background: monte carlo and experimental relative dose determination in a water phantom, due to a high dose rate (hdr) 192ir source is presented for real energy spectrum and monochromatic at 356 kev. materials and methods: the dose distribution has been calculated around the 192ir located in the center of 30 cm ×30 cm ×30 cm water phantom using mcnp4c code by monte carlo method. relative dose v...

Helical polymer bundles are an important fixture in biomolecular systems. The particular structural geometry of helix bundles is dependent on many factors including the length of the polymer chain. In this study, we performed Monte Carlo simulations of a coarse-grained model for helical polymers to determine the influence of polymer length on tertiary structure formation. Helical structures of ...

MOTIVATION Chromatin breakage by ionizing radiation is relevant to studies of carcinogenesis, tumor radiotherapy, biodosimetry and molecular biology. This article focuses on computer analysis of chromosome irradiation in mammlian cells. METHODS Polymer physics and Monte Carlo numerical methods are used to develop a coarse-grained computational approach. Chromatin is modeled as a random walk o...

The use of diamond as material for X-ray detector is subject of investigation and practice in radiotherapy, space and material science and technology. This paper presents the results of application of Monte Carlo method for simulation of photon transport through diamond detector. The aim is restitution and demonstrating of numerical technique for characterization of electrical properties for di...

Grid-based deterministic dose-calculation methods for radiotherapy planning require the use of six-dimensional phase space grids. Because of the large number of phase space dimensions, a growing number of medical physicists appear to believe that grid-based deterministic dose-calculation methods are not competitive with Monte Carlo methods. We argue that this conclusion may be premature. Our re...

Reported MOSFET measurements concern mostly external radiotherapy and in vivo dosimetry. In this paper, we apply the technique for absolute dosimetry in the context of HDR brachytherapy using an 192Ir source. Measured radial dose rate distributions in water for different planes perpendicular to the source axis are presented and special attention is paid to the calibration of the R and K type de...

As oncologists are able to treat smaller tumors with more complex external beams, the ability to optimize radiation treatment planning (RTP) becomes very important. Historically, Monte Carlo codes have been used for this type of work since they are equipped to accurately treat charged particles. However, these codes take a long time to run to obtain statistically accurate results. Discrete ordi...

Introduction: Polymer gel dosimeters contain chemical materials sensitive to the radiation which are polymerized by the radiation as a function of absorbed dose. So information of spatial dose distribution can be extracted by imaging from irradiated gel. Among imaging techniques, computed tomography (CT) poses as an attractive method because of practical advantages such as acce...

There are many examples of polymer systems, ranging in complexity from strands of DNA and protein molecules to examples of simple plastics. Regardless of the level of complexity, the three dimensional structure of a polymer chain will determine many of its most important properties. Monte Carlo methods have shown great promise in studying polymer conformation problems [1]. In particular, a wide...