MCNP is widely used Monte Carlo program in reactor and nuclear physics. However, an option of simulating electrons was added into the code a few years ago. With this extension MCNP became a code, potentially applicable for applications in medical physics. In 1997, a new version of the code, named MCNP4B was released, which contains several improvements in electron transport modelling. To test s...

Monte Carlo calculations are frequently used to analyse a variety of radiological science applications using low-energy (10-1000 keV) photon sources. This study seeks to create a low-energy benchmark for the MCNP Monte Carlo code by simulating the absolute dose rate in water and the air-kerma rate for monoenergetic point sources with energies between 10 keV and 1 MeV. The analysis compares four...

Nuclear logging is one of most important logging services provided by many oil service companies. The main parameters of interest are formation porosity, bulk density, and natural radiation. Other services are also provided from using complex nuclear logging tools, such as formation lithology/mineralogy, etc. Some parameters can be measured by using neutron logging tools and some can only be me...

Background: In treating patients with radiation, the degree of accuracy for the delivery of tumor dose is recommended to be within ± 5% by ICRU in report 24. The experimental studies have shown that the presence of low-density inhomogeneity in areas such as the lung can lead to a greater than 30% change in the water dose data. Therefore, inhomogeneity corrections should be used in treatment pla...

introduction one of the best methods in the diagnosis and control of breast cancer is mammography. the importance of mammography is directly related to its value in the detection of breast cancer in the early stages, which leads to a more effective treatment. the purpose of this article was to calculate the x-ray spectrum in a mammography system with monte carlo codes, including mcnpx and mcnp5...

determination of the total body absorbed dose consists of two parts: beta radiation absorbed dose and gamma radiation absorbed dose. the first part is generally determined by clinical data, while the second part has a parameter called absorbed ratio and is determined by computational methods. the monte-carlo computational methods have been shown to be the most suitable in determination of the a...

Introduction: Thyroid cancer is at the ninth from ten of common malignant cancer. A man has higher risk to get Thyroid cancer that a woman has. This organ is lain near human neck. The use of radioactive I-131, I-123 and Tc-99m for diagnosis of thyroid cancer has a risk where other organs around Thyroid will accept dose of radiation. One of the risks is large dose which is accep...

A great challenge in simulations in the area of radiotherapy is to character the source, since the equipment’s manufacturers don’t provide specifics information about this. This work presents an empiric method for characterization of the ray-X beams of 6,0 MV and 10 MV originating from a linear accelerator of the mark Varian model 2100C. The experimental values of the percentage of deep dose (P...

Prediction of neutron flux at the irradiation devices of a research reactor facility is essential for the design and evaluation of experiments involving material irradiations. A computational model of the Greek Research Reactor (GRR-1) was developed using the Monte Carlo code MCNP with continuous energy neutron cross-section data evaluations from ENDF/B-VI library. The model included detailed g...