湍流雷诺协强及密度扰动对极向动量输运影响的实验研究

Effect of turbulence Reynolds stress and density perturbation on poloidal momentum transport

利用静电探针阵列对HL-2A边缘等离子体径向和极向速度进行了测量,获得了最后闭合磁面附近湍流的雷诺协强<v_rv_θ>以及v_r和v_θ间相位差的剖面。实验表明,虽然v_r、v_θ的幅值对雷诺协强的大小会有影响,但雷诺协强的变化趋势主要取决于二者相位差的变化;另一方面,欧姆放电以及不同电子回旋加热功率L模放电条件下的实验结果显示,密度扰动引起的粒子输运所带来的极向动量输运的贡献与雷诺协强项对极向动量输运的贡献是可比的。这表明在分析湍流引起的动量输运时必须考虑粒子输运的贡献。

In HL-2A tokamak, the profile of turbulent Reynolds stress （v0） and the cross-phase between vr and v0 was measured around the last closed flux surface. The result shows that the Reynolds stress is mainly determined by the cross-phase between v and v0 although the amplitude of vr and v0 influence the amplitude of Reynolds stress. Besides, ohmic discharge and ECRH L-mode discharge show that radial particle flux caused by density perturbation has an important effect on the poloidal momentum flux. Its value is comparable to that of Reynolds stress. This indicates that the contribution of particle transport in the analysis of the turbulent momentum transoort must be considered.