Geant4 modeling of the bremsstrahlung converter optimal thickness for studying the radiation damage processes in organic dyes solutions (original) (raw)
Related papers
Validation of the Geant4 simulation of bremsstrahlung from thick targets below 3MeV
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2015
The bremsstrahlung spectra produced by electrons impinging on thick targets are simulated using the Geant4 Monte Carlo toolkit. Simulations are validated against experimental data available in literature for a range of energy between 0.5 and 2.8 MeV for Al and Fe targets and for a value of energy of 70 keV for Al, Ag, W and Pb targets. All three independent sets of electromagnetic models available in Geant4 to simulate bremsstrahlung are tested. A quantitative analysis is performed reproducing with each model the energy spectrum for the different configurations of emission angles, energies and targets. At higher energies (0.5-2.8 MeV) of the impinging electrons on Al and Fe targets, Geant4 is able to reproduce the spectral shapes and the integral photon emission in the forward direction. The agreement is within 10-30%, depending on energy, emission angle and target material. The physics model based on the Penelope Monte Carlo code is in slightly better agreement with the measured data than the other two. However, all models overestimate the photon emission in the backward hemisphere. For the lower energy study (70 keV), which includes higher-Z targets, all models systematically underestimate the total photon yield, while still providing a reasonable agreement between 10 and 50%. The results of this work are of potential interest for medical physics applications, where knowledge of the energy spectra and angular distributions of photons is needed for accurate dose calculations with Monte Carlo and other fluence-based methods.
Bulletin of the National Technical University «KhPI» Series: New solutions in modern technologies, 2016
Ionization radiation is everywhere: cosmic rays, nuclear energy, medicine and etc. One of the main tasks during work with the ionization radiation human safety. There are a lot of radiation protected clothes. To define their protective characteristics two way are possible: experimental and simulation. The numerical simulation allows to speed up experiments and cheapen them.There are a lot of software toolkit for ionization radiation pass through the matter simulation. The article is devoted to following tasks: selection of software toolkit for numerical simulation of ionization irradiation passage through the matter;correct way of dose and dose ray calculation as dose rate should be calculated at the point; correct way of mass energy-absorption coefficient approximation by piecwise continuous function. For numerical simulation GEANT4 software toolkit was chosen. The GEANT4 is written in modern programming language: C++. GEANT4 is well documented, has a good supprot and free open software. To calculate dose and dose rate calculation should be made for the point. The absorbed dose calculaation method which is used in GEANT4 can not be used for dose rate calculation. Proper mathematical method for absorbed dose calculation was chosen and was described in the article.
Validation of Geant4 Physics Models Relevant for Space Radiation
In order to use GEANT4 toolkit in the energies relevant to the space radiation it has been tested few of electromagnetic and hadronic models of it by comparing simulated values with NIST data and other experimental data available. For the validation of electromagnetic models energy-loss and electronic stopping powers are considered whereas for the validation of hadronic models, isotope production cross-sections and total fragmentation cross-sections are considered. The stopping power values simulated for protons in Al are agreeing very well with NIST database values. The energy-loss and residual energy values simulated for alpha particles in Si and Al respectively are in good agreement with experimental values at high energies and low-thicknesses of target materials. The stopping power values of alpha particles and Fe ions in Al are also agreeing well with tabulated values at the small thickness of target materials. The proton-proton production cross-section values for liquid hydrogen and polyethylene are within the limits of experimental errors. Although total fragmentation cross-sections for Fe ions in polyethylene and aluminum are not agreeing with the experimental values at low energies, they are agreeing at the peak of GCR spectrum which is around 1 GeV/nucleon. So the selected physics models used in the present simulation work can be used for the space radiation protection studies.
APPLICATION OF GEANT4 CODE IN GAMMA IRRADIATION PROCESSING
International journal of …, 2009
The present work presents an overview of application of the Monte Carlo code, GEANT4, in the gamma irradiation processing field. In order to check the validity of such code, a successful calculation of expected dose rate and photon flux in the Tunisian gamma irradiation facility was carried out. In the same course of study, an ample set of comparison tests were done using the PMMA dosimeters and the GEANT4 version 8.2 code, for measurement and calculation purposes. Thus, the excellent agreement seen between data and calculations allow us to apply the GEANT4based tool in order to optimize some process parameters, specific to the studied 60 Co facility, and to systematically improve the dose uniformity within irradiated targets having different densities and volumes. Therefore, three irradiation processing procedures were studied let us to conclude that for a given carrier dimensions, more the product density is higher than a determined value, more a specific procedure will be performed. It is shown that Monte Carlo simulation improves the gamma irradiation process understanding. * Corresponding address: omrane.kadri@cnstn.rnrt.tn
Issue 2 2020, 2020
The present work is dedicated to study of the possibilities of improving the production method of 11 C and 18 F medical isotopes using a linear electron accelerator. Experimental studies of 11 C and 18 F isotopes production by the photonuclear technique were carried out in [1]. Various targets were irradiated by bremsstrahlung photons following by measurements targets' activities. This experimental research has been carried out in the energy range from 10 to 40 MeV. The current work studies an angular distribution of bremsstrahlung photons in order to estimate the possibilities of producing maximum achievable levels of medical isotopes 18 F and 11 С activities. The angular distribution of bremsstrahlung photons is an important property of the irradiation stand which contains an assembly of targets. This important property allows designing necessary changes in the target assembly setup used to produce medical isotopes. The research presented in the current work was done as a computer simulation. The computer software package 'KIPT' was developed in С++ programming language, using the Geant4 toolkit in order to obtain the angular distribution of bremsstrahlung photons. Experimental setup materials as well as structural elements positions were defined in the DetectorConstruction class of our program. The parameters of an electron beam were defined in the PrimaryGeneratorAction class. The electron beam diameter was defined as 8 mm, energy Е е =36.7 MeV, corresponding to the real experiment carried out at the "Accelerator" Science and Research Establishment of Kharkiv Institute of Physics and Technology [1]. Models of physical processes occurring while the electron beam crosses the target assembly were defined in the PhysicsList class. All classes and modules necessary for the analysis of simulation results were included to our program together with visualization modules. Visualization modules use the OpenGL graphics library and the Qt5 software to represent the relative position of experimental setup parts and to visualize particle trajectories. As a result of this work, the angular distributions were obtained for the beam of electrons and bremsstrahlung photons directly before the target. This result will allow target assembly parameter optimization for optimal production of medical isotopes by the photonuclear technique.
