A5006849902- Magnetic confinement fusion research
- Particle physics theoretical and experimental studies
- Particle accelerators and beam dynamics
- High-Energy Particle Collisions Research
- Quantum Chromodynamics and Particle Interactions
- Fusion materials and technologies
- Superconducting Materials and Applications
- Laser-Plasma Interactions and Diagnostics
- Ionosphere and magnetosphere dynamics
- Gyrotron and Vacuum Electronics Research
- Plasma Diagnostics and Applications
- Dark Matter and Cosmic Phenomena
- Solar and Space Plasma Dynamics
- Oil and Gas Production Techniques
- Particle Accelerators and Free-Electron Lasers
- Nuclear Materials and Properties
- Cosmology and Gravitation Theories
- Computational Physics and Python Applications
- Laser-induced spectroscopy and plasma
- Medical Imaging Techniques and Applications
- Nuclear reactor physics and engineering
- Cyclone Separators and Fluid Dynamics
- Radioactivity and Radon Measurements
- Fluid Dynamics and Turbulent Flows
- GNSS positioning and interference
Institute for Plasma Research
2010-2024
Abu Dhabi National Oil (United Arab Emirates)
2022
Aurel Vlaicu University of Arad
2022
Sikkim Manipal University
2022
East Asia School of Theology
2022
Universitat Politècnica de Catalunya
2022
GIET University
2022
Kyushu University
2014-2019
John Wiley & Sons (United States)
2019
Linde (United States)
2019
Fully non-inductive second (2nd) harmonic electron cyclotron (EC) plasma current ramp-up was demonstrated with a newlly developed 28 GHz system in the QUEST spherical tokamak. A high of 54 kA non-inductively ramped up and sustained stably for 0.9 s 270 kW wave. higher 66 also achieved slow vertical field. We have significantly than those previously 2nd EC waves. This fully method might be useful future burning devices fusion reactors, particular operations at half magnetic field same heating...
A 28~GHz system with a high-power gyrotron tube has been used for the QUEST spherical tokamak to form an over-dense plasma electron Bernstein wave heating (EBWH) and current drive 8.2~GHz-wave. Non-inductive high-density ramp-up experiments dual-frequency (dual$-f$) cyclotron (EC) [ 8.2~GHz ] waves were conducted. spontaneous density jump (SDJ) state was observed as bifurcation phenomenon in dual$-f$ experiment. The on 8.2~GHz-wave non-inductively ramped up 25~kA, maintained 0.4~s under...
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...
Successful production of high βp plasmas (εβp ⩾ 1) fully non-inductively (NI) and their long pulse sustainment with the help modest power (<100 kW) electron cyclotron waves is demonstrated. High are found for first time to be naturally self organized form a stable natural inboard poloidal field null (IPN) equilibrium. A critical value identified, which defines transition boundary from limiter (IL) IPN new feature plasma organization evidenced, enhances its negative triangular shape sustain...
Measurements of diamagnetic flux in Aditya tokamak for different discharge conditions are reported the first time. The measured a typical is less than 0.6 mWb and therefore it has required careful compensation various kinds pick-ups. hardware software compensations employed this measurement described. We introduce pick-up due to plasma current 20 kA short duration discharges, which pressure gradient supposed be negligible. during radio frequency heating also presented order validate compensation.
An orthogonal dynamic programming (ODP) based particle image velocimetry (PIV) technique is developed to measure the time resolved flow field of fluctuating structures at plasma edge and scrape off layer (SOL) tokamaks. This non-intrusive can provide two dimensional velocity fields high spatial temporal resolution from a fast framing sequence hence better insights into as compared conventional probe measurements. Applicability tested with simulated pairs. Finally, it applied tangential...
Statistical features of fluctuations are investigated using the fast camera imaging technique in scrape layer (SOL) electron cyclotron resonance heated Ohmic plasma. Fluctuations SOL towards low field side dominated by coherent convective structures (blobs). Two dimensional higher order moments (skewness s and kurtosis k) representing shape probability density function (PDF) studied. k seen to be functions magnetic lines. consistently bottom half vessel showing blob trajectory along lines...
Fusion energy development is quite successful in both getting equivalent breakevencondition large tokamak and clarifying many important physics the magnetically confinedplasma to proceed a fusion experimental reactor, ITER. Now, research has solvethe power handling toward demonstration reactor (DEMO). A plasma withstrongly negative triangularity may oer such an opportunity as innovative concept. Experimentaland theoretical works at CRPP-EPFL shows promising results for tokamak. In this...
A thermal imaging system to measure plasma Electron Bernstein Emission (EBE) emanating from the mode conversion region in overdense is discussed. Unlike conventional ECE/EBE imaging, this diagnostics does not employ any active mechanical scanning mirrors or focusing optics scan for emission cones plasma. Instead, a standard 3 × waveguide array antenna used as passive receiver collect and reconstruction done by accurate measurements of phase intensity these signals heterodyne detection...
Second harmonic heating experiments using fast waves are carried out on the Aditya tokamak in ion cyclotron resonance frequency (ICRF) range with help of a 200 kW, 20–40 MHz RF system, which is developed indigenously. Significant direct electron observed hydrogen plasma. The rise temperature prompt application power and increment increases linearly power. A corresponding increase plasma beta hence an stored diamagnetic energy also presence low-Z impurity radiation density do not...
In order to understand the atomic hydrogen distribution in different kinds of plasma and its influence on recycling, two plasmas were used: non-confined annular electron cyclotron resonance (ECR) confined long duration plasmas. The permeation probes are used measure directly flux at several poloidal positions. through metals due ion atom component wall is indistinguishable. To estimate contribution ions directly, Langmuir used. Гinc profile behind facing components (PFCs) almost constant, ∼2...
A Phased Array Antenna (PAA) was considered as launching and receiving antennae in reflectometry to attain good directivity its applied microwave range. well-focused beam obtained a antenna application, differential-phase evolution properly measured by using metal reflector plate the proof-of-principle experiment at low power test facilities. Differential-phase also evaluated PAA Q-shu University Experiment with Steady State Spherical Tokamak (QUEST). beam-forming technique phased-array...
High βp (εβp ∼ 1) equilibria obtained in a ECW heated Ohmic plasma is investigated using simple analytic solution of Grad-Shafranov equation. The formation natural inboard poloidal null associated with high explained consistently by diamagnetism and negative triangularity. As increased, the point penetrates further into vacuum vessel, which qualitatively model. Transition from (high field side) limiter bound to divertor configuration reduction edge safety factor without appreciable...
Spontaneous toroidal rotation of the plasma is observed in spherical tokamak QUEST with help electron cyclotron resonance (ECR) heating and without use any externally injected momentum. Several vertical magnetic field (B <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">z</sub> ) configurations varying mirror ratio (M) (a measure curvature) are applied evolution studied Doppler spectroscopy bulk impurity ions. Significant (V...
Heat flux and plasma flow in the scrape-off layer (SOL) are examined for inboard poloidal field null (IPN) configuration of spherical tokamak QUEST. In current (Ip) ramp-up phase, high heat (&gt;1 MW/m2) supersonic (Mach number M &gt; 1) found to be present simultaneously far-SOL. The is generated by energetic electrons excursed from last closed surface. Supersonic flows toroidal directions correlated with each other. quasi-steady state, sawtooth-like oscillation Ip at 20 Hz...