background : in spite of clinically useful photon and electron beams, high energy linacs produce secondary particles such as neutrons (photo-neutron production). neutrons have important roles during treatment with high energy photons in terms of protection and dose escalation. in this project, neutron dose equivalent of 18 mv varian accelerators is calculated by tld600 and tld700. materials and...

Background: The present study aimed to investigate the equivalent dose in vital organs, including heart and lung, due to secondary particles produced during breast proton therapy. Materials and Methods: The numerical ORNL female-phantom was improved and simulated using the Monte Carlo MCNPX code. The depth-dose profile of proton beams with different energies was simulated. The proper energy ran...

Introduction: Background radiation is originated from environmental radioactive sources cosmicandterrestrial.Materials distribution onsurface of the earth and height from sea level are not the same at various points.Absorbed dose caused by them were different at various points.In this research, Background radiation level inoutdoor different areas of Ilam province was measured and effective dose...

A large–signal model of AlGaN/GaN HEMTs grown on sapphire substrate with gate width Wg = 2 × 150 μm and gate length Lg = 250 nm is presented. The equivalent circuit model accurately describes the sub–threshold region and takes into account the self–heating effects. The thermal resistance has been calculated analytically. The DC, small–signal and large– signal behaviour are accurately described ...