The density scaling of n = 1 error field penetration is investigated under radio-frequency (RF)-dominant heated L-mode discharges in the EAST tokamak. It is found that the density scaling of the threshold field strength for error field penetration in lower-hybrid current drive (LHCD) plasmas is about , where b _r represents the error field amplitude. The results show a weaker density dependence compared to that observed in the previous ohmic heated discharges (Wang etal 2018 Nucl. Fusion 58 056024). For a better understanding of the density scaling, it is compared with field penetration theories, and it is found that it lies in the Waelbroeck regime. The observed scaling is consistent with that evaluated with the magnetohydrodynamic (MHD) theory on error field penetration, for which all the physical parameters are determined experimentally. Due to the density dependence of LHCD heating efficiency, the stronger negative correlation between density and temperature results in a weaker density scaling in these LHCD plasmas. Using realistic parameters under LHCD and ohmic heating as input, respectively, the numerical results based on a reduced MHD model reproduce well the scaling from the error field penetration theory and the observations. Besides, the density scaling in various tokamak operational regimes is also numerically investigated. This provides an excellent validation of MHD theory on error field penetration in the RF-dominant heated L-mode discharges.

在 EAST 托卡马克以射频 (RF) 为主的加热 L 模式放电下，研究了n = 1 误差场穿透的密度缩放。据发现，对于误差区渗透在低杂波电流驱动（LHCD）等离子体的阈值场强密度缩放是约，其中b _[R代表误差场幅度。结果表明，与之前的欧姆加热放电中观察到的相比，密度依赖性更弱（Wang et al 2018 Nucl. Fusion 58056024）。为了更好地理解密度标度，将其与场穿透理论进行比较，发现它位于 Waelbroeck 区域。观察到的缩放与用磁流体动力学 (MHD) 理论对误差场穿透进行评估的结果一致，所有物理参数都是通过实验确定的。由于 LHCD 加热效率的密度依赖性，密度和温度之间更强的负相关导致这些 LHCD 等离子体中较弱的密度缩放。分别使用 LHCD 和欧姆加热下的实际参数作为输入，基于简化 MHD 模型的数值结果很好地再现了误差场穿透理论和观测结果的缩放比例。除了，还对各种托卡马克操作机制中的密度缩放进行了数值研究。这为 MHD 理论在 RF 主导的加热 L 模式放电中的误差场穿透提供了极好的验证。