论文标题
喷气等离子体中剪切和声音连续图的高阶耦合
High-order coupling of shear and sonic continua in JET plasmas
论文作者
论文摘要
最新的模型耦合了剪切 - alfvén和声学连续图，该模型尤其取决于平衡形状，尤其是伸长率，用来解释在下面的JET等离子体上观察到的Alfvénic活性的特性，但接近于环形诱导的AlfvénEigenmodes（TaeS）的典型频率。该模型所预测的频率间隙是由血浆形状引起的地质场线曲率的高阶谐波（与低阶环形性相反）引起的，并引起高阶测量声原理（Hogaes），其频率值接近TAES ONE的一半。发现Hogae频率和径向位置的理论预测与JET实验中的测量（包括磁性，反射仪和软X射线数据）是公平吻合的。考虑到NBI和ICRH加热系统所产生的能量离子种群，使用线性混合MHD/漂移式Castor-K评估了观察到的Hogaes的稳定性。还讨论了波粒子的共振以及驱动/阻尼机制，以了解导致射流等离子体中霍加斯不稳定的条件。
A recent model coupling the shear-Alfvén and acoustic continua, which depends strongly on the equilibrium shaping and on elongation in particular, is employed to explain the properties of Alfvénic activity observed on JET plasmas below but close to the typical frequency of toroidicity-induced Alfvén eigenmodes (TAEs). The frequency gaps predicted by the model result from high-order harmonics of the geodesic field-line curvature caused by plasma shaping (as opposed to lower-order toroidicity) and give rise to high-order geodesic acoustic eigenmodes (HOGAEs), their frequency value being close to one-half of the TAEs one. The theoretical predictions of HOGAE frequency and radial location are found to be in fair agreement with measurements in JET experiments, including magnetic, reflectometry and soft x-ray data. The stability of the observed HOGAEs is evaluated with the linear hybrid MHD/drift-kinetic code CASTOR-K, taking into account the energetic-ion populations produced by the NBI and ICRH heating systems. Wave-particle resonances, along with drive/damping mechanisms, are also discussed in order to understand the conditions leading to HOGAEs destabilization in JET plasmas.
