Photon buildup factors for soft tissue, water, and dosimetric materials have been computed in the energy range of 0.2 to 2 MeV using geometric progression (GP) fitting approximation. The results for soft tissue and water have been compared with the values obtained through Monte Carlo code MCNP4C. Data obtained from GP fitting method quite well obey a semi empirical relation which is a function ...

Theoretical and experimental studies have been applied for dosimetric parameters determination of the brachytherapy sources (1-3). Usually, Monte Carlo method has been used to define such quantities as the anisotropy dose function, the radial dose function, and the dose calculation close to the source in brachytherapy (4-6). Ir source is used widely in brachytherapy to treat localized tumors ne...

Thermal neutron capture can be used as a successful technique for detection of non-metallic landmines via the detection of their constituent like nitrogen. Recently, it has been shown that the detection of 10.829 MeV photons from the N(n,γ)N reaction can be used for finding the landmines. In this method a high-energy neutron source like Am-Be inside water as a moderator is used to have thermal ...

BEBIG Ruthenium-106 ophthalmic plaques have been used for treatment of uveal melanoma, retinoblastoma, melanoma of the iris and other special applications for many years. The plaques consist of a thin film of Ru, a beta emitter, encapsulated in pure silver. The present work proposes a new mathematical eye model for ophthalmic brachytherapy dosimetry. This new model includes detailed description...

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...

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...

This paper presents the evaluation of the geometry correction factor for calibration of Bonner sphere spectrometer (BSS) equipped with the He counter (typical SP9), based on Monte Carlo simulation. Using the MCNP4C code, geometry factors and effectiveness parameters (d) of a 800 polyethylene sphere (r = 10.16 cm) were calculated for 10 different energies and 3 various distances between the sour...

The general purpose Monte Carlo N-particle radiation transport computer code (MCNP4C) was used for the simulation of x-ray spectra in diagnostic radiology and mammography. The electrons were transported until they slow down and stop in the target. Both bremsstrahlung and characteristic x-ray production were considered in this work. We focus on the simulation of various target/filter combination...