A5079585594- Atomic and Molecular Physics
- Advanced X-ray Imaging Techniques
- Advanced Chemical Physics Studies
- Laser-Matter Interactions and Applications
- X-ray Spectroscopy and Fluorescence Analysis
- Mass Spectrometry Techniques and Applications
- Advanced Electron Microscopy Techniques and Applications
- Electron and X-Ray Spectroscopy Techniques
- Laser-Plasma Interactions and Diagnostics
- Luminescence and Fluorescent Materials
- Molecular Sensors and Ion Detection
- Geochemistry and Geologic Mapping
- Ion-surface interactions and analysis
- Laser-induced spectroscopy and plasma
- Geophysical and Geoelectrical Methods
- Remote-Sensing Image Classification
- Particle Accelerators and Free-Electron Lasers
- Analytical Chemistry and Sensors
- earthquake and tectonic studies
- Photocathodes and Microchannel Plates
- Inorganic Fluorides and Related Compounds
- Crystallization and Solubility Studies
- X-ray Diffraction in Crystallography
- Laser Design and Applications
- Seismic Waves and Analysis
Haldia Institute of Technology
2024
Tohoku University
2013-2023
Indian Institute of Technology Dhanbad
2018-2022
Central Council for Research in Ayurvedic Science
2021
University of Kalyani
2017-2020
Indian Space Research Organisation
2019
National Remote Sensing Centre
2019
Sendai University
2016
Advanced Institute of Materials Science
2015
Saha Institute of Nuclear Physics
2012
The lifetime of interatomic Coulombic decay (ICD) [L. S. Cederbaum et al., Phys. Rev. Lett. 79, 4778 (1997)] in ${\mathrm{Ne}}_{2}$ is determined via an extreme ultraviolet pump-probe experiment at the Free-Electron Laser Hamburg. pump pulse creates a $2s$ inner-shell vacancy one two Ne atoms, whereupon ionized dimer undergoes ICD resulting repulsive ${\mathrm{Ne}}^{+}(2{p}^{\ensuremath{-}1})\ensuremath{-}{\mathrm{Ne}}^{+}(2{p}^{\ensuremath{-}1})$ state, which probed with second pulse,...
We have investigated multiphoton multiple ionization dynamics of xenon atoms using a new x-ray free-electron laser facility, SPring-8 Angstrom Compact free electron LAser (SACLA) in Japan, and identified that Xen+ with n up to 26 is produced at photon energy 5.5 keV. The observed high charge states (n≥24) are via five-photon absorption, evidencing the occurrence absorption involving deep inner shells. A newly developed theoretical model, which shows good agreement experiment, elucidates...
When exposed to ultraintense x-radiation sources such as free electron lasers (FELs) the innermost electronic shell can efficiently be emptied, creating a transient hollow atom or molecule. Understanding femtosecond dynamics of systems is fundamental achieving atomic resolution in flash diffraction imaging noncrystallized complex biological samples. We demonstrate capacity correlation method called "partial covariance mapping" probe neon atoms intense 8 fs pulses 1062 eV photons. A complete...
Abstract Using electron spectroscopy, we have investigated nanoplasma formation from noble gas clusters exposed to high-intensity hard-x-ray pulses at ~5 keV. Our experiment was carried out the SPring-8 Angstrom Compact free LAser (SACLA) facility in Japan. Dedicated theoretical simulations were performed with molecular dynamics tool XMDYN. We found that this unprecedented wavelength regime is a highly indirect process. In argon investigated, mainly formed through secondary cascading...
In recent years, free-electron lasers operating in the true X-ray regime have opened up access to femtosecond-scale dynamics induced by deep inner-shell ionization. We investigated charge creation and transfer context of molecular Coulomb explosion a single molecule, exposed sequential ionization within an ultrashort (10 fs) pulse. The target molecule was CH3I, methane sensitized X-rays halogenization with heavy element, iodine. Time-of-flight ion spectroscopy coincident analysis employed...
We have investigated multiphoton multiple ionization of argon and xenon atoms at 5 keV using a new x-ray free electron laser (XFEL) facility, the SPring-8 Angstrom Compact LAser (SACLA) in Japan. The experimental results are compared with theoretical presented here. absolute fluence XFEL pulse has been determined help calculations utilizing two-photon processes atom. high charge states up to +22 observed for Xe comparison point occurrence sequential L-shell absorption resonance-enabled ionization.
The Kaliguman Shear Zone (KSZ) in northwestern India marks the boundary between South Delhi Fold Belt to west and Aravalli east. Structural analysis reveals a narrow, high-strain zone characterized by development of mica schist along this boundary. principal structural orientation trends NE-SW direction. Strain indicates that rocks formed under transpressional deformation conditions.The metamorphic history KSZ is well-preserved schists, which predominantly contain garnet staurolite....
We report unambiguous experimental and theoretical evidence of intramolecular photoelectron diffraction in the collective vibrational excitation that accompanies high-energy photoionization gas-phase CF4, BF3, CH4 from 1s orbital central atom. show ratios between vibrationally resolved cross sections (v-ratios) exhibit pronounced oscillations as a function photon energy, which is fingerprint electron by surrounding atomic centers. This interpretation supported excellent agreement...
We report an experimental and theoretical study of single-molecule inner-shell photoemission measured over extended range photon energies. The vibrational intensity ratios $I(\ensuremath{\nu}=1)/I(\ensuremath{\nu}=0)$ from the C $1s$ photoelectron spectra carbon monoxide, although mostly determined by bond length change upon ionization, are shown to be affected also recoil scattering neighboring oxygen atom. Static-exchange density functional theory (DFT) is used encompass all these effects...
