Papers by Keyword: Scattered Radiation

Abstract: It is important to understand that the heel effect contributes higher dose to cathode bound. This study is to verify this effect and consequently utilized it to minimize the radiation dose to staff involved in fluoroscopy procedures especially those using mobile C-arm unit. Water phantom with size of 20 x 30 x 30 cm was used in this study. It was exposed to x-rays from a mobile C-arm unit with auto brightness control (ABC) function. An ion chamber and a solid state detector were used to measure the scattered radiation and primary beam profile. Based on the result it was clear that scattered radiation measured was highest on the cathode bound side. Hence personnel involves in fluoroscopy procedure should avoid or spend the least possible time within this cathode bound area in order to lessen the radiation risk.

Abstract: Correlation method for processing dynamic light scattering patterns observed when laser radiation passes through liquid media was developed. The method is based on procedure of spatial averaging of the data contained measured values of correlation functions of intensity of light scattered by moving small particles. The method allows one to measure particles diameters from 30 to 750 nm with measurement error less then 10%. The method makes it possible to decrease correlation functions measurement time down to 1 ms and provides opportunity to carry out measurements for different scattering angles simultaneously. The method offers a way of recognizing speckle pattern transformations caused by harmonic, translatory and Brownian motions of particles, and allows one to register influence of uncontrolled forces such as monochromatic and wideband acoustic fields upon particles size measurements results.