Accumulation Process of Negative Ions in a Hollow-Type Magnetized Plasma

空心型磁化等离子体中负离子的积累过程

基本信息

批准号：
12680477
负责人：
MIENO Tetsu
金额：
$ 1.98万
依托单位：
Shizuoka University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2000
资助国家：
日本
起止时间：
2000 至 2001
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-12680477/
关键词：
Reactive plasma Accumulation of negative ions Hollow-type magnetized plasma Cylindrical Plasma String-type plasma Carbon fluoride Negative ion beam source Diffusion coefficient 負イオン蓄積拡散系数プラズマプロセッシング

项目摘要

1) A magnetized plasma from CF_4 gas is generated by the electron cyclotron resonance discharge and a follow-type magnetized plasma is produced by use of a disk-type obstacle at the downstream region of the plasma. Inside the hollow-type plasma, fluorine positive and negative ions are accumulated, generating an ion-ion plasma. By means of a probe measurement, the ratio of negative ion density to electron density becomes more than 20. This phenomenon can be explained by a difference of radial diffusion speeds of electrons and negative ions. As the radial direction diffusion speed is decided by the collision frequency with neutral particles and a step length (a Lamor radius), the negative ions have much larger diffusion speed than that of electrons. As a result, positive and negative ions are preferably diffused into the vacuum region inside the hollow plasma. On the other hand, along the line of magnetic field, electron and ions freely move. At the end plates, high energy electrons tend … More s to flow into the plates beyond a barrier of sheath potential. Otherwise, the negative ions are reflected by the sheath barrier potential and well confined between the end plates. By this process, negative ions are effectively accumulated inside the hollow plasma2) By means of a multi-hole type obstacle, a multi-string plasma is produced at the down-flow region of the magnetized plasma from CF_4 gas. In this case, negative ions accumulate around the string plasmas. Here, many string plasmas are generated with same interval and large volume negative-ion accumulation can be produced. As a results, the large area negative ion source with cross-section of 30 cm^2 has been successfully generated. By use of a magnetic filter a negative ion-beam can be extracted from this plasma source and can be used for the large-area negative ion processing and the neutral beam processing.3) By means of a UV-range pulsed laser, amount of negative ions inside the follow plasma is measured and it is compared with the probe data. Less

1）通过电子回旋共振放电产生了来自CF_4气体的磁化等离子体，并通过在等离子体的下游区域使用磁盘型障碍物产生后续型磁化等离子体。在空心型血浆内部，积累氟阳性和负离子，产生离子离子等离子体。通过探测测量，负离子密度与电子密度的比率超过20。这种现象可以通过电子和负离子的径向差异速度的差异来解释。由于径向方向差的速度是由中性颗粒和步长（lamor半径）的碰撞频率决定的，因此负离子的扩散速度比电子的扩散速度大得多。结果，正优先将正离子和负离子分为空心等离子体内的真空区域。另一方面，沿着磁场，电子和离子自由移动。在末端，高能电子趋于……更多的s可以流入板势障碍的板上。否则，负离子会被鞘屏电位反映，并且限制在末端板之间。通过此过程，通过多孔类型障碍物在空心等离子2中有效积累了负离子，在CF_4气体的磁化等离子体的下流区域产生了多弦的等离子体。在这种情况下，负离子围绕等离子体积聚。在这里，许多串等离子体具有相同的间隔，并且可以产生大容量的负离子加速度。结果，已经成功产生了横截面为30 cm^2的大面积负离子源。通过使用磁过滤器，可以从该等离子体源中提取负离子梁，并可用于大面积的负离子处理和中性束处理。3）通过使用紫外线脉冲激光器，以下等离子体中的紫外离子量进行测量，并将其与探针数据进行比较。较少的