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In this study, a gamma-ray detector probe with a thallium bromide (TlBr) semiconductor detector was developed for particle-induced gamma-ray emission (PIGE) analysis. Owing to the high atomic numbers of thallium (81) and bromine (35) and high density (7.56g/cm³) of TlBr, it exhibits a high photon stopping power, making it promising for PIGE analysis. An approximately 5-mm thick TlBr detector was fabricated from a crystal grown through the traveling-molten zone method using a zone-purified material. The detector comprised a planar cathode and small anode ($1.5\mathrm{\text{mm}}\times 1.5$mm) surrounded by a guard electrode. The detector obtained full-width-at half-maximum (FWHM) energy resolutions of 1.7 and 1.6% for 356- and 511-keV gamma rays, respectively, at room temperature using a depth correction and rejection method based on the cathode-to-anode signal ratio. The TlBr detector probe was installed in a beamline at the Aomori Prefecture Quantum Science Center, Japan, where PIGE analysis was conducted using a 20-MeV proton beam. Gamma rays at 478keV from ⁷Li(p,p${}^{\prime }\gamma$)⁷Li reactions, 197 and 110keV from ${}^{19}$F(p,p${}^{\prime }\gamma$)${}^{19}$F reactions, and 718keV from ${}^{10}$B(p,p${}^{\prime }\gamma$)${}^{10}$B reactions were successfully detected using the proposed TlBr detector probe in PIGE analysis.

A thallium bromide (TlBr) gamma-ray detector was developed for particle-induced gamma-ray emission (PIGE) applications. The PIGE spectrum of a lithium fluoride (LiF) crystal was obtained for the first time using the TlBr detector. This detector was fabricated using a zone-purified crystal with dimensions of approximately 2mm × 2mm × 5mm. An energy resolution of 2.3% full-width at half maximum for 511 keV gamma rays was obtained from the detector at room temperature. The LiF crystal target was irradiated with a 20 MeV proton beam at the Aomori Prefecture Quantum Science Center. Full-energy peaks of 478 keV and 197 keV were successfully detected from lithium and fluorine, respectively, using the TlBr detector in the PIGE experiment.