A study of barrier discharge mechanisms using self-organized atmospheric pressure plasmas

为了弄清阻挡放电中介质上积累的电荷与放电方式之间的关系，我们进行了实验。在使用具有振铃部分的施加电压的实验中，清楚地示出了通过第二个相对小的脉冲抵消（或初始化）在第一个脉冲放电中积累的表面电荷而产生均匀的放电模式。此外，我们还利用普克尔斯效应构建了累积电荷表征设备。这是首次成功地观察到等离子体显示器（PDP）型表面放电中累积电荷的二维空间分布的动态行为。在PDP的Xe/Ne气体放电中，二维分布变得相对均匀，并且不能有效地利用该设备的二维测量的特性。然而，当使用氦气时，在电极上局部开始电荷积累，并且我们能够观察到电荷积累域逐渐扩展。将该技术应用于本研究的初衷--自组织自发放电模式。在不存在灯丝的部分中，累积的电荷量为零。在存在细丝的部分，发现每根细丝积累了67 nC/cm^2的电荷密度。最后，我想提到的是，作为未来的前景，通过使用更薄的电光晶体来测量灯丝附近的累积电荷的空间分布成为可能。此外，通过结合使用图像增强CCD摄像机，可以阐明单个灯丝的电荷积累的二维空间分布的动态行为。

We have conducted the experiment for clarifying relation between the accumulated charge on the dielectric in barrier discharges and discharge mode. In the experiments using an applied voltage with ringing parts, it was shown clearly that a uniform electric discharge mode is brought about by cancelling (or initializing) surface charge accumulated in the 1st pulse discharge by the 2nd relatively small pulse. Furthermore, we have constructed accumulated charge characterization equipment using the Pockels effect. This succeeded in observing the dynamic behavior of two-dimensional spatial distribution of the accumulated charge in plasma display (PDP) type surface discharge for the first time. In the Xe/Ne gas discharge for PDP, two-dimensional distribution became relatively uniform and was not able to employ efficiently the special feature of two-dimensional measurement of this equipment. However, when helium gas was used, electric charge accumulation began locally on the electrodes, and we were able to observe that charge accumulating domain spreads gradually. This technique was applied to the self-organized filamentary discharge mode which was the original purpose of this research. The amount of accumulated charges was zero in the part where a filament did not exist. In the part where a filament existed, the charge density of 67 nC/cm^2 was found to be accumulated per a filament. Finally, I would like to mention that it becomes possible to measure spatial distribution of the accumulated charge near the filament by using a thinner electro optic crystal as a future prospective. Moreover, by using together the image intensified CCD camera, it is possible to clarify the dynamic behavior of two-dimensional spatial distribution of the charge accumulation for one filament.