Experimental Check of Bremsstrahlung Dosimetry Predictions for 0.75 MeV Electrons
IEEE Transactions on Nuclear Science, 2000
Bremsstrahlung dose in CaF2 TLDs from the radiation produced by 0.75 MeV electrons incident on Ta/C targets is measured and compared with that calculated via the CYLTRAN Monte Carlo code. The comparison was made to validate the code, which is used to predict and analyze radiation environments of flash x-ray simulators measured by TLDs. Over a wide range of Ta target thicknesses and radiation angles the code is found to agree with the 5% measurements.
Journal of Physical Science and Application, 2015
Dynamitron DC1500/25/04 type EBA (Electron beam accelerator), model JOB 188, was manufactured by IBA Industrial (Radiation Dynamics, Inc.) and installed at IPEN-CNEN/SP, in 1978. The technical specifications of the EBA are: energy 0.5 to 1.5 MeV; beam current: 0.3 to 25.0 mA; beam scanning: 60 to 120 cm; beam width: 25.4 mm and frequency: 100 Hz. Nowadays, this accelerator has been used for innumerable applications, such as: For sterilization of medical, pharmaceutical and biological products, treatment of industrial and domestic effluents and sludge, preservation and disinfestations of foods and agricultural products. Other important application are lignocellulosic material irradiation as a pre-treatment to produce ethanol bio-fuel, decontamination of pesticide packing, solid residues remediation, organic compounds removal from wastewater, treatment of effluent from petroleum production units, crosslinking of foams, wires and electric cables. Electron accelerator JOB 188 is, also, very important composite and nanocomposite materials and carbon fibers irradiation, irradiated grafting ion-exchange membranes for fuel cells application, natural polymers and multilayer packages irradiation and biodegradable blends production. The energy of the electron beam is calculated as a function of the current in the accelerator high-voltage divisor, taking into account the thickness and density of the material to be irradiated. This energy is calculated considering the electron through the entire material and the distance from the titanium foil window, so that the absorbed doses at the points of entrance and exit are equivalent on the material. The dose is directly proportional to the beam current and the exposure time of the material under the electron beam and inversely proportional to the scan width. The aim of this paper is to analyze the power system parameters of the EBA Dynamitron DC1500/25/04, such as, voltage and RMS (Root-mean-square) current in the oscillator system, high voltage generator and waveform. For this purpose software developed in the Radiation Technology Center at IPEN/CNEN-SP to simulate the energy efficiency of this industrial accelerator. Finally, it is also targeted to compare theoretical dosimetry using parameters of energy and beam current with data from the accelerator power system. This knowledge and technology will be very useful and essential for the control system upgrade of EBA, mainly Dynamitron DC1500/25/04 taking into consideration that radiation processing technology for industrial and environmental applications has been developed and used worldwide.
Computational study of radiation doses at UNLV accelerator facility
EPJ Web of Conferences, 2017
A Varian K15 electron linear accelerator (linac) has been considered for installation at University of Nevada, Las Vegas (UNLV). Before experiments can be performed, it is necessary to evaluate the photon and neutron spectra as generated by the linac, as well as the resulting dose rates within the accelerator facility. A computational study using MCNPX was performed to characterize the source terms for the bremsstrahlung converter. The 15 MeV electron beam available in the linac is above the photoneutron threshold energy for several materials in the linac assembly, and as a result, neutrons must be accounted for. The angular and energy distributions for bremsstrahlung flux generated by the interaction of the 15 MeV electron beam with the linac target were determined. This source term was used in conjunction with the K15 collimators to determine the dose rates within the facility.
Simulation of the Gamma Absorption by Lead Bronze Alloys Using Geant4
Rafidain Journal of Science
Shielding materials are extremely important in production or handling isotopes, nuclear reactors, accelerators, and medical centers, etc. The Monte Carlo simulation code Geant4 is one of the most important and common platforms for the simulation of the interaction of radiation with matter. Therefore, this paper is devoted to simulating the partial absorption of the gamma-ray by Lead bronze alloys (Pb, Sn, Cu) in different proportions using the Monte Carlo simulation code Geant4 from 1.5 keV to 15 MeV. The accuracy of the simulated results of the total and partial mass attenuation coefficients () for the photoelectric effect, Compton Scattering and pair production, and tenth value layers (TVL) were evaluated by using the XCOM program. The agreements were good, but it depends on the energy of the incident photon. The mass attenuation coefficients decreased when the photon energy increased and many peaks are observed. The effect of adding Pb was clear, as the increases while the TVL decreases.