Space, radiotherapy, X-ray imaging/screening, nuclear reactors, large research facilities (linear accelerators and synchrotron radiation facilities) and nuclear accidents are all examples associated with the need for monitoring high-energy radiation. Herein, we report the luminescent and dosimetric properties of a radiation sensitive phosphor based on CaB₆O₁₀:Tb³⁺,Ag⁺ compounds. The operation principle here is the optically stimulated luminescence (OSL), which is the luminescence of a previously irradiated material under optical stimulation. The phosphor presented strong UV-OSL under blue stimulation (a minimum detectable dose of 2.3 μGy), with dose linearity in the whole dose range analysed (30 mGy-20 Gy) and no signs of saturation. The thermoluminescence (TL) of the phosphor featured mainly a peak at 275 °C, whose trapping center was shown to be associated with the main OSL component. Furthermore, the TL emission is dominated by Tb³⁺ emission lines (main emission at 541 nm). Overcoming the main limitation of the commercial Al₂O₃:C phosphor, OSL was observed after neutron irradiation. Besides reporting the luminescent and dosimetric properties of a novel neutron sensitive OSL phosphor obtained through a low-cost synthesis method, this work sheds light on how lanthanide and silver ions influence the charge trapping and radiative processes in borate compounds.