The amount of cosmic rays varies widely with the altitude, latitude and longitude in each region. In this study, the radiation doses due to the cosmic rays were estimated in two steps: in the first step, the neutron and gamma components of the radiation dose were measured for a roundtrip flight on 3 flight routes (Shiraz-Asaluye, Asaluye-Rasht and Shiraz-Mashhad) using a gamma-tracer photon detector and a Thyac 190N, neutron detector. The minimum values of the measured gamma and neutron doses of 0.15 and 0.04 mSv were measured on the Asaluyeh-Shiraz route at the lowest altitude of 19000 ft, while for Rasht-Asaluyeh route at an altitude of 35000ft those values were found to be 2.52 and 1.09mSv, respectively. In the second step, a number of aircrew members were equipped with THERMOLUMINESCENCE DOSIMETERS (TLD cards) for evaluating the gamma dose and polycarbonate DOSIMETERS (SSNTD) for assessing the neutron dose for one year. The measured value of the annual effective dose received by the crew ranged between 0.5 mSv/y and 1.16 mSv/y, with an average of 0.9 mSv/y for the gamma component and between 0.37 mSv/y and 0.77 mSv/y with an average of 0.61 mSv/y for the neutron component. The results of this investigation are comparable with the investigations that have been conducted in other countries. For instance in UK, the reported annual effective dose of aircrew is about 2mSv, and in Canada, it is estimated to be between 1 to 5mSv, depending on the flight situations (such as the latitude and longitude of the cities, the flight altitude, etc).

Introduction: LiF dosimeter has the most application in medicine. This study aimed to evaluate some dosimetric properties of a novel LiF: Mg, Ti.Materials and Methods: An ELEKTA Precise linear accelerator was used to calibrate DOSIMETERS at 6 MV. In this survey, responses of DOSIMETERS were evaluated up to 1000 cGy. Background effect was investigated in two different dosimeter states including irradiated and unirradiated. THERMOLUMINESCENCE response dependence to dose rate was investigated, as well. Energy dependence was evaluated in diagnostic and therapeutic ranges. Furthermore, fading effect was evaluated by reading the DOSIMETERS every 2 h up to 12 h post-irradiation.Results: The DOSIMETERS had linear response up to 250 cGy. Readout values of DOSIMETERS receiving 120 cGy at three dose rates of 21, 212, 425 cGy.min-1 were calculated equal to 125, 123, 121 cGy, respectively. The measured values of delivering 80, 120, and 150 cGy prescribed doses at 6 MV, 10 MV, and 15 MV were accurate at 6 MV and about 1.5 times higher than the prescribed doses at 10 and 15 MV. THERMOLUMINESCENCE response in diagnostic energy range showed an uprising trend with increasing energy.Conclusion: The raising THERMOLUMINESCENCE response with increasing energy contradicts with the findings of Nunn. Due to the reproducibility and linear response of DOSIMETERS in an acceptable dose range, they could be used in diagnostic and therapeutic fields. Effects of absorbed doses from background in low-dose studies, mainly in diagnostic radiology range, could be evaluated in more detail in future surveys.

Background: The compositions of Ferrous sulphate, Agarose and Xylenol orange dye (FAX) and Ferrous sulphate, Gelatin and Xylenol orange dye (FGX) in solution of distilled water and sulphuric acid are two tissue-equivalent gel DOSIMETERS. Ionizing radiation causes oxidation of Fe2++ ion to Fe3+ ions which diffuse through the gel matrix and blur the image of absorbed dose over a period of hours after irradiation. Materials and methods: 25 mM sulphuric acid, 0.4 mM ferrous ammonium sulphate, 0.2 mM xylenol orange dye and 1% by weight agarose in distilled water named FAX and 0.1 mM ferrous ammonium sulphate, 0.1 mM xylenol orange dye, 50 mM sulphuric acid and 5% by weight gelatin in distilled water named FGX are used as two gel DOSIMETERS. All chemicals were supplied by Sigma Aldridge Company, Germany . The gels were poured in Perspex casts and were irradiated to a beam of X ray from linear accelerators or x ray machine. Results: In this study diffusion coefficients of FAX and FGX DOSIMETERS have been measured through a computer program for different temperatures. The ferric ion diffusion coefficient (D) for the FAX and FGX DOSIMETERS were measured as (1.19 ± 0.03) x 10-2 cm2.hr-1 and (0.83 ± 0.03) x 10-2 cm2.hr-1 respectively at room temperature. Conclusion: For both DOSIMETERS the diffusion coefficients decreased with gel storage temperatures down to 6oC. FGX DOSIMETERS have advantage of lower diffusion coefficient for a specified temperature

Modern radiotherapy techniques try to deliver the radiation dose by steep gradient. Protocols for these complex treatment delivery techniques are important and extremely sensitive to errors in treatment delivery. To minimize such errors, 3D DOSIMETERS were developed as a relative method for improving dose monitoring and delivery. The aim of this study is to analyze the capability and drawbacks of different types of 3D DOSIMETERS such as Fricke gel DOSIMETERS, Hypoxic gel polymers, Normoxic gel polymers and 3D radiochromic solid polymer known as PRESAGE. The results of studies show that the optimum method of dosimetry in radiation therapy is using PRESAGE dosimeter.

