22nd joint workshop on electron cyclotron emission (ECE) and electron cyclotron resonance heating (ECRH)

Session

Experiments (Oral)

22 Apr 2024, 11:00

Royal Ball Room (Ramada Hotel, Daejeon, Republic of Korea)

49. Progress of the electron cyclotron resonance heating system and the related experiments on J-TEXT

donghui Xia (Huazhong University of Science and Technology)

22/04/2024, 11:30

Experiments

In order to improve the ability of the J-TEXT tokamak which firstly only had the ohmic heating, we had begun to develop the electron cyclotron resonance heating (ECRH) system since 2017. The first ECRH system with the frequency of 105 GHz and the output power of 500 kW for 1s was successfully operated in 2019. This system is a traditional one which consists of a gyrotron from GYCOM, a...

67. Appearance and analysis of a reflecting coating damage

Martin Schubert (Max-Planck-Institut f. Plasmaphysik)

22/04/2024, 11:50

Experiments

Eight reflecting gratings are installed into the plasma facing wall of ASDEX Upgrade (AUG) in order to provide a controlled second pass through the plasma center in 140 GHz heating scenarios with reduced single pass absorption. Four of these gratings are machined out of W1.4901 steel and coated with tungsten to increase the reflectivity. During plasma operation three of the W1.4901 gratings...

63. Various Ohmic startup schemes with electron cyclotron heating via direct XB mode conversion in VEST

Yong-Seok Hwang (Seoul National University)

23/04/2024, 09:30

Experiments

In Spherical Torus (ST) with relatively low toroidal field, electron Bernstein wave (EBW) is known to be an efficient heating mechanism for high density plasmas without accessibility problem even at low frequency. Over-dense plasmas beyond L cut-off density was obtained via direct XB mode conversion from perpendicular low-field-side injection in Versatile Experiment Spherical Torus (VEST),[1]...

70. Analysis of Neoclassical Tearing Mode stabilization experiment by Electron Cyclotron Injection in KSTAR

Mr MinSoo Cha (Department of Energy Systems Engineering, Seoul National University, Seoul, Korea)

23/04/2024, 09:50

Experiments

We report the neoclassical tearing mode (NTM) stabilization experimental results by injection of the electron cyclotron (EC) beam in KSTAR, and its analysis by calculating tearing stability index Δ′. In KSTAR #31747 experiment, the neoclassical tearing mode (NTM) is intentionally induced, and the KSTAR plasma control system (PCS) injects EC beam to stabilize the NTM. Here the EC is injected...

58. Influence of ECH on Magnetohydrodynamic (MHD) Instabilities Driven by Energetic Particles in Heliotron J

YAO ZHONG (Sun Yat-sen University)

23/04/2024, 10:10

Theory

Recent experiments in Heliotron J have delved into the response of energetic-particle-driven MHD
instabilities to electron cyclotron heating and current drive (ECH/ECCD) [1]. Specifically, we
conducted ECH modulation experiments to scrutinize mode stabilization and its underlying physical
mechanisms [2]. In our initial modulation experiment, the NBI power was modest at 90 kW in...

54. Performance of the ECRH system of Wendelstein 7-X during the experimental campaign OP2.1

Torsten Stange (Max-Planck-Institute for Plasma Physics)

24/04/2024, 09:30

Experiments

One of the main goals of the superconducting stellarator Wendelstein 7-X (W7-X) is to demonstrate steady state plasma operation at reactor relevant plasma parameters in discharge scenarios with a length of up to 30 minutes. For this reason, W7-X was equipped with a steady state capable 140 GHz electron cyclotron resonance heating (ECRH) system with an installed power of currently 8.3 MW....

46. Results on the 1 MW CW 170 GHz gyrotron TH1509UA at the FALCON test stand

Falk Braunmueller (Swiss Plasma Center, Lausanne, Switzerland)

24/04/2024, 09:50

Technology

In this contribution, recent results achieved at the FALCON test facility are presented. This versatile facility proves useful for testing continuous wave high-power gyrotrons, but also serves as a platform for testing the transmission line components and RF-loads for ITER and other future facilities. The gyrotron currently under test at SPC is the TH1509UA [1] gyrotron for the Divertor...

75. Result of ECRH operation in the integrated commissioning phase and upgrade to the initial research phase on JT-60SA

Dr Hibiki Yamazaki (National Institutes for Quantum Science and Technology (QST))

24/04/2024, 10:10

Technology

In the commissioning of JT-60SA, two ECRH systems were operated at 110 GHz with a small-diameter waveguide of 31.75 mm (Unit1) and 82/110/138 GHz with a large-diameter waveguide of 60.3 mm (Unit2) [1]. The large-diameter waveguide potentially has a larger mode conversion loss due to misalignment than the small-diameter waveguide, and its feasibility in a 100 m-class transmission line (TL) is...