A. L. Thakur
A5018481875- Magnetic confinement fusion research
- Gamma-ray bursts and supernovae
- Particle accelerators and beam dynamics
- Astrophysical Phenomena and Observations
- Pulsars and Gravitational Waves Research
- Particle Detector Development and Performance
- Superconducting Materials and Applications
- Plasma Diagnostics and Applications
- Astronomy and Astrophysical Research
- Nuclear Physics and Applications
- Astrophysics and Star Formation Studies
- Atmospheric Ozone and Climate
- Gyrotron and Vacuum Electronics Research
- Microbial Applications in Construction Materials
- Stellar, planetary, and galactic studies
- Quantum Mechanics and Applications
- Quantum Information and Cryptography
- Methane Hydrates and Related Phenomena
- Adaptive optics and wavefront sensing
- Astronomical Observations and Instrumentation
- Fusion materials and technologies
- Advanced Measurement and Metrology Techniques
- Electricity Theft Detection Techniques
- Particle physics theoretical and experimental studies
- Silicon Carbide Semiconductor Technologies
Institute for Plasma Research
2010-2024
Raman Research Institute
2024
University of Rome Tor Vergata
2021-2023
Institute for Space Astrophysics and Planetology
2020-2023
Visva-Bharati University
2021-2023
Abstract The Einstein Probe (EP) is an interdisciplinary mission of time-domain and X-ray astronomy. Equipped with a wide-field lobster-eye focusing imager, EP will discover cosmic transients monitor the variability known sources in 0.5–4 keV, at combination detecting sensitivity cadence that not accessible to previous current monitoring missions. can perform quick characterisation or outbursts Wolter-I telescope onboard. In this paper, science objectives are presented. expected enlarge...
We report on our observing campaign of the compact binary merger GW190814, detected by Advanced LIGO and Virgo detectors August 14th, 2019. This signal has best localisation any observed gravitational wave (GW) source, with a 90% probability area 18.5 deg$^2$, an estimated distance ~ 240 Mpc. obtained wide-field observations Deca-Degree Optical Transient Imager (DDOTI) covering 88% down to limiting magnitude $w$ = 19.9 AB. Nearby galaxies within high region were targeted Lowell Discovery...
The detection and follow-up observations of high-redshift (z>6) gamma-ray bursts (GRBs) provide a unique opportunity to explore the properties distant Universe. Unfortunately, they are rather rare, with only dozen them identified so far. We present here discovery GRB second highest spectroscopic redshift measured date, GRB,240218A at z=6.782, broadband analysis its afterglow. Following by high-energy satellites, we obtained multi-epoch multi-wavelength photometric observations, from 68...
The nature of the minute-to-hour long Fast X-ray Transients (FXTs) localised by telescopes such as Chandra, Swift, and XMM-Newton remains mysterious, with numerous models suggested for events. Here, we report multi-wavelength observations EP240315a, a 1600 s transient detected Einstein Probe, showing it to have redshift z=4.859. We measure low column density neutral hydrogen, indicating that event is embedded in low-density environment, further supported direct detection leaking ionising...
A steady state superconducting tokamak (SST-1) has been commissioned after the successful experimental and engineering validations of its critical sub-systems. During 'engineering validation phase' SST-1; cryostat was demonstrated to be leak-tight in all operational scenarios, 80 K thermal shields were uniformly cooled without regions 'thermal runaway hot spots', toroidal field magnets their nominal conditions charged up 1.5 T at major radius. The further assembled SST-1 machine shell a...
Parametric characterization of multiple double layers is done during high pressure glow discharge in a toroidal vessel small aspect ratio. Although (without magnetic field) known to be independent device geometry, but the boundary conditions are conducive plasma growth and eventually occupy volume partially. At higher anode potential, visibly glowing spots on body spatially extended transform into intensely luminous spherical blob structures attached tip positive electrode. Dynamics observed...
Context. Photoionisation is one of the main mechanisms at work in gaseous environment bright astrophysical sources. A great deal information on gas physics, chemistry and kinematics, ionising source itself, can be gathered through optical to X-ray spectroscopy. While several public time equilibrium photoionisation codes are readily available used infer average properties equilibrium, time-evolving models have only very recently started become available. They needed when varies faster than...
Long gamma-ray bursts (GRBs) are believed to originate from core collapse of massive stars. High-redshift GRBs can probe the star formation and reionization history early universe, but their detection remains rare. Here we report a GRB triggered in 0.5--4 keV band by Wide-field X-ray Telescope (WXT) on board Einstein Probe (EP) mission, designated as EP240315a, whose bright peak was also detected Swift Burst Alert Konus-Wind through off-line analyses. At redshift $z=4.859$, EP240315a showed...
Rydberg atoms have highly controllable exotic properties such as strong inter-atomic interaction, high polarizability, and long lifetimes which enabled unprecedented progress in atom-based quantum Technologies. We present a brief review of recent the development technologies using atoms. highlight advances various regimes Information processing, sensing, simulation many-body physics single-photon sources for communications.
