A5006184996- Magnetic confinement fusion research
- Particle accelerators and beam dynamics
- Superconducting Materials and Applications
- Ionosphere and magnetosphere dynamics
- Plasma Diagnostics and Applications
- Fusion materials and technologies
- Gyrotron and Vacuum Electronics Research
- Laser-Plasma Interactions and Diagnostics
- Plasma Applications and Diagnostics
- Physics of Superconductivity and Magnetism
- Electromagnetic wave absorption materials
- Advanced Antenna and Metasurface Technologies
- Advanced Data Storage Technologies
- Dust and Plasma Wave Phenomena
- Combustion and Detonation Processes
- Surface Modification and Superhydrophobicity
- Wireless Power Transfer Systems
- Photonic and Optical Devices
- Experimental Learning in Engineering
- Full-Duplex Wireless Communications
- Electromagnetic Simulation and Numerical Methods
- Induction Heating and Inverter Technology
- Electrohydrodynamics and Fluid Dynamics
- Advanced Computational Techniques and Applications
- Smart Grid and Power Systems
Institute of Plasma Physics
2015-2024
Chinese Academy of Sciences
2015-2024
Hefei Institutes of Physical Science
2010-2024
The first high-confinement mode (H-mode) with type-III edge localized modes at an H factor of IPB98( y ,2) ∼ 1 has been obtained about MW lower hybrid wave power on the EAST superconducting tokamak. H-mode plasma appeared after wall conditioning by lithium (Li) evaporation before breakdown and real-time injection fine Li powder into edge. threshold for access follows international tokamak scaling even in low density range a identified. With increasing accumulation deposited duration was...
A 4.6 GHz lower-hybrid current drive (LHCD) system has been firstly commissioned in EAST the 2014 campaign. The first LHCD results with show that LHW can be coupled to plasma a low reflection coefficient, and rotation, modify profile, heat effectively. By means of configuration optimization local gas puffing near antenna, good LHW–plasma coupling coefficient less than 5% is obtained. maximum power up 3.5 MW. (CD) efficiency 1.1 × 1019 m−2 W−1 central electron temperature above 4 keV,...
A long pulse electron cyclotron resonance heating (ECRH) system has been developed to meet the requirements of steady-state operation for EAST superconducting tokamak, and first EC wave was successfully injected into plasma during 2015 spring campaign. The is mainly composed four 140 GHz gyrotron systems, 4 ITER-Like transmission lines, independent channel launchers corresponding power supplies, a water cooling, control & inter-lock etc. Each expected deliver maximum 1 MW be operated at...
Aimed at high-confinement (H-mode) plasmas in the Experimental Advanced Superconducting Tokamak (EAST), effect of local gas puffing from electron and ion sides a lower hybrid wave (LHW) antenna on LHW–plasma coupling high-density experiments with current drive (LHCD) are investigated EAST. results show that side is more favourable to improve compared side. Investigations indicate without affected by density near LHW grill (grill density), hence leading multi-transition low–high–low (L–H–L)...
Lower-hybrid waves have been shown to induce a cocurrent change in toroidal rotation of up 40 km/s the L-mode plasma core region and 20 edge EAST tokamak. This modification develops on different time scales. For edge, scale is no more than 100 ms, but for around 1 s. A simple model based turbulent equipartition thermoelectric pinch predicts experimental results.
EAST has been equipped with two high power lower hybrid current drive (LHCD) systems operating frequencies of 2.45 GHz and 4.6 GHz. Comparative LHCD experiments the different were performed in same conditions plasma for first time. It was found that (CD) efficiency heating effect are much better LH waves than one High confinement mode (H-mode) discharges as sole auxiliary source have obtained is higher respect to produced previously by A combination ray-tracing Fokker-Planck calculations...
Using a 2 MW 2.45 GHz lower hybrid wave (LHW) system installed in experimental advanced superconducting tokamak, we have systematically carried out LHW-plasma coupling and current drive experiments both divertor (double null single null) limiter plasma configuration with (Ip) ∼ 250 kA central line averaged density (ne) 1.0–1.3 × 1019 m−3 recently. Results show that the reflection coefficient (RC) first is flat up to some distance between LHW grill, then increases distance. Studies indicate...
Abstract Two important issues in achieving lower hybrid current drive (LHCD) high confinement plasma EAST are to improve wave (LHW)-plasma coupling and the at a density. Studies different configurations with directions of toroidal magnetic field ( B t ) show that density near antenna is affected by both radial electric induced without LHW E r_plasma scrape off layer (SOL), power r_LH grill. Investigations indicate r × SOL leads effect configuration on LHW-plasma accounts for asymmetric...
