Investigation on self-organization mechanisms of Coulomb crystal in complex plasmas

复杂等离子体中库仑晶体自组织机制研究

• 批准号: 18540498
• 负责人: ADACHI Satoshi
• 金额: $ 2.55万
• 依托单位: Japan Aerospace Exploration Agency
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2006
• 资助国家: 日本
• 起止时间: 2006 至 2007
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-18540498/
• 关键词: Complex Plasmas; Plasma Parameter Measurement; Pair Distribution Function; Mean Inter-particle Distance; Self-organization Mechanisms; Coulomb crystal

The objective of this research is to investigate the self-organization of the Coulomb crystal in complex plasmas, which will be caused by the attractive and repulsive forces. In order to accomplish this objective, dependencies of the inter-parbcle distance on various conditions are experimentally investigated in 2006. Through the research in 2006, a new hypothesis that the inter-particle distance is determined by the balance between the Coulomb repulsive force and the pushing force from the plasma pressure, which is similar to the attractive force, is obtained. In order to confirm this hypothesis, particles with different diameters are used in 2007. In both cases of monodisperse particles with 1 micrometer and 5 micrometers in diameter, the Coulomb crystals are successfully obtained without any artificial particle-confinement mechanisms. In order to investigate the self-organization mechanisms of the Coulomb crystal, the images of the crystals are obtained first under various gas pressure and rf power conditions. Then, the coordinates of the particles are obtained from the images. By using the coordinates, the pair distribution function are obtained. In addition, the coordination number of the crystal is also obtained from the pair distribution function. From the latter information, the structure can be discussed. From the former information, the inter-particle distance is obtained. The dependencies of the inter-particle distance on the ratio of the square of the surface charge of the particte to length are obtained. In the 1 micrometer case, it was found that the inter-particle distance is proportional to that ratio in 2006. This is the reason why the previous hypothesis is proposed. In 2007, the same dependencies in the case of 5 micrometers are obtained. It is found that this dependency supports the hypothesis. The hypothesis being similar to this one has never been proposed.

本研究的目的是研究复杂等离子体中库仑晶体的自组织，这是由吸引力和排斥力引起的。为了实现这一目标，2006年对粒子间距离对各种条件的依赖性进行了实验研究。通过2006年的研究，提出了粒子间距离由库仑斥力和库仑斥力之间的平衡决定的新假设。获得来自等离子体压力的推力，类似于吸引力。为了证实这一假设，2007年使用了不同直径的粒子。在直径为1微米和5微米的单分散粒子的情况下，在没有任何人工粒子限制机制的情况下成功获得了库仑晶体。为了研究库仑晶体的自组织机制，首先在不同气压和射频功率条件下获得晶体的图像。然后，从图像中获得粒子的坐标。通过使用坐标，可以获得对分布函数。此外，晶体的配位数也是由对分布函数得到的。从后面的信息可以讨论结构。根据前面的信息，可以获得粒子间距离。获得了颗粒间距离对颗粒表面电荷的平方与长度之比的依赖性。在1微米的情况下，2006年发现颗粒间距离与该比率成正比。这就是提出先前假设的原因。 2007年，在5微米的情况下得到了相同的依赖性。发现这种依赖性支持了假设。与此类似的假设从未被提出过。

项目成果

Experimental investigation on dependency of interparticle distance in Coulomb crystal on various parameters

库仑晶体粒子间距离对各种参数依赖性的实验研究

• 发表时间: 2007
• 期刊: JAXA Research and Development Report JAXA-RR-06-018E
• 作者: Satoshi;Takeuchi;M. Murakami and M.Tanaka;Satoshi Adachi and Masahiro Takayanagi
• 通讯作者: Satoshi Adachi and Masahiro Takayanagi

Experimental investigation on dependency of interparticle distance in Coulomb crystalon various parameters

库仑晶体粒子间距离对各种参数依赖性的实验研究

• 发表时间: 2007
• 期刊: JAXA Research and Development Report JAXA-RR-06-018E
• 作者: Yusuke Nihei;Yusuke Sasakawa and Kunio Okimura;Satoshi Adachi and Masahiro Takayanagi
• 通讯作者: Satoshi Adachi and Masahiro Takayanagi

Experimental Investigation on Conditions of Microgravity Experiment for Critical Point in Dusty Plasmas

尘埃等离子体临界点微重力实验条件的实验研究

• 发表时间: 2007
• 作者: Y.Nihei;Y.Sasakawa and K.Okimura;Satoshi Adachi
• 通讯作者: Satoshi Adachi

日本および海外における微粒子プラズマの微小重力実験の現状

日本国内外利用粒子等离子体进行微重力实验的现状

• 发表时间: 2007
• 期刊: J. Plasma and Fusion Research Vol.82 No.2
• 作者: 足立 聡;高柳昌弘;依田眞一
• 通讯作者: 依田眞一