Dosimetry is important in diagnostics and interventional radiology for the verification of equipment performance and the optimization of patient dose
[1]
-
[3]
. Ionization chambers and semiconductor dosimeters are used in diagnostic and interventional radiology for dosimetry and quality control (QA)
[4]
[5]
. Semiconductor detectors are now widely used for dosimetry because they are sensitive to radiation, rigid, and do not require temperature and pressure correction, making them suitable for field application
[6]
. The dosimeter must be calibrated with standard radiation quality of well-defined properties to ensure the accuracy of the measurement. The International Atomic Energy Agency (IAEA) Technical Report Series (TRS) 457 outlines the specific standards and procedures for calibrating dosimeters at the Secondary Standard Dosimetry Laboratory (SSDL)
[2]
. The standard radiation qualities for diagnostics and interventional radiology, which are characterized by their tube voltage and Half Value Layers (HVLs), are the RQR, RQT, RQA, and RQM
[2]
. The Nigerian Secondary Standard Dosimetry Laboratory (SSDL), domiciled in the National Institute of Radiation Protection and Research (NIRPR), is responsible for the calibration of dosimeters in Nigeria. The standard of the SSDL is traceable to IAEA Laboratories in Seibersdorf. The Nigerian SSDL calibrates different detectors for diagnostics and interventional radiology using the established radiation qualities from TRS 457. Although there is substantial research on the performance of semiconductor detectors in diagnostic radiology, much of it is from developed regions with advanced healthcare systems
[7]
. Have established the importance of continuous performance monitoring of these detectors
[8]
. Further underscore the importance of detector accuracy, noting that inaccuracies can lead to misdiagnoses and affect patient outcomes
[1]
. Also concluded that the dosimeters evaluated exhibit varying degrees of performance, with some demonstrating high accuracy and reliability in measuring radiation doses in interventional radiology settings. However, there is a notable absence of studies that explore the performance of these detectors in developing countries, particularly in Africa, where factors such as extreme environmental conditions, resource limitations, and varied equipment usage may uniquely impact detector performance. This work aims to investigate the performance of semiconductor detectors used in diagnostics and interventional radiology across different diagnostic radiology radiation qualities at the SSDL in Nigeria. It also includes assessing these detectors in radiological beams for which they were not originally designed or calibrated, providing crucial data that could lead to improved diagnostic accuracy and patient safety in similar settings across the continent.
2. Material and Method2.1. Hopewell X-Ray Machine
This work used a Hopewell X-ray machine to generate different radiation reference beam qualities. The machine is a dosimetry-grade X-ray machine with a Comet Tube head, generator, and controller. The machine specification includes inherent filtration of 1 mm Be, tungsten target material, emergent angles of 40˚ and 15˚ for tube head and from shield respectively, 225 kV maximum tube voltage, and double focus.
<xref ref-type="bibr" rid="scirp.138739-"></xref>2.2. Exradin A4 Ion Chamber and PTW Electrometer
Standard imaging’s Exradin A4 spherical ion chamber, 300 cc was used as the reference dosimeter for establishing the radiation quality beams and dose rate generations. The Exradin A4 was calibrated at the IAEA laboratory in Vienna. PTW UNIDOS electrometer was also used in conjunction with the Exradin A4.
2.3. Semiconductor Dosimeter
Five semiconductor devices were investigated for their response in RQR, RQR-M, RQA, and RQT beams. Some of the devices have more than one detector, while some operate in various selectable modes. The indication and ranges of Dose, HVL, and Tube Voltage of the detectors are shown in
Table 1
.
<xref ref-type="bibr" rid="scirp.138739-"></xref>Table 1. Semiconductor detectors and their properties.
