vii
TABLE OF CONTENTS
CHAPTER
1
TITLE
PAGE
DECLARATION
ii
DEDICATION
iii
ACKNOWLEDGEMENT
iv
ABSTRACT
v
ABSTRAK
vi
TABLE OF CONTENTS
vii
LIST OF TABLES
xi
LIST OF FIGURES
xii
LIST OF ABBREVIATIONS
xvi
LIST OF SYMBOLS
xviii
LIST OF APPENDICES
xix
INTRODUCTION
1
1.1
Background
1
1.2
Lithium Borate Glass
2
1.3
Modifiers and Activators
4
1.3.1 Lithium Carbonate and Sodium
4
Carbonate Modifiers
1.3.2 Samarium Oxide and Dysprosium
5
Oxides Activators
1.4
Problem Statement
6
1.5
Objectives
7
1.6
Scope of Study
8
viii
1.7
2
Organization of Study
10
LITERATURE REVIEW
11
2.1
Introduction
11
2.2
General Structure of Glass
11
2.3
Structure of Lithium Borate
13
2.3.1 Borate Glass
13
2.3.2 Modifiers Borate Glass
15
2.3.2.1
Sodium and Lithium
2.3.2.2
Glass
15
Properties 15
Improvement
2.3.3 Structure of Lithium Sodium Borate
2.3.3.1
Lithium Sodium Borate
17
18
2.3.3.2 Samarium and Dysprosium 19
Oxides
2.4
Optical Properties
21
2.5
Luminescence Dosimetry
23
2.6
Thermoluminescence
23
2.6.1 Thermoluminescence Dosimeter
24
System
2.6.1.1 Glow Curve
25
2.6.1.2 Annealing
27
2.6.1.3 Sensitivity
27
2.6.1.4 Dose Response
27
2.6.1.5 Heating Rate
28
2.7
2.5.2 Previous Studies
29
2.7.1 Related to Optical Properties of Borate
29
2.7.2 Thermoluminescence Properties of
31
Borate
3
MATERIAL AND METHODS
33
3.1
Introduction
33
3.2
Sample Preparations
34
ix
3.3
3.4
3.5
3.6
Sample Characterizations
36
3.3.1 X-ray Diffraction Analysis
37
3.3.2 Infrared Spectroscopy
37
Physical Parameters
37
3.4.1 Density and Molar Volume
38
3.4.2 Ion Concentration
38
3.4.3 Reflection measurement
39
3.4.4 Oscillator Strengths
40
3.4.5 Differential Thermal Analysis
41
Optical Properties
42
3.5.1 UV-Vis-NIR Measurements
42
3.5.2 Photoluminescence Measurement
42
Thermoluminescence Measurement
44
3.6.1
Preparation
the
chips
for 44
(LNB:Dy,Sm)
3.6.2 TLD-Reader Harshaw
45
3.6.2.1 Dark Current
46
3.6.2.2 PMT Nose
47
3.6.2.3 Background Noise
47
3.6.3 Exposure to Iradiation
47
3.6.3.1 University of Malaya Medical 48
Center, Clinical Oncology Unit, KL
4
3.6.3.2 Photons
48
3.6.3.3 Electrons
49
3.6.4 Annealing
50
3.6.5 Heating Rate
52
3.6.6 Sensitivity
52
RESULTS AND DISCUSSION
54
4.1
54
Introduction
Part A : Li2CO3 − B2O3 − Na2CO3 doped Sm2O3
55
4.2
55
X-Ray Diffraction Analysis
x
5
REFERENCES
4.3
Physical Parameters
57
4.4
DTA Analysis
60
4.5
FTIR Analysis
62
4.6
UV-vis-Absorption Spectra
63
4.7
Energy Band Gap
68
4.8
Photoluminescence Spectra
72
4.9
TL Glow Curve
75
Part B : Li2CO3 − B2O3 − Na2CO3 doped Dy2O3
77
4.2
X-Ray Diffraction Analysis
77
4.3
Physical Parameters
79
4.4
FTIR Analysis
81
4.5
UV-vis-Absorption Spectra
83
4.6
Energy Band Gap
87
4.7
Photoluminescence Spectra
92
4.8
TL Glow Curve
95
4.9
Golden Card
96
4.10
Annealing
98
4.11
Heating-Rate Effect
101
4.12
Linearity
103
4.13
TL – Sensitivity
107
CONCLUSION
109
5.1
Introduction
109
5.2
Recommendation and Future Studies
112
114
xi
LIST OF TABLES
TABLE No.
3.1
TITLE
PAGE
Raw materials employed in the concentration of each 35
chemical.
4.1
Physical parameters calculated for LNB doped with Sm3+ 57
ions.
