While developing a liquid argon detector for dark matter searches we investigate the influence of air contamination on the VUV scintillation yield in gaseous argon at atmospheric pressure. We determine with a radioactive αsource the photon yield for various partial air pressures and different reflectors and wavelength shifters. We find for the fast scintillation component a time constant τ1 = 1...

introduction: osteoporosis is a bone disease in which there is a reduction in the amount of bone mineral content leading to an increase in the risk of bone fractures. the affected individuals not only have to go through lots of pain and suffering but this disease also results in high economic costs to the society due to a large number of fractures.  a timely and accurate diagnosis of this disea...

A high-energy photon beam that is more than 10 MV can produce neutron contamination. Neutrons are generated by the [γ,n] reactions with a high-Z target material. The equivalent neutron dose and gamma dose from activation products have been estimated in a LINAC equipped with a 15-MV photon beam. A Monte Carlo simulation code was employed for neutron and photon dosimetry due to mixed beam. The ne...

Dosimetric comparisons of radiation fields produced by Varian's newest linear accelerator, the TrueBeam, with those produced by older Varian accelerators are of interest from both practical and research standpoints. While photon fields have been compared in the literature, similar comparisons of electron fields have not yet been reported. In this work, electron fields produced by the TrueBeam a...

The presented virtual energy fluence (VEF) model of the patient-independent part of the medical linear accelerator heads, consists of two Gaussian-shaped photon sources and one uniform electron source. The planar photon sources are located close to the bremsstrahlung target (primary source) and to the flattening filter (secondary source), respectively. The electron contamination source is locat...

Out-of-field doses from radiotherapy can cause harmful side effects or eventually lead to secondary cancers. Scattered doses outside the applicator field, neutron source strength values, and neutron dose equivalents have not been broadly investigated for high-energy electron beams. To better understand the extent of these exposures, we measured out-of-field dose characteristics of electron appl...

In the present study, temporal behavior of entanglement between photonic binomial distributions and a two-level atom in a leaky cavity, in equilibrium with the environment at a temperature T, is studied. In this regard, the master equation is solved in the secular approximation for the density matrix, when the initial photonic distribution is binomial, while the atomic states obey the Boltzmann...

ntroduction:  monte  carlo  simulation  is  the  most  accurate  method  of  simulating  radiation  transport  and  predicting doses at different points of interest in radiotherapy. a great advantage of the monte carlo method  compared  to  the  deterministic  methods  is  the  ability  to  deal  accurately  with  any  complex  geometry.  its  disadvantage is the extremely long computing time r...

background: physical wedges are still widely used as beam modifiers in external beam radiotherapy. however the presence of them in the beam trace may cause beam hardening which may not be considered in many treatment planning systems. the aim of this study is to investigate the beam hardening effect generated by physical wedges via different beam quality indexes as photon spectrum, half value l...

This paper addresses the noticeable increase of 137Cs activity concentrations in soil and fallout in the area surrounding Zagreb (Croatia) that occurred at the time of the 2011 Fukushima accident. This topic is important for public health as 137Cs is highly toxic due to its long half-life of radioactive decay and chemical similarity to potassium. 137Cs concentrations in fallout were much greate...