EAST装置高能粒子阿芬波本征模与多尺度湍流藕合的实验探索

The energetic α particles produced in burning plasma of fusion reactors are required to heat the plasma efficiently, and thus the thermonuclear burn can be sustained. Understanding of the energy transfer mechanism of energetic α particles in fusion reactors is of fundamental importance for the future of fusion career. These mechanisms span a wide parameter range,including the small scales of microturbulence, the intermediate scales of Alfvén instabilities, and large scales of applied magnetic perturbation. the energetic particle transport have been investigated in some experiments, which suggest that the effect of Alfvén eigenmode and 3D MHD on the energetic particle transport is greater than that of turbulence alone under the operational conditions of ITER. Nevertheless, the research about the coupling between Alfvén eigenmode and microturbulence has not been reported. The homemade CO2 laser collective Thomson scattering diagnostic on EAST tokamak can measure the modulation of microturbulence by Alfvén eigenmode, about which we have preliminary results. We will use the special four-channel CO2 laser collective Thomson scattering diagnostic, in the experiments of neutral beam injection (NBI), ion cyclotron resonance wave (ICRH), electron cyclotron resonance wave (ECRH) and the lower hybrid current drive (LHCD) on EAST, to detect the modulation of multi-scale microturbulence from the Alfvén eigenmode driven by energetic particles, study the coupling between Alfvén eigenmode and multi-scale microturbulence, and investigate the transport mechanism of energetic particles in thermal plasma.

聚变装置燃烧等离子体的聚变产物--高能α粒子只有将其携带的能量有效的传递给热等离子体，聚变装置等离子体才能自持燃烧。聚变装置中高能α粒子的能量传递机制必需要搞清楚，这关系到聚变事业的成败。从小尺度微湍流、中间尺度的阿芬波不稳定性到大尺度的磁扰动对高能粒子输运的作用已进行了实验探索，初步发现,在ITER装置运行条件下,阿芬波本征模、3D磁扰动对高能粒子输运的影响大于纯粹的微湍流的因素。但是阿芬波本征模与微湍流藕合条件下的实验探索还未见报道,EAST装置自制的CO2激光相干汤姆逊散射诊断可以测量阿芬波本征模对微湍流的调制，己有初步的实验结果。我们将运用EAST装置上特有的四道CO2激光相干汤姆逊散射诊断，在EAST装置中性束加热、离子回旋加热、电子回旋加热和低杂波驱动实验中，监测高能粒子阿芬波本征模对多尺度微湍流的调制，研究阿芬波本征模与多尺度微湍流的藕合，研究高能粒子在热等离子体中的输运机制

聚变装置燃烧等离子体的聚变产物--高能α粒子只有将其携带的能量有效的传递给热等离 子体，聚变装置等离子体才能自持燃烧。现有实验证据是高能α粒子主要加热电子，聚变装置中高能α粒子的能量传递机制必需要搞清楚，这关系到聚变事业的成败。聚变装置燃烧等离子体运行时，其芯区和梯度区等离子体是低碰撞率等离子体，湍流输运是主要的能量传输途径。本项目研究的是高能α粒子激发的阿芬波与小尺度湍流（电子模湍流)的相互作用，属于多尺度物理问题。我们用EAST装置上的多道二氧化碳激光相干散射诊断，同步监测EAST装置芯区和梯度区小尺度等离子体密度涨落，实验验证了阿芬波与小尺度湍流之间可以发生非线性耦合现象。我们也实验验证了大尺度阿芬波与小尺度湍流存在相互作用。另外我们也实验研究了聚变装置L-H模转换时芯区、梯度区小尺度湍流的演化。我们通过聚变装置芯区、梯度区小尺度湍流的空间相关，展示出托卡马克装置中L-H模转换过程中小尺度湍流空间结构的变化。.聚变装置燃烧等离子体运行时，芯区等离子体电导无穷大，外部电磁场调节很难影响芯区、梯度区等离子体。高参数聚变装置芯区、梯度区等离子体的反常输运主要是小尺度湍流主导，当小尺度湍流与高能粒子阿芬波耦合、相互作用时，必然产生聚变装置炉芯等离子体控制问题。因为小尺度湍流垂直于磁力线，控制聚变装置磁位形就能控制等离子体，但是阿芬波与磁位形不存在直接关系。