S/N
Measuring Assembly
Detector/Mode
Indication
Range
Dose
HVL
Tube Voltage
Dose (mGy)
HVL (mm Al)
Tube Voltage (kVp)
1
PTW CONNY II (Two modes)
70/100
x
-
-
2E−3 to 9.99E3
-
70 - 100
2
30
x
-
-
5E−3 to 9.99E3
-
30
3
PTW DIADOSE E (Two External Detectors)
40 - 150
x
-
-
1E−4 to 5E6
-
40 - 150
4
25 - 45
x
-
-
1.5E−4 to 13E6
-
25 - 45
5
PTW DIAVOLT UNIVERSAL (Three Modes)
RAD/FLU
x
-
x
5.0E−2 to 5.0E4
-
40 - 150
6
CT
x
-
x
5.0E−2 to 5.0E4
-
40 - 150
7
MAM
x
x
5.0E−2 to 5.0E4
-
22 - 40
8
PIRANHA 657 (With one external detector and one internal detector)
Internal Detector
x
x
x
1.3E−3 to 1.5E3
0.72 - 13
35 - 160
9
DOSE PROBE
x
-
-
1E−7 to 1.5E6
-
-
10
RAYSAFE X2 (External detectors)
RF
x
x
x
1E−3 to 9.99E6
1 - 14
40 - 150
11
MAM
x
x
x
1E−3 to 9.99E6
1 - 14
20 - 50
2.4. X-Ray Beam Qualities
RQR, RQR-M, RQA, and RQT beam qualities were generated using the procedure in IAEA TRS 457 with reference Exradin A4 dosimeter. The added filtration and HVL of the generated RQR, RQA, RQR-M, and RQT are shown in
Table 2
and
Table 3
. The generated beam qualities are within the allowable limit standards prescribed in TRS 457.
<xref ref-type="bibr" rid="scirp.138739-"></xref>Table 2. Added filtration and HVL of RQR and RQA beam qualities.
RQR
RQA
Beam quality
kV
Added filtration (mmAl)
First HVL (mmAl)
Beam quality
kV
Added filtration (mmAl)
First HVL (mmAl)
RQR 2
40
2.25
1.41
RQA 2
40
7
2.22
RQR 3
50
2.4
1.82
RQA 3
50
12.2
3.85
RQR 4
60
2.4
2.16
RQA 4
60
18.2
5.3
RQR 5
70
2.65
2.65
RQA 5
70
24.4
6.9
RQR 6
80
2.7
3
RQA 6
80
27
8.1
RQR 7
90
2.85
3.4
RQA 7
90
32
9.3
RQR 8
100
3.3
4
RQA 8
100
37
10.3
RQR 9
120
3.6
5
RQA 9
120
40
11.5
RQR10
150
4.2
6.4
RQA 10
150
49.2
13.5
<xref ref-type="bibr" rid="scirp.138739-"></xref>Table 3. Properties of RQM and RQT beam qualities.
RQM Beam Quality
RQT Beam Qualities
Beam quality
kV
Added filtration (mmAl)
First HVL (mmAl)
Beam quality
kV
Added filtration
(mmAl + Cu)
First HVL (mmAl)
RQM 25
25
0.55
0.325
RQT 8
100
3.3 + 0.18
7.1
RQM 28
28
0.5
0.35
RQT 9
120
4.0 + 0.23
8.5
RQM 30
30
0.5
0.392
RQT10
150
4.2 + 0.28
10.35
RQM 35
35
0.52
0.445
2.5. Dose Rate Generation for the Beam Qualities
The dose rates for different beams from RQR 2 to RQR 10 and RQA 2 to RQA 10 were generated using the Exradin A4 reference ionization chamber. Charges collected from the electrometer for each beam quality were recorded for 2.5, 5, 10, 12.5, and 15 mA selected current at a fixed source-detector distance (SDD) of 1 m. The charges were corrected for temperature and pressure using Equation (1)
[2]
, and the dose rates were calculated using Equation (2)
[2]
.
(1)
where KTP is the Temperature-Pressure correction factor, Pref and Tref are the Reference Pressure and Temperature respectively from the Exradin A4 calibration certificate, P and T are the Laboratory pressure and Temperature.
(2)
DR is the dose rate at a particular mAs, Nk is the Reference calibration coefficient from the Exradin A4 calibration certificate and RE is the Electrometer Reading.
2.6. Assessment of Semiconductor Detector
The responses of the semiconductors were calculated as the ratio of the dose value indicated by the semiconductor detectors to the reference value calculated from the Exradin A4 dose rate. The dose from the reference dosimeter and the response of the dosimeter was calculated using Equation (3) and Equation (4)
[2]
respectively.
(3)
(4)
where t is the exposure time in seconds, DRef is the reference dose while DI is the dose indicated by the semiconductor device. The absolute response deviation in percentage was then obtained for the detectors for all the beams using Equation (5).
(5)
The energy responses of the detectors were also obtained by finding the quotient of the detector response at each energy beam and the detector response at the reference beam as stated in Equation (6)
[2]
.
