Lee K D, Lee J H, Nam Y U, Pyo S
Korea Institute of Fusion Energy, Daejeon 34133, South Korea.
Hanbat National University, Daejeon 34158, South Korea.
Rev Sci Instrum. 2024 Aug 1;95(8). doi: 10.1063/5.0218522.
The Korea Superconducting Tokamak Advanced Research (KSTAR) tokamak is capable of operating at a wide range of toroidal magnetic fields up to 3.5 T at the major radius. The electron cyclotron emission (ECE) diagnostic on KSTAR is required to cover a broad frequency range for electron temperature profile measurements in both the low and high field sides. To meet these broadband requirements, the ECE system consists of W-band (78-110 GHz) and D-band (110-162 GHz) heterodyne radiometers. The two radiometers are connected to 28 and 48 detection channels, respectively. However, since the absolute ECE calibration based on the hot-cold calibration has been very challenging, an alternative method of calibration was performed using Thomson scattering measurements and varying toroidal magnetic fields. As the toroidal magnetic field is scanned from 1.6 to 3.2 T in steps of 0.2 T, most of the 76 ECE channels are calibrated relatively by the electron temperature values of Thomson scattering in a narrow region (0.2 < r/a <0.6). In this article, the methodological details of the ECE calibration are described. In addition, to demonstrate the robustness of the ECE calibration factors, the calibrated electron temperature profiles from ECE measurements are compared with the ion temperature profiles in terms of the plasma position as the plasma positon shifts outward.
韩国超导托卡马克先进研究装置（KSTAR）托卡马克能够在高达3.5T的环向磁场下，在较大半径范围内运行。KSTAR上的电子回旋辐射（ECE）诊断需要覆盖较宽的频率范围，以便在低场侧和高场侧测量电子温度分布。为满足这些宽带要求，ECE系统由W波段（78 - 110GHz）和D波段（110 - 162GHz）外差辐射计组成。这两个辐射计分别连接到28个和48个检测通道。然而，由于基于热冷校准的ECE绝对校准极具挑战性，因此采用了一种替代校准方法，即利用汤姆逊散射测量和变化的环向磁场进行校准。当环向磁场以0.2T的步长从1.6T扫描到3.2T时，76个ECE通道中的大多数通过汤姆逊散射在狭窄区域（0.2 < r/a <0.6）的电子温度值进行相对校准。在本文中，描述了ECE校准的方法细节。此外，为证明ECE校准因子的稳健性，随着等离子体位置向外移动，将ECE测量得到的校准电子温度分布与离子温度分布在等离子体位置方面进行了比较。
