Introduction: The presence of heterogeneities such as air-filled cavities in the head and neck treatment fields region, may result in potential dosimetric disagreement because the losses of charged particle equilibrium. Most of treatments planning systems are not able to predict dose distribution of inhomogeneities region accurately. Therefore, dose calculation algorithms need to...

Introduction The first medical intervention for many breast cancer patients is breast conserving surgery (BCS) and/or modified radical mastectomy (MRM). Most of these patients undergo radiation therapy, following surgery. The most common side-effect of breast radiotherapy is skin damage. In the present study, the severity of acute skin changes and the underlying causes were investigated in pati...

this paper describes the impact of the distance and the size of the corona ring, on the magnitude anddistribution of electrical potential across the polymer insulators. the procedure is based on finiteelement method numerical analysis and stochastic optimization algorithm of differential evolution(de). the optimal selection of corona ring has a significant impact on the control of potential and...

Background: Small photon fields are increasingly used in modern radiotherapy especially in intensity modulated radiation therapy (IMRT) and stereotactic radiosurgery (SRS) treatments. Accurate beam profile and central axis depth doses measurements of such beams are complicated due to the electron disequilibrium. Hence the EBT2 (external beam therapy) Gafchromic film was used for dosimetry of sm...

The LHCb experiment will use two RICH detectors to provide particle identification. The Hybrid Photon Detectors (HPDs) adopted for these detectors are required to operate in the fringe field of the 4Tm LHCb dipole magnet. In fields in excess of 15G, photoelectrons are lost from the active area of an HPD. Shielding the HPDs from the fringe field is therefore essential for the efficient operation...