(6)
is the response of the detectors at a particular beam, and
is the response of the reference beam. The reference beams are RQR 5 for the RQR beam, RQA 5 for the RQA beam, RQR-M 2 for the RQR-M beam, and RQT 9 for the RQT beam. The energy response of the detectors was plotted against the Half Value Layers of the beam qualities.
2.7. Uncertainty Measurement
The measurement uncertainty was evaluated for each detector in the four diagnostic beam qualities. The uncertainty assessment measurement procedure was based on IAEA TECDOC-1585
[9]
, and the major sources of uncertainty contributors are type A and type B uncertainties. Type A uncertainty is determined through the statistical analysis of a series of laboratory measurements. Type B uncertainty includes the transferred uncertainty from the calibration coefficients of the reference chamber, as well as long-term stability and detector positioning. The uncertainty in the calibration result is computed by combining the type A and type B uncertainty in the calibration result presented as a 95% confidence interval. In all cases, the expanded combined uncertainty (k = 2) ranges from 3% to 7% for all the dosimeter measurements in the SSDL.
3. Results
This study assessed five semiconductor devices across four diagnostic radiation beam qualities: RQR, RQA, RQR-M, and RQT. The PTW Diavolt Universal (MAM mode) did not respond to radiation in RQR, RQA, and RQT beams, while the PTW Diavolt Universal (CT mode) failed to respond in RQR 2, RQR 3, RQA 2, and RQA 3 and displayed KV over-range (KVO) in RQR 10, RQA 9, and RQA 10. The PTW Diavolt Universal (RAD/FLU mode) exhibited similar issues, not responding in RQR 2 and RQA 2 and displaying KVO in higher energy beams. The PTW Diavolt Universal (CT mode) and the Piranha Dose Probe did not respond to RQR-M beam qualities. The acceptable limit for energy dependency of semiconductor detectors is 5%
[10]
.
Performance of the detectors in RQR Beams: The graph of energy dependency of the detectors in RQR beam qualities against the HVL is shown in
Figure 1
. The energy dependency of detectors in RQR beams was generally within the acceptable 5% limit except for certain deviations noted in the PTW CONNY II (30 kV), PTW DIADOSE E (24 - 45 kV), and RAYSAFE X2 MAM mography detectors. Specifically, the PTW DIADOSE E exhibited response deviations ranging from 62.77% to 74.97%, and PTW CONNY II (30 kV) indicating significant response at higher energy of 11.95% to18.61% at RQR8 to RQR 10 as shown in
Table 4
.
<xref ref-type="bibr" rid="scirp.138739-"></xref>Table 4. Response deviation of detectors in RQR beam.
Beam Energy
RQR2
RQR3
RQR4
RQR5
RQR6
RQR7
RQR8
RQR9
RQR10
Response Deviation (%)
PTW CONNY IIa
9.58
5.58
3.79
1.89
1.29
3.37
11.95
16.76
18.61
PTW CONNY IIb
7.20
7.01
7.68
8.00
6.37
5.57
3.44
2.66
3.54
PTW DIADOSE Ec
6.93
2.92
7.57
7.46
4.96
3.15
5.79
3.46
5.90
PTW DIADOSE Ed
62.77
65.32
65.26
66.68
68.79
71.17
73.62
74.16
74.97
PTW DIAVOLTe
0.67
0.99
0.67
2.37
0.99
4.98
PTW DIAVOLTf
2.27
4.45
6.11
3.59
6.39
4.49
7.30
PIRANHA 657
5.86
4.90
3.81
1.98
2.42
1.92
1.62
3.48
0.82
PIRANHA 657g
2.91
2.61
0.90
0.63
1.04
0.68
0.83
1.84
0.45
RAYSAFE X2 RF
4.72
0.49
3.32
3.86
5.44
5.65
2.66
3.55
5.35
RAYSAFE X2 MAM
3.09
0.08
1.07
0.94
2.09
5.39
6.05
9.75
7.02
a = 30 kV, b = 70/100 kV, c = 40 - 150 kV, d = 25 - 45 kV, e = CT, f = RAD/FLU, g = Dose Probe.
