Developments of Mutiple Pellet Injectors

本文设计了两种多粒丸喷射器，并进行了试验：（1）挤出式，一次射出5粒丸;但是，时间间隔被限制在150 ms左右，其原因可能是由于残留的推进剂气体附近的外燃点。(2)通过旋转盘型，6个丸粒同时射出，并且也延迟（30-50 ms）。弹丸速度为1.1Km/s。这种类型对于Heliotron E中的弹丸注入实验非常有用。设计了另外两种类型，即（3）管枪式和（4）离心式。这些似乎也是有希望的。为了提高密度分布控制的灵活性，研制了改变弹丸飞行方向的驱动机构。还通过使用快速照相机（20 us曝光时间）对弹丸烧蚀进行了实验研究。

Two types of multiple pellet injectors are constructed and tested;(1) By an extrunder type, 5 pellets are shot out in one sequence. But, the time interval is limited at about 150 ms. The reason may be due to the residual propellant gas near the exterunding point.(2) By a rotating disk type, 6 pellets are shot out in the same time, and also delayed (30-50 ms). The pellet valocity is 1.1 Km/s. This type is very useful for pellet injection experiments in Heliotron E. the other two types, that is, (3) pipe gun type, and (4) centrifugal type, are designed. These seem to be also promising. The driving mechanism for changing pellet flight direction is developed for increasing flexibility of density profile control. The pellet ablation is also expermentally studied by using a fast camera (20 us exposure time).