background: tangential irradiation of intact breast is one of the most common procedures performed in any radiotherapy center. this method is performed by using 2d and 3d treatment planning. the aim of this study was to compare 2d with 3d plans in breast conserving radiotherapy. homogeneity of isodose, and lung received dose were compared. materials and methods: twenty patients with breast canc...

background: radiation therapy  uses high-energy radiation to kill cancer cells. photoneutron contamination and induced radioactivity of high energy therapeutic photon beams are considered as the main source of occupational exposure to radiation therapists who works with linear accelerators operating above 10 mv. materials and methods: the gamma dose rates were measured after termination of diff...

in this work we investigate the thermal entanglement between two-level atoms and photons in a nonlinear cavity. we consider intensity-dependent couplings and calculate the negativity, as a measure of atom-photonentanglement. the cavity is assumed to be at a temperature t, so that all number of photons, and at the same time, both atomic states, with definite probabilities, are present. we then d...

background: attenuation coefficient (μ) plays an important role in calculations of treatment planning systems, as well as determination of dose distributions in external beam therapy, dosimetry, protection, phantom materials and industry. so, its exact measurement or calculation is very important. the aim of this study was to evaluate the μ in different points in the water phantom analytically ...

The semi-classical model of atom-field interaction has been fully studied for some multilevel atoms, e.g. Vee, L, Cascade X , Y, and inverted Y and so on. This issue is developed into the full-quantum electrodynamics formalism, where the probe and coupling electromagnetic fields are quantized. In this article, we investigate the full-quantum model of absorption and dispersion spectrum of trappe...

introduction in this study, we aimed to assess the medium-term energy stability of a 6mv elekta compacttm linear accelerator. to the best of our knowledge, this is the first published article to evaluate this linear accelerator in terms of energy stability. as well as investigating the stability of the linear accelerator energy over a period of several weeks, the results will be useful for esti...

the semi-classical model of atom-field interaction has been fully studied for some multilevel atoms, e.g. vee, l, cascade x , y, and inverted y and so on. this issue is developed into the full-quantum electrodynamics formalism, where the probe and coupling electromagnetic fields are quantized. in this article, we investigate the full-quantum model of absorption and dispersion spectrum of trappe...

Introduction:In an ideal parallel-hole collimator, thickness of septal material should be sufficient to stop more than 95% of incident photons. However, some photons pass the septa without interaction or experience scattering before they reach the detector. In this study, we determined different contribution of collimator responses consist of geometrical response, septal penetr...