A5063619759- Magnetic confinement fusion research
- Fusion materials and technologies
- Superconducting Materials and Applications
- Particle accelerators and beam dynamics
- Ionosphere and magnetosphere dynamics
- Laser-Plasma Interactions and Diagnostics
- Nuclear Materials and Properties
- Nuclear Engineering Thermal-Hydraulics
- Power System Optimization and Stability
- Plasma Diagnostics and Applications
- Solar and Space Plasma Dynamics
- Japanese History and Culture
- Smart Grid Security and Resilience
- Atomic and Subatomic Physics Research
- Scientific Measurement and Uncertainty Evaluation
- Magnetic Field Sensors Techniques
- Viral Infections and Vectors
- Target Tracking and Data Fusion in Sensor Networks
- Refrigeration and Air Conditioning Technologies
- Acoustic Wave Phenomena Research
- Metallurgical Processes and Thermodynamics
- Nuclear reactor physics and engineering
- Vehicle Noise and Vibration Control
- Advanced Measurement and Metrology Techniques
Max Planck Institute for Plasma Physics
2024
Institute for Plasma Research
2016-2024
Homi Bhabha National Institute
2019-2024
École Polytechnique Fédérale de Lausanne
2021-2022
Pandit Deendayal Petroleum University
2021
Koneru Lakshmaiah Education Foundation
2007
Abstract The Tokamak à Configuration Variable (TCV) tokamak is in the midst of an upgrade to further its capability investigate conventional and alternative divertor configurations. To that end, modular removable gas baffles have been installed decrease coupling between plasma core. primarily seek suppress transit recycling neutrals closed flux surfaces. A first experimental campaign with has shown baffled remains compatible a wide range configurations including snowflake super- X divertors....
Experiments on ADITYA-U tokamak show a marked enhancement in the sawtooth period by application of short gas puffs fuel that cause modification radial density profile. A consequent suppression trapped electron modes (TEMs) then leads to an increase core temperature. This slows down heat propagation following crash, causing delay achieving critical temperature gradient inside q = 1 surface required for next crash happen. The overall scenario has strong similarities with behavior under...
This article reports the development of a versatile high-speed reciprocating drive system (HRDS) with interchangeable probe heads to characterize edge plasma region ADITYA-U tokamak. consisting Langmuir and magnetic heads, is designed, fabricated, installed, operated for studying extent fuel/impurity gas propagation its influence on dynamics in far-edge inside last closed flux surface (LCFS). The HRDS driven by highly accurate, easy-to-control, dynamic, brushless, permanently excited...
The 2-D edge plasma fluid transport code, UEDGE has been used to simulate the region of circular limiter plasmas ADITYA-U for modelling measured electron density profile. geometry introduced in which is primarily developed and divertor configuration. computational mesh defining generated by a routine in-house, successfully integrated with code parameters ADITYA-U. radial profiles scrape-off layer (SOL) density, ne temperature are obtained from simulations model profile using Langmuir probe...
Several experiments, related to controlled thermonuclear fusion research and highly relevant for large size tokamaks, including ITER, have been carried out in ADITYA, an ohmically heated circular limiter tokamak. Repeatable plasma discharges of a maximum current ~160 kA discharge duration beyond ~250 ms with flattop ~140 obtained the first time ADITYA. The reproducibility has improved considerably lithium wall conditioning, are by precisely controlling position plasma. In these discharges,...
The first Indian tokamak, ADITYA, operated for over two decades with a circular poloidal limiter, has been upgraded to tokamak named ADITYA Upgrade (ADITYA-U) attain shaped-plasma operations an open divertor in single and double-null configurations. Experimental research using ADITYA-U made significant progress since the last FEC 2016. After installation of plasma facing component standard diagnostics ADITYA-U, Phase-I were initiated December 2016 graphite toroidal belt limiter. Ohmically...
The Tokamak à Configuration Variable (TCV) has recently been equipped with gas baffles to increase its divertor closure for a broad range of magnetic geometries. First experimental results reported in Reimerdes et al. (2021) demonstrated compatibility geometries and confirmed the main design constraints baffles, particular an increased neutral pressure. present article presents more in-depths analysis extended experiments this first baffle assessment on TCV boundary plasma. It is shown that...
Abstract Since the 2018 IAEA-FEC conference, in addition to expanding parameter horizons of ADITYA-U machine, emphasis has been given dedicated experiments on inductively driven particle injection (IPI) for disruption studies, runaway electron (RE) dynamics and mitigation, plasma rotation reversal, radiative-improved modes using Ne Ar injection, modulation magneto–hydrodynamic modes, edge turbulence periodic gas puffs electrode biasing (E-B). Plasma parameters close design circular plasmas...
