Abstract In the present paper thermoluminescence properties of argon ions irradiated barium strontium mixed sulphate phosphor are reported. The Ba 0.12Sr 0.88SO 4 phosphor was prepared by chemical co-precipitation method. The X-ray diffraction study of prepared sample suggests orthorhombic structure with average grain size of 37 nm. The samples were irradiated with 1.2 MeV Argon ions at fluences varying between 10 11–10 15 ions/cm 2. The argon ions penetrate to the depth of 1.89 μm and lose their energy mainly via electronic stopping. Due to ion irradiation, a large number of defects in the sample are formed. Thermoluminescence (TL) glow curves were recorded for each of the ion fluence. These curves exhibit one broad peak with maximum intensity at 498 K composed of three overlapping peaks. This indicates that different sets of traps are being activated within the particular temperature range each with its own value of activation energy ( E) and frequency factor ( s). The peaks were observed due to formation of trap levels by ion irradiation and subsequently activation of traps on thermal stimulation. The TL response of the nanophosphor is linear in the dose range 59 kGy–590 MGy. Kinetic parameters associated with the prominent peaks were calculated using glow curve deconvolution (GCD) and verified by different glow curve shape and sample heating rate methods.