Five samples of \(\hbox {LiMgPO}_4\) :Gd were prepared via five different production processes using a solid-state reaction method. The effects of the preparation process on optically stimulated luminescence (OSL) and thermoluminescence (TL) were investigated. Considering its high sensitivity, low fading, and minimum detectable dose (MDD), the \(\hbox {LiMgPO}_4\) :Gd phosphor heated to \({900}\,^{\circ }\) C for 15 h is concluded to be optimal. The effects of annealing on the OSL sensitivity, relative residual OSL signals measured after 24 h of irradiation, and MDD of \(\hbox {LiMgPO}_4\) :Gd phosphors heated to \({900}\,^{\circ }\) C for 15 h were also investigated. Considering its high sensitivity, low fading, and MDD, annealing at \({350}\,^{\circ }\) C for 1 h is concluded to be optimal. The OSL signal of \(\hbox {LiMgPO}_4\) :Gd was derived from the principal TL glow peak. For a maximum integration time of 5 s, the OSL signal was stable, with no fading 30 days after irradiation. \(\hbox {LiMgPO}_4\) :Gd eliminated approximately 2.2% of the OSL signal at each readout for a readout time of 0.1 s, which is sufficient for fast and multiple OSL readout. The sensitivity of \(\hbox {LiMgPO}_4\) :Gd phosphor, annealed for 1 h at \({350}\,^{\circ }\) C with a reading time of 0.1 s, was found to be approximately 98% of that observed for \(\alpha\) - \({\hbox {Al}_2\hbox {O}_3}\) :C(TLD-500k), which should be sufficient for low-dose measurements in personal, workplace, and environmental dosimetry.