4.2
DTA
studies
of
LNB
with
different
dopants 60
concentrations.
4.3
The variation between the transition levels and their 67
oscillator strengths of Sm3+.
4.4
Optical parameters calculated for LNB doped with Sm3+ 71
ions.
4.5
Physical parameters calculated for LNB doped with Dy3+ 79
ions.
4.6
The variation between the transition levels and their
87
oscillator strengths of Dy3+.
4.7
Optical parameters calculated for LNB doped with Dy3+ 91
ions.
4.8
TLD yield obtained after photon irradiation for LNB:Dy.
105
.
4.9
TLD yield obtained after electron irradiation for LNB:Dy 107
4.10
The Sensitivity of the proposed dosimeters and TLD-100 108
using fixed incident energy and different absorbed dose.
xii
LIST OF FIGURES
Figure No.
TITLE
PAGE
1.1
Structure of borate glass network (Bekker et al., 2012).
3
1.2
Scope of study
9
2.1
Structural groups postulated for borate glasses (Krogh-Moe, 14
1965).
2.2
A schematic diagram of structure for lithium sodium borate 17
glass (Bekker et al., 2012).
2.3
A schematic diagram of TLD reader (Podgorsak, 2005).
2.4
Glow curve of LiF:Mg,Ti measured with a TLD reader 26
24
(Podgorsak, 2005).
3.1
The flow chart of LNB:Sm, Dy glass preparation
36
3.2
The steps to calculate the oscillator strength
41
3.3
The machines performed to characterize and determine the 43
optical properties of the new glasses (a: XRD; b: FTIR;
c: UV-Vis spectrometer; d: PL spectroscopy).
3.4
Preparation of sample LNB:Sm and LNB:Dy, a) sample 44
preparation; b) annealing; c) read out process using TLDreader.
xiii
3.5
A Harshaw 4500 TL reader belonging to Physics 46
Department, UTM.
3.6
The position of LINAC and solid phantom for irradiation to 50
determine response of doped optical fibre and TLD-100 for
various electron energies at 200 MU min−1 dose rate.
3.7
A furnace (Harshaws) used to anneal TL materials.
51
4.1
XRD pattern obtained for Li2CO3-Na2CO3-B2O3 doped with 56
mol% of Sm2O3.
4.2
The glass density with different concentration of Sm3+ ions.
4.3
The refractive index with different concentration of Sm3+ 59
58
ions.
4.4
DTA studies of LNB: (A: 0.0 mol % of Sm2O3 and B: 0.3 61
mol % of Sm2O3).
4.5
IR spectra of Li2CO3-Na2CO3-B2O3 glasses doped Sm2O3 62
regions from 0.3 - 1.3 mol% indicate by G2 to G6.
4.6
UV-vis-NIR absorption of Li2CO3 – Na2CO3– B2O3 doped 64
with (0.3, 0.5, 0.7, 1.0, 1.3 mol%) Sm3+ ions.
4.7
Absorption spectra of Sm3+ ions with (0.3 - 1.3 mol%) 65
doped Li2CO3 – Na2CO3– B2O3.
4.8
Indirect Band Gap of Li2CO3 – Na2CO3 – B2O3 doped with
68
Sm3+ ions.
4.9
Indirect Band Gap of Li2CO3 – Na2CO3 – B2O3 doped 0.7
69
mol% of Sm2O3.
4.10
Direct Band Gap of Li2CO3 – Na2CO3 – B2O3 doped with
70
Sm3+ ions.
4.11
Direct Band Gap of Li2CO3 – Na2CO3 – B2O3 doped 0.7
71
mol% of Sm2O3.
4.12
Emission spectra of Li2CO3–Na2CO3–B2O3 doped with (0.3, 72
0.5, 0.7, 1.0, 1.3 mol%) Sm3+ ions, λexcitation is 400nm.
4.13
Emission energy levels diagram of Li2CO3-Na2CO3-B2O3 74
glass doped Sm3+.
xiv
4.14
Optimization of LNB:Sm samples.
4.15
XRD pattern obtained for Li2CO3– Na2CO3–B2O3 doped 78
76
with mol% of Dy2O3.
4.16
The glass density with different concentration of Dy3+.
4.17
The refractive index with different concentration of Dy
80
3+
81
ions.
4.18
IR spectra of Li2CO3–Na2CO3–B2O3 glasses doped (1) 0.3, 82
(2) 0.5, (3) 0.7, (4) 1.0, (5) 1.3 mol% of Dy2O3.
4.19
UV-vis-NIR absorption of Li2CO3 – Na2CO3 – B2O3 doped 84
with (0.3, 0.5, 0.7, 1.0, 1.3) mol% of Dy2O3.
