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Please use this identifier to cite or link to this item: http://hdl.handle.net/123456789/84

Title: A STUDY OF GAMMA RAY TOTAL ATTENUATION AND PHOTO ABSORPTION COEFFICIENT IN DIFFERENT ELEMENTS
Authors: Dilbetigle, Assefa
Date Added: 6-Sep-2007
Abstract: The study intends to measure the transmission of gamma rays such as 137Cs, through Aluminium, Iron, Nickel, Copper, Tin, and lead absorbers using gamma ray spectroscopy techniques. Electrical pulses, carrying the physical information is displayed on the computer screen with the number of channels on the horizontal scale and number of pulses on the vertical scale. The multichannel Analyzer will then process there pulses, which are digitized. The total linear attenuation coefficient (μ) of 662Kev gamma rays have been measured in the extended media of six elements under different geometry condition and using HPGe and NaI(Tl) detectors. Better result of total linear attenuation coefficient is obtained when an absorber near to a detector and using HPGe detector. This is due to the decreases in the exposure of the detector to the beams of gamma rays and high resolution power of HPGe detector respectively. It also aims to determine the total linear attenuation coefficients for Tin using the energy of photons 122kev, 662kev, 1172kev, and 1332kev and to evaluate how it varies as a function of gamma rays energy. The result generally agree with theoretical calculations. Some discrepancies can be explained by the collimation, media and geometry of absorber. The dependence of cross-section on the atomic number and the energies of gamma ray is also seen due to the increases of binding energy and penetration power of gamma ray.
Description: A THESIS PRESENTED TO THE SCHOOL OF GRADUATE STUDIES ADDIS ABABA UNIVERSITY IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE in PHYSICS
URI: http://hdl.handle.net/123456789/84
Appears in:Thesis - Physics

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