In this scientific research ZnS nanoparticle was synthesized via precipitation method. Two samples were synthesized by this method. The nanoparticle was characterized by XRD techniques, and the size and kind of crystallinity were identified by X-ray diffraction pattern as well. The size measurement has been done by using scherrer’s equation. The average sizes of nanoparticles in two samples were 11nm and 23nm. In fact, the velocity of stirrer affects the size of particles. Moreover, the study of XRD pattern indicates the cubic structure. This nanoparticle exposed to Gama ray source of 60Co and investigated their THERMOLUMINESCENCE’s properties. The result shows that the THERMOLUMINESCENCE intensity increases by the size reduction of nanoparticles.

The loess deposits in central Asia, China, Europe and the USA provide records of past climate, which permits the study of paleoclimatology. Although luminescence dating has had an important role in dating loess, significant challenges still remain. UV-blue emission from polymineral and feldspar suffer from anomalous fading. UV-blue emission from quartz saturates at c.<500 Gy. Fattahi (2001) reported the ability of red THERMOLUMINESCENCE for dating volcanic quartz to c.1.3 Ma.This paper investigates the possibility of applying single aliquot regeneration red THERMOLUMINESCENCE (SARRTL) protocol for dating loess and demonstrating that: 1- It is possible to detect red THERMOLUMINESCENCE from loess. 2- Red THERMOLUMINESCENCE from loess is bleachable.3- SARRTL is able to recover a known laboratory dose.4- Equivalent doses around 1000 Gy are accessible.This information suggests that SAR RTL is a powerful protocol for dating loess which can extend the time range of luminescence dating of unburnt Aeolian sediments.

In this work the chemical ethanol-chlorobenzene (ECB) DOSIMETERS were prepared. A cobalt-60 irradiation source was used at the dose range of 0-30 kGy. Titration, spectrophotometry, and oscillometry read-out methods were applied, and the latter method was adopted throughout this experiment. The dose responses were found to agree favourably with the ASTM standards. The homogeneity and the reproducibility of the produced ECB DOSIMETERS were also controlled and found satisfactory.

Thennoluminescence DOSIMETERS are well known for their widespread applications in dosimetry specially neutron dosimetry. In low neutron fluences it is usual to use (n, a) reaction for direct measurement of neutron fluence, but in higher values, some gray filters are necessary. And also supralinearity because of the high absorbed dose makes the direct reading of TLDs difficult. After anealing of DOSIMETERS the absorbed dose from the internal activity was used as a mass for neutron fluence. In this work thermal neutron fluence in the range between 1011 and 1013 n/cm2 in the reactor core of Tehran Research Reactor was measured using TLD-600 thennoluminescence DOSIMETERS. The influence of irradiation-induced damage effect on the response of TLDs and their subsequent readings have been minimized. The measurements were made reproducible in this manner. The induced TL-light reader due to self-activity in TLD-600 dependens on the neutron fluence caused a conveniently: measurable TL glow curve. The accumulated TL-light was measured after storage periods of 24, 48 and 72 hours. A short theoretical treatment is also presented at this work.

Background: THERMOLUMINESCENCE DOSIMETERS are the most widely used inactive in vivo DOSIMETERS. Nanoparticles have more suitable dosimetry properties than similar bulk materials. The purpose of this study was to synthesize and to determine the kinetic parameters of nanophosphor equivalent to human tissue for using in medical purposes. Methods: After synthesis of LiB3O5 nanophosphor, structure and its dimensions were investigated using X-ray diffraction pattern (XRD) and scanning electron microscopy (SEM). Different activators were added to each nanophosphor with 0. 5, 1, and 2 percent of weight, to select the most suitable compound as a usable THERMOLUMINESCENCE dosimeter in medicine. The kinetic parameters of the glow peaks were calculated using four methods, and the results of these methods were compared. Findings: SEM and XRD analysis showed that the dimensions of synthesized phosphorus were less than 100 nm, and had a relatively high purity. By irradiating and reading the samples, the best peak position and intensity of the glow curve were obtained by 2 percent of weight aluminum (Al) activator at the peak temperature of 183 ° C. Conclusion: The results of different methods were in good agreement. The calculated mean value of the activation energy was 1. 243 eV, which had a good energy level for the thermoluminescent dosimeter (TLD) reader. By comparing the experimental and computational values, the validity of the computational methods was confirmed.

Considering the importance of quality control of radiotherapy systems and 3D dose mapping possibility done with a Fricke agarose gel dosimeter, this dosimeter based on ferrous solution and agarose gel was prepared. The prepared Fricke gel DOSIMETERS was investigated under gamma irradiation with a dose range up to 20 Gy. Concerning the effect of the gel dosimeter constituent’, s concentration on the response of the dosimeter, different compositions were surveyed for better sensitivity and repeatability. So, the responses were evaluated for different concentrations of ferrous ion, sulphuric acid, and the indicator. We found that the Fricke agarose gel dosimeter has a linear behavior up to 20 Gy. In addition, the best composition of Fricke agarose gel dosimeter with high sensitivity and stability was determined to be 0. 2 mM ferrous, 25 mM sulphuric acid, and 0. 15 mM Xylenol orange.