11B, and thermoluminescence (TL) properties irradiated with X-ray, heavy particles, or neutron were investigated. X-ray- or heavy-particles-induced TL properties of 10B glass was similar to that of nB or 11B glass, but neutron-induced TL properties of 10B was not similar to that of 11B glass.
The DIAµDOS guard-ring microdosimeter prototypes have been fabricated at the Diamond Sensor Laboratory of the CEA in France. The characterization of the diamond detectors has been performed with the use of ion microbeam facilities at AIFIRA in France and ANSTO in Australia. The DIAµDOS detector has been evaluated by means of experimental measurements at CPO in France and experimental results supported by GEANT4 simulations.
The response to dose of commonly used solid state dosimeters show a strong energy dependence in the low energy range. Here we explore the alanine/EPR response to dose-to-water for a low filtered 40kV x-ray beam, and correct for the dose gradient within the 2.7mm thick dosimeter.
An inter-comparison of personal electronic dosimeters used by various nuclear facilities was performed. The overall results suggest that these active dosimeters have achieved the same dose responses as those passive dosimeters at each facility for legal dose records.
The transmission silicon strip detector is a dual purpose device capable of providing real time dosimetric data in addition to beam monitoring for rapid response in case of incident during treatment. The effect of a 375 µm thick transmission detector upon the depth dose response within solid water and a water tank was measured with a pinpoint ionisation chamber. The experimental results were found to be in agreement with Monte Carlo simulation results for three different beam filtration configurations corresponding to three different mean energies. The amount of perturbation (1-5%) of the beam due to the thick transmission detector directly corresponds to the mean energy and thus beam filtration used. Silicon based transmission detectors are deemed to be a suitable material of choice given accurate compensation of the known beam attenuation during the treatment planning.
The response of organic photodetectors for use in medical radiation therapy including, dose linearity, energy dependence and dose rate dependence, is characterised. Prior exposure to ionizing radiation (40kGy) increases device sensitivity.
A new RPL readout system has been developed to obtain dose in the range between 1 Gy and 1 MGy. The system combines the measurement of the emitted RPL light with a transmission measurement to cover the aforementioned dose range.
• Bismuth-doped plastic scintillators were successfully fabricated.
• The maximum value of detection efficiency is 2.3%.
• The time resolution hardly depends on the concentration of Bi, and has high values between ~0.2–0.3 ns.
Ce doped LaCl3/AECl2 (AE=Mg,Ca,Sr) system eutectics were explored. Ce:LaCl3/CaCl2 showed light output of 9,000 photon/MeV. Scintillation decay time of the Ce:LaCl3/CaCl2 was 26.8 ns (26%) 282 ns (74%).
This work studied the microdosimetric distributions and corresponding the relative biological effectiveness (RBE) of different ions, namely 12C, 14N and 16O, using a silicon-on-insulator (SOI) microdosimeter with well-defined 3D sensitive volumes (SV). We demonstrated the possibility of using SOI microdosimeter for Q ̅ and Hp(10) derivation in a radiation field mimicking Galactic Cosmic Rays outside and inside the International Space Station.
NOVAC 7 mobile IntraOperative Radiation Therapy (IORT) that involves the administration of a single dose of radiation to the tumor during surgery. To measure the relative dosimetry like Output Factors, PTW 60019 microDiamond detector exhibited the best performance.
A tailor made equipment was made for advance lyoluminescence (LL) measurements. The LL measurements were applied to recover information about absorbed dose in pure NaCl and halite crystals. Spectral properties of the emission were analyzed.
• The dosimeter can be cured by the photopolymerisation process in any shape
• Fluorescence response of the dosimeter serves as a tool for measuring depth-dose distributions
• Measured depth-dose profiles can be used as a dose verification in radiation processing of surfaces
Spectrum of X-rays around 20keV was estimated using high-performance Peltie type cloud chamber. Such low energy X-rays knock out photoelectrons that fly only several mm in air. Measurements of track length in cloud chamber give energy distribution of these photoelectrons. The track length was calibrated by characteristic X-rays from several metals excited by Sr-90 shielded beta-source.
The laser-accelerated protons from hydrogen clusters are measured by CR-39 track detectors. A step-wise energy moderator is installed in front of CR-39 to obtain the energy spectrum with the resolution of a few MeV. The designed detector unit revealed that the maximum energy and energy spectra depends on the size distributions of the hydrogen clusters.
Laser-based Thermoluminescent Dosimetry (TLD) can deliver very high heating rates. It is simple and can be used for measurements in remote locations. Noncontact close-loop temperature control makes more accurate results.
・Photoluminescence and scintillation properties of TlSr2Cl5 were studied.
・TlSr2Cl5 crystals were prepared under vacuum using a self-seeding solidification method.
・TlSr2Cl5 crystals showed broad emission bands peaking at 450 and 500 nm under X-ray excitation.
・Light yield of TlSr2Cl5 crystals reached 16,000 photons/MeV under gamma-ray irradiation.
The photoluminescence and scintillation properties of TlMg(Cl1–xBrx)3 were studied.
・TlMg(Cl1–xBrx)3 crystals were prepared under vacuum using a self-seeding solidification method.
・TlMg(Cl1–xBrx)3 crystals showed emission bands at 420 nm under X-ray excitation.
・The light yields obtained for TlMg(Cl1–xBrx)3 crystals can reach 45,000 photons/MeV upon gamma-ray excitation.
A new neutron radiography method was developed for fast neutron measurement, in which b-rays from irradiated threshold detectors such as 27Al(n,a)24Na and 24Mg(n,p)24Na are transferred and accumulated on X-ray imaging plate (IP).
Flexible OSL detectors with CaSO4:Dy were produced to be used for dose mapping. The matrix of the detector is based in high temperature silicone that allows thermal bleaching. OSL dosimetric properties demonstrate potential application in radiation measurements.
Fluorescent nuclear track detectors (FNTD) based on LiF crystals were successfully used for imaging tracks of various ionizing particles. This was achieved by exploiting photoluminescence of radiation induced F2 and F3+ color centers and a wide-field fluorescence microscope.
Dosimetrics GmbH München has developed a new detector element based on BeOSL technology. It can be used for extremity dosemeters without compromising the concept of automated bulk processing.
This study will firstly report the photo-physical and scintillation properties on different Pr concentrations in Lu2Si2O7 single crystals. Photoluminescence (PL) quantum yield (QY), scintillation light yield and other properties has been observed. Throughout the systematic studies on these properties, we found the optimum concentration for the Pr doped in Lu2Si2O7 for scintillator purpose.
This communication describes the different versions of a broad energy range, directional, neutron spectrometer consisting of several solid-state detectors within a single cylindrical moderator. Appropriate choice of detectors and dimensions made it suitable for a wide range of applications.
The CR-39 track detectors were used to measure neutrons emitted from DT neutron generator. The Monte Carlo simulations of experimental setup were performed. Activation method was used as a complementary diagnostics.
Thermal neutron fluxes of therapeutic intensities (> 1 × 109 cm-2 s-1) are required for basic researches of boron neutron capture therapy (BNCT). We developed polyethylene moderators obtaining the thermal neutron fluxes of 1.8 × 109 cm-2 s-1 in NIRS accelerator-based neutron source, named NASBEE facility. Additionally, dose contaminations of fast neutrons and gamma rays are estimated using CR-39 nuclear track detector and optically stimulated luminescence (OSL, Al2O3:C) dosimeters.
We developed new bulk-density controlled thermoluminescence dosimeters (TLDs) based on Al2O3 ceramics, aimed at developing an anthropomorphic dosimeter for photon radiation therapy. Their potential was evaluated by measurements of thermoluminescence (TL) properties and theoretical calculations.
Polyvinyl alcohol-iodide (PVA-I) radiochromic gel dosimeter utilizes the red-coloration due to PVA-iodide complex formed in the gel matrix by irradiation. The transparency is improved significantly by optimizing of the composition and the addition of sucrose without impairing the other desirable properties such as the high sensitivity and the dose-rate-independence. Furthermore, it is also found that the addition of sucrose results in the suppression of auto-oxidation of the gel dosimeter.
