This paper deals with the calculation of the absorbed dose in an irradiation cell of gamma rays. Direct measurement and simulation have shown that they are expensive and time consuming. An ...alternative to these two operations is numerical methods, a quick and efficient way can furnish an estimation of the absorbed dose by giving an approximation of the photon flux at a specific point of space. To validate the numerical integration method based on the Haar wavelet for absorbed dose estimation, a study with many configurations was performed. The obtained results with the Haar wavelet method showed a very good agreement with the simulation highlighting good efficacy and acceptable accuracy.
•A numerical integration method using Haar wavelets is detailed.•Absorbed dose is estimated with Haar wavelets method.•Calculated absorbed dose using Haar wavelets and Monte Carlo simulation using Geant4 are compared.
In this work, we focus on the buildup correction of dose calculation using Tchebyshev wavelets in the Tunisian gamma irradiation facility. The buildup effect of gamma rays was used to adjust absorbed ...dose calculation for different depth in two irradiated products (water and lPropane).
•A buildup correction method of calculated dose using Tchebyshev wavelets is presented.•Corrected absorbed dose is calculated for lPropane and water.•Buildup effect of gamma rays was used to adjust absorbed dose calculation for different depth for lPropane and water.
In this article, an approach to compute the dose conversion coefficients (DCCs) is described for the computational voxel phantom 'High-Definition Reference Korean-Man' (HDRK-Man) using artificial ...neural networks (ANN). For this purpose, the voxel phantom was implemented into the Monte Carlo (MC) transport toolkit GEANT4, and the DCCs for more than 30 tissues and organs, due to a broad parallel beam of monoenergetic photons with energy ranging from 15 to 150 keV by a step of 5 keV, were calculated. To study the influence of patient size on DCC values, DCC calculation was performed, for a representative body size population, using five different sizes covering the range of 80-120 % magnification of the original HDRK-Man. The focus of the present study was on the computation of DCC for the human heart. ANN calculation and MC simulation results were compared, and good agreement was observed showing that ANNs can be used as an efficient tool for modelling DCCs for the computational voxel phantom. ANN approach appears to be a significant advance over the time-consuming MC methods for DCC calculation.
•We assessed the patient and staff exposures in cardiac procedures using the voxellized phantoms.•We determined the HT/KAP and E/KAP coefficients considering several dose-dependent parameters.•We ...evaluated the effectiveness of the mobile radiation protection cabin against routine equipment.•We demonstrated the efficiency of GEANT4 to estimate the effective and organ doses in IC procedure.
The aim of this study is to assess the radiation exposure of the patient and the medical staff during interventional cardiology procedures. Realistic exposure scenarios were developed using the adult reference anthropomorphic phantoms adopted by the International Commission on Radiological Protection (ICRP110Male and ICRP110Female), and the radiation transport code Geant4 (version 10.3). The calculated equivalent and effective doses were normalised by the simulated Kerma-Area Product (KAP), resulting in two conversion coefficients HT/KAP and E/KAP. To properly evaluate the risk of exposure, several dose-dependent parameters have been investigated, namely: radiological parameters (tube kilovoltage peak (kVp), type of projection, field size (FOV)), and operator positions. Four projections (AP,PA,LAO25° and RAO25°) were simulated for three X-ray energy spectra (80,100 and 120 kVp) with four different values of FOV (15×15 cm2,20×20 cm2,25×25 cm2 and 30×30 cm2). The results showed that the conversion coefficients values increase with increasing tube voltage as well as the FOV size. Recommended projection during the interventional cardiology procedures, whenever possible, should be the PA projection rather than AP projection. The most critical projection for the patient and the main operator is the RAO25° projection and the LAO25° projection respectively. The comparison of our results with the literature data showed good agreement allowing their use in the dosimetric characterization of interventional cardiology procedures.