4.20
Absorption spectra of Dy3+ ions with (0.3 - 1.3 mol%) doped 85
Li2CO3 – Na2CO3– B2O3.
4.21
Indirect Band Gap of Li2CO3 – Na2CO3– B2O3 doped with 88
Dy3+
4.22
Indirect Band Gap of Li2CO3 – Na2CO3 – B2O3 doped 0.5 89
mol% of Dy 2O3.
4.23
Direct Band Gap of Li2CO3 – Na2CO3 – B2O3 doped with 90
Dy3+
4.24
Direct Band Gap of Li2CO3 – Na2CO3 – B2O3 doped 0.5 91
mol% of Dy 2O3.
4.25
Emission spectrum of Li2CO3–Na2CO3–B2O3 doped with 92
(0.3, 0.5, 0.7, 1.0, and 1.3 mol%) Dy3+ ions, λexcitation is
380nm.
4.26
Emission energy levels diagram of Li2CO3-Na2CO3-B2O3
94
glass doped Dy3+.
4.27
Optimization of LNB:Dy samples
95
4.28
Golden Card of LNB:Dy samples (σ represents the standard 97
deviation)
4.29
The behavior of TL response as a function of the annealing 99
temperature.
xv
4.30
The behavior of TL response as a function of the annealing 100
time.
4.31
The effect of heating rate (2, 4, 6, 8 and 10 °C.s-1) on glow 102
Curve of Dy3+ doped LNB.
4.32
TL photon response of LNB:Dy versus the doses obtained 104
using linear accelerator.
4.33
TL electron response of LNB:Dy versus the doses obtained 106
using linear accelerator.
xvi
LIST OF ABBREVIATIONS
BOHC
- Boron Oxygen Hole Center
B2O3
- Boron Oxide
BO3
- Trigoal Borate
BO4
- Tetrahedral Borate
DTA
- Differential Thermal Analysis
Dy2O3
- Dysprosium Oxide
ECC
- Elemental Correlation Coefficient
FTIR
- Fourier transform infrared spectroscopy
FWHM
- Full Width at Half Maximum
GFA
- Glass Former Ability
GeO2
- Germanium Dioxide
IR
- Infra-Red
H3BO3
- Boric Acid
HC
- Hole Center
LiB3O5
- Lithium Triborate
Li2B4O7
- Lithium Tetraborate
LiF
- Lithium Fluoride
Li2CO3
- Lithium Carbonate
Li2B4O7:Mn
- Lithium Tetraborate Doped with Manganese
LET
- Linear energy transfer
LINAC
- Linear accelerator
LNB
- Lithium Sodium Borate
MDD
- Minimum Delectable Dose
Na
- Sodium
xvii
Na2O
- Sodium Oxide
Na2CO3
- Sodium Carbonate
NBO’s
- Non-Bridge Oxygen’s
P2O5
- Phosphorus Pentoxide
PL
- Photoluminescence
PMT
- Photomultiplier Tube
PMMA
- Poly Methyl Metha Crylate
RCF
- Read Calibration Factor
SiO2
- Silicon Dioxide
STD
- Standard Deviation
Sm2O3
- Samarium Oxide
SSD
- Source Skin Distance
SSDL
- Secondary Standard Dosimeter Lab
TL
- Thermoluminescence
TSL
- Thermally Stimulated Luminescence
TLD
- Thermoluminescence dosimetery
UMMC
- University of Malaya Medical Center
UTM
- University Technology Malaysia
UV
- Ultra Visible
XRD
- X-Ray Diffraction
xviii
LIST OF SYMBOLS
α
- Alpha Particle
b
- Weight of glass sample in the toluence
c
- Speed of light
D
- Distance between atomic layers in a crystal
e
- Charge of electron
E
- Activation Energy for Trapped Electron
Eg
- Optical band gap
eV
- Electron Volt
fexp
- Oscillator strengths
N
- Ion Concentration
ri
- Inter-nuclear distance
rp
- Polaron radius
T
- Temperature
Tg
- Glass Transition
Tm
- Maximum Temperature
Tc
- Crystaline Temperature
Vm
- Molar Volume
ρ
- Density
υ
- Frequency
λ
- Wavelength
σ
- Standard deviation
xix
LIST OF APPENDICES
APPENDIX
TITLE
PAGE
A
The quantity needed to prepare glass samples
122
B
The refractive index of samarium and dysprosium with
148
different concentration
C
The oscillator strength of samarium and dysprosium with
149
different concentration
D
List of Energy Band Gaps
154
E
List of the Optimization of LNB:Dy samples
174
F
The standard deviation of Golden Card for the samples
175
G
Rate of annealing for timing and temperature.
178
H
Rate of heating rate for samples
180
I
List of Publications
181