The feedback control system to plasma current and position on the HT-7 superconducting tokamak was greatly improved in early 1998. Lower hybrid drive (LHCD) experiments with were performed sustain long pulse discharges improve confinement. Partial non-inductive full for several seconds by means of LHCD demonstrated. It observed that confinement could be considerably LHCD. Experimental evidence suggests this improvement during phase due modification profile outer region plasma. MHD modes...
A quasi-steady-state alternating current operation assisted by lower hybrid wave (LHW) was achieved on a HT-7 superconducting tokamak with plasma of I p = 125 kA, line-averaged density 1.5 × 10 19 m −3 , electron temperature T e 500 eV and 30–50 s duration. Plasma sustained smoothly transferred from one direction to the other without loss ionization. position control, LHW assistance, strong gas puffing good wall condition are key issues have smooth transition current. Our modelling results...
The experimental advanced superconducting tokamak (EAST) is a tokamak, which successfully achieved the first plasma discharge in 2006. major radius of EAST 1.9 m, and its central magnet field 3.5 T. In past few years, has made many achievements, such as 60-s double-null divertor configuration 1-MA plasma. 2012, 411-s long-pulse with 0.28-MA current 32-s H-mode operation was at seventh campaign. addition, various means for mitigating ELMs have also been demonstrated to facilitate operation....
Lower hybrid current drive (LHCD) is an effective tool to achieve high confinement (H-mode) plasma in EAST. To utilize LHCD for accessing H-mode plasma, efforts have been made improve LHW (lower wave)-plasma coupling and capability at density. Improved LHW-plasma by means of local gas puffing from the electron side routinely used during EAST operation with LHCD. High density experiments suggest that low recycling LH frequency are preferred density, consistent previous results other machines....
A 140GHz electron cyclotron resonance heating and current drive (EC H&CD) project for EAST Tokamak is launched in 2011 with a total power of 4MW pulse length 100 s. The main objectives the system are to provide central H&CD, assist start-up control MHD activities. comprises four gyrotrons each nominal output 1MW at 140GHz. RF power, transmitted through evacuated corrugated waveguides will be injected into plasma from low field side (radial port). front steering equatorial launcher directs...
Electromagnetic-wave (EMW) absorbers with strong reflection loss (RL) and a wide absorption frequency band under extremely thin thicknesses are highly desirable. Heterostructured multi-interface Fe3O4/FeO/Fe (FeOx) nanoparticle/coal gasification fine slag (CGFS) hybrids were successfully synthesized by coating graphitized CGFS FeOx nanoparticles. The crystal structure, morphology, composition, magnetic performance, electromagnetic (EM) parameters of FeOx/CGFS tested using modern analysis...
A new soft x-ray pulse height analyzer (PHA), based on a Silicon Drift Detector (SDD) linear array consisting of 15 SDD detectors, has been installed in the HT-7 tokamak. The energy resolution 150–180 eV at photon 6 keV is achieved for with Peltier cooling. effective time response PHA 50 ms. profiles electron temperature and intensity metallic impurities can be obtained spatial 3 cm. performance first experimental results from system are presented.
In lower hybrid current drive (LHCD) plasmas with non-zero loop voltage, the fast electron tail can act as a seed population of runaways. The runaways are found to be enhanced in presence (LH) waves when extends above critical velocity for electrons run away. runaway discharges, LH may suppress due drop electric field linked non-inductive drive. this paper, behaviour an extensive range LHCD is presented.
The launcher of the 4.6 GHz lower hybrid current drive (LHCD) system for Experimental Advanced Superconducting Tokamak (EAST) consists 24 antenna modules, each composed an array 3 (row) × 8 (column) waveguides. In order to verify radio frequency (RF) design and feasibility manufacturing process, a mock-up module has been fabricated measured. measured return losses all three input waveguides are less than −25 dB at GHz. transmission coefficients from waveguide output −9.13 ± 0.2 insertion...
Experiments of simultaneous injection LHWs and IBWs into plasmas have been conducted in the HT-7 tokamak. Evidence that IBW can control plasma pressure profile was observed LHCD plasmas. It found electron Landau damping (ELD) occurred around maxima parallel refractive index, n||, ion cyclotron resonant layer enhance off-axis LHW power deposition create a localized fast current channel. But global efficiency during an pulse not improved obviously. As result localization pulse, density...
The frequency spectral broadening of lower hybrid (LH) waves at 2.45 and 4.6 GHz, which denotes the change in original properties LH wave, was investigated by using a radio (RF) probe Experimental Advanced Superconducting Tokamak long-pulse plasmas. dependency RF spectrum on plasma density, power magnetic configuration is reported analyzed. A link between degradation current drive (CD) efficiency found, shows that has negative significant effect CD for both waves. In addition, absorption...