scholarly journals Conversion coefficients from fluence and air kerma to personal dose equivalent for monoenergetic photons using analytical fit and Monte Carlo simulation

2020 ◽  
Vol 26 (1) ◽  
pp. 31-44
Author(s):  
Hassan Al Kanti ◽  
O. El Hajjaji ◽  
T. El Bardouni
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Monte Carlo Methods ◽  
Analytical Approach ◽  
Absorbed Dose ◽  
Dose Equivalent ◽  
Air Kerma ◽  
Conversion Coefficients ◽  
New Equation ◽  
Operational Quantities

AbstractThe present study aims to calculate a new database of conversion coefficients from fluence and air Kerma to personal dose equivalent in two terms: absorbed dose and Kerma-approximations. In this work, we propose a new equation to perform an analytical fit of our Monte Carlo (MC) calculated conversion coefficients for photons for different angles. Also, we have calculated the conversion coefficients using the EGSnrc code. The conversion coefficients have been calculated for beams of monoenergetic photons from 0.015 to 10 MeV, incident on phantom ICRU for angles of incidence from 0° to a 75° in steps of 15°. Our computed values agree well when compared with those published for the ICRU 57 in Kerma-approximations with statistical uncertainties in the calculation around 2%. We can conclude from this work that the analytical approach is successful and powerful such as Monte Carlo methods to calculate the operational quantities.

INFLUENCE OF NEW MASS ENERGY-ABSORPTION COEFFICIENTS FROM ICRU REPORT NO. 90 ON AIR KERMA TO DOSE EQUIVALENT CONVERSION COEFFICIENTS

2018 ◽  
Vol 185 (1) ◽  
pp. 27-33
Author(s):  
Katharina Bairlein ◽  
Oliver Hupe
Keyword(s):  
Energy Absorption ◽  
Radiation Protection ◽  
Cross Sections ◽  
Mass Energy ◽  
Dose Equivalent ◽  
Absorption Coefficients ◽  
X Ray ◽  
Air Kerma ◽  
Conversion Coefficients ◽  
Operational Quantities

Abstract In Report No. 90 of the International Commission on Radiation Units and Measurements (ICRU), new mass energy-absorption coefficients are listed which are based on renormalized Scofield photoeffect cross-sections. The mass energy-absorption coefficients are the basis for the conversion coefficients from air kerma to the operational quantities listed in ISO 4037-3. Although ICRU does not give a recommendation if these new mass energy-absorption coefficients should be applied instead of the values used so far, an examination of the possible consequences for radiation protection quantities is necessary. We calculated the conversion coefficients for the X-ray qualities specified in ISO 4037-1 with the new mass energy-absorption coefficients and with the mass energy-absorption coefficients used so far to determine the deviations. Our calculations show that the change of the conversion coefficients due to the new values from ICRU Report No. 90 is negligible.

Development of SiO2 based doped with LiF, Cr2O3, CoO4 and B2O3 glasses for gamma and fast neutron shielding

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Bünyamin Aygün ◽  
Erdem Şakar ◽  
Abdulhalik Karabulut ◽  
Bünyamin Alım ◽  
Mohammed I. Sayyed ◽  
...  
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Fast Neutron ◽  
Cross Sections ◽  
Gamma Ray ◽  
Absorbed Dose ◽  
Neutron Shielding ◽  
Shielding Properties ◽  
Effective Neutron ◽  
Simulation Codes

AbstractIn this study, the fast neutron and gamma-ray absorption capacities of the new glasses have been investigated, which are obtained by doping CoO,CdWO4,Bi2O3, Cr2O3, ZnO, LiF,B2O3 and PbO compounds to SiO2 based glasses. GEANT4 and FLUKA Monte Carlo simulation codes have been used in the planning of the samples. The glasses were produced using a well-known melt-quenching technique. The effective neutron removal cross-sections, mean free paths, half-value layer, and transmission numbers of the fabricated glasses have been calculated through both GEANT4 and FLUKA Monte Carlo simulation codes. Experimental neutron absorbed dose measurements have been carried out. It was found that GS4 glass has the best neutron protection capacity among the produced glasses. In addition to neutron shielding properties, the gamma-ray attenuation capacities, were calculated using newly developed Phy-X/PSD software. The gamma-ray shielding properties of GS1 and GS2 are found to be equivalent to Pb-based glass.

scholarly journals Monte Carlo simulation study on the 241Am-Be radionuclide source reference neutron radiation

