External-field-dependent Tunable Emissions of Er3+-In3+ Co-doped Cs2AgBiCl6 for Applications in Anti-counterfeiting

Structural, mechanical, thermal and optical properties of NaCl:Ce3+ single crystals grown in large size by the Czochralski method

The pure and Ce3+-doped NaCl crystals were grown using the resistance heating Czochralski method The structural, mechanical, and optical properties of the grown crystal were investigated by X-ray diffraction (XRD), micro-hardness, optical absorption, photoluminescence (PL), PL excitation (PLE) spectroscopy, and decay time measurement The XRD data indicated that the NaCl host lattice was compressed when Ce atoms were incorporated and the peaks shifted to the large angle side The ICP-AES and XPS analyses verified that Ce3+ is the dominant state of cerium in NaCl crystal The hardness of the NaCl:Ce3+ crystal was larger than that of pure NaCl crystal and it was anisotropic Optical absorption confirmed that the three states of 5d level splitting of Ce correspond to the absorption peaks of 202, 215, and 227 nm The intense emissions located at 342 and 356 nm were attributed to the radiation transitions 5d → 2F5/2 and 5d → 2F7/2 in Ce3+, respectively The energy-level scheme for the Ce3+ ion in the NaCl crystal was proposed from the PL and PLE analysis The luminescence decay time of NaCl:Ce3+ crystal is 3857 ± 016 ns These observations indicate that the NaCl:Ce3+ crystal should be a promising material for use in radiation dosimetry and scintillation applications

Optical and mechanical properties of NaCl: Ce 3+ crystal grown by the Czochralski method

To effectively avoid the bottleneck of optical collimation system distortion in the use of tactical high-energy laser weapons (THELWs), this paper proposes and realizes an optical-multiphysics-finite-element coupling analysis method Combined with dynamic physical parameters, we construct and verify a structure-thermal-optical-performance (STOP) model and accurately restore the multiphysics coupling phenomenon in the THELW lens Finally, we conclude that the limiting output power of THELW assembled with the doublet lens is 11556 W Then, we draw a series of conclusions from different physical fields and make a comprehensive analysis of the optical collimation system performance The analysis methods and conclusions described in the paper are of great significance for the R & D of future laser weapons and other optical systems

STOP model development and analysis of an optical collimation system for a tactical high-energy laser weapon.

In this study, the thermoluminescence characteristics of naturally occurring salt (NaCl) were assessed for the development of a radiation dosimeter. For this purpose, mined crystalline samples of salt were procured directly from Khewra salt mines in Pakistan. The samples were hand crushed, sieved, and compressed to pellets comparable in size to standard TLD chips, and irradiated to gamma radiation doses in the range of 5 mGy and 5000 mGy. Thermoluminescence (TL) response showed three main peaks in the glow curve around 115–130 °C, 150–170 °C, and 220–240 °C. A linear TL response was observed for the dose range of 5–100 mGy. The TL response became supra-linear for the dose ranges of 100–1000 mGy and 1000–5000 mGy. The Tm-Tstop method was applied to identify the overlapping peaks of the glow curve. Computerized glow curve deconvolution (CGCD) was then employed for the characterization of electron trap parameters such as frequency factor (s), activation energy (E), and the kinetic order (b), using General Order (GO) kinetics. The figure-of-merit (FOM) was found to be 1.08%, 0.94%, 0.77%, and 0.75%, at 500 mGy, 1 Gy, 2 Gy, and 5 Gy, respectively. The TL intensity faded by 20% within the first 24 h after irradiation and finally stabilized after two weeks. In addition, structural, morphological, and elemental analyses, were also performed using various analytical techniques. X-ray diffraction (XRD) showed that the salt crystallizes in a face-centered cubic structure. Scanning electron microscope (SEM) micrographs indicated that the crystallites are closely packed and cubic-shaped with non-uniform size, and mostly found in the agglomerated form. Similarly, the elemental analysis confirmed the presence of impurities such as Mg, Sr, S, K, O, and Ca, in the samples. The present study concludes that the pellets made from salt samples from Khewra mines have a potential for use as radiation dosimeters.

C.K. Mahadevan

Papers

Structural, mechanical, thermal and optical properties of NaCl:Ce3+ single crystals grown in large size by the Czochralski method

Large size crystal growth and structural, thermal, optical and electrical properties of KCl 1−x Br x mixed crystals

Luminescent and Mechanical Properties of Cerium Doped Potassium Chloride Single Crystal

The Structure and Liquid Flow Effect of Melt during NaCl Crystal Growth

Effect of Ce concentration on the structural, mechanical, electrical and optical properties of Ce-doped large-sized KCl0.5Br0.5 crystals