A5022180779- Laser-induced spectroscopy and plasma
- Laser-Plasma Interactions and Diagnostics
- High-pressure geophysics and materials
- Atomic and Molecular Physics
- Energetic Materials and Combustion
- Analytical chemistry methods development
- Diamond and Carbon-based Materials Research
- Glass properties and applications
- Laser Material Processing Techniques
- Luminescence Properties of Advanced Materials
- Analytical Chemistry and Sensors
- Solid State Laser Technologies
- Chemical Synthesis and Characterization
- Electrochemical Analysis and Applications
- Laser-Matter Interactions and Applications
- Laser Design and Applications
- Advanced X-ray Imaging Techniques
- Advanced Chemical Sensor Technologies
- Ion-surface interactions and analysis
- Analytical Chemistry and Chromatography
- Ocular and Laser Science Research
- Heavy Metal Exposure and Toxicity
- Bee Products Chemical Analysis
- Extraction and Separation Processes
- Advanced Photocatalysis Techniques
Queen's University Belfast
2023-2025
Indian Institute of Technology Kanpur
2024
Homi Bhabha National Institute
2017-2022
Bhabha Atomic Research Centre
2013-2022
Bhabha Atomic Research Center Hospital
2019-2021
University of Delhi
2019
University of York
2019
Department of Atomic Energy
2017
P.N. Lebedev Physical Institute of the Russian Academy of Sciences
2010
National Centre for Compositional Characterisation of Materials
2001-2009
Cyclohexane, a key saturated cyclic hydrocarbon in petroleum, is prospective molecular framework for energetic materials, making its phase diagram subject of critical interest. Our work pushes the boundaries by exploring transitions under ultrafast (nanosecond timescale) dynamic compression using laser-driven shock and situ time-resolved Raman spectroscopy contrast to previous study [Yuan et al., J. Mol. Liq. 363, 119836 (2022)] reporting novel phases cyclohexane at millisecond time scale....
Abstract Vanadium-doped black TiO 2 nanoparticles were synthesized by modified sol-gel method. The characterisation of vanadium doped was carried out using DRS, XRD, and SEM with EDX analysis to determine band gap energy, crystal structure, surface morphology elemental composition. coated on pre cleaned glass beads dip coating technique. Methylene blue employed as a model dye the photo-catalytic efficiency nanoparticles. degradation aqueous methylene performed in packed re-circulated photo...
Abstract Time‐resolved Raman spectroscopy for visualizing molecular fingerprint snapshots at nanosecond time scale is a useful tool detailed understanding of in situ shock behaviour materials. This technique was applied to study the changes vibrations poly (methyl methacrylate) (PMMA) under laser driven compression up ~1.9 GPa confinement geometry. A layered target configuration used enhance pressure. The vibrational modes are measured as function dynamic and static compression. Grüneisen...
The spectroscopic properties of Tellurium Calcium Zinc Niobium oxide Borate (TCZNB) glasses composition (in mol%) 10TeO2 + 15CaO 5ZnO 10 Nb2 O5 (60 - x)B2 O3 Nd2 (x = 0.1, 0.5, 1.0 or 1.5 have been investigated experimentally. three phenomenological intensity parameters Ω2 , Ω4, Ω6 calculated using the Judd-Ofelt theory and in turn radiative such as transition probabilities, emission cross-sections, branching ratios lifetimes estimated. trend found JO parameter is > Ω4 If glass system...
We have carried out Raman spectroscopic measurements on atactic polystyrene (aPS) under shock compression up to 2 GPa. Observed wavenumber shifts of active modes been used determine their Grüneisen parameters and bond anharmonicities. mode at 798 cm −1 displays maximum blue shift 4.95 /GPa. Our observed are found be consistent with the earlier results obtained hydrostatic pressure. also evaluated pressure through 1D radiation hydrodynamic simulations, in good agreement experimental values....
Aluminium Kα emission (1.5 keV) produced by an 8 J, 500 ps, Nd:glass laser incident at 45° onto a layered target of 0.8 µm thick aluminium (front side) and 1 iron (backside) has been used to probe the opacity plasma. Source broadened spectroscopy continuum analysis show that whole beam self-focusing within plasma results in two-temperature spatial distribution. Thermal conduction from laser-irradiated into layer, enhanced self-focusing, temperature ∼10–150 eV layer. The photon energy 1.5 keV...
The concentration dependent Yb3+: phosphate (P2O5 + K2O MgO Al2O3 Yb2O3) glasses have been prepared and characterized their fluorescence laser properties. stimulated emission cross-section performance parameters were determined from the measured absorption spectra using method of reciprocity. refractive index, cross-sections lifetimes varied with Yb3+ ion concentration. higher was found to be 1.01 × 10-20 cm2 at extraction wavelength 1005 nm. lifetime 2F5/2 level decreases 1.04 ms 0.28...
The transient state of excitation and relaxation processes in materials under shock compression can be investigated by coupling the laser driven facility with Raman spectroscopy. For this purpose, a time resolved spectroscopy setup has been developed to monitor physical chemical changes such as phase transitions, reactions, molecular kinetics etc., nanosecond resolution. This system consist mainly three parts, 2 J/8 ns Nd:YAG used for generation pump probe beams, spectrometer temporal...
The microscopic and dynamic response of the atactic polystyrene molecules under shock compression at laser power density 4.9 GW/cm 2 was studied using time‐resolved Raman spectroscopy. pressure estimated in sample GPa, temporal wavenumber resolutions these experiments were 3 ns cm −1 , respectively. shocked showed a blue shift 5 7 for 1004 (C―C―C ring bending mode ν 12 ) 1606 (C―C stretching . changes modes are observed with respect to wave propagation. It is that intensities peaks decrease...
Advancements in laser glass compositions and manufacturing techniques has allowed the development of a new category high-energy high-power systems which are being used various applications, such as for fundamental research, material processing inertial confinement fusion (ICF) technologies research. A ceramic is remarkable revolution solid state lasers. It exhibits crystalline properties, high yields, better thermal conductivity, uniformly broadened emission cross-section, higher mechanical...
Enhancement in x-ray emission from laser plasmas produced an alloy of gold and copper (Au 0.43+Cu 0.57 atomic composition) has been observed a narrow spectral region 1.5–3.9Å. X-ray is to be as high six nine times compared pure 1.5 1.8 targets. In these experiments, single pulse Nd:glass (λ=1.06μm) having energy up 2J 500ps duration was used obtain focused intensity 1013–1014W∕cm2 on the The results are explained basis enhanced group Rosseland opacity (Rosseland mean over range under...