الفهرس 
INTRODUCTION AND LITERATURE REVIEWيوجد فقط 14 صفحة متاحة للعرض العام
 |  | from | 250 |  |  |
| | | from | 250 | | |
المستخلص
The main target of this study is to find the comparative studies between α and γ-techniques for measuring radionuclides and it’s radiological hazards in 238U decay series for different sedimentary rock samples from southwestern Sinai, Egypt. First, find out the natural radioactivity by using high purity germanium detector (HpGe) and an account the radiological risks. Second, measuring the concentration of the emitted radon by the solid state nuclear track detector (CR-39) and comparing between the two results for 226Ra concentration.
The sample locations, collection methods and preparation procedures have been discussed. Ten samples of sedimentary rocks were collected from different three locations: 4 samples from Dabbet Abu Thor location, 3 samples from Wadi Um Hamd location and 3 samples from Gabal Farsh El Azrak location.
In First stage, the activity concentrations (Bq/kg) of the naturally occurring radionuclide’s 238U,235U,234U, 226Ra, 232Th, and 40K were measured by using high purity germanium detector (HpGe) and the activity ratios 234U/238U, 226Ra/238U, 238U/235U, 234U/235U were calculated to estimate the radioactive equilibrium/disequilibrium in the area under study, also the radiation hazard indices were calculated. The results demonstrated high concentrations of the natural radioactivity and the associated hazard indices.
In Second stage, CR-39 SSNTD fixed at the top of a cylindrical container filled with a crushed sample was employed to estimate the values of the radon concentration (222Rn), Effective radium content, radon mass exhalation rates, radon surface exhalation rates and the ratio of 226Ra (α)/226Ra (γ) for the studied areas.
The results indicated that, the γ-measurements of 226Ra are usually higher than the α-measurements. These variations in measurements of two techniques are due to α-recoil and the difference of rock types.