Faezeh Rahmani

K.N.Toosi University of Technology | KNTU · Faculty of Physics

The aim of this study is to compare dose enhancement of various agents, nanoparticles and chemotherapy drugs for neutron capture therapy. A (252)Cf source was simulated to obtain its dosimetric parameters, including air kerma strength, dose rate constant, radial dose function and total dose rates. These results were compared with previously publish...

The feasibility of using the HEC-1 beam port of the IRT-T research reactor to generate an epithermal neutron beam for Boron Neutron Capture Therapy (BNCT) was investigated using MCNPX2.6 Monte Carlo simulation. The reactor was first simulated to design and optimize a Beam Shaping Assembly (BSA) that meets the neutron beam criteria recommended by th...

The possibility of creating technical means for controlling the processes of accumulation and conversion of the energies of thermal and epithermal neutrons into the energy of monoenergetic photons due to neutron pumping of an active medium consisting of nuclei with long-lived isomeric states was studied in this work. The system under study consiste...

In this research, a ThErmal Neutron Imaging System (TENIS) consisting of two perpendicular sets of plastic scintillator arrays for boron neutron capture therapy (BNCT) application has been investigated in a completely different approach for neutron energy spectrum unfolding. TENIS provides a thermal neutron map based on the detection of 2.22 MeV ga...

Corrigendum to “Neutron and gamma-ray signatures for the control of alpha-emitting materials in uranium production: A Nedis2m-MCNP6 simulation” [Radiat. Phys. Chem. 208 (2023) 110919]

The radiations emitted via 19F(α,nγ), 19F(α,pγ), and 19F(α,α′γ) reactions in compounds containing alpha-emitting elements and fluorine are used for non-destructive neutron and gamma-ray analyses in monitoring the contents of nuclear fissile materials during the manufacture, processing, and storage of nuclear fuels. As far as the literature survey c...

The feasibility study of the landmine identification system (LIS) based on the angular distribution of thermal neutrons for buried landmines was undertaken in this work. The operation of the system was based on both artificial neural networks (ANN) and least-squares methods in which the input data were prepared by the MCNP6.1 Monte Carlo code befor...

As a powerful, non-destructive analysis tool based on thermal neutron capture reaction, prompt gamma neutron activation analysis (PGNAA) indeed requires the appropriate neutron source. Neutrons produced by electron Linac-based neutron sources should be thermalized to be appropriate for PGNAA. As a result, thermalization devices (TDs) are used for t...

The Tehran Research Reactor is the only appropriate and available neutron source in Iran for clinical boron neutron capture therapy (BNCT). One of the requirements for BNCT is to carefully evaluate and measure the therapeutic neutron beam (epithermal neutrons) as well as the fast and thermal neutron components for successful treatment. In this rese...

In this research, a rapid and accurate gamma finder system which can find orphan gamma-ray sources has been designed based on NaI(Tl) detector. By proposing complementary methods to our previous researches, an attempt has been made to provide an approach to solve the problem of 3D localization in multiple orphan gamma-ray sources scenario. Based on...

This work presents an alternative method for Mo-99 production as a parent nuclide of Tc-99m which is the most used radioisotope in diagnostic imaging processes. Regarding to some benefits of accelerator-based methods over reactor-based methods for Mo-99 production, the electron Linac-based method has been selected. In this way of production, two ap...

The hybrid use of Nedis-2m and Serpent 2.1.30 codes to predict the radiation characteristics (i.e., neutron yield and energy spectrum) of an Am-Be source with a fine-grained mixture of americium dioxide (AmO2) and beryllium (Be) core was studied with a focus on the grain size influence on the simulation results. The study showed that the fine-grain...

Abstract The hybrid use of Nedis-2m and Serpent 2.1.30 codes to predict the radiation characteristics (i.e., neutron yield and energy spectrum) of an Am-Be source with a fine-grained mixture of americium dioxide (AmO2) and beryllium (Be) core was studied with a focus on the grain size influence on the simulation results. The study showed that the f...

Although the beam shaping assemblies (BSAs) for reactor-based Boron Neutron Capture Therapy (BNCT) facilities are typically of a single design, the accelerator beams with the possibility to provide neutron spectrum to give characteristics which are optimum for different treatment sites and tumor depth generally may require a fine-tuning procedure w...

The hybrid use of Nedis-2m and Serpent 2.1.30 codes to predict the radiation characteristics (i.e., neutron yield and energy spectrum) of an Am-Be source with a fine-grained mixture of americium dioxide (AmO2) and beryllium (Be) core was studied with a focus on the grain size influence on the simulation results. The study showed that the fine-grain...

We present new capabilities of the Gate6.2 code that enable the precision simulation of CsI(Tl) and CsI(Tl-Eu) detectors within a comprehensive Monte Carlo code for the first time. Firsty, single crystals were grown by the vertical Bridgman method. A comparison study of the scintillation properties of crystals including energy resolutionand photolum...