The portable thyroid dose monitoring system available in a situation of a severe nuclear accident is in development. In this presentation, the detailed design of the thyroid dose monitor and experimental results using prototype model will be described.
An in-situ, sub-surface environmental monitoring system is described based on radiophotoluminescence (RPL) from Ag-doped alkali-phosphate glass. The system uses a fiber-optic probe encased in a metal or plastic sheath. Once placed in the ground dose measurements can be made in-situ.
Designed calculations, simulation, and fabrication of a Nested Neutron Spectroscopy (NNS) have been carried out in this study based on MCNP6 and PHITS codes and a CAD software. With some benefits as light-weight and field portable, cylinders easily be positioned upright on a flat stand, quick configuration for measurements in demanding environments, and able to run in the current mode for high flux environments, the aims of this study is to fabricate the NNS system.
The RPL depth profiles of microscale patterns in Ag-activated glass and LiF crystal written using proton and carbon beams are compared and evaluated using multi- and single-photon microscopes.
A real-time fibre-optic-coupled dosimetry system using Ag-activated phosphate glass and LiF crystal based on the radiophotoluminescence phenomena are demonstrated.
Conceptual design of a passive TL/OSL dosemeter with ability of deconvolution of ambient photon energy composition. Application areas are emergency response (first respondents, military) and other applications where knowledge of incident photon spectrum is essential. The design is substantiated by Monte Carlo calculations and energy spectrum deconvolution algorithm.
Performance of a 2nd generation of Fluorescent Nuclear Track Detector (FNTD) reader prototype, utilizing laser line excitation and parallel multipixel fluorescence readout is described. The instrument demonstrated a 30-time increase in the readout speed, compared to the speed of the 1st generation commercial reader and improved image quality. The fluorescent imaging of 32 mm2 of FNTD area takes about 3 min and provides the sensitivity of 21 tracks/mm2/mSv for the Am-Be neutrons. Blind tests of the new reader prototype after irradiation with Am-Be neutrons in combination with M30 X-ray photons were performed and have demonstrated compliance with the ISO-14146 standard.
The responses of a diamond detector to gamma-rays, neutrons and alpha-particles were measured and simulated. We demonstrated that a diamond detector can be used for neutron dosimetry under extreme radiation environments with high-level gamma-ray contamination.
Real-time neutron personal dosimeters based on silicon sensor indicate smaller neutron energy response functions than the ICRP dose response curves at the neutron energy range between 10 keV and 1 MeV. Measurement values of these dosimeters are dependent on neutron fields having different energy spectra due to the disagreement between the energy response of dosimeters and the ICRP curves. We have simulated the neutron energy responses using PHITS3 code to improve the energy responses, by considering neutron angular responses in the response functions and reproducing a package of thermal neutron absorber.
A correction method for the background photons in high dose rate environment was developed to apply to the thyroid dose monitoring using the portable thyroid dose monitoring system developed at the Japan Atomic Energy Agency.
Stationary and portable equipment for OSL dosimetry based on BeO is presented, with an achievable coefficient of variation of 0.66 % for the OSL signal induced by the same dose with more than 100 repeats for a single MyOSLdosimeter.
Simulation of experimental chemical cross section induced by ions in a poly allyl diglycol carbonate (PADC – CR39) based on the radial dose deposited by secondary electrons removed by the incoming ion.
The proton-boron fusion reaction was investigated within the Plasma Focus facility. The distribution and energies of fast protons emitted during Plasma Focus discharges were determined. The CR-39 track detectors and silicon detector were used to measure emitted alpha particles.
Radon is a radioactive, carcinogen and naturally occurring gas present in indoor and outdoor environment. In the present paper, radon and thoron concentrations with their decay products has been measured by using passive measurement technique and compared with the recommended limits of WHO, ICRP and UNSCEAR.
The framework for testing the performance of neutron dosemeter has evolved. A first feedback on the new ISO 21909 standard will be presented based on experimental measurements obtained with our routine measurement process. An upgrade of our dose estimation algorithm using a Monte-Carlo method will also be discussed.
The VVR-S nuclear research reactor with thermal neutrons from Romania, used for radioisotopes production and physics research purposes was operated between 1957 and 1997 and finally shut down in 2002 in order to be decommissioned for safety reasons. The separator for fuel assemblies, was dismantled in 2014 using plasma torch technology. The process involved radiological risks for the workers due to the high levels of dose rate. The workers external exposure was monitored continuously and the internal exposure was assessed based on the activity concentration of the aerosols released during the cutting process.
The upper limits of the measurement uncertainty of passive personal and area dosimetry systems were estimated according to the IEC 62387 dosimetric performance requirements. The corresponding limits of the response of these dosemeters were calculated for 90 % and 95 % confidence probabilities and compared to the ISO 14146 ‘trumpet curve’ criteria for intercomparisons.
Gamma dose rates were measured using a portable NaI(Tl) dosimeter at two cities of Karnataka State in India. The dose rates in Mangalore and its surrounding were found to be within the normal level. Relative higher gamma dose rates were recorded within Mysore city due to the granite region.
The application of different Time-Temperature-Profiles and the influence of fading in the routines of the individual monitoring services were investigated at Seibersdorf Labor GmbH. Several Harshaw TLD-100 dosimeters have been irradiated and fully read out after different periods of storage. A following fade study with an optimization of the standard procedure was performed.
Determination of neutron exposures configurations encountered in well-logging activities.
In-situ evaluation of neutron correction factors for each irradiation condition.
Implementation of neutron personal dosimetry in Well-logging Oil industry.
DFT calculation was applied to know the substituent effect on the separation of Am(III) from Eu(III) by bis(trifluoromethylphenyl)dithiophosphinic acids. Optimized strictures revealed that Eu-S and Am-S distances are similar for all complexes, but m-,m-trifluoromethyl derivative has a relatively larger Am-S distance, while o-,o- and o-,m-trifluoromethyl derivatives have the relatively shorter Am-S distance.
Workplace field with high-energy neutron component usually available from May to December with a mean availability of 95 % at the Paul Scherrer Institute (PSI).
In this paper are presented the collective doses recorded during the period 1976 – 1995 for occupational exposed worker from nuclear research area, especially for Horia Hulubei, National Institute for R&D in Physics and Nuclear Engineering, IFIN-HH. The individual doses are also studied in this paper.
222Rn and 220Rn discrimination is investigated using a solid-state nuclear track detector (SSNTD) based passive detector named Radout used by Mi.am company. The analysis of track morphological parameters performed by Politrack allows to identify a critical parameter for the discrimination of the two radon isotopes: the recalculated reduced etch rate.
The Individual Monitoring Service (IMS) at the Helmholtz Zentrum München has developed a new ring dosemeter, a new eye lens dosimeter (ELD) for integration in radiation protection (RP) glasses and a new environmental dosemeter based on BeOSL technology.
The Individual Monitoring Service (IMS) at the Helmholtz Zentrum München has developed and characterized a new ring dosemeter for the measurement of Hp(0.07), based on BeOSL technology. The new detector element can be read out by means of standard BeOSL readers and fulfills IEC requirements.
Methods of imaging and detection for fast neutron using advanced nuclear emulsion technique with the automated scanning system were developed. Fast neutron pinhole imaging and collimated detection of fast neutrons were demonstrated.
Noble scintillation paper functionalized for detecting ß-particles was prepared. The paper had different structures to capture ß-particles from 90Y. Scintillation images were obtained and analyzed.
Possible application of a recently developed electronic personal dosimeter having a long-life battery for management of aviation doses of frequent flyers was investigated through the measurements onboard selected international flights.
CaF2 presented changes in the curve shape of OSL emission according to type and energy of radiation. Using parameters of curve deconvolution, the energy range can be estimated from OSL emission.
Existing shallow (skin) dose dosimeters, with modifications for the possibility to accurately measure personal dose equivalent Hp(3) for eye dosimetry, were tested on 5 different models. Most models performed suitably well to be considered as potential Hp(3) eye dosimeters.
