This research presents results on the full energy peak efficiency of a high purity germanium (HPGe) detector from point source as a function of photon energy and source-detector distance. The directions of photons emitted from the source and the photon path lengths in the detector were determined by Monte Carlo technique. A major advantage of this technique is the short computation time compared to the experiments. Another advantage is the flexibility for inputting detector-related parameters (such as source–detector distance, detector radius, length and attenuation coefficient) into the algorithm developed, thus making it an easy and flexible method to apply to other detector systems and configurations. It has been designed and written the program for this computational. The results of the full energy peak counting efficiency were compared with the published results. It appears in a good agreement with quantity and behavior.
(1)
(1)
In this study, mean free path and positron elastic-inelastic scattering are modeled for the elements hydrogen (H), carbon (C), nitrogen (N), oxygen (O), phosphorus (P), sulfur (S), chlorine (Cl), potassium (K) and iodine (I). Despite the enormous amounts of data required, the Monte Carlo (MC) method was applied, allowing for a very accurate simulation of positron interaction collisions in live cells. Here, the MC simulation of the interaction of positrons was reported with breast, liver, and thyroid at normal incidence angles, with energies ranging from 45 eV to 0.2 MeV. The model provides a straightforward analytic formula for the random sampling of positron scattering. ICRU44 was used to compile the elemental composition data. In this
... Show More
(1)
The temperature distributions are to be evaluated for the furnace of Al-Mussaib power plant. Monte Carlo simulation procedure is used to evaluate the radiation heat transfer inside the furnace, where the radiative transfer is the most important process occurring there. Weighted sum of gray-gases model is used to evaluate the radiative properties of the non gray gas in the enclosure. The energy balance equations are applied for each gas, and surface zones, and by solving these equations, both the temperature, and the heat flux are found.
Good degree of accuracy has been obtained, when comparing the results obtained by the simulation with the data of the designing company, and the data obtained by the zonal method. In
... Show More
In this research the active volume for a number of solid-state detectors of the type of high-purity germanium (HPGe) crystal was evaluated with different radii and depths using scanning method for diagonal (front) and lateral (side). It has been used for this purpose Monte-Carlo efficiency program after its development by adding a subroutine-program for its (subroutine scanning).Also a program has been written to calculate the stopping power and range for incident charged particle on the detector, in order to determine the exact sufficient energy to stop it inside the detector material. The calculations of our results of efficiency were compared with the results of published efficiency and the comparison is very good in terms of improvin
... Show MoreIn this article, a numerical method integrated with statistical data simulation technique is introduced to solve a nonlinear system of ordinary differential equations with multiple random variable coefficients. The utilization of Monte Carlo simulation with central divided difference formula of finite difference (FD) method is repeated n times to simulate values of the variable coefficients as random sampling instead being limited as real values with respect to time. The mean of the n final solutions via this integrated technique, named in short as mean Monte Carlo finite difference (MMCFD) method, represents the final solution of the system. This method is proposed for the first time to calculate the numerical solution obtained fo
... Show More
(15)
(9)
A program using Mont Carlo techniques has been written to calculate the effective solid angle of the detection system and simulate the response of the HPGe to mono-energetic protons from an extend source. It has been found that the fraction of the protons which leave through the cylindrical surface and deposit only part of their kinetic energy in the crystal increases with proton energy and the consequent increase in their range.
Estimations of specific activity concentrations in eight commercial porcelain tiles made in different countries were performed by the use of HPGe detector. We have found that the highest specific activity concentrations for 238U, 40K were equal to (21.120 Bq/kg) and (283.862 Bq/kg) respectively, Iranian origin, while the highest specific activity concentration for 232Th was found to be equal to (29.292 Bq/kg), Iraqi origin; all of which were less than their corresponding recommended values given by (UNSCEAR, 2000). The radiation hazard indices [IÉ£ , Hin ,Hex , Raeq ,DÆ” , (AEDE) in and (AEDE) out] w
... Show More
(1)
The result of concentration varying of mixture methane with argon and neon gas are believed to study the change in electrons energy distribution function and then the change of the electrons transport parameters including the drift velocity, the mean energy, characteristics energy and diffusion coefficient. In the present work,a contemporary developed computer, simulation program known as Bolsig+ is being used for calculating the electron transport parameters.
(4)
Measurement of 238U, 233Th and 40K concentrations in soil samples collected from Ziggurat of Dur-Kurigalzu west region of Baghdad, have been evaluated, using high purity germanium detector. The activity concentrations of 238U, 233Th and 40K varied from 16.040 to 26.620 , 14.510 to 31.480 , and 153.820 to 266.320 with average values of 20.604±2.9 , 24.534±3.3 , 212.22±25.1 , respectively. The importance of these measurements lies in the estimation of radiation risk, radium equivalent, absorbed dose, annual effective dose, risk indices, gamma index, and cancer risk. The average value of the absorbed dose ranged from 33.187 outdoors to 63.111 indoo
... Show More