2020 ◽  
Vol 35 (4) ◽  
pp. 283-293
Author(s):  
Yixin Liu ◽  
Song Zhang ◽  
Yikun Qian ◽  
Yuchen Huang ◽  
Benjiang Mao ◽  
...  
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Free Field ◽  
Neutron Radiation ◽  
Neutron Energy Spectrum ◽  
Measurement Instruments ◽  
Dose Equivalent ◽  
Monte Carlo Simulation Study ◽  
Neutron Measurement ◽  
Radionuclide Source

In order to study the feasibility of using lightweight 241Am-Be radionuclide reference neutron radiation field for the calibration of neutron measurement instruments, this paper reported the Monte Carlo simulation work on free field reference neutron radiation, standard reference neutron radiation regulated by ISO-8529 series standards and minitype reference neutron radiation we designed. The distributions of dose equivalent rates and neutron energy spectrum in different conditions, such as different room types, different room sizes and different shield materials were the main simulation contents for analyzing the characteristics of the three types of reference neutron radiation. According to the simulation results, theoretical supports were provided for the discussion on the minitype reference neutron radiation for calibration purpose.

scholarly journals MONTE CARLO SIMULATION IN INTERNAL RADIOTHERAPY OF THYROID CANCER

2020 ◽  
Vol 3 (9) ◽  
pp. 16-24 ◽  
Author(s):  
Hammam Oktajianto ◽  
Evi Setiawati
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Thyroid Cancer ◽  
Monte Carlo Method ◽  
Effective Dose ◽  
Radiation Effect ◽  
Cervical Vertebrae ◽  
Absorbed Dose ◽  
Particle Track ◽  
Internal Radiotherapy

Thyroid radiotherapy is a cancer therapy that is treated by giving radioactive I-131 in Thyroid gland. This cancer is at the ninth from ten of common malignant cancer. A man has higher risk to get Thyroid cancer than a woman has. This organ is lain near human neck. This research aim was to simulate particle track of radiation I-131 and determine an absorbed dose and effective dose in Thyroid and other organs around Thyroid such as Brain, Lung and Cervical vertebrae. The simulation and calculation used Monte Carlo method operated by MCNPX software. Geometry of Thyroid and other organs used ORNL MIRD phantom geometry. From the results, it shown that particle track of radiation was distributed at Thyroid while several particles radiated other organs. The absorbed dose in Thyroid and other organs increased every rising activity of I-131 used, but the absorbed dose in other organs was less than in Thyroid. Radiation effect for damage cancer in Thyroid was shown by an effective dose which it increased every rising activity of I-131 used and the maximum effective dose was at 200 mCi activity of I-131. Although the effective dose in Thyroid increased, the effective dose in other organs like Brain, Lung and Cervical vertebrae was still less than in Thyroid so that the use of I-131 each activity did not really influence other organs around Thyroid.  

An investigation of the effect of gold nanoparticles with different concentrations on increasing absorbed dose: an empirical and simulation study

2018 ◽  
Vol 18 (02) ◽  
pp. 191-197
Author(s):  
Masoumeh Hoseinnezhad ◽  
Mohammad Mahdavi ◽  
Seyyed R. M. Mahdavi ◽  
Mobarake Mahdavizade
Keyword(s):  
Monte Carlo Simulation ◽  
Gold Nanoparticles ◽  
Monte Carlo ◽  
Absorbed Dose ◽  
Simulation Method ◽  
Dose Enhancement ◽  
Depth Dose ◽  
Optical Ct ◽  
Ct System ◽  
Monte Carlo Simulation Model

AbstractPurposeThe purpose of this study was to determine the dose enhancement factor (DEF) of gold nanoparticles in a dosimeter gel and construct percentage depth dose curves, using the Optical CT system and the Monte Carlo simulation model, to determine the effect of increasing the dose caused by increasing the concentration of gold nanoparticles at depths in the gel.Materials and methodsThe Magic-f Gel was made based on the relevant protocol in the physics lab. To determine the amount of the increase in the absorbed dose, the gold nanoparticles were added to the gel and irradiated. An increase in the dose after adding nanoparticles to the gel vials was estimated both with the Optical CT system and by the Monte Carlo simulation method.ResultsDose enhancement curves for doses of 2, 4 and 6 Gy were prepared for gel vials without adding nanoparticles, and nanoparticle gels at concentrations 0·17, 3 and 6 mM. Also, the DEF was estimated. For the 0·17 mM molar gel, the DEF for 2, 4 and 6 Gy was 0·7, 0·743 and 0·801, respectively. For the 3 mM gel, it was 1·98, 2·5 and 2·2, and for the 6 mM gel, it was 37·4, 4·24 and 4·71, respectively.ConclusionThe enhancement of the dose after adding gold nanoparticles was confirmed both by experimental data and by simulation data.

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