The Legacy Survey of Space and Time (LSST) at Vera C. Rubin Observatory is planned to begin in the Fall 2025. LSST survey cadence has been designed via a community-driven process regulated by Cadence Optimization Committee (SCOC), which recommended up 3% observing time carry out Target Opportunity (ToO) observations. Experts from scientific community, personnel, members SCOC were brought together deliver recommendation for implementation ToO program during workshop held March 2024. Four main...
To operate superconducting steadystate tokamak (SST1) for 1000 seconds, lower hybrid current drive (LHCD) system has been designed at a frequency of 3.7 GHz., which would couple 1.0 MW CW microwave power to the shaped plasma. The consists various rf passive components and transmission line, employing from source is transported antenna. During calibration it was observed that losses in line substantial eventually lead less coupled Further anticipated more LH be required advanced operation...
Abstract We report on our observing campaign of the compact binary merger GW190814, detected by Advanced LIGO and Virgo detectors August 14th, 2019. This signal has best localisation any observed gravitational wave (GW) source, with a 90% probability area 18.5 deg 2 , an estimated distance ≈240 Mpc. obtained wide-field observations Deca-Degree Optical Transient Imager (DDOTI) covering 88% down to limiting magnitude w = 19.9 AB. Nearby galaxies within high region were targeted Lowell...
Abstract The steadystate superconducting tokamak (SST1) is aimed to demonstrate long pulse plasma discharges employing non-inductive current drive by means of lower hybrid (LHCD) system. major and minor radius the machine 1.1 m 0.2 m, respectively. LHCD system for SST1 comprises klystrons, each rated 0.5 MW-CW rf power at a frequency 3.7 GHz. grill antenna two rows, row accommodating 32 waveguide elements. Electron cyclotron resonance breakdown assisted Ohmic formed in overcome issues...
Sustainability has been expected in all fields recent years, and civil engineering is no exception. Therefore, it crucial to handle sustainability carefully. Subsequently, research on self-healing materials concrete increasingly focused this concern. When a crack the occurs, can repair it. A portion of damage induced by mechanical loads (pores, microcracks, etc.) be recovered these materials, which belong superfamily “smart materials.” The crystalline additive current investigation induces...
SST-1 Tokamak has recently completed the 1st phase of up-gradation with successful installation and integration all its First Wall components. The comprises ∼ 3800 high heat flux compatible graphite tiles being assembled installed on 132 CuCrZr sink back plates engraved 4 km leak tight baking cooling channels in five major sub groups equipped 400 sensors weighing 6000 kg total thirteen isolated galvanic six hydraulic circuits. phase-1 spectrum also includes addition Supersonic Molecular Beam...
Photoionisation is one of the main mechanisms at work in gaseous environment bright astrophysical sources. Many information on gas physics, chemistry and kinematics, as well ionising source itself, can be gathered through optical to X-ray spectroscopy. While several public time equilibrium photoionisation codes are readily available used infer average properties equilibrium, time-evolving models have only very recently started become available. They needed when varies faster than typical...
The experiments at the Large Hadron Collider are upgrading their detectors for coming High Luminosity run. Powering on board electronics of highly segmented tracking is a challenge because stringent requirements location, space constraint, fine segmentation, radiation and magnetic field tolerance, thermal loss, etc. Similar issues will be relevant future colliding beam experiments, also. This paper reports early studies Low Voltage Power Supply upgrade Outer Tracker detector Compact Muon...
A 2.0 MW CW lower hybrid current drive (LHCD) system based on 3.7 GHz klystron sources, is in advanced stage of commissioning, which would and sustain plasma current, non-inductively, superconducting steadystate tokamak (SST1) for long pulse operation. Four klystrons, each rated 0.5 rf power, delivers power to four layer the LHCD system, finally feeds grill antenna. The antenna along with vacuum window transmission line successfully integrated machine. Its pressurization compatibility has...
A Regulated High Voltage Power Supply (RHVPS) and its results are presented for initial integration operation with LHCD system. Experimental shown to show the ability of RHVPS as a practical source electrical power LHCD. Klystron is operated at 3.7 GHz. continuous wave (CW) RF level 500 kW various subsystems. has proven capability feeding klystron safe good required quality. Up 65 kV load current in excess 18 was imparted trapezoidal pulse voltage. Repeatability by successive shot results....
Abstract Supplying power at low voltage to the front-end electronics of very fast and highly segmented detectors, typical in experiments Large Hadron Collider, involves several issues, including transient currents voltages. This study investigates a chain that long cables, DC-DC converters, input filters. Due presence common ground close converter, can run with lower value supply. It is seen capacitor filter plays significant role process growth converter. The effects ramp during turning ON...
To drive plasma current non-inductively in ADITYA tokamak, 120 kW pulsed Lower Hybrid Current Drive (LHCD) system at 3.7 GHz has been designed, fabricated and installed on tokamak. In this system, the antenna consists of a grill structure, having two rows, each row comprising four sub-waveguides. The coupling LHCD power to strongly depends density near mouth antenna. Thus be precisely positioned for efficient coupling. movement mechanical bellow, which contracts or expands up 50mm, governs