Introduction: This study aimed to report the measurement of photon and Electron beams to configure the Analytical Anisotropic Algorithm and Electron Monte Carlo used in clinical treatment. Material and Methods: All measurements were performed in a large water phantom using a 3-dimensional scanning system (PTW, Germany). For photon beams, the data were measured with a 0. 125cc cylindrical chamber. For Electron, the data were performed with a Roos chamber. Results: In photon beams, flatness and symmetry for reference field size 10×10cm2 were within the tolerance intervals. Flatness were 0. 79% and 1. 55% for X6MV and X18MV, respectively. Symmetry were 0. 57 and 0. 25 for X6MV and X18MV, respectively. The output factor vary between 0. 83 and 1. 11 for X6MV. Moreover, it varies between 0. 74 and 1. 09 for X18MV. The leaf transmission factors were 0. 97% for X6MV and1. 14% for X18MV. The DLG were 1. 31 and 1. 34 for X6MV and X18MV, respectively. For Electron beams, the quality index R50 for applicator 15×15cm2 were in the tolerance. Maximum depth dose for 6, 9, 12, 16 and 20MeV were 1. 2, 1. 9, 2. 7, 2. 99 and 2. 4cm, respectively. Bremsstrahlung tail were 6MeV– 2. 86cm, 9MeV– 4. 32cm, 12MeV– 5. 96cm, 16MeV– 7. 93cm, and 20MeV– 10. 08cm per energy levels. Conclusion: The obtained results and international recommendations were in a good agrement.

Dosimetry of ionizing radiations are based on standard methods issued by competent national and international organizations. Establishment of reference radiations at standard dosimetry laboratories are essential to transfer measurement standards to radiation users. This paper presents attempts made at Ionizing Radiation Division of PTB to produce a reference 20 MeV Electron beam based on the German standard DIN 6800-2. The quality of the 20 MeV Electron beam of a Philips SL75-20 linear accelerator (linac) is determined by a well designed plane-parallel ionization chamber, in terms of mean energy of the Electron beam at the surface of a water phantom. Three types of cylindrical ionization chambers are calibrated against the primary standard of absorbed dose to water at PTB in Co-60 gamma radiation. Based on DIN 6800-2, independent measurements of absorbed dose to water are then carried out by these three calibrated chambers at a reference depth in water phantom and with reference to the dose monitoring system of the linac which consists of two other ionization chambers located in water phantom. The results are compared and a mean calibration factor for the monitor chambers with a combined standard uncertainty is determined.

Effects of Electron beam irradiation on the mechanical properties and morphological structure of natural rubber (NR)/ linear-low density polyethylene (LLDPE) blend was investigated. The NR/LLDPE blends were prepared by melt blending in a Haake internal mixer at 14oC, rotor speed of 50 rpm, and in 15 min. Liquid natural rubber (LNR) was incorporated into the blend as a compatibilizer. Samples in the form of 1 mm sheets were exposed to 50-300 kGy of Electron beam irradiation and analysed for swelling index and gel content, tensile strength, and surface morphology. The result indicated that gel content and mechanical properties of the samples increased with radiation dosage. The honey-comb structure of the surface morphology in low dosage samples slowly transformed into a continuous matrix on increasing radiation dose. The variation of mechanical and physical properties was due to increase in cross-linking density in the rubber and plastic phases and rubber-plastic interaction on irradiation.

Background: Breast cancer is the most common cancer in women and the second cause of death among them. There are several treatment methods for breast cancer, one of which is radiation therapy. There are two important methods of radiation therapy: tangential field and single oppositional field. Main goal of this study is evaluation of factors that have a role in producing acute side effects such as skin burning in breast cancer patients treated by Electron beam, in order to decrease these side effects. Methods: From 1/2003 through 7/2004, 200 consecutive patients were evaluated during 18 months in seid-al-shohad hospital, whose mean age was 49 years old. In this study a questionnaire was used including some questions about personal profile such as patient's name, address, registration number, age and some other factors. All patients who were candidated to enter in this investigation filled out the questionnaire at the end of radiation therapy. The patients were examined and their skin burning grades were evaluated by RTOG scale. Data were analyzed by chi-square test using SPSS 11 software. Results: None of patients showed grades O or 4 of burning. 31.5 % of Patients showed grade 1, 64.5 % showed grade 2, 4 % showed grade 3 of burning. There was statistically significant correlation between posterior axillary field and skin burning and there was not any meaning between the other factors. Conclusion: It is necessary to pay more attention to posterior axillary field planning including field size, location, photon energy, depth and dose of treatment.  

The effect of evaporation rate on structural, morphological, and optical properties of Electron beam evaporated CdS thin films has been investigated. CdS thin film was deposited by Electron beam evaporation method in 12nm/min and 60nm/min evaporation rates on glass substrates. X-ray diffraction (XRD), scanning Electron microscopy (SEM), UV-Vis-NIR spectroscopy and Atomic Force Microscopy (AFM) were used to characterize the thin films. The xray diffraction analysis confirms that the films have polycrystalline hexagonal phase and exhibit preferred orientation along the (002) plane. The crystallite size was calculated and found to increase from 23 to 30 nm by increasing the deposition rate. Results of Atomic Force Microscopy revealed that the RMS roughness values of the CdS films decreased as the deposition rate increased. The relation between deposition rates and optical properties of deposited films was also investigated. It was found that stoichiometric properties and band gap values of the deposited films are correlated to the deposition rates. These dependencies are associated with the Cd/S ratio variation by the deposition rate. The optical band gap values of CdS films increased slightly in a range of 2.32–2.34 eV for deposition rate varied from 12nm/min and 60nm/min.