In this study, the idea Mo-99 production using hybrid method based on the electron accelerator has been presented. Two different main production channels, 100Mo (γ,n) 99Mo and 98Mo (n,γ) 99Mo, can be used for Mo-99 production in this system. By considering high power Linac (30 MeV - 1 mA) and one-stage approach, the calculation of 100Mo(γ,n) 99Mo r...

In this paper, a conceptual design of a gamma finder including four identical NaI (Tl) cylindrical scintillation detectors has been presented. This gamma finder can determine the position and the energy (in the energy range of 35 keV to 3 MeV) of an orphan gamma-ray point source in a limited space such as a treatment room or industrial lab. The nov...

Today providing enough supplies of 99mTc / 99Mo as a most applicable radioisotope in diagnostic nuclear medicine for the world demand is an important challenge. One of the proofed ways to access reliable source of this radioisotopes is the production using e-Linac [1]. In this investigation it has been tried to find the simple and the optimized des...

A 20 MeV electron Linac based neutron beam has been shaped for neutron activation analysis (NAA) technique. A beam shaping assembly (BSA) has been simulated using MCNPX2.6 code to increase the thermal neutron flux and decrease the epithermal and fast neutrons as much as possible at the beam port for NAA facility. Final BSA containing 1.5 cm tungste...

The Monte Carlo simulation code, FLUKA version 2011.2 c.5, has been used to estimate the in–phantom dosimetric parameters for use in BNCT studies. The in–phantom parameters of a typical Snyder head, which are necessary information prior to any clinical treatment, have been calculated with both FLUKA and MCNPX codes, which exhibit a promising agreem...

Molybdenum99 is used for preparing 99m Tc, which is the most widely used isotope in nuclear medicine. As a recent and now shortages in reactor-based supplies of 99 Mo/ 99m Tc and also some problems due to the time limitation in a direct production approach such as 100 Mo(p,2n) 99m Tc reaction by cyclotrons, many of developed countries have started...

In this study, a ⁹⁰Sr radioisotope thermoelectric generator (RTG) with power of milliWatt was designed to operate in the determined temperature (300–312 K). For this purpose, the combination of analytical and Monte Carlo methods with ANSYS and COMSOL software as well as the MCNP code was used. This designed RTG contains ⁹⁰Sr as a radioisotope heat...

Purpose In this work, gold nanoparticles (GNPs) were embedded in the MAGIC-f polymer gel irradiated with the ¹⁹²Ir brachytherapy sources. Material and methods At the first plexiglas phantom was made as the human pelvis. The GNPs were synthesized with 15 nm in diameter and 0.1 mM (0.0197 mg/ml) in concentration by using a chemical reduction method....

Aim: Determination of boron neutron capture therapy in-phantom parameters by response matrix (RM) method. Materials and methods: In this study, various in-phantom figures-of-merit including therapeutic gain, advantage depth dose rate, advantage depth, therapeutic depth, treatment time, skin dose rate, and skull dose rate have been analyzed using...

Background: Normoxic type MAGICA gel dosimeters are established for dose quantification in three dimensions for radiotherapy. Objective(s): The ability of MAGICA polymer gel was assessed by experimental measurements method for studying the effect of gold nanoparticles (GNPs) in dose enhancement under the external 18MV radiotherapy practices. Method...

A study was conducted to dose analysis of human body organs of ORNL mathematical phantom as a personnel in radiation field of the 2.5 kJ plasma focus device. The dose calculations were performed for 108 fusion neutrons per shot (with energy of 2.45 MeV) from deuterium and deuterium fusion (D–D) using Monte Carlo MCNP code. Based on the results, ass...

Theoretical studies on the optimization of Silicon (Si) parameters as the base of betavoltaic battery have been presented using Monte Carlo simulations and the state equations in semiconductor to obtain maximum power. Si with active area of 1 cm2 has been considered in p-n junction and Schottky barrier structure to collect the radiation induced-cha...

Objective(s): In this study we evaluate the impact of the different aspects of Gold Nano-Particles (GNPs) on the target absorptive Dose Enhancement Factor (DEF) during external targeted radiotherapy with photon beams ranging from kilovolt to megavolt energies using Monte Carlo simulation. Methods: We have simulated the interaction of photon beams w...

The effects of gold nanoparticles (GNPs) in ¹²⁵ I brachytherapy dose enhancement on choroidal melanoma are examined using the Monte Carlo simulation technique. Usually, Monte Carlo ophthalmic brachytherapy dosimetry is performed in a water phantom. However, here, the compositions of human eye have been considered instead of water. Both human eye an...

Materials of high atomic number such as gold, can provide a high probability for photon interaction by photoelectric effects during radiation therapy. In cancer therapy, the object of brachytherapy as a kind of radiotherapy is to deliver adequate radiation dose to tumor while sparing surrounding healthy tissue. Several studies demonstrated that the...

An electron accelerator, ILU-14, with current of 10mA and 100kW in power has been considered as one of the options for neutron source in Boron Neutron Capture Therapy (BNCT). The final design of neutron target has been obtained using MCNPX to optimize the neutron production. Tungsten in strip shape and D2O in cylindrical form have been proposed as...

