الفهرس 
Chapter1 Introduction and Literature ReviewOnly 14 pages are availabe for public view
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Abstract
This thesis aims to study of the radioactivity concentration of natural radionuclide gamma rays emitted by 238U,226Ra,232Th and 40K to recognize the level of radioactivity in soil and consequently we can estimate the external exposure on Ras Hankorab beach, south Marsa Alam City, southeastern Desert, Egypt and aims too to know the important minerals found in sand of beach to be used as therapeutic environment.
To achieve these targets, we make the following:
Thirty-Four sand samples were collected where seventeen samples from surface and seventeen samples from 40 cm depth and were taken for radiometric and geochemical analysis.
Firstly, for gamma analysis Hyper Pure Germanium detector (HPGe) was used where:
• The samples were collected from Ras Hankorab beach located on the red sea coastal plain about 80 km south of Marsa Alam city. The analysis of the samples demonstrates that the measured average activity concentration for the samples from surface were 116.1, 113.8, 7.7 and 181.2 Bq/Kg for 238U, 226Ra,232Th and 40K respectively. While the average activity concentration for the samples from 40 cm depth were 113.4, 117.8, 7.9 and 181.5 Bq/Kg for 238U, 226Ra,232Th and 40K respectively. The activity concentrations in samples for uranium and radium were higher than the permissible level while for thorium and potassium were lower than the permissible level. The activity ratios 232Th/238U for samples were measured and were lower than Clark’s value which indicate the uranium enrichment of the area.
• The outdoor absorbed dose rate (Dout), the outdoor effective dose (Eout), outdoor excess lifetime cancer risk (ELCRout), radium equivalent (Raeq), external hazard index (Hex)and radiation level index (Iγ) were estimated for all samples where average values of Dout and Eout were slightly higher than permissible value while average values of ELCRout, Raeq, Hex and Iγ were lower than permissible value.
• Radon gas measurements were carried out. The results show the activity concentration of 222Rn, Radon mass exhalation rate (ERn)and annual effective dose (AEDRn).
Secondly, for geochemical analysis X-Ray Diffraction (XRD) technique was used to determine the important minerals while X-Ray Fluorescence (XRF) technique was used to determine trace elements where:
• The identified important minerals in the studied samples at Ras Hankorab beach which they are confirmed by the XRD technique and seen by the binocular microscope were Ilmenite, Rutile, Magnetite, Ggeothite, Garnet, zircon, Sphene, monazite, Uranothorite, Xenotime, and Apatite.
• Seventeen samples were analyzed by XRF technique to recognize trace elements existing at Ras Hankorab sand beach important minerals, eleven trace elements have been determined: Cr, Ni, Cu, Zr, Rb, Y, Ba, Pb, Sr, V and Nb.