Development of a Novel Radiation Detector Based on Nigerian Geological Crystals for Environmental Monitoring

The development of radiation detectors from locally available Nigerian geological materials offers a pathway for establishing domestic manufacturing capability in nuclear instrumentation and reducing dependence on expensive imported detector systems for environmental monitoring, medical physics, and nuclear security applications. Nigeria's geological endowment includes quartz, fluorite, and calcite crystal deposits that are candidate detector materials for ionising radiation sensing. This study develops and characterises a novel radiation detector based on fluorite crystals from Plateau State's mineral deposits, evaluated for thermoluminescence dosimetry and scintillation counting applications. Fluorite samples are characterised by optical absorption spectroscopy, electron paramagnetic resonance, and photoluminescence prior to radiation detector development. Thermoluminescence glow curves are recorded following Co-60 irradiation at doses of 1 mGy to 100 Gy using a Harshaw TLD reader. The scintillation mechanism is characterised by time-resolved photoluminescence and X-ray excited emission spectroscopy. Results indicate that naturally doped Plateau State fluorite exhibits a principal TL glow peak at 215 degrees Celsius suitable for environmental dosimetry. The sensitivity per unit dose is 0.42 times that of commercial LiF-TLD100 material. Linearity extends from 5 mGy to 10 Gy. After thermal annealing optimisation, residual signal from previous irradiation cycles is below 0.3 percent. Keywords: thermoluminescence, fluorite, radiation detector, Nigerian minerals, environmental dosimetry