Design and operation of a load-tolerant ICRH system in Experimental Advanced Superconducting Tokamak

oleh: L.N. Liu, X.J. Zhang, C.M. Qin, Y.Z. Mao, S. Yuan, W. Zhang, H. Yang, L. Wang, Y. Cheng, K. Zhang

Format: Article
Diterbitkan: IOP Publishing 2024-01-01

Deskripsi

Ion Cyclotron Resonance Heating (ICRH) has been a dependable tool for sturdy plasma heating with high RF power of several megawatts. However, a sudden increase in the reflected power during ICRH heating experiments is a problem that should be solved for future fusion experimental devices. To solve this issue, a load tolerant matching network has been designed for the ICRH system in EAST. The matching network includes a 3-stub tuner impedance matching system with conjugate-T structure, 30 Ω to 50 Ω transmission line and center grounded antenna strap. By maintaining a low reflection ratio in the network for a wide range of resistance, this matching network can allow sturdy high-power operations without fast impedance matching in EAST. In our matching network, the two arms of a conjugate-T are designed to have a $\lambda/2$ length difference which could mitigate current imbalance and antenna poloidal phasing outside of the control problem. The T-point corresponds to the maximum point of the standing wave voltage, which could greatly improve the input impedance of the antenna.