Studying glasses for dosimetric applications offer lots of possibilities, as well as challenges. Different borate glasses were analyzed regarding some important characteristics that may be considered in dosimetric studies using the OSL technique.
To clarify the eye lens dosemeters positioning the shielding effect of full face mask respirators, photon irradiation experiments to various eye lens dosemeters attached on the head phantom was performed at the secondary photon calibration fields of Japan Atomic Energy Agency.
A new thyroid monitor using multiple Gd3(Al,Ga)5O12 (GAGG) detectors with each crystal size of one cubic centimeter has been developed. The GAGG detectors can be placed around the front surface of the human neck to increase the sensitivity for 131I in the thyroid, especially with the intension of measuring infants and small children. The arrangement of 8 GAGG detectors was tested using age-specific phantoms with thyroid shaped container filled with 131I solution, demonstrating that the minimum detectable activity (MDA) of the new monitor was lower than that of a conventional NaI(Tl) spectrometer (a crystal size of 2.54 cm in diameter x 2.54 cm in thickness).
The X-ray energy radiated from a Crookes tube is approximately 20 keV. It caused a distribution of Hp(0.07) dose enclosing the Crookes tube at 0.015 – 0.11 mSv in 1 hour. The dose concentrates in the central human body and relatively descend to expanded area.
Computational simulations were performed to investigate the availability of FASTSCAN, the whole-body counter widely used after the Fukushima nuclear disaster in 2011, for the population monitoring focusing on 131I accumulated in the human thyroid.
The plastic solid-state nuclear track detectors become more and more popular in the charged particles detection and environmental monitoring. In this paper, the characteristics of the CR-39 and cellulose acetate are compared , on the basis of the track-etching condition(6.5mol/L, 70℃, 8h) ,the CR-39 detector is calibrated with a calibration coefficient of 0.035 Tc/cm2/Bq﹒h/m3. Based on track-etching system, the Radon concentration of Anyang district and Chengdu city is measured. Some factors affecting the radon concentration are also discussed. The results indicate that radon concentrations in Anyang district are 13.0Bq/m3～54.2Bq/m3,while in Chengdu are 14.1Bq/m3～43.2 Bq/m3.
MgB4O7:Ce,Li detectors presented wide dose-response range required in clinical dosimetry and no significant energy dependence for irradiations with 6 and 10 MV.
Tb3+ doped LiMgBO3 was synthesized using sol gel method. Its structural characterizations were done using XRD, PL and SEM techniques. It has shown very good thermoluminescence (TL) response for thermal neutrons from graphite moderated 241Am-Be neutron source. The TL signal is stable with low fading rate.
Network of monitoring stations continuously measuring artificial gamma activity in surface water is being built in the Czech Republic. Functionality of the system is based on the failure resistant monitoring stations assembled to a network equipped with central data processing. Stations are automated, autonomous and of a simple construction, therefore failure protected, and their detection capabilities are enhanced by the Noise Adjustment Singular Value Decomposition (NASVD) method, which is used for data processing. This mathematical tool decreases the detection limits, what enables employment of the network not only for the purpose of emergency preparedness but also for normal monitoring with particularly more demanding requests due to detection limits.
Chiyoda Technol Corporation started eye lens dosimetry service using Hp(3) dosemeter DOSIRIS. Compatibility assessment for IEC 62387 of DOSIRIS was performed, and the characteristics of DOSIRIS met the requirements except for the angular dependence for 90Sr-90Y beta radiation. Angular dependence can be improved by optimization of filter.
Trees in the large area around the Fukushima Daiichi Nuclear Power Plant were contaminated by radioactive cesium owing to the accident in 2011, damaging mushroom industry using logs. To promote the industry again, no-contaminated safe trees should be selected. Herein, we developed a portable and sensitive radioactive detection system to select the trees before felling. By measuring in the field, we confirmed that the detector could operate in outdoor environments contaminated with low-level radiation, ~0.05 μSv/h.
Nowadays machine learning (ML) methods provides extremely important tools for intelligent environmental data analysis, processing and visualization. We describe application of ML to environmental sciences in the emphasis to radon exhalation rate.
Nowadays machine learning (ML) methods provide extremely important tools for intelligent environmental data analysis, processing and visualization. We describe the application of ML to environmental sciences in relation to the radon exhalation rate.
The study investigates the effective subtraction of background components due to terrestrial radionuclides for environmental radiation monitoring using a scintillation spectrometer.
We present a measurement and an evaluation of high LET thermoluminescence glowcurve peaks and their advantage regarding new prospect in neutron dosimetry.
A new fluorite-based pellet has been produced with the objective of substituting the detector currently in use at the Laboratory of Dosimetry of the University of São Paulo.
We developed an omnidirectional scintillator-based Compton camera that visualizes low energy gamma rays radiated from radiopharmaceuticals with high sensitivity. We verified the performance of the detector by measuring the 99mTc and 111In in a nuclear medicine facility.
In order to improve angular dependence of small a radiophotoluminescence (RPL) glass dosemeter, DoseAce, the holder and filter were reviewed. It was confirmed by irradiation examination that the angular dependence of DoseAce with the new holder was improved.
The presence of gamma dose rate effects was investigated on the TL signal of 6 different dosimetric phosphors as well as the OSL signal of 3 of them.
To evaluate the relationship between the whole-body and eye lens dosimeters a field study using humanoid phantoms with different dosemeters attached were made at selected locations at the Fukushima Daiichi Nuclear Power Station.
A tentative uncertainty budget of track-etch detectors used in radon in thoron survey is presented. The consequences of uncertainty for decision making related to radon regulation are discussed.
To discuss how to monitor and manage the equivalent dose for the lens of the eye of radiation workers at nuclear facilities, the dose was measured at the head and the chest of the radiation workers around water storage tank areas (90Sr/90Y dominant area) and the nuclear reactor buildings (high dose gamma areas) of the Fukushima Daiichi Nuclear Power Station. The relationship between Hp(10) and Hp(3) for the workers in these areas and the doses measured at the head wearing a full-face mask and the chest were clarified.
Radioactive cesium inventory and air dose rate were measured in very sloped catchment. The radioactive cesium was distributed along the gradient elevation, however forest zone still maintained higher radioactive contamination.
A new BeOSL eye lens dosimeter (ELD) for integration in radiation protection (RP) glasses has been investigated in laboratory tests with an Alderson head phantom. The results show both the measurement capabilities of the dosemeters and the protective effect of the glasses. Results are supplemented by data from Monte Carlo Simulations and first clinical applications in radiology.
To propose a new methodology for prototyping and benchmarking based on the Dose Equivalent to the sensitive part of the eye lens; demonstrate the integration of CAD Software and Monte Carlo Simulation in Geant4 with mesh modeling simulation and 3d printing; demonstrate the use of strengths and drawbacks of 3D printing on the fast prototyping of new dosimeters.
The response of RPL (Radiophotoluminescence) glass ring dosemeter was improved by optimizing the dosemeter filter based on the Monte Carlo simulation. It was confirmed by irradiation experiments that the dosemeter fulfills the energy and angular criteria of IEC 62387:2012 standard1) in the energy range from 24 keV to 1,250 keV.
Mixed radiations were generated in high-energy radiation field. Equivalent dose of the environment during radiotherapy from neutrons and photons was measured to assess radiation risk of workers and patients using optically stimulated luminescence dosimeters (OSLDs).
In response to a change in legislation, lots of manufacturers started to offer the special type of personal dosemeters designed to measure dose equivalent at the depth of 3 mm (Hp(3)), which represents the operational quantity for the dose to the eye lens (Deye). Nevertheless, it has some properties that can limit its usability. What is more, introducing another dosemeter to the equipment of radiation workers may be difficult. These are the reasons why another ways of Deye monitoring are considered.
We have developed a non-doped LiF/CaF2 eutectic for thermoluminescence (TL) dosimetry. While the non-doped LiF/CaF2 eutectic and a CaF2 single crystal showed similar luminescence properties, the non-doped LiF/CaF2 eutectic can be obtained using a simple melt-solidification method with a lower melting temperature than that of CaF2. The TL intensity of the non-doped LiF/CaF2 eutectic was higher than that of the CaF2 single crystal, and the integrated TL intensity of the non-doped LiF/CaF2 eutectic monotonically increased as a function of X-ray dose from 10 to 1000 mGy.
