Elemental Concentration and Natural Radioactivity Studies for Some Biological and Geological Samples Taken from Selected Zone of Ethiopia by the Method of Instrumental Neutron Activation Analysis(INAA)
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Date
2015-06
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Abstract
This dissertation is devoted to the use of NAA to be applied for the determination of the
qualitative and quantitative elemental analysis of selected samples. It involves the use of
the knowledge of nuclear reaction particularly (n;
) reaction and implement its practical
applications to determine element types and their concentrations in the sample. In lab,
a total of Five di erent biological and geological samples were studied, four samples were
studied for their qualitative and quantitative elemental analysis and one soil sample was
studied for its natural radioactivity. Long lived and short lived radionuclides spectra were
measured using HPGe gamma detector. Using known values of gamma-ray energies ema-
nating from calibrating point gamma sources, an energy calibration curve and full energy
peak e ciency curve were determined and plotted. The best t line matched the data
with a least squares t, R2, of approximately equal to 1.
A gamma spectrum is created by taking measurements of emitted gamma-rays from dif-
ferent radio nuclei which emit many gammas of di ering energies. Special softwares,
acquisition software MAESTRO and analysis software WINSPAN, installed in comput-
ers identify an unknown radioisotope by measuring features on the gamma spectrum and
comparing them to known spectra, and calculate the concentrations of the elements which
gives out the gamma radiation. The peaks of di erent energies in the spectrum were tested
analytically using the half lives of radionuclides whether the assignment of an element to
each peak by the analysis software is correct. The analysis methodologies were validated
by analyzing the IAEA-multi elemental standard having the same matrices as the sample.
The irradiation facility used was the Nigeria Research Reactor-1 (NIRR-1) at the Center
for Energy Research and Training (CERT), Ahmadu Bello University, Zaria, Nigeria. A
high resolution gamma-ray spectrometer comprising of HPGe detector coupled with asso-
ciated electronics and basic spectroscopy softwares were employed in the analysis. From
the analysis of samples of biological and geological origin, di erent concentrations of el-
ements were obtained and an e ort is made to explain the function of the elements for
human or animals. In this dissertation a mineral soil was measured for its radioactivity
and the concentration of radioactive materials were analysed and the level of radiation
hazard due to the soil is calculated
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Fermion-Antifermion bound States