A5002911272- Magnetic confinement fusion research
- Plasma Diagnostics and Applications
- Particle accelerators and beam dynamics
- Dust and Plasma Wave Phenomena
- Superconducting Materials and Applications
- Ionosphere and magnetosphere dynamics
- Nuclear Physics and Applications
- Quantum, superfluid, helium dynamics
- Electrohydrodynamics and Fluid Dynamics
- Fusion materials and technologies
- Atomic and Molecular Physics
- Laser-induced spectroscopy and plasma
- Vacuum and Plasma Arcs
- Particle Accelerators and Free-Electron Lasers
- Plasma Applications and Diagnostics
- Atomic and Subatomic Physics Research
- Electromagnetic Launch and Propulsion Technology
- Theoretical and Computational Physics
- Magnetic Field Sensors Techniques
- Solar and Space Plasma Dynamics
- Radioactive contamination and transfer
- Nuclear physics research studies
- Lightning and Electromagnetic Phenomena
- Metal and Thin Film Mechanics
- Diamond and Carbon-based Materials Research
National Institute of Technology Agartala
2011-2023
Forschungszentrum Jülich
2009-2011
Ghent University Hospital
2010
Institute for Plasma Research
2005-2009
ITER as a superconducting fusion machine needs efficient wall conditioning techniques for application in the presence of permanent high toroidal magnetic field (i) reducing in-vessel impurity content, (ii) controlling surface hydrogen isotopic ratio and (iii) mitigating long-term tritium inventory build-up. Encouraging results recently obtained with ion-cyclotron (ICWC) present-day tokamaks stellarators have raised ICWC to status one most promising available routine inter-pulse overnight...
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...
Potential double layers are observed to form as nested cylindrical sheaths that energize charge particles in the absence of any externally applied magnetic field. These visibly glowing named “Fire Tube” present work. Sheaths, unmagnetized collisionless plasmas, have been be functional generating energetic particles. Two characteristically different plasma sources compared terms dependence potential and density profiles on sheath formations near source boundary. The structures, complex fire...
Intensely luminous double layers develop and then expand in size a visibly glowing RF discharge produced using plasma source consisting of semi-transparent cylindrical mesh with central electrode, linear chamber. Although is known to be independent device geometry the absence magnetic field, initiation such results electron drift further expansion vessel. The dynamics complex structures are studied through electric probe diagnostics expanding plasma. measurements made study parametric...
Helicon breakdown in a toroidal vessel is observed with right helical antenna (m=+1) at frequency of 32MHz. A magnetic field 1kG (max) applied the central axis aspect ratio equal to 3. During experiments, transition from sustained helicon wave discharge also observed. Nonlinear increase plasma density input rf power and However, profiles measured this experiment are different earlier experiments conducted similar configurations.
Helicon waves are launched in a toroidal device of small aspect ratio, to form and sustain high-density plasma with 1018m−3 peak density 12eV electron temperature. Owing the strong poloidal asymmetry wave magnetic field structures, nonresonant current is driven by dynamo electric field, which arises due helicity injection helicon waves. A study parametric dependence electron-magnetohydrodynamic regime, at very high frequency, along numerical estimations components, presented here. The...
Low-frequency sheath oscillations, initiated by the sheath-plasma instability, are observed in connection with complex structure formations expanding radio frequency (RF) plasma generation. The temporal variations of floating potential during double layer formations, measured using electric and magnetic probe diagnostics, suggest significant role instability charged particle dynamics present operational regime. burst oscillations occur due to field associated high-gradient source geometry,...
Helicity in the dynamo field components of helicon wave is examined during novel study induced helicity current drive. Strong poloidal asymmetry magnetic observed discharges formed a toroidal vacuum chamber small aspect ratio. High frequency regime chosen to increase phase velocity waves which turn minimizes resonant wave-particle interactions and enhances contribution nonresonant drive mechanisms. Owing strong structures, plasma driven mostly by dynamo-electric-field, arise due injection...
Low magnitude plasma current measurements by conventional Rogowski coils are susceptible to error induced electrostatic pickup in a radio frequency (RF) environment. This paper highlights and provides remedy for the various sources of errors encountered low performed with traditional coil designs. A comparative study most commonly used designs is done respect their capacitive rejection, simple technique developed measure less than 50 A, minimum possible error, our experimental conditions. In...
We report on the self-organization of multiple double layers (MDLs) and self-organized criticality (SOC) behavior through subsequent layer reduction process around anode during DC glow discharge in a linear cylindrical vacuum vessel. The present study provides an insight into characteristic features MDLs itself effect external magnetic field its evolution. MDL formations initiate abrupt jump floating potential, ion saturation, current signals, which suggests associated sheath—plasma...
Experimental investigations of a hollow cathode discharge through the controlled variation anode potential inside cylindrical cavity, in absence and presence magnetic field, reveal self-organization uniform complex space charge structure formation around spherical into concentrated localized spots. The current–voltage (<inline-formula> <tex-math notation="LaTeX">$I$ </tex-math></inline-formula>–<inline-formula> notation="LaTeX">$V$ </tex-math></inline-formula>) characteristic...
Ion Cyclotron Wall Conditioning (ICWC) discharges, in pulsed‐mode operation, were carried out TEXTOR to simulate a scenario of ITER wall conditioning at half‐field. The ICWC discharges performed continuous Helium flow with adjunction molecular Hydrogen, puffed after the ICRF ignition thus achieving better antenna coupling Mode Conversion improved performance. Reproducible generation plasmas and reliable conditioning, proper preloading Deuterium glow, achieved by RF power 29 MHz from one or...
ITER and future superconducting fusion machines need efficient wall conditioning techniques for routine operation in between shots the presence of permanent high magnetic field cleaning, surface isotope exchange to control in‐vessel long term tritium retention. Ion Cyclotron Wall Conditioning (ICWC) based on ICRF discharge is fully compatible needs field. The present paper focuses principal aspects ICWC performance large‐size machines: (i) neutral gas RF breakdown with conventional heating...
Abstract Multiple luminous sheath structures develop in the localised plasma formation inside a cylindrical gridded cathode source. These gradually expand into whole vessel and undergo critical state through self‐organised criticality (SOC) along with pronounced oscillations during variation of anode potential. The present investigation emphasises stability properties associated potential cylindrical‐gridded glow discharge regime SOC phenomena non‐linear time series analysis. temporal...
Abstract Wave magnetic field components are measured across the radius (−10 cm ≤ r 10 cm) for a low-pressure (0.3 mbar) helicon discharge, in toroidal vacuum chamber of small aspect ratio. Radial variation wave components, during mode exhibit strong poloidal asymmetry which contribute significantly to wave-induced helicity. The rise magnitude radial electric with radiofrequency power, observed discharge transition, supports better confinement plasma discharge. dependence current on has been...