Abstract A first-of-its-kind, inductively driven micro-particle (Pellet) accelerator and injector have been developed operated successfully in ADITYA-U circular plasma operations, which may ably address the critical need for a suitable disruption control mechanism ITER future tokamak. The device combines principles of electromagnetic induction, pulse power technology, impact, fracture dynamics. It is designed to operate variety environments, including atmospheric pressure ultra-high vacuum....
An impurity ion toroidal rotation profile has been observed in the ohmic discharges of Aditya-U tokamak from Doppler-shifted passive charge exchange line emission C5+ at 529 nm. The monitored using a space-resolved visible spectroscopy diagnostic consisting 1 m multi-track spectrometer coupled with device (CCD) detector. In typical central chord-averaged electron density ≲2.5 × 1019 m−3, maximum velocity plasma core is found to be −20 km s−1 counter-current direction. Reversal for high ~5...
Abstract Effective control of impurities and precise regulation the fueling gas are supreme prerequisites for optimal operation in any fusion device. Conventional wall-conditioning methods fall short achieving wall conditioning. methods, such as vessel baking H 2 /(D )-fueled glow discharge cleaning (GDC), generally required to remove wall-absorbed bulk after venting. The excess amount hydrogen, injected during GDC, can be reduced by helium (He)-fueled GDC. However, He removal from is more...
Two dimensional interchange turbulence has been used to describe neon gas interaction with tokamak plasma, and is able include anomalous transport effects self-consistently in the edge scrape-off layer (SOL) regions. Model equations related plasma coupled have solved numerically using BOUT++ framework code. different fluid models of investigated, this context a few results Aditya are presented. Numerical indicate that ionization radiative cooling processes modify turbulence. The existence...
Nitrogen seeded detachment has been achieved in the Tokamak a Configuration Variable (TCV) advanced divertor configurations (ADCs), namely X-divertor and X-point target, with without baffles H-mode plasmas high core confinement. Both ADCs show remarkable reduction inter-ELM particle heat fluxes to target compared standard configuration. 95-98% of peak flux is mitigated as synergetic effect ADCs, baffling, nitrogen detachment. The geometry on core-divertor compatibility investigated detail....
Short bursts (1 -2 ms) of gas, injecting ~ 10 17 -10 18 molecules hydrogen as well deuterium, lead to observations phenomena cold pulse propagation in plasmas the ADITYA-U tokamak.After every injection gas-pulse, a sharp increase chord-averaged density followed by an core temperature has been observed.Simultaneously edge and decreases, suggesting due gas-pulse application.It observed that subsequent depend on both value plasma at instant gasinjection amount gas injected up threshold...
In the ADITYA Upgrade tokamak, glow discharge wall conditioning (GDC) is performed regularly during high-temperature plasma operation cycle using hydrogen (H) and helium (He) gases. H GDC carried out after long durations (few hours) of operations on every day in automatic mode to control oxygen (O) carbon (C) containing impurities. This leads high retention gas graphite limiter plates stainless steel (SS) vessel walls. Subsequently, outgassing requires a prolonged pumping time recycling...
The neutral particle temperature in the edge region of Aditya-U tokamak has been measured by recording hydrogen Balmer alpha emission spectra at 656.28 nm from different lines sight both high and low field sides. spatial profile Hα recorded using a 1 m multi-track spectrometer. is estimated Doppler broadening spectrum appropriately removing contribution Zeeman splitting spectral lines. A computer simulation code was developed to estimate including mechanisms such as effect simulate along...
The effect of a periodic train short gas-puff pulses on the rotation frequency and amplitude drift-tearing modes has been studied in ADITYA/ADITYA-U tokamak.The gas puffs, injecting approximately ~10 17 -10 18 molecules fuel (hydrogen) at one toroidal location, are found to concomitantly decrease mode during period injection then recover back its initial values when pulse is over.This leads modulation that correlated with periodicity injection.The underlying mechanism for this change...
Abstract The generation and subsequent loss of runaway electrons (REs) during the operation sequence in a tokamak is potent threat to plasma-facing components interface actively cooled parts. Control mitigation REs are prime importance safe machine health fusion device. A supersonic molecular beam injection (SMBI) system has been installed ADITYA-U explore effects high Mach number on ways mitigate REs. In majority discharges which SMBI injected, burst hard x-rays observed accompanying pulse,...
A diamagnetic diagnostic system is designed, prepared and installed at Aditya Upgrade Tokamak. Also, the raw data acquired in a specified acquisition with suitable front-end electronics. The entire consists of separate loops first calibrated presence all coils, which conduct electricity during plasma discharge. Then, change toroidal magnetic field due to measured using system, hence, several parameters including poloidal beta, stored energy, etc. are estimated. measurements were then...