Eu:BaAl2O4 single crystals were prepared by the floating zone method, and the ionizing-radiation-induced radioluminescence and storage luminescence properties were evaluated for dosimetry applications.
The thermoluminescence properties of Y3Al5O12 (YAG):Ce (Ce concentrations: 0.5, 0.8, and 2 mol%) were characterized after irradiation with heavy charged particles or gamma-rays. The effects of linear energy transfer (LET) were significant for YAG:0.5 mol% Ce. The LET dependence of the glow curve has a trend opposite to that of the gamma-ray dose dependence.
Functions describing PB broadening in water and EBT3 film sensitivity quenching were experimentally searched, for both protons and carbon ions. The results allow to perform suitable correction of the acquired dose images.
We have examined X-ray-induced luminescence of Sn-doped zinc borate (SZB) glasses prepared in Ar atmosphere. The scintillation intensity of SZB glasses increases with increasing tin concentration while the intensity of thermally stimulated luminescence (TSL) decreases. Clear inverse relationship between scintillation and TSL in SZB glasses is observed.
Equations for a bi-localized system with quasi-equilibrium conditions are considered. The system is solved analytically for TL (thermoluminescence) and OSL (optically stimulated luminescence). TL curve has a double peak structure.
Optically Stimulated Luminescence (OSL) intensity is enhanced upon interaction with Localized Surface Plasmons (LSP) but the exact mechanism is still not clear. Our results suggest that trapped electrons optically unreachable can be converted into useful luminescence information via plasmonic coupling. As a consequence, higher dosimetric sensitivity and smaller bleaching times are obtained.
A novel method for the detection of glow curves (GCs) anomaly is presented. The method uses machine learning algorithms in order to detect abnormal GCs shapes and categorize them. A high detection performance rate for either ‘anomalous’ or ‘regular’ GC shape class of up to 96% is achieved, depending on the algorithm type.
Experimental and theoretical regularities of the compensation effect observed are studied on the example of the analysis of thermally stimulated kinetics in the luminescence mechanisms of irradiated dosimetric materials.
Several kinds of luminescence from electric components of mobile devices induced by irradiation (RL), thermal stimulation (TL), optical stimulation (OSL) and their combinations (PTTL, TA-OSL etc.) were studied in both aspects of experimental and theoretical.
Photoluminescence and thermostimulated luminescence of LiGaO2 crystal was studied in 10-500 K temperature region after UV irradiation. Luminescence mechanisms were elucidated. TL peak at 350 K and the corresponding emission spectrum in visible region makes LiGaO2 potentially applicable as material for TL dosimetry.
Ionizing radiation induced color centers in KMgF3:Tm fluoroperovskite. UV and blue emission from thulium doped-polycrystal was observed. KMgF3:Tm [1 mol %] displays several thermoluminescent (TL) peaks in an aceptable temperature range suitable for ionizing radiation dosimetry.
The F and F+ bands associated with radioluminescence in Al2O3:C,Mg are affected by thermal quenching but the behaviour for the F+ band depends on prior annealing.
We recorded the scintillation temporal profiles of CdWO4 under different linear energy transfers (LETs). The LET dependence was analyzed from the viewpoint of quenching due to excited state interaction.
Oxygen dangling bonds (“non-bridging oxygen hole centers”, NBOHCs), are peculiar to amorphous state of SiO2 and cannot be induced in α-quartz by purely ionizing irradiation. Their presence in quartz normally is an indication of particle-induced damage. Here were detected NBOHCs for the first time in high-dose electron-irradiated α-quartz crystal. Their presence may signal the formation of nucleation centers in crystal structure as the first step to radiation-induced amorphization just below the amorphization threshold.
Specific changes have been discovered in the photoluminescence kinetics of F centers in anion-deficient corundum crystals over the temperature range of 200-700 K. In the intervals 290£Tmeas£370 K and 420£Tmeas£700 K, the fast component tfast equal to the F center lifetime in excited state tF has a slow component with tslow occurring alongside it. The contribution of the slow component and its time constant are maximal at the beginning and minimal at the end of each of these intervals.
An improved Monte Carlo method for calculating TL in a cluster system is proposed.
New cluster TL model with deep electron trap is analyzed by Monte Carlo method.
TL dose dependencies are simulated for the first time in a cluster system.
The heating rate effect on superlinearity of TL dose response was found using the model under study.
The TM-OSL method applied to separate the slow OSL component in quartz
Parameters of trap responsible for the slow component
Dose response curve of the slow component observed in TM-OSL measurements
The dosimetric characteristics of three types of smartphone screen protective films were confirmed by electron paramagnetic resonance (EPR) spectroscopy. The tempered glass (TG) film showed similar characteristics to the touchscreen glass so that it could be used as a dosimetry sample instead of touchscreen glass in radiation accident.
Ox bone, clam shell, cyclina shell, chitin, tooth, and fingernail can be used as the environmental dosimeters. Linear dose-response curves of ox bone, clam shell, cyclina shell, chitin, tooth, and fingernail are presented. The grain size and storage temperature of the materials on the sensitivity of EPR spectra are examined.
The natural signals emitted by polymineral fine grains (post-IR IRSL290 and post-IR IRSL225 protocols) and by 63-90 µm quartz SAR-OSL, enter field saturation for samples immediately below the Eemian palaeosol (500 Gy, 400 Gy and 300 Gy, respectively). Although the laboratory dose response curves on 4-11 µm quartz grow beyond 5000 Gy, accurate ages are obtained only for samples from the last interglacial-glacial cycle (<240 Gy). The measurable range of doses for each signal depends on the degree of overlap between the natural and laboratory dose response curves.
We present infrared stimulated luminescence (IRSL) ages of Spituk Lake deposits in Ladakh, India. The IRSL ages for seven samples from the Spituk section range from 105 to 170 ka, and suggest that deposition in the Spituk area began at ~170 ka after damming of the Indus River. These ages are substantially older than ~50,000 years BP reported previously by Phartiyal et al (2005). The uppermost unit in this section marks a change in climate and fluvial activity and the IRSL ages suggest that lake existed for another ~70 ka, and later disappeared due to breaching of the dam at ~100 ka.
Sediment dating by EPR was successfully performed. Signal of E´1 center was used.
Equivalent dose dependence on emission wavelength is resolved both within and across the main emission bands of quartz and feldspar using an automated spectrometer. This is the first systematic dating study using spectrally-resolved OSL/TL.
Characteristics of thermoluminescence of SIM cards in South Korea for accident dosimetry were identified.
Analysis of the thermoluminescence (TL) signal and inherence physical characteristics of resistor elements in the electronic personal dosimeter (EPD) was performed. Then the estimated accident dose was derived by using measurement of TL from resistor extracted from the EPD and verified the results.
Computational modelling of beta dose rate in heterogenous materials
Stimulated luminescence properties of limestone (CaCO3) collected from the Mawsmai Cave, India have been studied using thermoluminescence (TL) and infrared light stimulated luminescence (IRSL) techniques. The radiation dosimetric features of the sample have been assessed.
Human fingernails were used to evaluate the exposed dose in a radiation accident situation. The characteristic of radiation induced signal in Korean fingernails were researched by the EPR dosimetry.
OSL (Optically Stimulated Luminescence) dosimetric properties of silica chip present in RFID (Radio Frequency IDendification) based identity cards were studied for emergency retrospective dosimetry. The protocol for retrieval of the absorbed dose was developed using SAR (Single Aliquot Regenerative Dose).
Resistor TL/OSL zero-dose is very important to TL/OSL retrospective dosimetry using electric personal dosimeter (EPD). We evaluated the zero-dose for the resistor TL/OSL signal, respectively. We also examined the thermal and optical dependence of the zero-dose.
Optically stimulated luminescence properties of smart chip cards were identified.
