Study on Structural Change of Coulomb Crystals in Plasmas

等离子体中库仑晶体结构变化的研究

基本信息

批准号：
09680464
负责人：
HAYASHI Yasuaki
金额：
$ 2.18万
依托单位：
Kyoto Institute of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1998
项目状态：
已结题

项目摘要

Structural change of Coulomb crystals, which were formed by growing carbon particles in a methane plasma, have been analyzed with the use of 2 CCD video cameras and Mie-scattering ellipsometry. Three dimensional structures of the crystals were observed from the top and the side at the same time and at the same position. As a result, it has been understood that the structure was three-dimensional like face-centered or body-centered for smaller particles (1.2-1.5 mu m) while two-dimensional of simple hexagonal one for larger particles (>1.8 mu m). It has bee also found that the three-dimensional crystal once became in the liquid phase before changing to two-dimensional one and that transition to three-dimensional structure occurred from the lower region while the particle alignment , 1. e., transition to two-dimensional one from the upper.The three-dimensional structure of a three-dimensional Coulomb crystal was precisely analyzed and proved to be strictly face-centered orthorohmbic. It was understood that the structure was formed from the slip of (111) plane of a face-centered cubic structure and the reconstruction of particles for minimum Coulomb energy in the plane.The force of aligning particles in the direction perpendicular to an electrode in the two-dimensional Coulomb crystal was investigated by the application of radiation pressure or photophoretic force of laser light and the decrease of particle density. Consequently it has been found that the particle alignment is caused by the resultant of an attractive and the Coulomb repulsive forces.

通过使用2个CCD摄像机和MIE散射的椭圆法，已经分析了由甲烷等离子体中生长的碳颗粒形成的库仑晶体的结构变化。从顶部和侧面观察到晶体的三维结构，同时和相同位置。结果，已经理解，该结构是针对较小的颗粒（1.2-1.5 mu M）的三维以面部为中心或以身体为中心的，而二维对于较大颗粒（> 1.8 mu m）的简单六边形。蜜蜂还发现，三维晶体曾经在液相变为二维晶体，然后过渡到三维结构是从下部区域发生的，而粒子对齐（e。e。）从上部过渡到二维结构。从上部到二维结构。 It was understood that the structure was formed from the slip of (111) plane of a face-centered cubic structure and the reconstruction of particles for minimum Coulomb energy in the plane.The force of aligning particles in the direction perpendicular to an electrode in the two-dimensional Coulomb crystal was investigated by the application of radiation pressure or photophoretic force of laser light and the decrease of particle density.因此，已经发现粒子比对是由吸引人和库仑排斥力的产生的。