Plasma density buildup after pellet injection
Plasma density buildup after pellet injection
复制标题
注射颗粒后血浆密度增加
DOI：
10.1063/1.872030
复制
发表时间：
1996
影响因子：
2.2
通讯作者：
J. Picchiottino
中科院分区：
文献类型：
--
作者：
B. Pégourié;J. Picchiottino
弹丸注入后等离子体密度增加的细节已经用高时间分辨率（16 μs）和用四流体流体动力学代码建模的烧蚀物质的平行膨胀进行了测量。膨胀的驱动力是平行的压力梯度，通过背景等离子体的压缩逐渐平衡。结果表明，烧蚀后的材料经历了一个强大的瞬态极向运动（<$5 ×103 ms−1，<$100 μs），因为它沿着场线扩展。这种运动是由弹丸本身引起的，是由动能守恒引起的：在烧蚀材料片中的对流运动（由于其相对于等离子体的正电势）被整个磁表面的全局漂移所补偿。该模型再现了放电中烧蚀剂平行传播的主要观测结果。特别是，它表明，由磁剪切和极向旋转的烧蚀材料片的拉伸。
Details of the increase of the plasma density following a pellet injection have been measured with high temporal resolution (16 μs) and the parallel expansion of ablated matter modeled with a four‐fluid hydrodynamic code. The driving force of the expansion is the parallel pressure gradient, progressively balanced by the compression of the background plasma. It is shown that the ablated material experiences a strong transient poloidal motion (≊5×103 ms−1, ≊100 μs) as it expands along the field lines. This motion, which is induced by the pellet itself, results from the conservation of kinetic momentum: the convective motion in the sheet of ablated material (due to its positive potential with respect to the plasma) is compensated by a global drift of the whole magnetic surface. This model reproduces the main observations concerning the parallel propagation of the ablatant in the discharge. In particular, it shows that the stretching of the sheet of ablated material by the magnetic shear and the poloidal rota...