3.1. Performance in RQA Beams
The energy dependence and response deviations for various detectors across RQA beam qualities in
Figure 2
and
Table 5
reveal that detectors like the PTW DIADOSE E 40 - 150 kV, PIRANHA 657, and RAYSAFE X2 RF consistently performed within acceptable energy dependencies threshold of 5% and response deviations under 10%. However, other detectors, such as the PTW DIADOSE E 25 - 45 kV, PTW CONNY II, and RAYSAFE X2 MAM, showed higher energy dependencies and greater variability in response, indicating less stability and accuracy across different RQA beam qualities.
Figure 1. Energy response in RQR beam.
Figure 2. Energy response in RQA beam.
<xref ref-type="bibr" rid="scirp.138739-"></xref>Table 5. Response deviation of detectors in RQA beam.
Beam Energy
RQA2
RQA3
RQA4
RQA5
RQA6
RQA7
RQA8
RQA9
RQA10
Response Deviation (%)
PTW CONNY IIa
15.97
9.60
13.12
23.08
32.92
23.34
22.26
39.16
74.35
PTW CONNY IIb
14.81
21.72
4.85
7.03
15.45
14.72
4.07
6.27
2.73
PTW DIADOSE Ec
2.40
6.57
2.39
2.20
1.74
0.95
1.38
1.14
0.93
PTW DIADOSE Ed
58.81
60.81
71.79
80.95
73.80
83.32
86.00
82.34
92.99
PTW DIAVOLTe
15.84
14.31
11.28
6.29
1.45
PTW DIAVOLTf
20.20
23.58
20.91
15.65
9.60
0.21
PIRANHA 657
2.15
4.55
3.77
3.99
4.46
1.60
5.58
5.40
5.22
PIRANHA 657g
5.48
4.04
2.93
3.19
3.71
2.02
6.81
4.09
4.54
RAYSAFE X2 RF
6.51
2.98
0.11
2.78
5.24
5.59
3.64
2.18
0.16
RAYSAFE X2 MAM
4.82
9.85
1.48
8.30
11.08
17.64
30.32
32.34
49.88
a = 30 kV, b = 70/100 kV, c = 40 - 150 kV, d = 25 - 45 kV, e = CT, f = RAD/FLU, g = Dose Probe.
3.2. Performance in RQR-M Beams
The energy dependence of PTW CONNY II 30 kV, PTW DIADOSE E 25 - 45 kV, PIRANHA 657, and RAYSAFE X2 MAM as presented in
Figure 3
, reveals reliable performance in RQR-M beams, all maintaining energy dependencies below 5%. In contrast, PTW DIADOSE E 40 - 150 kV shows higher variability, peaking at 16.31% for RQR-M 1, while PTW DIAVOLT UNIVERSAL MAM exceeds 5% in RQR-M 3 and RQR-M 4. Notably, PTW CONNY II 70/100 kV exhibits significant instability, with energy dependencies ranging from 49% to 221%. Response deviations as shown in
Table 6
are below 10% for PTW CONNY II 30 kV, PTW DIADOSE E 25 - 45 kV, PTW DIAVOLT UNIVERSAL MAM, PIRANHA 657, and RAYSAFE X2 MAM, while RAYSAFE X2 RF show moderate deviations (10% - 30%), and PTW DIADOSE E 40 - 150 kV and PTW CONNY II 70/100 kV exceed 50%, indicating limited precision in RQR-M beams.
Figure 3. Energy response in RQR-M beam.
Performance in RQT beams
In RQT beams, the energy dependence analysis indicates that PTW DIADOSE E 40 - 150 kV, PTW DIAVOLT UNIVERSAL CT, PTW DIAVOLT UNIVERSAL RAD/FLU, PIRANHA 657, PIRANHA 657 dose probe, and RAYSAFE X2 RF maintain energy dependencies below 5% as presented in
Figure 4
. In contrast, PTW CONNY II 30 kV, PTW CONNY II 70/100 kV, PTW DIADOSE E 24 - 45 kV,
<xref ref-type="bibr" rid="scirp.138739-"></xref>Table 6. Response deviation of detectors in RQR-M beam.
