Newly developed highly sensitive LiF:Mg,Cu,Si TL discs with good stability to heat treatment

Comparative studies on radioluminescent and thermoluminescent spectra of LiF:Mg,Cu,P and LiF:Mg,Cu,Si

The influence of various annealing treatments on radioluminescent (RL) and thermoluminescent (TL) spectra of LiF:Mg,Cu,Si and LiF:Mg,Cu,P was investigated. The TL and RL emission bands for LiF:Mg,Cu,P are not the same; however, the emission band peaking at ∼383 nm is predominant in the TL and RL emission for LiF:Mg,Cu,Si. With the increase in annealing temperatures in the range of 240-300°C, for LiF:Mg,Cu,P, the intensity of TL decreases much more rapidly than that of RL. For LiF:Mg,Cu,Si, the area ratios of the two bands of RL and TL remain constant within experimental errors. It suggests that there is a significant decrease in the concentration of recombination centres in LiF:Mg,Cu,P after the annealing, in addition to the decrease in trapping centres, the recombination centres for main TL emission and RL emission in LiF:Mg,Cu,Si are the same, and the recombination centres for TL emission and RL emission in LiF:Mg,Cu,P are not the same. P is a more effective dopant than Si.

Further studies on the role of dopants in LiF:Mg,Cu,Si thermoluminescent material

The 3-D thermoluminescence spectra and glow curves of LiF:Mg,Cu,Si, LiF:Mg,Cu, LiF:Mg,Si and LiF:Cu,Si with low concentrations of Mg and Cu were measured and were compared with those with high concentrations to investigate further the role of dopants in LiF:Mg,Cu,Si material. The shape of glow curves of the four samples is similar; however, LiF:Cu,Si sample had no Mg dopant. It is concluded that the TL emission to be from self-trapped excitons in LiF, and this emission could be enhanced and altered by Mg, Cu and Si dopants in LiF:Mg,Cu,Si; all three dopants are necessary to obtain the bright TL emission and may be involved in the luminescence process; Mg seems to be the most essential dopant and Cu is involved in the trapping although the role of Mg dominates; both Cu and Si play a role in the main emission process and Cu also plays a role in reducing the emission around 610 nm.

Thermoluminescent Phosphors for Radiation Dosimetry

The use of thermoluminescence (TL) as a method for radiation dosimetry of ionizing radiation has been established for many decades and has found many useful applications in various fields, such as personnel and environmental monitoring, retrospective dosimetry, medical dosimetry, space dosimetry, high-dose dosimetry. Method of preparation, studies and applications of thermoluminescence (TL) dosimetric materials are reviewed. Several high sensitivity thermoluminescent dosimeters (TLDs) are now commercially available in different physical forms. These commercial TL dosimeters comply with a set of stringent requirements stipulated by the International Electrotechnical Commission (IEC). Specific features of TL phosphors for thermal neutron, fast neutron and high-energy charged particle (HCP) dosimetry are also considered. Some of the recent developments in the field of optically stimulated luminescence (OSL) and radiophotoluminescence (RPL) are also summarized. Comparative advantages of TL, OSL and RPL dosimeters are given. Results of recent studies of TL in nanosized materials are briefly presented. Future challenges in this field will also be discussed. Contents of Paper

On the roles of dopants in LiF:Mg,Cu,Si thermoluminescent material

The 3D thermoluminescent spectra and glow curves of LiF:Mg,Cu,Si with various Mg, Cu and Si concentrations were measured. The shapes of the glow curves in LiF:Mg,Cu,Si, LiF:Mg,Cu and LiF:Mg,Si are similar and the glow curves have peaks at approximately the same temperatures, but with significantly different intensities. Neither the temperature of the glow peak nor the wavelength of the emission maximum changes with variation of dopants concentrations when Cu is more than 0.01 mol % in LiF:Mg,Cu,Si. The spectrum structure in LiF:Mg,Cu,Si, LiF:Mg,Cu and LiF:Mg,Si is similar in the 300-550 nm range. Some weak emissions around 610 nm are shown in LiF:Mg,Cu,Si with a Cu concentration of 0.01 mol % and in LiF:Mg,Si. It is concluded that Mg dopant mainly plays a role in the formation of trapping centres, both Cu and Si play a role in the main emission process and Cu also plays a role in reducing the emission around 610 nm.