The method of electron paramagnetic resonance (EPR) dosimetry has been applied to human tooth enamel to obtain individual absorbed doses of victims of Hiroshima atomic bombing.
ESR intensity for E1′ center increased linearly on new surfaces of quartz grains formed by brittle fracture. This result implies that E1′ center can be increased by various fault motions without frictional heating: brittle fracture of seismic fault movement fault creep, landslide and so on. E1′ center can also be an index of displacements of such fault motions.
Memory cards from mobile phones have potential as fortuitous individual dosimeters; two OSL emissions at 330 and 370-390 nm; linear dose-response to several Gy; assessment of detection limit and signal fading
Pulsed Electron Spin Resonance (P-ESR) technique for tooth-based dosimetry shows great promise in providing direct estimate of spin concentration without a-priori knowledge of the measured tooth volume. The proposed technique could be used as a basis for accurate retrospective dosimetry.
The PTTL method for an additional independent measure on the glass material extracted from mobile phones is tested as a tool for retrospective dosimetry.
Monte Carlo simulation was performed to reconstruct a body dose from a mobile phone dose. Doses were calculated with the different size of mesh phantoms for various exposure conditions.
Optical dating was carried out for the early Neolithic potteries collected from the Gosan-ri site. Gosan-ri-type pottery known as the oldest pottery in Korea was manufactured and utilised from the late 8th century BC. Gosan-ri site was formed after the late 10th century BC and had been lasted during about 500 years.
Fossils of mammals found in Mirim Lake, southern Brazil were dated by ESR and OSL, providing consistent results with site stratigraphy and literature data from nearby sites.
We have tested the applicability of the post-infrared infrared stimulated luminescence dating of 90-150 mm quartz grains in five dune samples collected from a ~3.5 m deep trench near Ramanathapuram, Tamil Nadu. The pIRIR ages are stratigraphically consistent, and suggest aeolian activation began in this region before 60 ka, and continues until 2000 years ago.
Dosimetric properties of optically stimulated luminescence (OSL) from human fingernails are presented and their possible application to retrospective dosimetry of a hand exposure is discussed.
The time dependent behaviors of electron spin resonance (ESR) signals from fingernails were different between different-quality radiations; this fact should be considered carefully for standardization of fingernail ESR as a retrospective dosimetry for radiological accident.
Ag-doped phosphate glass was assessed as a potential high-dose dosimeter using radiophotoluminescence (RPL), optical absorption (OA), thermoluminescence (TL) and electron paramagnetic resonance (EPR). OA and EPR responses demonstrated a monotonic increase with dose and, with the proper calibration, may be used for dosimetry up to several hundreds of kGy.
The present study shows a geochronological novel data of the Solimões-Amazonas river system’s Holocene lower terrace, range between the Manacapuru and Madeira river mouths, Central Amazonia. To improve the precision of the young ages sediments, comparisons between the ages found by central age (CAM), minimum age (MAM) and finite mixture model (FMM) models were made and ages between 2.9 to 9.7 kyears were evaluated.
Detection limit of the electron spin resonance (ESR) dosimetry using tooth enamel of Japanese macaque, extracted by a novel enamel-dentine separation technique, was estimated to be ~40 mGy. The external exposure dose for Japanese macaques collected in Fukushima prefecture were estimated.
Towards the effective use of porcelain samples to accidental retrospective dosimetry applications, new experimental data are presented, including a comparison of luminescence features among various porcelain-based items collected from Turkey.
Improvement of eye lens dosimetry and potential for high ocular radiation doses to interventional radiology and cardiology staff.
The obtained dosimetry data could be used for epidemiological studies to assess retrospectively eye lens dose.
Possibility of dose reassessment by using phototransferred method to the height sensitive thermoluminescent MCP-N detectors applied to environmental and eye lens dosimetry.
The features of X-ray tube and assessed doses for relative person and working environments for X-ray diagnostic imaging and nuclear medicine processes were investigated in this paper. More than 250 veterinary hospitals using X-ray machines and a hospital performing veterinary nuclear medicine in Taiwan were assessed.
For the estimation of dose reduction effect by shielding vest, exposure tests by 137Cs source and X-ray generator were done using water phantom covered with shielding vest made of heavy metal. That effect including of photon energy dependence was also surveyed by the Monte Carlo simulations.
For the quality control of blood irradiators, a jig for irradiation of alanine dosimetry is produced, and the dose distribution and uncertainty of blood irradiator container are evaluated using EPR spectroscopy.
Tooth enamel samples from staff of the uranium mining enterprise in comparison with the population of the control territory have been investigated by the EPR dosimetry method.
Peter MacCallum Cancer Centre (Peter Mac) is a dedicated oncology hospital providing nuclear medicine, radiation therapy, and radiology services. It also includes a large research department that uses X-ray devices and unsealed radioactive material. Currently, approximately 28 % of Peter Mac staff is monitored for personal dose equivalent (Hp10). In 2007 the type of dosimeter and provider was changed from a thermoluminescent detector (TLD) to optically stimulated luminescence detector (OSL) dosimeter. An examination of the Peter Mac occupational radiation dose register showed a marked decrease in the average Hp10 when use of the OSL dosimeter commenced.
Instead of using a set standard samples of irradiated tooth enamel, tempol is shown to be useful in ESR (electron spin resonance, or EPR) retrospective dosimetry to determine the doses given to tooth enamel.
The method of ESR (EPR) dosimetry is applied to cattle tooth enamel to obtain retrospective radiation doses by Fukushima Dai-ichi Nuclear Power Plant accident in 2011. The obtained doses are up to 1.2 Gy, being roughly consistent with the accumulated environmental dose rates. The study shows that mammal tooth enamel is useful in ESR dosimetry.
All the categories of performance of current 8 tested laboratories meet the ANSI/HPS N13.11-2009(R2015) criteria and the reanalysis results were suggested to be an important step of an accreditation procedure for the personnel dosimetry system in Taiwan.
A new methodology is presented for assessing linear energy transfer (LET) and relative biological effectiveness (RBE) in proton therapy beams using thermoluminescent detectors. The assessed LET and RBE values were compared with respectively the results of Monte Carlo computer simulations and of an in vitro cell survival study, showing good agreement.
Gel dosimetry has attracted attention as a useful tool for dose verification in advanced radiotherapy because gel dosimeters can be used as phantoms in the same way as the phantoms used in an actual radiotherapy treatment chain. This study evaluates the effects of scavengers of water decomposition radicals on fluorescent degradation yield of a nanoclay-based radio-degradation fluorescence gel using 7-diethylamino-4-methylcoumarin (7D4MC). Results of this study revealed that OH radicals are the most important factor in a reaction employing 7D4MC. Oxygen is the second most important factor, whereas hydrated electrons do not significantly affect the reaction.
Linear energy transfer (LET) measurement system with thermoluminescent dosimeter (TLD) has been developed in our previous study. The aim of this research is to apply the LET measurement system to patient-specific treatment fields of pediatric cancers and glioblastoma multiforme in proton therapy with TLD.
SPICE microbeam profile was measured using FNTDs. Localized dose distribution by the SPICE microbeam irradiation was calculated using the measured beam profile. Correlation between the localized dose distribution and DNA double strand break region was investigated using human lung normal WI-38 cells.
A genipin gel dosimeter was shown to have potential as a clinical radiotherapy dosimeter for relatively high doses and small gel volumes.
We propose a novel rectum dosimeter made from a piece of OSL sheet and a catheter to measure absorbed doses of rectum during high-dose-rate 192Ir brachytherapy for cervical cancer. The dosimeter can be analyzed in a similar way as a commercial type dosimeter by inserting the disk punched out from the sheet into commercial type dosimeter cases. We will demonstrate availability of our dosimeter in an actual clinical situation.
This study assessed the health risks for the patients after cervical cancer radiotherapy. After performing the treatments of IMRT and brachytherapy for the patients with different cervical cancer sizes, the effective doses were assessed and reported in the results. The total induced secondary cancers risks (for tissues outside the treatment fields) induced by the treatments of cervical cancer were assessed. According to the results, the treatment parameters such as field sizes and total monitor units were the main factors of affecting the probability of secondary cancer risk.
