Thermoluminescent glow curve of GdREAlO (RE=Dy or Pr) beta irradiated phosphors.

Phosphors composed of GdREAlO (0≤x ≤ 5 RE = Dy or Pr) stoichiometries were synthesized using the reverse coprecipitation pathway. The thermoluminescent responses of all phosphors were studied under beta radiation exposure. Doping the gadolinium aluminate host improved the thermoluminescent response of the phosphors, with the phosphors composed of GdDyAlO and GdPrAlO being the most sensitive.

TL glow curve and kinetic analysis of NaSiO:Pr under beta radiation effect.

Ionizing radiation dosimetry with thermoluminescence (TL) materials based on silicon or glass can be interesting in its potential use in radiation monitoring as the solution to the constant looking of development of new radiation detectors. In this work, TL characteristics of sodium silicate exposed to beta radiation effects were studied. TL response beta irradiated exhibited a glow curve with two peaks centered at 398 K and 473 K.

Fluorescence intensity ratio for BaHfO:Eu temperature sensor.

We use 395 nm ultraviolet radiation to excite the matrix of barium hafnate doped with europium ions to develop an optical temperature sensor. Luminescent analysis as a function of temperature was performed in the physiological range. The Emission spectra showed significant variations in luminescent intensity at all transitions, obtaining a relative sensitivity of 1574.

Thermoluminescence analysis of beta particle irradiated GdEuAlO phosphors.

The suitable choice of an activator and host combination is essential for synthesizing very sensitive thermoluminescence phosphors. In addition, conspicuous synthesis variables must be optimized to achieve the maximal response. The research presented herein shows that the most recommendable conditions to improve the thermoluminescence response of beta irradiated GdEuAlO phosphors were: x = 0.

Thermoluminescent studies of GdAlO powders.

The increasing use of thermoluminescence (TL) materials as radiation detectors with application in different areas of ionizing radiation has motivated research on new materials with adequate luminescent characteristics. In this work, experimental results gadolinium aluminate (GdAlO) analyzed by thermoluminescent phenomenon under beta irradiation effect are studied. To prepare GdAlO powders the coprecipitation method was used.

Thermally coupled energy levels of Eu within the BaHfO matrix, excited with UV radiation.

The present work reports the study of the thermally coupled energy levels of the trivalent europium ion in the barium hafnate matrix, in the temperature range of 289.7-323.8 K, through the application of ultraviolet radiation.

Measurement of percentage dose at the surface for a 6 MV photon beam.

Aim: To evaluate if a radiochromic film (RF) Gafchromic EBT3 is suitable for surface dose measurements of radiotherapy treatments performed with a 6 MV linear accelerator. Two aspects of RF were analyzed, beam energy dependence and surface dose determination.

Background: The measurements done at the surface or near the radiation source are done without charged electronic equilibrium and also have contribution of electron contamination.

Luminescent behavior of Eu doped BaHfO perovskite ceramic under UV radiation.

In this paper, luminescent properties of Europium trivalent ion in the matrix with unbalanced charge of barium hafnate under UV radiation, with special emphasis on the D → F transition are reported. The synthesis was conducted by the hydrothermal route at 200 °C with a reaction time of 90 min using chlorides as raw materials. In order to determinate the luminescent quenching concentration, the samples were doped with different amounts of Europium trivalent ions being the sample doped with 1 and 3% at of Eu which shows the highest luminescent emission.

OSL dosimeters for dental panoramic radiography.

The aim of the present work is to determine dosimetric characteristics of commercial optically stimulated luminescence dosimeter (OSLD) to estimate equivalent dose in the patient undergoing panoramic radiography procedure. Digital panoramic unit "Instrumentarium OP200D" was used. OSL dosimeters were optically bleached before any exposure procedure.

Optically and thermally stimulated luminescence characteristics of LaAlO:Pr beta irradiated.

This paper reports on an investigation into the thermally stimulated luminescence (TL) and optically stimulated luminescence (OSL) characteristics of novel luminescent phosphor. A new Pr-doped, lanthanum aluminate (LaAlO)-based luminescent phosphor is developed. Samples of LaAlO:Pr were irradiated to beta doses, in air, from 0.

Synthesis and thermoluminescence of LaAlO:Pr to UVC radiation dosimetry.

Thermoluminescent (TL) response of trivalent praseodymium ion doped lanthanum aluminate (LaAlO:Pr) obtained by Pechini method and Spray Dryer was studied. TL response of LaAlO:Pr powders submitted at 1600°C exhibited one peak centered at 157°C. Sensitivity of LaAlO:Pr was improved in around 90 times compared with undoped LaAlO.

Neutron H*(10) estimation and measurements around 18MV linac.

Thermoluminescent dosimetry, analytical techniques and Monte Carlo calculations were used to estimate the dose of neutron radiation in a treatment room with a linear electron accelerator of 18MV. Measurements were carried out through neutron ambient dose monitors which include pairs of thermoluminescent dosimeters TLD 600 (LiF: Mg, Ti) and TLD 700 (LiF: Mg, Ti), which were placed inside a paraffin spheres. The measurements has allowed to use NCRP 151 equations, these expressions are useful to find relevant dosimetric quantities.

