vii
TABLE OF CONTENTS
CHAPTER
1
2
TITLE
PAGE
DECLARATION
ii
DEDICATION
iii
ACKNOWLEDGEMENT
iv
ABSTRACT
v
ABSTRAK
vi
TABLE OF CONTENTS
vii
LIST OF TABLES
xi
LIST OF FIGURES
xiv
LIST OF SYMBOLS
xx
LIST OF APPENDICES
xxii
INTRODUCTION
1
1.1. Overview
1
1.2 Statement of the Problem
4
1.3 Objectives of the Study
5
1.4 Scope of the Study
6
LITERATURE REVIEW
7
2.1 Introduction
7
2.2 Theory of Thermoluminescence Process
8
2.2.1 Simple Model of Thermoluminescence
8
2.2.2 First-order Kinetics
10
viii
2.2.3 Second-order Kinetics
12
2.2.4 General-order Kinetics
16
2.3 Glow curve Analysis
16
2.3.1 Initial Rise Methods
17
2.3.2 Peak Shape Methods
18
2.3.2.1 Method of Lushchik
19
2.3.2.2 Method of Chen
19
2.3.3 Methods of Various Heating Rates
22
2.3.4 Curve Fitting
23
2.4 Characteristics of Thermoluminescent Dosimetry
3
(TLD)
24
2.4.1 Linearity
24
2.4.2 Energy Response
26
2.4.3 Fading
27
2.4.4 Annealing Procedures
28
2.4.5 Stability and Reproducibility
29
2.4.6 Precision and Accuracy
30
2.5 Glass Formation
31
2.6 Theory of Energy Band Gap
32
2.7 Photoluminescence
33
RESEARCH METHODOLOGY
34
3.1 Introduction
34
3.2 Material for Glass Sample Preparation
34
3.2.1 Borates Glasses
35
3.2.2 Lithium Carbonate
35
3.2.3 Potassium Carbonate
36
3.2.4 Copper
36
3.2.5 Tin Oxide
37
3.3 Powder Mixing
37
3.4 Glass Preparation
38
3.5 Structural Characterization Measurements of
Samples
38
ix
3.5.1 X-Ray Diffraction Analysis
39
3.5.2 Field Emission Scanning Electron
4
Microscopy (FE-SEM)
40
3.6 UV-Vis-NIR Measurements
42
3.7 Photoluminescence Measurement
42
3.8 Annealing Precedure
43
3.9 Exposure to Radiation
44
3.9.1 Linear Accelerator Primus MLC 3339
44
3.9.2 X-Ray Machine
45
3.9.3 Cobalt – 60 Gamma-Rays (60Co)
46
3.10 Perspex Sheet
47
3.11 TLD -Reader 4500
48
RESULTS AND DISCUSSION
50
4.1 Introduction
50
4.2 Glass Samples and Composition
50
4.3 Energy Band Gap
53
4.4 Photoluminescence Measurements
56
4.5 FE-SEM Analysis
58
4.6 Effective Atomic Number
58
4.7 TL Response of Undoped Lithium Potassium
Borate Glasses
60
4.8 Annealing Procedures
61
4.9 Effect of Heating Rate on TL Response
65
4.10 Borate Glass Glow Curve
68
4.11 Dose-TL Response Relationship
70
4.11.1 TL Response of LKB: Cu Glass Subjected
to Photon Irradiation
70
4.11.2 TL Response of LKB: Cu and LKB: Cu
with co-doped SnO2 Glass Subjected to
Photon Irradiation.
76
4.12 Comparison of TL Response of LKB: Cu and
LKB: Cu with co-doped SnO2 Glass.
