A5000260488- Magnetic confinement fusion research
- Plasma Diagnostics and Applications
- Semiconductor materials and devices
- Laser-Plasma Interactions and Diagnostics
- Advanced Antenna and Metasurface Technologies
- Fusion materials and technologies
- Advanced Measurement and Metrology Techniques
- Sensor Technology and Measurement Systems
- Antenna Design and Analysis
- Laser-induced spectroscopy and plasma
- Particle accelerators and beam dynamics
- Solar and Space Plasma Dynamics
- Microwave Engineering and Waveguides
- Ionosphere and magnetosphere dynamics
- Advancements in Semiconductor Devices and Circuit Design
- Optical measurement and interference techniques
Seoul National University
2017-2025
The 94 GHz single-channel interferometer at the versatile experiment spherical torus has been upgraded into a multi-channel heterodyne for electron density profile measurements. Five Gaussian beam chords generated by pair of Powell lenses and collimating are vertically spaced 75 mm intervals from midplane to lower part main chamber. beams passing through plasma received detector array consisting half-wave rotator modules an integrated lens antenna mixer. local oscillator is expanded another...
Abstract Interferometers based on phase measurement technique have been widely used to measure the plasma line integrated density (LID) in magnetic fusion devices. Phase jump is an inherent drawback of techniques. Once a occurs, errors should be compensated for by referring complementary diagnostics. In multi-chord interferometer profiles, can using relationship between adjacent receivers. To utilize receivers, microwaves emitted from single transmitter are spatially distributed all The...
An optimum plasma pressure/current density profile and corresponding heating/current drive (H/CD) determination scheme is newly developed by integrating equilibrium, stability, confinement, H/CD, self-consistently subject to maximize the fusion gain for Korean demonstration reactor (K-DEMO) steady-state operation scenarios. The integrated modeling package, FASTRAN/IPS, adopted numerical apparatus. target pressure with a pedestal structure investigated varying its peaking, height width as...
The fast wave branch in lower hybrid resonance frequency range, especially higher than 2ωlh, has been proposed for the central or off-axis electron heating and current drive density plasmas slow scheme. With a cutoff launching, efficient coupling between antenna plasma would be priority issue feasibility. characteristics with frequency, gap size, profile of Versatile Experiment Spherical Torus (VEST) device are investigated using commercial full FEM solver, COMSOL. Maximum combline is...
Experimental investigation of lower hybrid fast wave (LHFW) coupling and propagation is carried out by measurements utilizing magnetic probes in Versatile Experiment Spherical Torus. Coupling experiments are conducted marginal (ne≥nconfluence) prohibited (ne≫nconfluence) regimes for coupling. In the regime Ip = 25 kA, about two folds n∥-upshift observed. The path largely modified compared to that full simulation, more waves detected inside last-closed-flux surface despite unsatisfied...