Photon spectrum and absorbed dose in brain tumor.

Using Monte Carlo methods a BOMAB phantom inside a treatment hall with a brain tumor nearby the pituitary gland was treated with photons produced by a Varian 6MV linac. The photon spectrum and the absorbed dose were calculated in the tumor, pituitary gland and the head. The treatment beam was collimated to illuminate only the tumor volume; however photons were noticed in the gland.

Diagnostic radiology dosimetry: Status and trends.

Since 1970s the expression of protection standards shifted from a dose -to a risk-based approach, with dose limits established to yield risks to medical radiation workers. Worldwide interest in patient dose measurement was stimulated by the publication of Patient Dose Reduction in Diagnostic Radiology by the UK National Radiological Protection Board (NRPB). This has resulted in the development of new dosimetric measuring instruments, techniques and terminologies which present challenges to those working in the clinic al environment and those supporting them in calibration facilities.

Thermoluminescent dosimeters for low dose X-ray measurements.

The response of TLD-100, CaSO4:Dy and LiF:Mg,Cu,P for a range of X-ray low dose was measured. For calibration, the TLDs were arranged at the center of the X-ray field. The dose output of the X-ray machine was determined using an ACCU-Gold.

Effect of correction methods of radiochromic EBT2 films on the accuracy of IMRT QA.

Radiochromic films are dosimeters with more favorable characteristics than other two-dimensional (2D) radiation detectors. Transmission film scanners using a linear charge-coupled device (CCD) array have a drawback of variation in response along the detector array, which may result in a nonuniform transmission of signal over the scanned image. This study uses 2D gamma index analysis to compare two methods for correcting the nonuniform response of EBT2: the first method was based on the new red:blue method proposed by the manufacturer (to compensate for small nonuniformities in the film coating) and the second method, proposed by Menegotti et al.

Thermal effect on thermoluminescence response of hydroxyapatite.

This paper presents the experimental results of the thermoluminescence (TL) induced by gamma radiation in synthetic hydroxyapatite (HAp) obtained by the precipitation method, using Ca(NO3)2·4H2O and (NH4)2HPO4 and calcined at different temperatures. The structural and morphological characterization was carried out by X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques. TL response as a function of gamma radiation dose was in a wide range, where intensity was enhanced in the sample annealed at 900°C, which tricalcium diphosphate (TCP) phase appear.

Effect of dosimeter type for commissioning small photon beams on calculated dose distribution in stereotactic radiosurgery.

Purpose: To assess the impact of the detector used to commission small photon beams on the calculated dose distribution in stereotactic radiosurgery (SRS).

Methods: In this study, six types of detectors were used to characterize small photon beams: three diodes [a silicon stereotactic field diode SFD, a silicon diode SRS, and a silicon diode E], an ionization chamber CC01, and two types of radiochromic film models EBT and EBT2. These detectors were used to characterize circular collimated beams that were generated by a Novalis linear accelerator.

Dose distribution response in HDRB measured with EBT2 and compared with PLATO SYSTEM.

Dose distribution of a High Dose Rate Brachytherapy (BHDR) oncological treatment with (192)Ir was measured using a Gafchromic EBT2 film. The film calibration was performed with a (60)Co unit and a LINAC of 6 mV and 18 mV. Gafchromic behavior of a dosimeter varies in respect of energy.

Semiconductor diode characterization for total skin electron irradiation.

In this paper, a semiconductor diode characterization was performed. The diode characterization was completed using an electron beam with 4 MeV of energy. The semiconductor diode calibration used irradiation with an electron beam in an ion chamber.

Radiation therapy dosimetry system.

New therapeutic treatments generally aim to increase therapeutic efficacy while minimizing toxicity. Many aspects of radiation dosimetry have been studied and developed particularly in the field of external radiation. The success of radiotherapy relies on monitoring the dose of radiation to which the tumor and the adjacent tissues are exposed.

Thermoluminescent characterization of HfO2:Tb3+ synthesized by hydrothermal route.

Thermo and photoluminescent properties of nanoparticles (NPs) of hafnium oxide (HfO2), both intrinsic and doped with terbium (Tb(3+)) are reported. The NPs of HfO2 were synthesized by hydrothermal route, using hafnium tetrachloride (HfCl4) and terbium chloride hexahydrated (TbCl3∙6H2O) as precursors and sodium hydroxide (NaOH) to adjust the pH. Deionized water was used as solvent in all cases.

Thermoluminescent dosimetry in total body irradiation.

The aim of this paper was to develop a thermoluminescent dosimetry method for the absorbed dose determination of 6 MeV high-energy electron beams by thermoluminescent dosimetry. Total body irradiation (TBI) was performed using four dual fields angled at 252° and 285° in high-dose rate (HDR) mode. TBI measurements were investigated to estimate the absorbed dose in different anatomical parts of the patient.

Thermoluminescent dosimetry in veterinary diagnostic radiology.

This paper presents the results of Environmental and Personnel Dosimetry made in a radiology area of a veterinary hospital. Dosimetry was realized using thermoluminescent (TL) materials. Environmental Dosimetry results show that areas closer to the X-ray equipment are safe.