In this work, we focus on the buildup correction of dose calculation using Haar wavelets in the Tunisian gamma irradiation facility. The buildup effect of gamma rays was used to adjust absorbed dose ...calculation for different depth in the irradiated products. A buildup study with different product densities was carried out to generalize the dose adjustment approach to any product at any depth.
•A buildup correction method of calculated dose using Haar wavelets is presented.•Corrected absorbed dose is calculated for lPropane and water.•Buildup factor fit as function of product density is performed.•Buildup factor fit is applied to diethyl ether and polypropylene.
•Description of the theoretical method used by the ParShield program.•Description of the ParShield program.•Test and validation the ParShield program.
This study aims to present a new computer ...program called ParShield which determines the neutron and gamma-ray shielding parameters. This program can calculate the total mass attenuation coefficients (μt), the effective atomic numbers (Zeff) and the effective electron densities (Neff) for gamma rays and it can also calculate the effective removal cross-sections (ΣR) for fast neutrons for mixtures and compounds. The results obtained for the gamma rays by using ParShield were compared with the results calculated by the WinXcom program and the measured results. The obtained values of (ΣR) were tested by comparing them with the measured results,the manually calculated results and with the results obtained by using MERCSFN program and an excellent agreement was found between them. The ParShield program can be used as a fast and effective tool to choose and compare the shielding materials, especially for the determination of (Zeff) and (Neff), there is no other programs in the literature which can calculate.
The Semi-Digital Hadronic CALorimeter (SDHCAL) is one of the two hadronic calorimeter options proposed by the International Large Detector (ILD) project for the future International Linear Collider ...(ILC) experiments. It is a sampling calorimeter with 48 active layers made of Glass Resistive Plate Chambers (GRPCs) and their embedded electronics. A fine lateral segmentation is obtained thanks to pickup pads of 1 cm 2 . This ensures the high granularity required for the application of the Particle Flow Algorithm (PFA) in order to improve the jet energy resolution in the ILC experiments. The performance of the SDHCAL technological prototype was tested successfully in several beam tests at CERN. The main point to be discussed here concerns the energy reconstruction in SDHCAL. Based on Monte Carlo simulation of the SDHCAL prototype using the GEANT4 package, we present different energy reconstruction methods to study the energy linearity and resolution of the detector response to single hadrons. In particular, we highlight a new technique based on the Artificial Neural Network giving promising results compared to analytic methods.
An integration method based on Chebyshev wavelets is presented and used to calculate the Hubbell rectangular source integral. A study of the convergence and the accuracy of the method was carried out ...by comparing it to previous studies.
•A numerical integration method using Chebyshev wavelets is detailed.•Hubbell rectangular source integral is estimated using Chebyshev wavelets method.•Convergence study of the Chebyshev wavelet method is performed.•Comparison with earlier studies is presented.
The computational voxel phantom 'High-Definition Reference Korean-Man (HDRK-Man)' was implemented into the Monte Carlo transport toolkit Geant4. The voxel model, adjusted to the Reference Korean Man, ...is 171 cm in height and 68 kg in weight and composed of ∼30 million voxels whose size is 1.981 × 1.981 × 2.0854 mm
The Geant4 code is then utilised to compute the dose conversion coefficients (DCCs) expressed in absorbed dose per air kerma free in air for >30 tissues and organs, including almost all organs required in the new recommendation of the ICRP 103, due to a broad parallel beam of monoenergetic photons impinging in antero-postero direction with energy ranging from 10 to 150 keV. The computed DCCs of different organs are found to be in good agreement with data published using other simulation codes. Also, the influence of patient size on DCC values was investigated for a representative body size of the adult Korean patient population. The study was performed using five different sizes covering the range of 0.8-1.2 magnification order of the original HDRK-Man. It focussed on the computation of DCC for the human heart. Moreover, the provided DCCs were used to present an analytical parameterisation for the calculation of the cardiac absorbed dose for any arbitrary X-ray spectrum and for those patient sizes. Thus, the present work can be considered as an enhancement of the continuous studies performed by medical physicist as part of quality control tests and radiation protection dosimetry.