We report on a detailed investigation into the electron emission processes of Ne atoms exposed to intense femtosecond x-ray pulses, provided by Linac Coherent Light Source Free Electron Laser (FEL) at Stanford. The covariance mapping technique is applied analyse data, and capability this approach disentangle both linear nonlinear correlation features which may be hidden coincidence maps same data set demonstrated. Different correction techniques enable improvements quality spectral extracted...
The hitherto unexplored two-photon doubly excited states [Ne^{*}(2p^{-1}3s)]_{2} were experimentally identified using the seeded, fully coherent, intense extreme ultraviolet free-electron laser FERMI. These undergo ultrafast interatomic Coulombic decay (ICD), which predominantly produces singly ionized dimers. In order to obtain rate of ICD, resulting yield Ne_{2}^{+} ions was recorded as a function delay between pump and UV probe pulses. extracted lifetimes long-lived states, 390(-130/+450)...
Abstract In high-intensity laser light, matter can be ionized by direct multiphoton absorption even at photon energies below the ionization threshold. However on tuning to lowest resonant transition, system becomes multiply excited, and more efficient, indirect pathways become operative. These mechanisms are known as interatomic Coulombic decay (ICD), where one of species de-excites its ground state, transferring energy ionize another excited species. Here we show that a higher previously...
We have investigated interatomic Coulombic decay (ICD) after resonant Auger in Ar2, ArKr, and ArXe following 2p3/2 → 4s 3d excitations Ar, using momentum-resolved electron-ion-ion coincidence. The results illustrate that ICD induced by the is a well-controlled way of producing energy-selected slow electrons at specific site.
Intense X-ray free electron laser pulses can completely obliterate molecules, but the process also sheds light on energetic ions that are created. Researchers experimentally and theoretically investigate how 5-iodouacil responds to x-ray radiation.
Few-photon ionization and relaxation processes in acetylene (C2H2) ethane (C2H6) were investigated at the linac coherent light source x-ray free electron laser (FEL) SLAC, Stanford using a highly efficient multi-particle correlation spectroscopy technique based on magnetic bottle. The analysis method of covariance mapping has been applied enhanced, allowing us to identify pairs associated with double core hole (DCH) production competing multiple including Auger decay sequences. experimental...
We studied the electronic and nuclear dynamics of I-containing organic molecules induced by intense hard X-ray pulses at XFEL facility SACLA in Japan. The interaction with pulse causes absorption multiple photons iodine atom, which results creation many vacancies (positive charges) <italic>via</italic> sequential relaxation iodine, followed intramolecular charge redistribution. In a previous study we investigated subsequent fragmentation Coulomb explosion simplest I-substituted hydrocarbon,...
We identified interatomic Coulombic decay (ICD) channels in argon dimers after spectator-type resonant Auger $2{p}^{\ensuremath{-}1}3d\ensuremath{\rightarrow}3{p}^{\ensuremath{-}2}3d,4d$ one of the atoms, using momentum-resolved electron-ion-ion coincidence. The results illustrate that core excitation is a very efficient way producing slow electrons at specific site, which may cause localized radiation damage. find also ICD rate for $3{p}^{\ensuremath{-}2}4d$ significantly lower than...
Chromenone-rhodamine conjugate 1 has been synthesized and its metal ion binding properties have studied in CH3CN/water (3:1, v/v; 10 mM HEPES buffer; pH = 6.85). Compound senses multiple ions such as Al3+ Hg2+ by exhibiting turn on fluorescence color change (colorless to pink). distinguished with the aid of tetrabutylammonium iodide (TBAI). While presence I− pink 1.Hg2+ complex was completely discharged; under identical conditions 1.Al3+ retained.
Ne clusters (∼5000 atoms) were resonantly excited (2p→3s) by intense free electron laser (FEL) radiation at FERMI. Such multiply can decay nonradiatively via energy exchange between least two neighboring atoms. Benefiting from the precise tunability and narrow bandwidth of seeded FEL radiation, specific sites probed. We found that relaxation cluster surface atoms proceeds a sequence interatomic or intermolecular Coulombic (ICD) processes while ICD bulk is additionally affected surrounding...
Abstract The increasing availability of X-ray free-electron lasers (XFELs) has catalyzed the development single-object structural determination and dynamics tracking in real-time. Disentangling molecular-level reactions triggered by interaction with an XFEL pulse is a fundamental step towards developing such applications. Here we report real-time observations XFEL-induced electronic decay via short-lived transient states diiodomethane molecule, using femtosecond near-infrared probe laser. We...
In this article, we discuss the potential of airborne hyperspectral data in mapping host rocks mineral deposits and surface signatures mineralization using AVIRIS-NG a few important geological provinces India.We present initial results from study sites covering parts northwest India, as well Sittampundi Layered Complex (SLC) Tamil Nadu Wajrakarur Kimberlite Field (WKF) Andhra Pradesh southern India.Modified spectral summary parameters, originally designed for MRO-CRISM analysis, have been...
We present a combined analysis of remote sensing, gravity and magnetic data across Moyar Bhavani Shear Zone (MBSZ), Southern Granulite Terrane (SGT), India to study crustal architecture tectonics. The horizontal gradient shows strong density inhomogeneity the MBSZ. residual corroboration NE–SW trending linear anomaly zone high strip along low anomalies dominate northern part MBSZ, while southern is dominated by moderate anomalies. integration potential sensing clearly reveals that ENE–WSW...