## 3 Results and Discussion  
### C-V Response to kVp  
Generally, the LED strip signal C-V response to kVp fluctuated across all the LED strip colors. For the cold white, warm white, and red LED strip colors, signal increments of 0.1, 0.1 and 0.3 mV were \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Variable/Parameter** & **Setting/Exposure** & **kVp** & **mAs** & **SID** \\ \hline  & 1 & 40 & 50 & 60 \\  & 2 & 50 & 50 & 60 \\ Tube & 3 & 70 & 50 & 60 \\ voltage/Kilovoltage & 4 & 81 & 50 & 60 \\ peak (kVp) & 5 & 102 & 50 & 60 \\  & 6 & 109 & 50 & 60 \\  & 7 & 117 & 50 & 60 \\ \hline  & 8 & 70 & 0.5 & 60 \\  & 9 & 70 & 5 & 60 \\  & 10 & 70 & 10 & 60 \\  & 11 & 70 & 20 & 60 \\ Tube current & 12 & 70 & 25 & 60 \\ second/Milliampere & 13 & 70 & 50 & 60 \\ second (mAs) & 14 & 70 & 85 & 60 \\  & 15 & 70 & 100 & 60 \\  & 16 & 70 & 125 & 60 \\  & 17 & 70 & 150 & 60 \\  & 18 & 70 & 200 & 60 \\  & 19 & 70 & 250 & 60 \\ \hline  & 20 & 70 & 50 & 30 \\  & 21 & 70 & 50 & 45 \\ Source-to-image & 22 & 70 & 50 & 60 \\ distance (SID) & 23 & 70 & 50 & 75 \\  & 24 & 70 & 50 & 90 \\  & 25 & 70 & 50 & 95 \\  & 26 & 70 & 50 & 100 \\ \hline \hline \end{tabular} Note: Three measurements were collected for each setting. For assessment of degradation after 1–2 months, the 12 varied mAs were used. For each LED strip color, the total number of data for the C–V signal and dose was 114 (26 \(\times\) 3 + 12 \(\times\) 3). In the reproducibility study, the same procedures were repeated with extra settings of 12 varied mAs with a fixed SID of 30. Therefore, the total number of data for the C–V signal and dose was 150 (26 \(\times\) 3 + 12 \(\times\) 3 + 12 \(\times\) 3).  
\end{table} 
Table 2: The settings of kVp, mAs, and SID in each exposure. observed when the kVp was increased from 40 to 117. On the contrary, the blue LED strip's signal decreases from 0.3 mV at a kVp of 40 to 0.1 mV at the kVp of 117. Although the green LED strip signal initially increases by 0.3 mV as the kVp is increased from 40 to 80, it decreases to 0 when the kVp is further increased to 117--as seen in Figure 3.  
EM radiation such as light is a wave and a particle simultaneously. When radiation is incident on a PN junction, interactions between radiation photons and PN junction particles/electrons occur. These interaction mechanisms include photoelectric effect, Compton scattering, pair production, coherent scattering, and bremsstrahlung radiation emission. However, the incident photon energy dictates the interaction mechanism, for instance, energies \(<\) 100 keV give rise to the photoelectric effect, energies from 100 keV to 10 MeV produce Compton scattering, and energies \(>\) 1 MeV cause pair production [44]. For low energy photons, the photoelectric effect is dominant whereas Compton scattering is dominant for high-energy photons [45; 46]. Low energy photons could also stimulate coherent scattering and this occurs when the incident photon energies are less than 10 keV [47; 48]. However, coherent scattering takes place in high atomic number elements [48]. Because semiconductor PN junctions are not made of high atomic number elements, coherent scattering would be non-existent in the LED strip's structure. Electron-hole combinations in LED strips are as a result of mainly the photoelectric effect and Compton scattering. This simultaneous contribution of the photoelectric effect and Compton scattering to radiation-induced current could be a possible explanation for the inconsistent graphs in Figure 3; kVp alters the energy of the incident photons [41]. In other words, kVp changes the beam quality similar to the half-value layer (HVL) [49]. Additionally, post-Compton scattering photons could similarly excite electrons in the form of impact ionization [50]. In [PERSON]'s study [6], photodiode signals of four different brands were also inconsistent when the incident photon energy was varied [6]. Modification of LEDs to emit colored light involves altering the structural composition of LEDs. For instance, phosphors could be added.