81
x
4.13 Fading Characteristics Measurement
82
4.14 Optical Bleaching Measurement
86
4.15 Reproducibility
89
4.16 Sensitivity
90
4.17 Minimum Detectable Dose
91
4.18 TL Energy Response Subjected to X-ray Photon
Irradiation
92
4.19 Comparison Between Theoretical Calculation of
Relative Energy Response and Experimental
Results
5
94
4.20 Thermoluminescence Parameters
97
CONCLUSION
102
5.1 Summary
102
5.2 Recommendations and Future Research
106
REFERENCES
107
Appendices A-E
118-135
xi
LIST OF TABLES
TABLE NO
TITLE
PAGE
2.1
Annealing procedures applied to lithium borate.
29
4.1
The nominal composition of LKB glass
51
4.2
The nominal composition of LKB: Cu glass
51
4.3
The nominal composition of LKB: Cu co-doped
with SnO2 glass
52
4.4
Energy band gap of LKB glass with different Cudoped concentrations.
54
4.5
Energy band gap of LKB: Cu glass co-doped with
different SnO2 concentration.
55
4.6
Fraction of elemental composition of LKB: 0.1 Cu
mol% glass using FE-SEM
59
4.7
Composition of elemental fraction of LKB: Cu
glass co-doped with SnO2 using FE-SEM
60
4.8
Annealing procedures for different types of borate
64
glass.
xii
4.9
Dose responses for LKB: 0.1Cu mol% glass
71
subjected to 6 MV photon irradiation.
4.10
Dose responses of LKB: 0.1 Cu mol% glass
72
subjected to10 MV photon irradiation
4.11
Dose response of LKB: 0.1 Cu mol% subjected
73
to12 MV photon irradiation
4.12
Dose response of LKB: 0.1 Cu mol% subjected
73
60
Co gamma-ray irradiation
4.13
Dose response of LKB: 0.1 Cu mol% glass codoped with 0.1 SnO2 mol% subjected to 6 MV
photon irradiation
.
77
4.14
Dose response of LKB: 0.1 Cu mol% glass codoped with 0.1 SnO2 mol% subjected to 10 MV
photon irradiation
78
4.15
Dose response of LKB: 0.1 Cu mol% glass codoped with 0.1 SnO2 mol% subjected to 12 MV
photon irradiation
78
4.16
Dose response of LKB: 0.1 Cu mol% glass codoped with 0.1 SnO2 mol% subjected to 60Co
gamma irradiation
80
4.17
Fading of LKB: Cu glass and LKB: Cu glass co-
85
doped with SnO2 compared to previous work
4.18
The sensitivity of different TL materials for various
photons energy.
91
4.19
Minimum detectable dose for various TL materials.
92
4.20
TL response of LKB: Cu glass and LKB: Cu glass
co-doped with SnO2 samples at various photon
energies after exposed to absorbed dose of 0.2 m
Gy.
93
xiii
4.21
the relative energy response (RER) of LKB: 0.1Cu
mol% glass sample determined theoretically and
experiment
95
4.22
The relative energy response (RER) of 0.1 SnO2
mol% sample determined theoretically and
experiment.
96
4.23
Values of constant c and b depending on τ, δ, or
98
ω for LKB: 0.1Cu mol% glass.
.
4.24
Activation energy of samples /eV for LKB: 0.1Cu
mol% glass.
99
4.25
Values of c and b depending on τ, δ, or ω for
LKB: 0.1Cu mol% glass co-doped with 0.1SnO2
mol%.
100
4.26
Activation energy of samples /eV for LKB: 0.1 Cu
mol% glass co-doped with 0.1SnO2 mol%
100
4.27
Trap frequency factor of samples /s–1 for LKB: 0.1
Cu mol% glass.
101
4.28
Trap frequency factor of samples /s–1 for LKB: 0.1
Cu mol% glass co-doped with 0.1SnO2 mol%
101
xiv
LIST OF FIGURES
FIGURE NO
2.1
TITLE
PAGE
Simple two-level model for mechanism of
9
Thermoluminescence
2.2
Energy levels in the forbidden band gap of a
12
solid.
2.3
General TL glow curve, showing also the
21
parameters discussed in the peak shape glow
curve analysis methods
2.4
Linearity curve (Oberhofer, 1981)
25
2.5
Energy gap diagram
32
3.1
Electric furnace
38
3.2
XRD instruments used to study the amorphous
39
phase of glasses samples.
