Introduction: The main advantage of using ion beams over photons in radiotherapy is due to their inverse depth-dose profiles, allowing higher doses to tumors, while better sparing normal tissues. When calculating dose distributions with ion beams, one crucial point is the uncertainty of the Bragg-peak range. Recently great effort is devoted to enhance the accuracy of the comput...

This paper compares fault position and Monte Carlo methods as the most common methods in stochastic assessment of voltage sags. To compare their abilities, symmetrical and unsymmetrical faults with different probability distribution of fault positions along the lines are applied in a test system. The voltage sag magnitude in different nodes of test system is calculated. The problem with the...

monte carlo methods designed base on stochastic reiterations and can be useful in uncertainty conditions. the purpose of this research was investigation of uncertainty to rank desertification indicators. in order to decrease uncertainty have been applied monte carlo reiterations for each value of indicator, if rank of xi is higher than rank of xk constantly. using multi dimension integrals the ...

background: monte carlo method (mc) has played an important role in design and optimization of medical linacs head and beam modeling. the purpose of this study was to compare photon beam features of two commercial linacs, varian 21ex and elekta sl-25 using mcnp4c mc code. materials and methods: the 6mv photon beams of varian 21ex and elekta sl-25 linacs were simulated based on manufacturers pro...

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...

background: in the current study the effect of shielded colpostat on rectum received dose was calculated in cervical brachytherapy using monte carlo (mc) method. materials and methods: two 60co sources of gzp6 brachytherapy unit used for intracavitary treatments were simulated using mcnpx monte carlo code. also the two types of colpostats including shielded and unshielded were simulated inside ...

Copper electrodeposition in submicron trenches involves phenomena that span many orders of magnitude in time and length scales. In the present work, two codes that simulate electrochemical phenomena on different time and length scales were externally linked. A Monte Carlo code simulated surface phenomena in order to resolve surface roughness evolution and trench in-fill. A 2-D finite difference...

background: monte carlo simulations play a vital role in the calculation of the necessary shielding both for neutrons and photons. advanced and simple shielding materials against neutron and gamma rays were compared by simulation using the mcnb4b monte carlo code. the simulations were carried out for the three common neutron sources, namely the 252cf, the 241am/be and the dd neutron generator w...

The REBUS-3 burnup code, used in the ANL RERTR Program, is a very general code that uses diffusion theory (DIF3D) to obtain the fluxes required for reactor burnup analyses. Diffusion theory works well for most reactors. However, to include the effects of exact geometry and strong absorbers that are difficult to model using diffusion theory, a Monte Carlo method is required. MCNP, “a general-pur...