Investigation of the Properties of K₂SO₄:Cu,Na Phosphor as a Novel Sensitive OSL Detector Under Infrared Stimulation

This work presents the dosimetric characteristics of a newly developed phosphor material-potassium sulfate doped with copper and sodium (K₂SO₄:Cu,Na). The measurements were carried out using the TORAIMS reader and X-ray irradiation. Detectors based on K₂SO₄:Cu,Na were prepared in different forms, including pellets with Teflon as a binder and silicone thin films. The investigation included analysis of OSL excitation and emission spectra, as well as X-ray diffraction (XRD) measurements. The K₂SO₄:Cu,Na phosphor demonstrated high sensitivity as a radiation detector within the infrared stimulated luminescence (IRSL) method. Basic IRSL dosimetric properties were studied: signal reproducibility, reusability, dose-response, minimum detectable dose, X-ray energy dependence and fading characteristic. For all types of tested detectors, the dose-response was linear up to 200 mGy and saturated near 20 Gy. The material showed high sensitivity, with minimum detectable doses in the sub-milligray range. Fading effects were noted but could be significantly reduced by preheat treatment. The optimal preheating temperature was identified as 120°C. These findings highlight K₂SO₄:Cu,Na as a promising candidate for applications in luminescent dosimetry.