الفهرس 
Abstract
General review of radonOnly 14 pages are availabe for public view
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Abstract
This thesis deals with some properties of solid state nuclear track detectors and also measurement of radon levels in some closed environmental areas. The main points are: measurement of the bulk etch rate for both detectors CR39 and LR115, the sensitivity function (registration efficiency), the attenuation factor and the permeability through the used membrane filter, range of alpha particles in the detector by over etch profile technique. And also measurement of radon activity concentrations in some environmental areas in Mansoura city foe a whole year as determine the seasonal variation and the corresponding effective dose and the equilibrium factor by two different methods. We use in this thesis the following instruments: * the Can technique equipped with two different sensitive detectors and one external. * Distilled water system. * Water path with constant temperature. * Optical microscope with different magnification. * Micrometer eyepiece. * Alpha standard source (Americium241). And we found that the bulk etching rates (VB) for both detectors CR39 and LR115 to be equal 1.3 0.1 m/h and 3.22 0.25 m/h respectively. The attenuation factor of radon through the polymeric membrane filter and its permeability to be equal 0.73 and 1.42 x 1012 m2s1 respectively. For alpha ranges in CR39 at different energy values using over etched profile technique; the measured values were in good agreement with the theoretical ones. And the monthly variation of radon activity concentration was ranging from 34 to 423 Bq.m3 with average 170 Bq.m3, and the total annual variation 51.5% with higher levels during (winter and autumn) and lower levels during summer. These results are below the action level recommended by the International Atomic Energy Agency (IAEA, 1996). The corresponding annual effective dose was found to be in the range from 0.202 to 0.919 mSv and yearly mean value 0.636 mSv, which is lower than the bound of 310 mSv action level recommended by the International Committed Radiation Protection (ICRP65, 1993). Calculation of the equilibrium factor between radon and radon progeny concentrations by two different methods, from which the mean equilibrium (F) was found to be in range 0.003 to 0.597.