Beam Energy
RQR-M1
RQR-M2
RQR-M3
RQR-M4
Response Deviation (%)
PTW CONNY II 30 kV
3.81
8.01
3.37
6.74
PTW CONNY II 70/100 kV
58.77
72.34
15.65
11.03
PTW DIADOSE E 40 - 150 kV
57.79
88.53
85.69
96.49
PTW DIADOSE E 25 - 45 kV
2.34
1.48
5.53
0.49
PTW DIAVOLT UNIVERSAL MAM
6.92
1.99
5.53
5.20
PIRANHA 657
6.68
2.12
2.14
1.12
RAYSAFE X2 RF
29.58
29.09
26.71
20.37
RAYSAFE X2 MAM
3.98
1.43
2.00
2.74
and RAYSAFE X2 MAM exhibit energy dependencies exceeding 5%. In
Table 7
, response deviations of PTW DIADOSE E 40 - 150 kV, PTW DIAVOLT UNIVERSAL CT, PTW DIAVOLT UNIVERSAL RAD/FLU, PIRANHA 657, PIRANHA 657 dose probe, and RAYSAFE X2 RF are below 5%, while PTW CONNY II 30 kV, PTW CONNY II 70/100 kV, PTW DIADOSE E 25 - 45 kV, and RAYSAFE X2 MAM have deviations above 10% in RQT beams.
Figure 4. Energy response in RQT beam.
<xref ref-type="bibr" rid="scirp.138739-"></xref>Table 7. Response deviation of detectors in RQT beam.
Beam Energy
RQT8
RQT9
RQT10
Response Deviation (%)
PTW CONNY II 30 kV
24.84
39.55
52.27
PTW CONNY II 70/100 kV
9.01
17.29
29.86
PTW DIADOSE E 40 - 150 kV
3.57
2.05
3.13
PTW DIADOSE E 25 - 45 kV
78.74
82.86
86.73
PTW DIAVOLT UNIVERSAL CT
4.09
2.70
PTW DIAVOLT UNIVERSAL RAD/FLU
4.75
3.48
PIRANHA 657
0.62
1.20
2.46
PIRANHA 657+ Dose Probe
1.12
0.94
4.03
RAYSAFE X2 RF
3.10
3.22
2.80
RAYSAFE X2 MAM
15.23
23.85
33.61
4. Discussion
The energy dependency and response of all the semiconductor detectors tested in this research vary for different beam qualities. As discussed below, the variation determines the semiconductor suitability for the different beam qualities.
PTW Diavolt Universal
MAM mode
The PTW Diavolt Universal MAM’s complete lack of response suggests that this detector is highly specialized and not versatile across the broad range of diagnostic radiology beams. It may have an internal threshold that was not met by the tested beams, or it could be optimized for a very narrow range of energy levels typical of mammography, which often requires lower-energy X-rays. This lack of response implies that PTW Diavolt Universal in Mammo mode is not suitable for general diagnostic radiology.
CT mode
The PTW Diavolt Universal CT detector showed a clear limitation in its energy range, failing to respond to lower-energy beams (RQR2, RQR3, RQA2, and RQA3) and exhibiting KV over-range (KVO) errors at higher energies (RQR 10, RQA 9, RQA 10). This behavior suggests that the detector is designed for a specific range of energies typical of CT imaging. The KVO errors indicate that the detector’s design may not accommodate the full spectrum of energies encountered in a broader diagnostic setting, making it unsuitable for use outside of CT-specific applications.
RAD/FLU Mode
The PTW Diavolt Universal RAD/FLU detector exhibited similar limitations to the CT variant, with no response in lower-energy beams (RQR 2, RQA 2) and over-range errors in higher-energy beams (RQR 10, RQA 9, RQA 10). This suggests that the RAD/FLU detector is designed for moderate energy levels typical of general radiography and fluoroscopy, where mid-range X-rays are used.
PTW CONNY II
30 kV mode
The PTW CONNY II 30 kV detector showed significant variability in energy dependency, with deviations exceeding 5%, especially in higher-energy RQR beams, RQA and RQT. Response deviations also surpassed 10% in these beam conditions, indicating that the detector may not be well-suited for diagnostic beam outside of mammography beam. The high variability suggests that the detector is sensitive to changes in beam quality, which could lead to inaccuracies if used in a broader diagnostic context without proper calibration. This detector seems optimized in mammography beams where it can provide stable and accurate measurements, necessitating the need to adhere to manufacturer specifications when deploying it in clinical environments.
70/100 kV mode
This detector demonstrated stable performance in RQR beams, maintaining energy dependencies within 5%. However, it showed significant variability in RQA, RQT, and RQR-M beams, with response deviations often exceeding 10%. This variability suggests that while the detector performs reliably in mid-range energy levels typical of general radiography, it struggles with the broader spectrum of energies encountered in other diagnostic radiology procedures.
