Investigation of the Energy Confinement in Ohmic and LHCD Plasmas in HT-7

Investigation of the energy confinement in ohmic and lower hybrid current drive (LHCD) plasmas in HT-7 has been performed. In ohmic discharges at low densities the global energy confinement time τE increases almost linearly with the density, saturates at a critical density (2.5 × 1013/cm3 for HT-7) and is nearly constant at higher densities. The energy confinement time is in good agreement with the Neo-Alcator scaling law at different densities and currents. In the LHCD plasmas the global energy confinement time similar to that of the L-mode discharges has been observed to be in good agreement with the low confinement mode (L mode) scaling law of ITER89-P in higher electron density and plasma current.

对HT - 7托卡马克装置中的欧姆放电和低杂波电流驱动（LHCD）等离子体的能量约束进行了研究。在低密度的欧姆放电中，整体能量约束时间τE几乎随密度线性增加，在临界密度（HT - 7为2.5×10¹³/cm³）处达到饱和，在更高密度时几乎保持不变。在不同的密度和电流下，能量约束时间与Neo - Alcator定标律吻合良好。在LHCD等离子体中，在较高的电子密度和等离子体电流下，观察到整体能量约束时间与低约束模式（L模式）的ITER89 - P定标律吻合良好，类似于L模式放电的情况。