A5007411452- Laser-Plasma Interactions and Diagnostics
- Laser-Matter Interactions and Applications
- Laser-induced spectroscopy and plasma
- Advanced X-ray Imaging Techniques
- Laser Material Processing Techniques
- X-ray Spectroscopy and Fluorescence Analysis
- High-pressure geophysics and materials
- Organic and Molecular Conductors Research
- Ga2O3 and related materials
- Advanced Surface Polishing Techniques
- Inorganic Chemistry and Materials
- Iron-based superconductors research
- Particle accelerators and beam dynamics
- Semiconductor materials and devices
- Atomic and Molecular Physics
- Photonic and Optical Devices
- Strong Light-Matter Interactions
- Nanowire Synthesis and Applications
- Ion-surface interactions and analysis
- Molecular Junctions and Nanostructures
- Electron and X-Ray Spectroscopy Techniques
- Photocathodes and Microchannel Plates
Homi Bhabha National Institute
2019-2023
Raja Ramanna Centre for Advanced Technology
2013-2023
Abstract K α X-ray sources generated from the interaction of ultra-short laser pulses with solids are compact and low-cost source quasi-monochromatic X-rays compared synchrotron radiation source. Development collimated by 45 fs Ti:sapphire pulse Cu wire target is presented in this paper. A study parameters such as energy duration was carried out. The observed photon flux ~2.7 × 10 8 photons/shot at intensity ~2.8 17 W cm −2 . model developed to analyze results. coupled a polycapillary...
Charge density wave (CDW) induces periodic spatial modulation of the charge that is commensurate or incommensurate with host lattice periodicity, and leads to partial complete electronic band-gap opening at Fermi level (${E}_{\mathrm{F}}$). The recent finding unconventional hysteresis within CDW phase ${\mathrm{EuTe}}_{4}$, not observable in other rare-earth tellurides $R{\mathrm{Te}}_{n}$ ($n=2$, 3), has highlighted role relative distortion weakly coupled Te layers. However, detailed...
High-quality, stable electron beams are produced from self-injected laser wakefield acceleration using the interaction of moderate 3 TW, 45 fs duration Ti:sapphire pulses with high density ($>5\ifmmode\times\else\texttimes\fi{}{10}^{19}\text{ }\text{ }{\mathrm{cm}}^{\ensuremath{-}3}$) helium gas jet plasma. The beam has virtually background-free quasimonoenergetic distribution energy ${35.6}_{\ensuremath{-}2.5}^{+3.9}\text{ }\mathrm{MeV}$, charge ${3.8}_{\ensuremath{-}1.2}^{+2.8}\text{...
Generation of highly collimated (θdiv ∼10 mrad), quasi-monoenergetic electron beam with peak energy 12 MeV and charge ∼50 pC has been experimentally demonstrated from self-guided laser wake-field acceleration (LWFA) in a plasma plume produced by ablation solid nylon (C12H22N2O2)n target. A 7 TW, 45 fs Ti:sapphire system was used for LWFA, the forming pulse derived Nd:YAG pump same system. The results show that reproducible, high quality could be this scheme which is simple, low cost...
Development and characterization of a wire target based kHz rep rate Cu Kα x-ray source using Ti:sapphire laser system its use in time resolved diffraction (TXRD) the InSb (111) sample are presented. The observed photon flux is ∼3.2 × 109 photons sr−1 s−1 at intensity ∼3.5 1016 W cm−2. TXRD signal from crystal pumped by an ultrashort pulse (fluence ∼ 13 mJ cm−2) shows lattice expansion due to heating on multipicosecond scale. gradually cools down recovers ∼1.5 ns after excitation. strain...
Amplitude mode is collective excitation emerging from frozen lattice distortions below the charge-density-wave (CDW) transition temperature T CDW and relates to order parameter. Generally, amplitude non-polar (symmetry-even) does not interact with incoming infrared photons. However, if polar (symmetry-odd), it can potentially couple photons, thus forming a coupled phonon–polariton quasiparticle that travel light-like speed beyond optically excited region. Here, we present dynamics far depth...
Ultra-short laser-pulse-induced strain propagation in a Ge crystal is studied the [111] and [100] directions using time-resolved X-ray diffraction (TXRD). The velocity derived by analysis of TXRD signal from strained planes. Numerical integration Takagi–Taupin equations performed open source code, which provides very simple approach to estimate velocity. present method will be particularly useful for relatively broad spectral bandwidths weak sources, where temporal oscillations diffracted...
This article presents some of the recent experimental studies in ultra-high intensity laser-matter interaction, carried out at Raja Ramanna Centre for Advanced Technology, India, laser intensities ∼3×10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">18</sup> and ∼5×10 xmlns:xlink="http://www.w3.org/1999/xlink">19</sup> W/cm xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> , using 10TW 150 TW Ti:sapphire systems.
The effect of laser beam aperturing (Ti: sapphire laser; 800 nm, 45 fs) on the conversion efficiency (CE), harmonic yield and spatial coherence high order harmonics generated from a low excited plasma plume carbon (neutral singly charged ions) is studied. optimization CE by varying aperture size in combination with different parameters was carried out. 15th enhanced ~10−7 for an unapertured to ~10−6 ~¼ times diameter, at same energy both cases. Further, it found that, given size, there...
Understanding ultrafast response of a semiconductor is necessary for next-generation optoelectronic device applications. Here, we investigate the an archetypal Ge [111] crystal upon photoexcitation at two pump wavelengths, 800 nm (fundamental) and 400 (second harmonic, UV radiation), using time-resolved x-ray diffraction (TXRD). The simulated TXRD profiles proposed four-layer model Takagi–Taupin equations reveal that strain propagation primarily due to electron diffusion. Intriguingly,...