3.3
FE-SEM analysis machine
40
3.4
(a) A sputtering machine is used for the gold
41
coating procedure (b) The sample holders
3.5
UV-Vis-NIR spectrophotometer
42
3.6
Photoluminescence spectrophotometer
43
3.7
A furnace (Harshaws) used to anneal TL
44
materials
xv
3.8
Linear accelerator primus MLC 3339 (LINAC
primus, department of radiotherapy and oncology,
hospital sultan ismail, JB).
45
3.9
Industrial x-ray model mG165
46
3.10
60
47
3.11
Perspex sheet used to hold the samples while expose
to irradiation
48
3.12
TLD –Reader 4500
49
3.13
Schematic diagram illustrating common features of
TLD readers
49
4.1
XRD pattern at room temperature of LKB: 0.1 Cu
mol% glass.
52
4.2
XRD patterns for the LKB: 0.1 Cu glass co-doped
with 0.1 SnO2 mol%.
53
4.3
Graph (α E )1/2 versus ( E ) for LKB with different Cudoped concentrations.
54
4.4
Graph (α E )1/2 versus ( E ) of LKB: Cu glass codoped with different SnO2 concentration.
55
4.5
PL spectra of LKB with different Cu-doped
concentrations excited by 650nm source.
57
4.6
PL spectra of LKB: Cu glass co-doped with different
SnO2 concentration excited by 650nm source.
57
4.7
FE-SEM micrographs of LKB: 0.1Cu mol% glass codoped with 0.1SnO2 mol%.
58
4.8
The TL intensity as a function of lithium content
61
4.9
Behavior of TL response and the corresponding
standard deviation as a function of the annealing
temperature for LKB: Cu glass.
62
4.10
Behavior of the TL response and the corresponding
standard deviation as a function of annealing time for
LKB: Cu.
62
Co gamma ray source
xvi
4.11
Behavior of the TL response and the corresponding
standard deviation as a function of the annealing
temperature for LKB: 0.1Cu mol% glass co-doped
with 0.1SnO2 mol%.
63
4.12
Behavior of the TL response and the corresponding
standard deviation as a function of the annealing
temperature for LKB: Cu glass co-doped with SnO2.
64
4.13
Glow curve profile as a function of heating rate for
LBK: 0.1 Cu mol% glass.
65
4.14
TL response as a function of heating rate for LKB:
0.1 Cu mol% glass.
66
4.15
Glow Curve as a function of heating rate for LKB: 0.1
Cu mol% glass co-doped with 0.1SnO2 mol%.
67
4.16
TL response as a function of heating rate for LKB:
0.1Cu mol% glass co-dope with 0.1SnO2 mol%.
67
4.17
The glow curves of LKB glass with different Cu
concentration.
69
4.18
The glow curves of LKB: Cu glass co-doped with
different SnO2 concentration.
69
4.19
TL response of LKB: 0.1Cu mol% glass subjected to
6MV photon irradiation irradiation.
71
4.20
TL response of LKB: 0.1 Cu mol% glass subjected to
10 MV photon irradiation
74
4.21
TL response of LKB: 0.1 Cu mol% glass subjected to
12 MV photon irradiation
74
75
4.22
TL response of LKB: 0.1 Cu mol% glass subjected to
60
Co gamma irradiation
4.23
TL response for 6, 10, 12 MV and 1.25 MeV photon
irradiation of LKB: 0.1 Cu mol% glass.
76
4.24
TL response of LKB: 0.1 Cu mol% glass co-doped
with 0.1 SnO2 mol% subjected to 6 MV photon
irradiation
77
xvii
4.25
TL response of LKB: 0.1 Cu mol% glass co-doped
with 0.1 SnO2 mol% subjected to 10 MV photon
irradiation
79
4.26
TL response of LKB: 0.1 Cu mol% glass co-doped
with 0.1 SnO2 mol% subjected to 12 MV photon
irradiation
79
4.27
TL response of LKB: 0.1 Cu mol% with co-doped 0.1
SnO2 mol% subjected to 60Co gamma irradiation.
