China
Africa
Explore chapters and articles related to this topic
Fusion
Published in William J. Nuttall, Nuclear Renaissance, 2022
Another east Asian country with an interesting Fusion programme is South Korea. It led the world with the development of superconducting tokamak technology with the first plasma being achieved in June 2008 [70]. The tokamak is named KSTAR as an acronym for Korea Superconducting Tokamak Advanced Research. Although the nickname Korea’s Artificial Sun has also taken hold. In November 2020, the KSTAR team announced that they had achieved a new global record sustaining a 100 million-degree plasma for 20 seconds [71]. The team’s goal is to sustain such a plasma for 300s by 2025. KSTAR’s fully superconducting magnet technology is a precursor for ITERs use of superconducting windings. In 2021, the Korean fusion programme is in a scientific and technological competition with China. In May 2021, China took the record away from the Korean KSTAR team reporting that the EAST had achieved 120 million degrees for 101 seconds. An experimental run of 160 million degrees Celsius for 20 seconds was also reported [72].
A New Integrated Analysis Suite for Fast-Ion Study in KSTAR
Published in Fusion Science and Technology, 2023
M. W. Lee, J. Kang, N. C. Logan, M. J. Choi, L. Jung, J. Kim, M. G. Choi, M. H. Kim, B. A. Grierson, S. P. Smith, O. Meneghini, M. Romanelli, C. Sung
Furthermore, Fig. 1 shows the data flow between the modules and KSTAR database. The KSTAR database is connected to the system and is easily accessible to fetch raw tokamak data. The raw data are visualized or processed using a module for certain tasks. The outputs of a module can be converted into inputs for another task, and data exchange is straightforward within the framework. The facile interaction among the analysis modules is particularly important for the interpretive analysis of fast ions, which requires integrated modeling and analysis owing to its complicated nature. As an example of such integrated modeling, we can think of fast-ion loss analysis combining diagnostic data and plasma equilibrium. As shown on the right side of Fig. 1, plasma profiles, transport, and equilibrium modules can be simultaneously loaded on the framework. As a result, these modules can readily exchange the output data and get a more accurate equilibrium based on kinetic profile constraints.15 Then, the output equilibrium can be transferred to the fast-ion loss module in Fig. 1 for experimental data analysis. Moreover, the development of more modules for the analysis suite is actively undergoing to extend the capabilities of fast-ion study in KSTAR. NuBDeC (Ref. 16), which is a fast-ion orbit simulation code, in Fig. 1 is an example of the upcoming update for numerical simulation of fast-ion orbit and deposition in KSTAR geometry.
Theoretical Study of the Impedance Matching of the Ferrite Tuner System for ICRF Heating
Published in Fusion Science and Technology, 2022
Qingyi Tan, Xueyu Gong, Qianhong Huang, Yijun Zhong, Tao Yang
Ideas to improve the ELMy tolerance and L- to H-mode activity of the ICRF heating systems that have been tested experimentally include the use of conjugate-T networks to compensate for the variation in impedance,6,7 3-dB 90-deg hybrid junctions,8 a frequency feedback controlled system to modify the electrical length of the transmission line,9 a liquid tuner system for changing the electrical properties of silicone oil,10,11 variable vacuum capacitors,12 and fast ferrite tuning (FFT) systems that modify the ferrite magnetic properties.13 FFT systems are still under development and can in principle operate on millisecond timescales. A real-time FFT system was successfully implemented on the Alcator C-Mod’s ICRF antenna system. Experimental data indicated that the system can achieve and maintain a power reflection fraction below 1% under almost all plasma conditions.5,13,14 In EAST (Refs. 15 and 16), a fast-response ferrite tuner with a maximum power of 1.5 MW was deployed, and it demonstrated good response times, a differential phase shift, and insertion loss. In the KSTAR tokamak,17 a coaxial-type ferrite stub tuner was constructed and tested. The results showed reasonable matching capability for time-varying loading reactance. These experiments validated the feasibility of using ferrite stub tuners for antenna impedance matching.
CFD Analyses for the Upgrade Divertor System of KSTAR
Published in Fusion Science and Technology, 2021
Sungjin Kwon, Hong-Tack Kim, Suk-Ho Hong, Sang Woo Kwag, Yong Bok Chang, Nak Hyong Song, Hyung Ho Lee, Yang Soo Kim, Hyeongseok Seo, Soocheol Shin, Sangmin Kim, Junyoung Jeong
The Korea Superconducting Tokamak Advanced Research (KSTAR) device is a world-class superconducting tokamak fusion research device to develop fusion energy. Developed and constructed using Korean technology, KSTAR has been in full operation with excellent outcomes from an experimental campaign carried out every year since the first plasma achievement in July 2008, which performed the 20 000th plasma experimental shot in 2011 (Ref. 1). Recently, KSTAR achieved 100 million degrees Celsius for 20 s of ion temperature operation to demonstrate improved internal confinement through internal transport barrier mode.2 The expected heating power goal has been set to 12 MW by using an additional heating system, i.e., the second neutral beam injection (NBI) system NBI-2 (Ref. 3). As the heating power increases, resistance to high heat flux and cooling capacity at the divertor should be improved to exhaust the power in the scrape-off-layer domain. Therefore, the upgrade of the divertor system for KSTAR was launched in 2019, and the upgrade divertor will be installed by 2022.