Speaker
Description
Ion cyclotron emission (ICE) driven by fast ions is an electromagnetic radiation whose spectrum peaks correspond to the harmonics of the cyclotron frequencies of energetic ion species near the emission location. ICE carries numerous fast ions and substantial distribution information, and their detection and analysis can help understand the behavior of fast ions in a magnetically confined plasma. ICE holds great potential as a diagnostic tool for fast ions in fusion devices. To better study the ICE, we measured ICE signals on the Experimental Advanced Superconducting Tokamak (EAST), edge ICE excited by tritium ions. A fusion product derived from the deuterium–deuterium (D–D) fusion reaction, whose spectral peak matches the fundamental cyclotron frequency of the tritium ions (ωCT) in the plasma edge near the last closed flux surface, was observed using the ion cyclotron range of frequency (ICRF) antenna-based diagnostic system at the plasma boundary on the low field side in the EAST. In this study, we present the first observation of ICE with frequency matching at the plasma boundary. The excitation position of ICE is approximately R = 2.29 m on EAST, and we find that ICE is easier to excite below a certain threshold of plasma radiation. To investigate the excitation mechanism of ICE, we obtained the tritium ion distribution via the TRANSP/Fusion Products Model code and used it to explain the excitation mechanism of ICE. The given distribution has a bump-on tail structure in the energy direction and anisotropy in the pitch angle direction. In addition, we explain why fast tritium ions can reach and accumulate at the plasma boundary. It is important to study ICE because ICE can help distinguish the species of fusion-product ions, which can help monitor the fusion alpha ions in large fusion devices, such as CFETR, DEMO, and ITER.
| Presentation type | Oral |
|---|