80
4.28
TL response of LKB: 0.1 Cu mol% glass co-doped
with 0.1 SnO2 mol% subjected to 6, 10, 12 MV and
1.25 MeV photon irradiation.
81
4.29
TL response of LKB: 0.1 Cu mol% glass co-doped
with 0.1 SnO2 mol% subjected to 6MV photon
irradiation.
82
4.30
Fading of LKB: 0.1Cu mol% glass subjected to 6 MV
photon irradiation.
83
4.31
Residual signal characteristics of LKB: 0.1Cu mol%
glass subjected to 6 MV photon irradiation.
83
4.32
Fading of LKB: 0.1Cu mol% glass co-doped with
0.1SnO2 mol% of subjected to 6MV photon
irradiation for given dose of 1Gy.
84
4.33
Residual signal of LKB: 0.1Cu mol% glass co-doped
with 0.1SnO2 mol% subjected to 6 MV photon
irradiation for given dose of 1 Gy.
85
4.34
Optical bleaching of LKB: 0.1mol% Cu glass after
exposed to sunlight.
.
86
4.35
Optical bleaching of LKB: 0.1Cu mol% glass after
exposed to fluorescent lamp.
87
4.36
Optical bleaching of LKB: 0.1Cu mol% glass codoped with 0.1SnO2 mol% after exposed to sunlight.
88
xviii
4.37
Optical bleaching of LKB: 0.1Cu mol% glass codoped with 0.1SnO2 mol% after exposed to
fluorescent lamp.
88
4.38
TL response as a function to reproducibility test of
LKB: 0.1Cu mol% glass.
89
4.39
TL response as a function to reproducibility test of
LKB: 0.1Cu mol% glass co-doped with 0.1SnO2
mol%.
90
4.40
TL response of LKB: Cu glass and LKB: Cu glass codoped with SnO2 samples versus photon energies
after being exposed to absorbed dose of 0.2 m Gy.
94
4.41
The relative energy response as function energy for
LKB: 0.1Cu mol % glass.
.
96
4.42
The relative energy response as function energy of
LKB: 0.1Cu mol% glass co-doped with 0.1 SnO2
mol%.
.
97
4.43
The geometrical parameters of LKB: 0.1Cu mol%
glass.
98
4.44
The geometrical parameters of LKB: 0.1Cu mol%
glass co-doped with 0.1SnO2 mol%
99
xix
LIST OF SYMBOLS
Be
-
The binding energy of the electron
C
-
Coulomb
D
-
Absorbed dose
Do
-
Threshold dose
E
-
Trap depth
Ef
-
Fermi level
Eg
-
Forbidden energy
Emax
-
The maximum energy
Eγ
-
Energy of the incident photon
Eγ’
-
Energy of the scattered photon
F
-
TL system calibration factor
Gy
-
Gray
k
-
Boltzmann’s constant
Li
-
Lithium
LiF
-
Lithium fluoride
m
-
Mass
mo
-
The electron rest-mass
n
-
Number of electrons in a particular trap energy
no
-
The number of trapped electrons at the initial time
p
-
Probability of escaping by the trap
RER
-
Relative Energy Response
SE
-
Photon energy response
SnO2
-
Tin oxide
t
-
Time
Т
-
Temperature
TL
-
Thermoluminescence
xx
TLD
-
Thermoluminescence dosimeters
wi
-
Fraction of that element
Z
-
Atomic number of the atom
Zeff,
-
Effective atomic number
σ
-
Standard deviation
τ
-
Half-life of the phenomenon
xxi
LIST OF APPENDICES
APPENDIX
TITLE
PAGE
A
List of publications
115
B
Calculation effective atomic number
116
C
The Sensitivity of the lithium potassium borate with
D
Cu-doped
119
Calculation TL kinetic parameter
130