High radiation doses associated with PET/CT, compared with conventional exams have raised health care.
Evaluation of absorbed and effective dose to children of 2 and 10 years.
The technology of thin polymer films has been developed for clinical and radiation protection dosimetry of neutron entrance doses in mixed radiation fields.
In this study, we evaluated characteristics of L-alanine response to photon and electron beams, such as linearity, repeatability, and dependence for radiation energy and dose rate.
The NMIJ is developing a postal dosimetry service using an alanine dosimeter. The NMIJ’s alanine dosimeter responses were investigated in Co-gamma ray, electron and carbon beams. The postal dosimetry service will be used for radiation therapy, radiation processing and radiation monitoring at accelerator facility.
Optical evaluation method of polymer gel dosimeter irradiated to 400 MeV/n carbon-ion beam was researched. Regarding absorbed carbon dose to optical response, increasing the absorbed dose to irradiated gels, optical signal intensities were increased. When the prepared gels were irradiated to form carbon Bragg curve, the result of the scanned original optical computed tomography system was indicated dose concentration region.
Recently, radiotherapy has been attracting a great deal of attention. In radiotherapy, dosimeters that have high tissue equivalence and are capable of accurate dose measurement are required to reduce the risks to patients. This study focused on a photochromic reaction, and investigated the applicability of the photochromic compound 2,3-dihydro-2-spiro-4ʹ-[8ʹ-aminonaphthalen-1ʹ(4ʹH)-on]perimidine (PNO-p) to dosimeters. PNO-p was found to undergo a photochromic reaction when exposed to X-ray irradiation. In addition, the X-ray sensitivity increased with increasing the concentration of PNO-p and doping with an organic phosphor.
To elucidate the radiophotoluminescenece (RPL) center formation process in Ag-doped phosphate glasses, the temperature dependence of RPL intensities was measured. The Ag0 formation starting temperatures were found to be 100 K, 100 K, and 25 K and the activation energies of Ag0 formation were 51 meV, 56 meV, and 43 meV in Ag-doped phosphate glass having Na and Al (Na–Al/Ag), Na and K (Na–K/Ag), Al and K (Al–K/Ag), respectively. Electrons are trapped at negative ion vacancies before being transferred to Ag+ such that the activation energy increases with increasing distance between electron trapping sites and Ag+.
Gold Nanoparticles have a complex effect on dose enhancement and dose sensitivity that deserves more detailed studies. Using different animoacids and gold nanoparticles concentration DEF and sensitivity was studied.
We fabricated organic films containing a diarylethene-type photochromic compound and investigated their isomerization behavior upon X-ray irradiation to develop a tissue-equivalent and non-disposable radiation imaging element. The effect of adding the organic phosphor was also studied. The results show that absorbance of 400–600 nm increased upon X-ray irradiation. Irreversible reaction was also observed, and photochromic reaction can be sensitized by the addition of 2-4(-tert-butylphenyl)-5-(4-biphenylyl)-1,3,4- oxadiazole.
The dosimeteric impact of iodine content in a polyvinyl alcohol-iodide (PVA-I) radiochromic gel dosimeter was investigated through depth dose measurements and Monte Carlo (MC) simulations. Results enabled us to conclude that the dose response with iodine content can be ignored in high-energy X-rays used in the field of radiotherapy.
A ZnS scintillator with a small LET dependency and camera system is useful for quick and easy measurement of the dose distribution in scanned carbon-ion therapy with high spatial resolution.
To manage the exposure dose of patients during diagnostic X-ray examinations, it is necessary to evaluate the dose without taking into consideration complicated conditions related to X-ray photographic settings. In order to develop a practical analysis method in which energy dependence of an OSL dosimeter is considered, we performed some experiments. From the experimental results, we concluded that our calibration curve can be applied to various dosimetric points when we add a systematic uncertainty of 15%.
The temporal and the spatial stabilities of the absorbance on a novel radiochromic polyvinyl alcohol-iodide (PVA-I) gel dosimeter with different polymerization degrees of PVA were investigated. A slight dependence on the temporal change in the coloring and its distribution due to the difference in polymerization degrees of PVA was observed.
The study investigated radiation dose of staff undertaking percutaneous interventional procedures for peripheral arterial occlusive disease (PAOD). Optically simulated luminescent dosimeters were used to measure radiation dose and radiation risk was further evaluated in percutaneous interventional procedures.
• Single fiber dosimeter
• Temporal and neural network analysis for separation of Cerenkov signal
• Suitable for MRI-LINAC dosimetry
RL from Al2O3:C has a lower luminescence efficiency (η) with high LET particles, regardless of the beam type/energy, while η depends on crystal size. We use these results to determine fluence-averaged LET (LETf) calibration curves in the plateau region of variuous particle beams, so that a combination of measurements from two detectors can be used to calculate unkown LETf and dose. This method can be applied for daily QC in hadron therapy.
in vivo system capable of accurately measuring the 2D real time dose rate received by the patient and account for the proper patient positioning relative to the LINAC
New OSL glass detectors (80MgB2O4–20MgB4O7) presented wide dose-response range required in clinical beams dosimetry.
The glow curve shape of TLD-300 has been quantified by PHR, the peak-height ratio between high- and low- temperature peaks, as a function of photon energy, in the range 16-1250 keV. This has extended previous calibrations done up to 55 keV with diagnostic photons. We’ve found that the PHR sensitivity to the photon energy becomes negligible at about 700 keV.
TLD-300 dosimeters were exposed in-phantom to out-of-field radiation in a 6 MV linac. Preliminary results indicate mean energy equal to (394±20) keV at 1 cm from the 10×10 cm2 field edge, and a mean of (316±22) keV, independent of distance, at 3-15 cm from the edge.
Modified particle fluences behind metallic dental implants and plastic material were detected and perturbations in distribution of absorbed dose were quantified.
This work aims to characterise the scattered radiation field in an interventional radiology theatre and to generate a 3D map of energy spectra measured with a Timepix3 hybrid pixel detector. The information on the energy of the radiation field was then used to calculate operational quantities for external radiation exposure using the ICRU conversion factors. This approach brings new tools to better understand the worker’s exposition and provides crucial information to improve radiation protection gears. The approach is in line with the redefinition of the operational quantities proposed by the ICRU.
Proton radiotherapy strongly reduces the out-of-field doses in the CS treatment of paediatric patients compared to photon radiotherapy
Using the Geant4 Monte Carlo toolkit, we have developed a model of the Microbeam Radiation Therapy Beamline at the Australian Synchrotron facility. The resultant photon energy spectrum compares very well with that of a previously benchmarked toolkit, SPECT. Further simulations of dose distributions within a solid water phantom show good agreement with experimentally obtained results. The broad beam and microbeam data are within 3% and 5% respectively for all configurations and all depths studied.
Utilisation rates of TLD and MOSFET detectors for in vivo dosimetry were reviewed over a period of two years for two different radiotherapy facilities – one having an on-site TLD reader and the other a MOSFET system. Patient records were categorised according to treatment site. While MOSFETs were considered appropriate as an in vivo dosimetry system for most cases at the site with a MOSFET system, in some cases TLDs were requested from the other facility. TLDs were the preferred dosimeter for kilovoltage treatments and out-of-field dose measurements.
Dosimetric performance of the LiF:Mg,Ti employing the thermolumenecence technique for the application in dosimetry of small fields.
This work suggests that it is possible to assess the effect of low concentrations of radionuclides in inducing cellular damage using the micronucleus test in Allium cepa. Mutations are identified as small nuclei next to the main cellular nucleus making possible the use of Allium cepa as a biota for the analysis of radiation effects.
The three-dimensional absorbance distribution of the PVA-I radiochromic gel dosimeter irradiated by X-ray using an optical computed tomography apparatus was measured.
In order to evaluate the exposure dose to the eye lens during clinical X-ray diagnosis, we developed a precise calibration method of an optically stimulated luminescence (OSL) dosimeter. Our procedure took into consideration variations in X-ray spectra and energy dependence of the dosimeter. We present the results of our method using a phantom study.
