Teodorescu C, Reynolds E W, Koepke M E
Physics Department, West Virginia University, Morgantown, WV 26506-6315, USA.
Phys Rev Lett. 2002 May 6;88(18):185003. doi: 10.1103/PhysRevLett.88.185003. Epub 2002 Apr 22.
The predicted shear-induced shift of the wave phase velocity, the essence of the shear-modified ion-acoustic (SMIA) instability mechanism that reduces ion Landau damping for otherwise damped ion-acoustic waves [V. Gavrishchaka et al., 80, 728 (1998)], is verified with direct measurements in a strongly magnetized laboratory plasma. The SMIA growth rate is shown to increase with increasing shear, as predicted. SMIA wave propagation is shown to be possible at both small and large angles to the magnetic field, consistent with space observations of ion-acoustic-like waves.
预测的剪切诱导波相速度偏移，即剪切修正离子声（SMIA）不稳定性机制的本质，该机制可降低原本会衰减的离子声波的离子朗道阻尼[V. Gavrishchaka等人，80, 728 (1998)]，已在强磁化实验室等离子体中通过直接测量得到验证。结果表明，SMIA增长率如预期那样随剪切增加而增大。SMIA波在与磁场成小角度和大角度时都能传播，这与类离子声波的空间观测结果一致。
