Introduction: One of the important problems of using high energy linacs is the production of photoneutrons. High energy medical linacs produce secondary neutrons. These phtoneutrons increase patient dose   Materials and Methods: In this study, the effect of plastic trays on spectrum of photoneutrons produced by 18MV linac is investigated using the MCNP4C code...

background: one of the main problems of dedicated iort accelerators is to determine dosimetric characteristics of the electron beams. monte carlo simulation of iort accelerator head and produced beam will be useful to improve the accuracy of beam dosimetry. materials and methods: liac accelerator head was modeled using the beamnrcmonte carlo simulation system. phase-space files were generated a...

Background: One of the main problems of dedicated IORT accelerators is to determine dosimetric characteristics of the electron beams. Monte Carlo simulation of IORT accelerator head and produced beam will be useful to improve the accuracy of beam dosimetry.Materials and Methods: Liac accelerator head was modeled using the BEAMnrcMonte Carlo simulation system. Phase-space files were generated at...

background: field matching problems in abutting electron fields can be managed by using spoilers. objective: the aim of this study was to design a monte carlo framework for the assessment of spoiler application in abutting electron fields. methods: a siemens primus treatment head was simulated for a 5 mev electron beam using beamnrc and dosxyznrc, egsnrc user codes. validation of beam model was...

This paper presents dose calculation in proton therapy using Monte Carlo method and comparison with experimental data obtained at TOHOKU University’s cyclotron and isotope center in Japan. In this way, two Monte Carlo codes, FLUKA and MCNPX, has been employed to calculate percentage depth dose, lateral dose profiles, isodose curves and secondary particles production for proton pencil and broad ...

Measurement of cumulative dose ƒ(0,150) with a small ionization chamber within standard polymethyl methacrylate (PMMA) CT head and body phantoms, 150 mm in length, is a possible practical method for cone-beam computed tomography (CBCT) dosimetry. This differs from evaluating cumulative dose under scatter equilibrium conditions within an infinitely long phantom ƒ(0,∞), which is proposed by AAPM ...

The ionization yield of ion tracks in polymers and biomolecular systems reaches a maximum, known as the Bragg peak, close to the end of the ion trajectories. Along the path of the ions through the materials, many electrons are generated, which produce a cascade of further ionizations and, consequently, a shower of secondary electrons. Among these, very low energy secondary electrons can produce...