Thermoluminescence dosimetry properties of new Cu doped CaF(2) nanoparticles

Review of nanomaterial advances for ionizing radiation dosimetry

There are a wide range of applications with ionizing radiation and a common theme throughout these is that accurate dosimetry is usually required, although many newer demands are provided by improved features in higher range, multi-spectral and particle type detected. Today, the array of dosimeters includes both offline and online tools, such as gel dosimeters, thermoluminescence (TL), scintillators, optically stimulated luminescence (OSL), radiochromic polymeric films, gels, ionization chambers, colorimetry, and electron spin resonance (ESR) measurement systems. Several future nanocomposite features and interpretation of their substantial behaviors are discussed that can lead to improvements in specific features, such as (1) lower sensitivity range, (2) less saturation at high range, (3) overall increased dynamic range, (4) superior linearity, (5) linear energy transfer and energy independence, (6) lower cost, (7) higher ease of use, and (8) improved tissue equivalence. Nanophase versions of TL and ESR dosimeters and scintillators each have potential for higher range of linearity, sometimes due to superior charge transfer to the trapping center. Both OSL and ESR detection of nanomaterials can have increased dose sensitivity because of their higher readout sensitivity with nanoscale sensing. New nanocrystalline scintillators, such as perovskite, have fundamentally important advantages in sensitivity and purposeful design for key new applications. Nanoparticle plasmon coupled sensors doped within a lower Zeff material have been an effective way to achieve enhanced sensitivity of many dosimetry systems while still achieving tissue equivalency. These nanomaterial processing techniques and unique combinations of them are key steps that lead to the advanced features. Each must be realized through industrial production and quality control with packaging into dosimetry systems that maximize stability and reproducibility. Ultimately, recommendations for future work in this field of radiation dosimetry were summarized throughout the review.

SYNTHESIS, OPTICAL PROPERTIES AND THERMOLUMINESCENCE DOSIMETRY FEATURES OF MANGANESE DOPED Li2B4O7 NANOPARTICLES

Lithium tetraborate (Li2B4O7) nanoparticles (NPs) doped with manganese (Mn) were prepared for the first time by the solid-state sintering method. NPs were characterized using X-ray diffraction, scanning electron microscopy, photoluminescence and thermoluminescence (TL) techniques. The synthesized NPs exhibited highest TL response at 0.3 wt% of Mn dopant under gamma irradiation. TL dose response is linear for the absorbed dose from 1 Gy to 20 kGy and beyond this range behaves sub-linear. Such feature makes the synthesized nanophosphor as a promising material for high-dose dosimetry applications. Low fading and good reusability were obtained for the synthesized NPs. Tm-Tstop and computerized glow curve deconvolution procedures were utilized to identify the component TL glow peaks and kinetic parameters of the produced phosphor. Other TL dosimetry features of the prepared NPs are also presented and discussed.

Thermoluminescence properties of micro and nano structure hydroxyapatite after gamma irradiation

The goal of this study is to compare the thermoluminescence properties of nano and micro structure hydroxyapatite. Nano structure hydroxyapatite was synthesized via hydrolysis method, while the micro structure one was from Merck Company. X-ray diffraction and fourier transform infrared spectroscopy were used to determine the crystal structure and chemical composition of the hydroxyapatite samples. Particles sizes of each sample were estimated using Scherer equation and transmission electron microscopy system. Thermoluminescence properties of the samples were investigated under gamma irradiation. The glow curves of micro and nano structure samples show a peak at 150 °C and 200 °C, respectively. Thermoluminescence responses of both the samples were linear in the range of 25 – 1 000 Gy where, nano structure sample show a greater slope and stronger linearity in comparison to the micro sample. The results show that the thermoluminescence response of micro sample faded rapidly in comparison to the nano sample due to the existence of the peak at higher temperature.