This paper compares fault position and Monte Carlo methods as the most common methods in stochastic assessment of voltage sags. To compare their abilities, symmetrical and unsymmetrical faults with different probability distribution of fault positions along the lines are applied in a test system. The voltage sag magnitude in different nodes of test system is calculated. The problem with the...

Background: The dosimetric parameters required in lung cancer radiation therapy are taken from a homogeneous water phantom; however, during treatment, the expected results are being affected because of its inhomogeneity. Therefore, it becomes necessary to quantify these deviations.Objective: The present study has been undertaken to find out inter- and intra- lung density variations and its dosi...

Introduction: In recent decades, several Monte Carlo codes have been introduced for research and medical applications. These methods provide both accurate and detailed calculation of particle transport from linear accelerators. The main drawback of Monte Carlo techniques is the extremely long computing time that is required in order to obtain a dose distribution with good statistical accuracy. ...

Introduction: Brachytherapy is one type of internal radiation therapy where radiation sources, which are usually encapsulated, are placed as close as possible to the tumor site or inside the patient's body. In this technique, it is important to determine dose distribution around the brachytherapy capsule to create optimal treatment plant. In this way, dosimetric parameters are...

We have developed a Monte-Carlo simulation code for an aerogel Čerenkov Counter which is operated under a strong magnetic field such as 1.5T. This code consists of two parts: photon transportation inside aerogel tiles, and one-dimensional amplification in a fine-mesh photomultiplier tube. It simulates the output photoelectron yields as accurately as 5% with only a single free parameter. This co...

background: in the current study the effect of shielded colpostat on rectum received dose was calculated in cervical brachytherapy using monte carlo (mc) method. materials and methods: two 60co sources of gzp6 brachytherapy unit used for intracavitary treatments were simulated using mcnpx monte carlo code. also the two types of colpostats including shielded and unshielded were simulated inside ...

introduction lead-based shields are the most widely used attenuators in x-ray and gamma ray fields. the heavy weight, toxicity and corrosion of lead have led researchers towards the development of non-lead shields. materials and methods the purpose of this study was to design multi-layered shields for protection against x-rays and gamma rays in diagnostic radiology and nuclear medicine. in this...