Fedoseev A V, Litvinenko V V, Vasilieva E V, Vasiliev M M, Petrov O F
Joint Institute for High Temperatures RAS, Moscow, Russia, 125412.
Sci Rep. 2024 Jun 10;14(1):13252. doi: 10.1038/s41598-024-62486-1.
The paper presents the first experimental observation of an atypical phenomena during self-organization of dust particles into a one-dimensional chain structure levitated vertically in the plasma of a DC glow discharge. Using a laser, the third (middle) dust particle was removed from the chain of five particles so that the positions of the remaining particles did not significantly change, and a vacancy occurred in the place of the removed particle. This state of the chain turned out to be very stable, which is confirmed by the observation of the subsequent exchange of places of the fourth and the fifth particles of the chain upon the action of the laser on the forth particle. After the exchange process, vertical positions of all particles (first, second, fourth and fifth) in the chain remained almost the same as before the exchange, and the vacancy at the position of the third particle was preserved. The experimental data and the video record of the observed phenomena as well as the estimates of the plasma parameters are presented. An assumption has been made about the mechanism of the discovered phenomena that at present discharge conditions both the vacancy formation and the dust particles positions exchange are possible due to a strong ion wakes which are formed behind the upstream dust particles of the chain.
本文展示了在直流辉光放电等离子体中，尘埃颗粒自组织形成垂直悬浮的一维链状结构过程中一种非典型现象的首次实验观测。使用激光从由五个颗粒组成的链中移除了第三个（中间的）尘埃颗粒，使得其余颗粒的位置没有显著变化，并且在被移除颗粒的位置出现了一个空位。链的这种状态被证明非常稳定，这通过在激光作用于第四个颗粒时观察到链中第四和第五个颗粒随后发生的位置交换得到了证实。交换过程之后，链中所有颗粒（第一、第二、第四和第五个）的垂直位置几乎与交换之前相同，并且第三个颗粒位置的空位得以保留。文中给出了实验数据、所观测现象的视频记录以及等离子体参数的估计值。针对所发现现象的机制做出了一个假设，即在当前放电条件下，由于在链中上游尘埃颗粒后面形成的强烈离子尾流，空位形成和尘埃颗粒位置交换都是可能的。