Recent studies have shown that D-T neutron generator can be used as a proper neutron source for Boron Neutron Capture Therapy (BNCT) of deep-seated brain tumors. In this paper, radiation shielding calculations have been conducted based on the computational method for designing a BNCT treatment room for a recent proposed D-T neutron source. By using...

Dosimetric instruments must constantly monitor radiation dose levels in different areas of nuclear reactor. Tehran Research Reactor (TRR) has seven beam tubes for different research purposes. All the beam tubes extend from the reactor core to Beam Port Floor (BPF) of the reactor facility. During the reactor operation, the gamma rays exiting from ea...

In this paper, the conceptual design of the x-ray monitoring system of two energies including 160 kV X-ray lamp, a multi-stage superconductor and a detector is discussed. Design calculations were carried out by the MCNPX code in order to design the mixer and select the type of detector as well as their thicknesses. The X-rays by the coordination th...

One of the methods for material inspection is the dual energy X-ray technique. Although this method can be more useful in material distinguishing, but signal's intensities are still dependent on the thicknesses of materials in front of the detector, so the material identification results may be affected. In this paper, the new technique using Compo...

Background: High density concrete is extensively used for efficient radiation attenuation in radiotherapy rooms and nuclear reactors. Over the past eight years, some efficient galena-based concrete samples for shielding X or gamma rays was produced. The goal of this study was to produce a novel high density concrete against neutron and photon radia...

A study was conducted to investigate a photoneutron spectrum based on a 25 MeV electron linac for treatment of deep-seated brain tumors in the context of boron neutron capture therapy (BNCT). Based on a series of Mont Carlo N-Particle simulations, tungsten and uranium with optimized geometry were selected as the most appropriate converters for (e,g...

Background: The aim of this work was to establish how well gel dosimeters performed, as substitutes for brain tissue compared with standard phantom materials such as water, polymethyl-methacrylate (or PMMA), A150 plastic and TE- liquid phantom material for dosimetry of neutron beams in boron neutron capture therapy. Materials and Methods: Thermal n...

In this paper, we introduce a silicon semiconductor sandwich spectrophotometer and its resolution, and some ways to improve it. The spectrograph consists of a lithium target and two semiconductor detectors on both sides for detecting and measuring the neutron spectrum. The collision of neutrons with the purpose of lithium causes the emission of cha...

A theoretical study of the use of a beta-cell as a temperature sensor using MCNP4C Monte Carlo code is presented in this paper. Nickel-63 and silicon were selected as the beta source and semiconductor material, respectively. The maximum open-circuit voltage (VOC) is equal to 0.445V with doping concentrations of NA=4×10(18)#/cm(3) and ND=8×10(19)#/c...

Dual X-ray bone densitometry may cause some errors in diagnosis due to heterogeneous distribution of adipose tissue. It is necessary to develop a more accurate technique to consider the effects of fat. In this research, a triple energy X-ray method has been introduced and conceptual design of a system consisting of 160 kV X-ray tube, multi-layer K-...

Recently, extensive research has been performed to produce neutron beams in hospitals using electron linear accelerator for neutron medical applications such as Boron Neutron Capture Therapy. In this article, we present the results of Monte Carlo calculations, using MCNPX code, for the possibility of setting up a 25 MeV electron linac based photone...

Recently, due to space and weight limitations, scientists have tried to design and produce concrete shields with increased attenuation of radiation but not increased mass density. Over the past years, the authors’ had focused on the production of heavy concrete for radiation shielding, but this is the first experience of producing intermediate-weig...

A hybrid photoneutron target including natural uranium has been studied for a 20MeV linear electron accelerator (Linac) based Boron Neutron Capture Therapy (BNCT) facility. In this study the possibility of using uranium to increase the neutron intensity has been investigated by focusing on the time dependence behavior of the build-up and decay of t...

In-phantom measurement of physical dose distribution is very important for Boron Neutron Capture Therapy (BNCT) planning validation. If any changes take place in therapeutic neutron beam due to the beam shaping assembly (BSA) change, the dose will be changed so another group of simulations should be carried out for dose calculation. To avoid this t...

Neutron activation analysis (NAA) is a precise chemical multielemental method of analysis which is satisfactorily used for qualitative and quantitative analyses. Repeated irradiation is needed because of mal-determination of some elements due to peak overlap in qualitative analysis. In this study, NAA procedure has been modified using a neuro-fuzzy...

Boron Neutron Capture Therapy (BNCT) is being studied as a possible radiotherapic treatment for some cancer types. Neutron energy for penetrating into tissue should be in the epithermal range. Different methods are used for neutron production. Electron accelerators are an alternative way for producing neutrons in electron–photon–neutron processes....

Neutron activation analysis (NAA) is a precise multi-elemental method which performs well for qualitative and quantitative analyses. This method has been applied to the laboratory of Radiation Applications Research School (RARS) at University of Tehran. The new pneumatic transfer system (Rabbit) has been designed and constructed for transferring sa...