ABSTRACT
Due to the development of nuclear technology and use of these technologies in various fields of industry, medicine, research and etc, protection against radioactive rays is one of the mostimportant topics in this field .The purpose of this is to reduce the dose rate from radioactive sources. The sources in terms of components are emitted various types of nuclear radiation with different energies. These radiations are involving of alpha particles, beta, and neutron and gamma radiation. Given that alpha and beta particles can be fully absorbed by the shield, the main issue in the debate protection radioactive rays is stopping of gamma rays and neutrons. Accordingly in shield design usually two types of radiation should be considered. First, X-rays and gamma rays, which have great influence, and by the mass of any suitable material, can be more efficiently attenuate the higher the density, the better the potential attenuation effect against gamma rays and the required shielding thickness decreases. The second type of radiation is neutrons. Often a combination of three materials is desirable that include heavy metals, light metals, and neutron-absorbing material to omit the slow neutrons through adsorption to the neutron shield. There are different materials that can be used to shielding against radioactive rays. The main materials that are used in protection include: water, lead, graphite, iron, compounds that contains B, concrete, and polyethylene. Accordingly, the main objective of this paper is evaluating the effectiveness of shielding materials against gamma and Beta particles.
TABLE OF CONTENTS
Title page
Certification
Dedication
Acknowledgement
Table of content
Abstract
CHAPTER ONE
1.0 INTRODUCTION
1.1 BACKGROUND OF STUDY
1.2 RADIATION
1.2.1 RADIATION AND MATTER
1.2.2 RADIATION AND RADIOACTIVITY
1.2.3 Radioisotopes
1.2.4 TYPES OF RADIATION
1.2.5 SOURCES OF IONIZING RADIATION
1.2.6 EFFECTS OF RADIATION
1.2.6.1 Epidemiological evidence
1.2.6.2 Cancer risk assessment
1.2.7 How radiation affects cells
1.3 MEDICAL USES OF RADIATION
1.3.1 RADIOTHERAPY
1.3.2 DIAGNOSTIC RADIOLOGY
1.4 REDUCING RADIATION DOSE
CHAPTER TWO
2.0 INTRODUCTION
2.1 HISTORY OF RADIATION SHIELDING
2.1.1 The early years
2.1.3 The decade of the 1950’s
2.1.4 The decade of the 1960’s
2.1.5 The decade of the 1970’s
2.1.6 The 1980’s and 1990’s
2.2 The future
2.3 PRACTICE OF RADIATION SHIELDING
2.3.1 Basic concepts
2.4 Basic analysis methods
2.6 Intermediate methods for photon shielding
2.7 Intermediate methods for neutron shielding
2.8 Gamma-ray and neutron reflection
2.9 Gamma-ray dose albedo approximations
CHAPTER THREE
3.0 MATERIALS AND METHOD
3.1 THEORY
3.1 Gamma rays interactions with matter
3.1.1 Photoelectric effect
3.1.2 Compton scattering
3.1.3 Pair production
3.1.4 Gamma Ray Attenuation
3.1.5 Build-up factor
3.1.6 Effect of Energy and Absorber Atomic Number on gamma Attenuation.
3.1.7 Beta interaction with matter
3.1.8 Ionisation and Excitation
3.1.9 Bremsstrahlung
3.1.10 Beta range in matter
3.2 Scintillation Detector
3.3 Calculation of detector’s efficiency
3.4 Uncertainty in measurements
3.4.1 Error propagation
3.5 MATERIALS AND METHOD
CHAPTER FOUR
4.O PRESENTATION OF DATA, ANALYSIS OF RESULT, INTERPRETATION AND DISCUSSION OF RESULT
4.1 Cs-137
4.1.1 Results