The responses of the FNTD dosimeter to the BNCT neutron beam were measured and simulated. We demonstrated that the FNTD dosimeter can be used as a personal neutron dosimeter during BNCT.
Besides limited range of penetration, electron beam has been questioned for scattered and transmission radiation out of treatment field. This contribute considerable amount of radiation dose to unintended normal tissue. In the present study, Out of filed (OOF) doses showed a trend of decrease with increase in applicators size and electron energy.
The research about right side breast cancer is studied. VMAT double arc design enhances dose homogeneity and conformality. Partial arc angle design reduces lung overlapped-irradiation area. 70% 3DCRT with 30% IMRT is optimized in dose calculation.
The direct dosimetry near the affected region is necessary for safety radiotherapy. For this purpose, we are developing a small-size dosimeter using radiation-induced phosphor and an optical fiber. In this paper, we conducted test experiments assuming that the small size dosimeter is inserted into the urethra.
Colloid-like centers in anion-deficient corundum crystals (α-Al2O3-d) are formed most efficiently under thermo-optical treatment (TOT) if the F center concentration (CF) is 1017 cm-3, temperature (TTOT) is 1200 К, photon energy (hvTOT) is 4.0-4.2 eV and supplied optical energy density (WTOT) is 50 – 150 J/сm2.
The effects of h-BN micro- and nanopowders high temperature treatment in carbon crucible (1273 – 1873 K) on luminescent properties were studied by the means of photoluminescence (PL) and spectrally resolved thermally stimulated luminescence (TSL) techniques. Energy and kinetic characteristics of TSL processes, activated in the 300 – 873 K temperature range, were studied in the frame of general order kinetics. It was shown that the increase of CN-centers concentration (carbon atom in the position of nitrogen atom) leads to the raise of 330-nm PL intensity and of high-temperature TSL response at 380-nm band.
Components of OSL signal in quartz separated by TM-OSL method
Trap parameters obtained by isothermal measurements for individual OSL components
Correlation of traps active in LM-OSL and TM-OSL processes
Hafnium oxide (HfO2) nanocrystals were successful obtained by precipitation method, with crystallite size of the 25 nm and monoclinic structure. This material showed high TL and OSL response for β and UV irradiations.
Sc3+ and La3+ doped perovskite crystals have been grown by micro-pulling-down (MPD) method. Thermoluminescent properties of YAlO3:Sc, YAlO3:La, LuAlO3:Sc, LuAlO3:La crystals with different dopant concentration were examined after alpha and beta irradiation.
Spectral measurements of optically stimulated luminescence (OSL), thermoluminescence (TL) and radioluminescence (RL) were obtained for high sensitive LiMgPO4 (LMP) crystals grown by a micro-pulling-down (MPD) method. Acquired spectra of TL, OSL and RL emission from the studied LMP crystals were comparable.
This work presents the results of response of blue quartz for low dose radiation detection. These dosimeters were placed on a patient skin undergoing heart, liver and thyroid scintigraphy for 10 minutes the patient ingered a solution of Tc(99m). An unexpected result was obtained; the peak of 230 °C did not appear in the TL glow curve of the blue quartz. Since the 230°C appears prominent when irradiated with gamma radiation of Co(60) or Cs(137). Similar measurements were carried out in other silicate minerals such as aquamarine and tourmaline, these crystals did not present this unexpected behavior.
In this study, commercially-available polycarbonate was evaluated for dosimetry application in industrial electron beam irradiation. Polycarbonate exhibited discoloration when irradiated and this change was quantified through spectrophotometry. The study evaluated the dose response, reproducibility, and stability of polycarbonate in high-level doses from a mega voltage electron source.
In this study, we successfully produced a SiO2 glass at temperature lower than the softening temperature by sintering at 1300 °C using the Spark Plasma Sintering (SPS) method. A very small amount of Sn2+ was added as the luminescence center into the prepared SiO2 glass and the radiation induced luminescence characteristics including the dosimetric characteristics were evaluated.
Samples of CaSO4:Mn and CaSO4:Mn,Ag(Np) were produced by means of the slow evaporation route.
X-ray diffraction confirmed the anhydrite crystalline structure of the samples and scanning electron microscopy confirmed the formation of the silver nanoparticles.
The incorporation of silver nanoparticles in the CaSO4:Mn matrix enchances the TL and OSL signal of the samples.
Crystals of CaSO4:Eu,Ag were produced by variations of the slow evaporation route.
The TL emission spectra confirmed the presence of Eu3+ and Eu2+ in the crystal matrix.
The CaSO4:Eu,Ag(a) and CaSO4:Eu,Ag(b) composites presented the most intense TL and OSL signals and showed a linear and reproducible dose response.
Investigation of sample to sample luminescence phenomena variability with different dose levels.
UV excitation spectra and kinetic parameters of thermally stimulated mechanisms have been studied in aluminum-deficient AlN submicrocrystals using spectrally resolved thermolumoinescence and varying heating rates techniques. The regularities of observed processes and origin of responsible active traps have been discussed.
Green quartz pellets were produced to measure ionizing radiation. Study of energy dependence was made.
Luminescence characterization is attempted for a batch of BeO dosimeters which yield double structured main dosimetric glow curve shape.
Characterization of ytterbium doped phosphate glass samples using the thermoluminescent and optically stimulated luminescence techniques for application in radiation dosimetry.
Assessing the potentials of potassium fluoride for dosimetry
The dependence of the isothermal TA – OSL of BeO dosimeters on the measurement temperature was studied. The TA – OSL dose response features depend strongly on the stimulation temperature.
The aim of this work is to study the possible application of calcium silicate for OSL dosimetry.
Sm-doped LiCaAlF6 compound was successfully obtained by the mechanochemical synthesis technique. The obtained material was found to show radio-photoluminescence (RPL) where strong photoluminescence (PL) appears around 700 nm (excitation at 360 nm) after irradiation with X-rays, and the intensity increases with radiation dose.
We have synthesized a series of garnet crystals doped with Nd3+, and they were studied as scintillators for dosimetric applications. The materials show strong NIR emission around 1050 nm under both UV-Vis light and X-rays. The NIR emission is useful when the scintillation signal is collected via optical fibre especially under strong radiation dose since the transmission through optical fibre is effective for the NIR light and the signal can be easily separated from Cherenkov radiation coming from interactions of ionizing radiations with the optical fibre, scintillator etc.
A new mechanism of enhancement of scintillation on scintillator–silica fine powder pellets was proposed on the basis of thermoluminescence glow curves of pellets divided into those irradiated and nonirradiated by LED light.
Eu-doped CsBr transparent ceramic samples with different concentrations of Eu (0.05, 0.1, 0.5, 1.0 and 5.0 mol.%) were synthesized by the spark plasma sintering (SPS) method. In the OSL properties, the OSL spectra of all the samples showed an emission band peaking at around 450 nm, which was attributed to the 5d-4f transitions of Eu2+.
∙ Tm-doped CaHfO3 crystals were synthesized by the floating zone method with xenon arc lamps. ∙ Scintillation and thermoluminescence properties of Tm-doped CaHfO3 were evaluated.
∙ The Tm-doped samples show thermoluminescence glow peaks at around 75 and 240 °C.
Production and characterization of crystalline LaAlO3:Ce,Dy with dosimetric properties was tested by means of a green synthesis using Copaiba oil.
The crystallite size of obtained LaAlO3:Ce,Dy was nanometric, and its luminescence properties were maintained in comparation to well-known production routes of these material.
Embedding an optically stimulated luminescence (OSL) active dosimeter material as microparticles in a transparent silicone matrix creates a 3D optically accessible dosimeter. Characterization of OSL properties provides crucial information for an efficient 3D readout procedure. The OSL properties of the promising material LiF:Mg,Cu,P are reported.
Higher proton generator concentration results to the increase of sensitivity of the radiochromic gel dosimeter based on a polyvinyl alcohol-iodide complex. The sensitivity of the gel dosimeter was nearly independent of the annealing temperature.
