## 2 Materials and Methods
The emitted optical-spectrum of LaBr\({}_{3}\):Ce, normalized to unity, compared to the spectral sensitivities of several commonly used optical photon-sensors, is illustrated in \[\mathrm{QDE}=\ \frac{\int_{0}^{\mathrm{E_{0}}}\Phi_{0}\ (\mathrm{E}) \Big{(}1-\mathrm{e}^{-(\mathrm{\mu_{att}}\ (\mathrm{E})/\mathrm{\rho})\mathrm{\rho}T}\Big{)} \mathrm{dE}}{\int_{0}^{\mathrm{E_{0}}}\Phi_{0}\ (\mathrm{E})\mathrm{dE}} \tag{2}\]5 The \(\Delta\)E values of LaBr\({}_{3}\):Ce, normalized to unity, compared to the spectral sensitivities of several commonly used optical photon-sensors, are shown in \[\mathrm{QDE}=\ \frac{\int_{0}^{\mathrm{E_{0}}}\Phi_{0}\ (\mathrm{E}) \Big{(}1-\mathrm{e}^{-(\mathrm{\mu_{att}}\ (\mathrm{E})/\mathrm{\rho})\mathrm{\rho}T}\Big{)} \mathrm{dE}}{\int_{0}^{\mathrm{E_{0}}}\Phi_{0}\ (\mathrm{E})\mathrm{dE}} \tag{2}\]6 The \(\Delta\)E values of LaBr\({}_{3}\):Ce, normalized to unity, compared to the spectral sensitivities of several commonly used optical photon-sensors, are shown in \[\mathrm{QDE}=\ \frac{\int_{0}^{\mathrm{E_{0}}}\Phi_{0}\ (\mathrm{E}) \Big{(}1-\mathrm{e}^{-(\mathrm{\mu_{att}}\ (\mathrm{E})/\mathrm{\rho})\mathrm{\rho}T}\Big{)} \mathrm{dE}}{\int_{0}^{\mathrm{E_{0}}}\Phi_{0}\ (\mathrm{E})\mathrm{dE}} \tag{2}\]7  
\[\mathrm{QDE}=\ \frac{\int_{0}^{\mathrm{E_{0}}}\Phi_{0}\ (\mathrm{E}) \Big{(}1-\mathrm{e}^{-(\mathrm{\mu_{att}}\ (\mathrm{E})/\mathrm{\rho})\mathrm{\rho}T}\Big{)} \mathrm{dE}}{\int_{0}^{\mathrm{E_{0}}}\Phi_{0}\ (\mathrm{E})\mathrm{dE}} \tag{2}\]8 QDE of the LaBr\({}_{3}\):Ce crystal in comparison with LaCl\({}_{3}\):Ce, BGO, LSO and CdWO\({}_{4}\) crystals. \[\mathrm{QDE}=\ \frac{\int_{0}^{\mathrm{E_{0}}}\Phi_{0}\ (\mathrm{E}) \Big{(}1-\mathrm{e}^{-(\mathrm{\mu_{att}}\ (\mathrm{E})/\mathrm{\rho})\mathrm{\rho}T}\Big{)} \mathrm{dE}}{\int_{0}^{\mathrm{E_{0}}}\Phi_{0}\ (\mathrm{E})\mathrm{dE}} \tag{2}\]9 AE values of the LaBr\({}_{3}\):Ce (4.25% error bar) crystal in comparison with previously published data for the LaCl\({}_{3}\):Ce, BGO, LSO and CdWO\({}_{4}\) crystals. Figures 7-10 [33; 40; 41; 42; 43]. The sensors listed are silicon photomultipliers (SiPMs), frequently employed in nuclear-medicine applications, charge-coupled devices (CCD) and complementary metal-oxide semiconductors (CMOS) utilized in imaging applications, and various photocathodes. The width of the LaBr\({}_{3}\):Ce spectrum is approximately 120 nm, from 320 to 440 nm, with a maximum at 380 nm [18]. Figure 1.0 Optical spectral distribution of LaBr\({}_{3}\):Ce crystal, and spectral sensitivity of CMOS photoreceptors. Figure 1.1 Optical spectral distribution of LaBr\({}_{3}\):Ce crystal, and spectral sensitivity of CCD photoreceptors. The compatibility of the crystal-detector combination, shown in Figures 7-10, is directly related to the calculated SMFs demonstrated in Figures 11-14. LaBr\({}_{3}\):Ce provides excellent compatibility with various flat-panel (FP) photocathodes, with the SMF values ranging from 0.95 to 0.98, as well as with the Multialkali photocathode (0.97) and the Bialkali photocathode (0.95). LaBr\({}_{3}\):Ce is a suitable choice for applications evolving silicon photomultipliers, since the SMF values ranged from 0.75 to 0.86 (0.86 for SiPM S10362-11-100U). On the other hand, LaBr\({}_{3}\):Ce was found to be incompatible with CCDs and CMOS detectors,  
Figure 1.2 Optical spectra distribution of LaBr\({}_{3}\):Ce, and spectral sensitivity of SiPMs. Figure 1.3 Optical spectra distribution of LaBr\({}_{3}\):Ce, and spectral sensitivity of photocathodes. with the SMF values ranging from 0.02 to 0.65 for the CCDs detectors, and from 0.0 to 0.37 for the CMOS detectors. More specifically, the lowest values were registered when coupled with the CCD with Polygates and the CCD no-Polygates LoD (both at 0.02), the CCD with traditional Polygates (0.03), the CMOS Pgate (0.02) and the CMOS RadEye HR (0.0). Figure 1.4 SMF values of LaBr\({}_{3}\):Ce with various SiPMs. Figure 1.5 SMF values of LaBr\({}_{3}\):Ce with various photocathodes.