Background: The lack of lateral electronic disequilibrium (LED) becomes a main problem in small field. This factor affects the dose in target volume cannot predict correctly. In addition, utilization of high-energy linear accelerator (10 MV) can emit some unwanted particles (electron contamination). Therefore, the aim of this study was to characterize head linear accelerator (linac) Varian Clin...

Formation flying of clusters of micro-, nanoand pico-satellites has been recognized to be more affordable,robust and versatile than building a large monolithic satellite in implementing next generation space missions requiringlarge apertures or large sample collection areas and sophisticated earth imaging/monitoring. We propose a propellantfree, thus contamination free, method that ...

Introduction: This study aimed to measure the neutron contamination of flattening filter (FF) and flattening filter-free (FFF) 10-MV photon beams delivered by the Elekta InfinityTM accelerator. Material and Methods: The photoneutron spectrum produced by the Linac head was evaluated using a Monte Carlo (MC) simulation. The geometry ...

We demonstrate an optical-fiber based source of polarization entangled photon-pairs with improved quality and efficiency, which has been integrated with off-the-shelf telecom components and is, therefore, well suited for quantum communication applications in the 1550 nm telecom band. Polarization entanglement is produced by simultaneously pumping a loop of standard dispersionshifted fiber with ...

This paper summarizes three mathematical models used to describe how contaminant concentration profiles in soil may be inferred from the intensities of neutron-induced capture-gamma photon intensities measured at the soil surface. In particular, the linear regularization, linear regularization with an iterative positivity constraint, and the Backus-Gilbert methods are applied to the soil contam...

BACKGROUND Electron linear accelerators in medical radiotherapy have replaced cobalt and caesium sources of radiation. However, medical accelerators with photon energies over 10 MeV generate undesired fast neutron contamination in a therapeutic X-ray photon beam. Photons with energies above 10 MeV can interact with the atomic nucleus of a high-Z material, of which the target and the head of an ...

Introduction: In radiation therapy with high-energy photon beams (E > 7 MeV) neutrons are generated mainly in LINACs head thorough (γ, n) interactions. These neutrons affect the shielding requirements in radiation therapy rooms. According to the protocol TG-34, photon absorbed dose of 10Gy can cause permanent damage to the pacemaker and the dose of 2Gy can make minor changes in...

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...