OSL is observed in NaMgF3 doped with Mn, Eu, or Sm and the response to radiation is linear over a wide dose range. PL and optical absorption data show that several radiation-induced defects contribute to the OSL and that these are primarily F-type centres. RPL is observed in the form of F-centre/Mn2+ complexes for Mn2+ doping, and is also observed in cases of lanthanide doping due to electron trapping by the divalent lanthanides. The OSL and RPL properties can be monitored in a complementary way to measure radiation doses.
This work presents OSL measurements using green light stimulation (532 nm) on four varieties of mineral fluorite (green, yellow, purple and yellow with purple highlights). For each sample it was analyzed the OSL intensity as a function of radiation dose and thermal treatment, fading on 24 hour period, and correlation with thermoluminescence.
Cs2BaCl4 crystal were fabricated by the Bridgeman method. Cs2BaCl4 had a short decay time of 1.2 ns, and the proportion of the first component was approximately 70%. Further, Cs2BaCl4 showed a fast component light yield of approximately 1700 photons/MeV. Although the decay time of Cs2BaCl4 was only slightly longer than that of BaF2, the proportion of the fast component was much larger than that of BaF2. The estimated fast component light yield of Cs2BaCl4 was found to be larger than that of BaF2 in a previous report.
We fabricated the LiF-Tl:CsI mixed powder neutron scintillators. We experimentally evaluated the neutron response and some properties of the fabricated scintillators. The LiF-CsI mixed powder scintillator shows higher light yield for neutron irradiation than the single crystal Eu:LiCaAlF6 scintillator.
We studied the effects of Al2O3 on the thermally stimulated luminescence (TSL) of Cu-doped Li2O-B2O3 glasses. The TSL sensitivities of 0.01Cu2O-33.33Li2O- 66.66B2O3 glass are enhanced by addition of Al2O3. In addition, the glow peak temperature shifted from 420 K to 380 K along with decrease of the glass transition temperature.
Radioluminescence of gadolinium activated CaB6O10: Gd3+exhibited a sharp UV emission (~ 313 nm), which corresponds to the transition 6PJ → 8S7/2 of Gd3+; The OSL signal showed to be strongly dependent on gadolinium concentration; The incorporation of silver on CaB6O10: Gd3+ has increased the OSL considerably.
NaCl pellets show a strong energy dependence at energies below 100 keV. Over response of a factor 15-17 compared to air kerma and personal dose equivalent at 30 keV.
The first investigation of alexandrite mineral (BeAl2O4:Cr3+) as a natural OSL dosimetric material was executed [1,2]. Moreover, alexandrite powder was used to fabricate composites, and the composite OSL dosimetric response was successfully demonstrated .
Sensitivity changes in halite were tested using multiple irradiation – OSL readout – bleaching procedure. The effect was reduced by pre-dose or test-dose administration. It was confirmed that both methods stabilized the sensitivity changes.
Monte Carlo simulations using the PHITS code were used to obtain the ideal geometric configuration of PVC loaded with OSL MgB4O7 microparticles using B-10 and B-11 in different films. By using a water phantom covered with the OSL film, it is possible to detect the differential dose deposited into the films due to the albedo neutrons on the surface of the body.
The fading curves of infrared stimulated luminescence of co-doped calcium fluoride are described; the material appears suitable for novel applications in safeguards.
We evaluated Nd-doped MSiO3 single crystals in photoluminescence, scintillation and dosimetric properties. Among the present samples tested, Nd-doped CaSiO3 samples showed the best performance.
The photoluminescence response of stable aggregate color centers in nominally pure lithium fluoride (LiF) crystals, after irradiation with 27 and 35 MeV protons, is linear up to doses just below 100 Gy. Such linearity was confirmed along the whole Bragg curve and the dose distribution with depth was obtained.
In this study we explored the dosimetric properties of MgB4O7:Zn,Li glass and its potential use for clinical dosimetry. Sensitivity, dose linearity and energy dependence are the dosimetric properties that were explored and reported.
The characteristics of detectors made of Si ceramics are considered. and analyzed their use for solving various dosimetric tasks.
We report on the photoluminescence, thermoluminescence and persistent luminescence properties of calcium aluminate synthesized by combustion method using urea as a fuel and co-doped with Eu2+ and Dy3+. The phosphor exhibited persistent luminescence immediately after ceasing irradiation exposure with a time decay of the order of hours. The long lasting luminescence was associated to the thermal empting of the traps related to the low temperature TL peaks.
For some dosimeters it is possible to reach reproducibility with low dose irradiation, sensitization with low doses irradiation.
We investigated the thermoluminescence (TL) efficiency and the glow curve of Cr-doped alumina (Al2O3) ceramic thermoluminescent detectors (TLD).The TL efficiency showed unique trend lines separated by particle beams and the shape of the glow curve remains the same in a wide range linear energy transfer (LET) between 0.5 keV/mm and 128 keV/mm.
The effects of hydrothermal treatment and irradiation with beta particles on the luminescent properties of SrMoO4 phosphors are investigated. Results from TL, OSL and PL data show that hydrothermal treatment affects the optical properties of SrMoO4 materials.
For shielding purposes, concrete is preferred because of its good attenuation property, which can be controlled by its composition. The mechanical and shielding properties of concrete were investigated by replacing some percentage of sand up to 20%, with ICW.
Characteristics of fluorescent nuclear track detection with the silver ion-activated phosphate glass were demonstrated for the application of heavy ion measurement in space.
New anion-deficient Al2O3-BeO ceramics were synthesized in vacuum in reducing conditions.
TL glow curve of Al2O3-BeO ceramics consists of three TL peaks.
The drop of TL output in TL peak at 520 K is not observed in the samples under study.
TL and OSL dose response is linear from 10 to 300 Gy for gamma-irradiation and is sublinear from 3 to 50 kGy for pulsed electron beam.
The luminescence intensity in the band of 678 nm increases significantly with growth of Mn ions concentration within the range of 0.1-1 wt. %. An intensity of high-temperature peak at 370 °С grows enormously within the sintering temperature range of 1200-1500 °С. Presence of carbon, temperature growth and sintering duration, together with the impurity ion concentration result in the sensitivity increase of Al2O3:Mn ceramics to the ionizing radiation.
We prepared undoepd and Tb-doped MgAl2O4 transparent ceramics by using the SPS technique, and then evaluated the optical and dosimetric properties. The dynamic ranges of the Tb-doped sample as TSL dosimeter was over the range of 0.01 to 100 mGy.
MgB4O7: Dy prepared by combustion synthesis and solid-state method. Comparison between Infra-red and blue stimulated luminescence.
Fabrication of new type of co-doping activator in phosphate glass radiophoto luminescence (RPL) dosimeter was demonstrated with complex of silver and europium. Through the response of those detector, RPL function was obtained by silver activators as a function of radiation dose, while europium activator constantly emitted the luminescence which could be utilized for in-situ measurement of radiation. Both activators are able to be exist at the same time in same glass substrate.
• LiMgPO4 crystals were grown from the melt by micro-pulling-down method
• The undoped and rare-earths (REs) ions co-doped crystals were investigated
• The highest luminescence enhancement was observed for Tb, Tm co-doped samples
Composite TL detectors based on the films and crystals of garnet and perovskite compounds were developed using LPE growth method. Difference between TL glow curves of film and crystal-substrate is observed under simultaneous registration of α- and β-particles.
We studied photoluminescence and scintillation properties of a Cs3PrCl6 crystal using by conventional Bridgman–Stockbarger method. The Cs3PrCl6 crystal showed an intense scintillation band with a short decay time of 16 and 110 ns in ultraviolet (UV) wavelength region owing to 5d-4f allowed transitions of Pr3+.
We reported photoluminescence and radiation-induced photoluminescence (RPL) properties of NaCl:Yb crystals grown by conventional Bridgman–Stockbarger technique. The NaCl:Yb crystals showed an emission band peaking at 435 nm owing to 5d-4f transitions of Yb2+ excited at 375 nm. The characteristic Yb2+ 5d–4f emission intensity increased after X-ray irradiation.