Anomalous cross-B field transport and spokes in HiPIMS plasma
Anomalous cross-B field transport and spokes in HiPIMS plasma
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DOI：
10.1088/0022-3727/49/18/18lt01
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发表时间：
2016-04
期刊：
影响因子：
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通讯作者：
A. Hecimovic
中科院分区：
文献类型：
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作者：
A. Hecimovic
在平面磁控管上进行高功率脉冲磁控溅射 (HiPIMS) 放电期间观察到的局部光发射图案（称为辐条或电离区）已被确定为异常交叉 B 场扩散的潜在来源。本文提出了实验证据，表明异常扩散是由辐条的出现引发的。霍尔参数 ωceτc（电子回旋频率和经典碰撞时间的乘积）随着辐条的出现从玻姆扩散值（~16 及更高）降低到 3，表明异常的跨 B 场传输。强化电荷耦合器件成像和电探针测量的结合表明，辐条上的离子立即从目标扩散开。从辐条侧面图像计算出的离子扩散系数比玻姆扩散系数高六倍，这与霍尔参数的减小是一致的。
Localized light emission patterns observed during on time of a high power impulse magnetron sputtering (HiPIMS) discharge on a planar magnetron, known as spokes or ionization zones, have been identified as a potential source of anomalous cross-B field diffusion. In this paper experimental evidence is presented that anomalous diffusion is triggered by the appearance of spokes. The Hall parameter ωceτc, product of the electron cyclotron frequency and the classical collision time, reduces from Bohm diffusion values (∼16 and higher) down to the value of 3 as spokes appear, indicating anomalous cross-B field transport. A combination of intensified charge coupled device imaging and electric probe measurements reveals that the ions from the spokes are instantaneously diffusing away from the target. The ion diffusion coefficients calculated from a sideways image of the spoke are six times higher than Bohm diffusion coefficients, which is consistent with the reduction of the Hall parameter.