background: one of the main causes of induction of secondary cancer in radiation therapy is neutron contamination received by patients during treatment. objective: in the present study the impact of wedge and block on neutron contamination production is investigated. the evaluations are conducted for a 15 mv siemens primus linear accelerator.  methods: simulations were performed using mcnpx mon...

Accurate measurement of quadrupole-to-BPM center offsets and use of this information in an auto-steering algorithm are two essential components of emittance preservation in the Next Linear Collider main linac. We present the results of an analytic/simulation study of possible statistical and systematic limitations on the measurement of quad-BPM center offsets. These results are incorporated in ...

Objective The aim of the present study is to simulate 6 MV and 18 MV photon beam energies of a Siemens Primus Plus medical linear accelerator (Linac) and to verify the simulation by comparing the results with the measured data. Methods The main components of the head of Siemens Primus Plus linac were simulated using MCNPX Monte Carlo (MC) code. To verify the results, experimental data of perc...

China has endeavored in the field of FEL research since the mid-eighties. Compton regime, Raman regime, Electromagnetic Pumping, Cherenkov FEL, and Harmonic Generator FEL, etc. based on the RF linac accelerator, induction linac accelerator, pulsed-line accelerator, and storage ring have all been developed. These experimental projects are in various stages of development and are discussed in seq...

ERL 04-7 Prodeedings EPAC04, Lucerne/CH (2004) Multi-pass, multi-bunch beam-breakup has been long known to be a potential limiting factor for the current in linac-based recirculating accelerators. New understanding of theoretical and computational aspects of the phenomenon are presented here. We also describe a detailed simulation study of BBU in the proposed GeV Energy Recovery Linac light sou...

The superconducting (SC) proton linac is proposed in the JAERI/KEK Joint Project for a high-intensity proton accelerator in the energy region from 400 to 600 MeV. Highly stable fields in the SC cavities are required under the dynamic Lorentz force detuning. A new model describing the dynamic Lorentz detuning has been developed and the validity has been confirmed experimentally. The model has be...

Monte Carlo simulation of linear accelerators (linacs) depends on the accurate geometrical description of the linac head. The geometry of the Varian TrueBeam linac is not available to researchers. Instead, the company distributes phase-space files of the flattening-filter-free (FFF) beams tallied at a plane located just upstream of the jaws. Yet, Monte Carlo simulations based on third-party tal...

Background: Megavoltage beams used in radiotherapy are contaminated with secondary electrons. Different parts of linac head and air above patient act as a source of this contamination. This contamination can increase damage to skin and subcutaneous tissue during radiotherapy. Monte Carlo simulation is an accurate method for dose calculation in medical dosimetry and has an important role in opt...

introduction electron linear accelerator (linac) can be used for neutron production in boron neutron capture therapy (bnct). bnct is an external radiotherapeutic method for the treatment of some cancers. in this study, varian 2300 c/d linac was simulated as an electron accelerator-based photoneutron source to provide a suitable neutron flux for bnct. materials and methods photoneutron sources w...

radiotherapy dose calculations can be evaluated by monte carlo (mc) simulations with acceptable accuracy for dose prediction in complicated treatment plans. in this work, standard, livermore and penelope electromagnetic (em) physics packages of geant4 application for tomographic emission (gate) 6.1 were compared versus monte carlo n-particle extended (mcnpx) 2.6 in simulation of 6 mv photon lin...