PTW DIADOSE E
40 - 150 kV probe
The PTW DIADOSE E 40 - 150 kV detector performed well across RQR, RQA, and RQT beams, maintaining energy dependencies below 5% and response deviations under 10%, suggesting that the detector is suitable for the energies for which it is designed. However, in RQR-M beams, the detector exhibited significant response deviations, ranging from 57.79% to 96.49%. This indicates that while the detector is versatile across standard diagnostic beam qualities, it is not desirable in RQR-M beams.
25 - 45 kV probe
This detector showed strong performance in RQR-M beams, with energy dependencies below 5% and response deviations under 10%. However, it exhibited significant energy dependencies and wider response deviations exceeding 10% in higher-energy beams, indicating that the detector is highly specialized for mammography beams.
PIRANHA
PIRANHA 657
The PIRANHA 657 detector demonstrated robust performance across all tested beam qualities, consistently maintaining energy dependencies below 5% and response deviations under 10%. This indicates a high degree of versatility and reliability, making the PIRANHA 657 suitable for a wide range of diagnostic radiology applications. Its consistent performance suggests that it is capable of providing accurate measurements across various diagnostic radiology applications.
PIRANHA 657 with Dose Probe model
The PIRANHA 657 Dose Probe variant also exhibited strong performance across all beam qualities, with energy dependencies within 5% and response deviations below 10%. However, there is more than 5% energy dependency in RQA 2 and RQA 3.
RAYSAFE X2
RAYSAFE X2 RF
The RAYSAFE X2 RF detector demonstrated generally good performance across most beam qualities, maintaining energy dependencies below the 5% threshold for RQR, RQA, and RQT beams. This indicates that the detector is suitable for the typical energy levels encountered in radiography. However, mammography beams, such as those simulated by RQR-M beams, the RAYSAFE X2 RF exhibited significant response deviations, sometimes exceeding 10%. This variability implies that while the detector is effective for conventional radiographic and fluoroscopic applications, it may not be as reliable in mammography beams.
RAYSAFE X2 MAM
The RAYSAFE X2 MAM detector is designed specifically for mammography. The detector performed reliably in RQR-M beams, maintaining energy dependencies below 5%, which is critical for the accurate measurement of low-energy radiation typical in mammography. However, when used outside its specialized application, such as in RQR beams, the RAYSAFE X2 MAM exhibited significant energy dependencies exceeding 5% and response deviations above 10%, indicating that the detector’s calibration is highly tuned to the lower energies used in mammographic imaging.
5. Conclusion
The comprehensive evaluation of twelve semiconductor detectors across various diagnostic radiation beam qualities (RQR, RQA, RQR-M, and RQT) provided critical insights into their performance, energy dependency, and response deviations, crucial for determining their suitability in specific clinical applications. Detectors like the PTW Diavolt Universal RF, MAM and CT were highly specialized, showing limitations in versatility, particularly failing to respond to certain beams or exhibiting over-range errors at higher energies. This indicates their use should be confined to specific applications like RF, mammography or CT. Conversely, the PIRANHA 657 and its dose probe variant displayed robust, reliable performance across all tested beam qualities, maintaining low energy dependencies and response deviations, making them versatile for a broad spectrum of radiological applications. The PTW CONNY II and DIADOSE E detectors performed well in their optimized energy ranges but struggled outside their designed beam conditions, indicating a need for careful application. The RAYSAFE X2 detectors generally performed well but showed significant deviations in some beam qualities outside their designed beam. This demonstrates that while some semiconductor detectors are versatile and reliable across multiple diagnostic applications, others are highly specialized and require careful selection and understanding of the detector operation for optimal performance. Knowledge of the specific strengths and limitations of each detector is essential for enhancing diagnostic accuracy, optimizing radiation protection, and ensuring patient safety in radiological practices.
Acknowledgements
We sincerely acknowledge the support of the International Atomic Energy Agency (IAEA) through the Coordinated Research Project E24024 (CRP E24024), which played a crucial role in funding this study. The financial assistance, resources, and expert guidance provided by the IAEA have greatly facilitated our research efforts. We also express our deep gratitude to the team at the Secondary Standard Dosimetry Laboratory, Nigeria, whose expertise and dedication were instrumental in the successful completion of this research.
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