الفهرس 
Introduction and aim of the workOnly 14 pages are availabe for public view
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Abstract
Mass attenuation coefficients J.l/p (cm2/ g) of some compounds and elements e been very accurately measured by using an extremelym transmission method. The effect of absorber position, collimation solid Ie and the sample thickness on the measured mass attenuation coefficient at
ee different gamma ray energies (59.54,661.6 and 1332.5 keV), have been died.
Mass attenuation coefficients, effective atomic numbe.”s, electron densities
d total atomic cross sections for some HC (Hydrogen-Carbon), HCO ydrogen-Carbon-Oxygen) and (-JCON (Hydrogen-Carbon- Oxygen-Nitrogen) mpounds (with different Hydrogen weight fraction Fir) have been measured. he experimental results of the mass attenuation coefficients are in agreement
ith the the theoretically calculated values. A linear relation betwecn the mass ttenllation coefficient and Fit (the hydrogen weight f.”action) in HC compounds ’as obtained. from this relation the hydrogen weight fraction of paraffin wax as determined as 20.11 % and its effective molecular structure can be written
s (C2 H6)’
Absolute values of coherent plus incoherent differential scattering cross sections of the 59.54 keY gamma ray of241Am from Anthracene, POPOP, Polystyrene and Paraffin were experimentally determined for ten scattcring angles between 30° and 120°. The corresponding theoretical differential cross sections were calculated by mcans of form factors and incoherent scattering functions. A comparison between the experimentally determined results and the
eorctically calculated values shows goo<l agreement, when the theoretical lculations of the atomic form factors and incoherent scattering functions were ed on the summation of the individual form factors an<l incoherent scattering octions of their constituent elements in the molecule according to the number atoms in the molecule.
The total (coherent plus incoherent) atomic differential scattering cross
ctions of 59.54 keY y - rays from Ni, Ag, Ca”Ta, and W between 400 and 120° ave been measured. The correspon<ling theoretical values were also calculated.
The coherent differential atomic cross sections have been computed from e experimentally determine<l total differential atomic cross section by ubtracting the calculate<l incoherent differential atomic cross section. The btained values coincided to a great extent with the puplished data.
Differential Compton scattering cross section of the 661.6 keY gamma rays f 137CS from twelve HC an<l HCO compounds with different hydrogen wieght ractions and electr’on densities were experimentally determined for three cattering angles ( 60°, 90° and 120° ). The experimental results shows good
a~reement with the theoretically calculated values.
A linear relation has been obtained between the differential Compton cattering cross section ( dGcol1lp/dfl cm2 / g . sr ) and the hydrogen wieght fraction for He compounds and not for the case of IlCO compounds.