Measurements of plasma parameters and transmitted microwaves are performed in a composite of double-split-ring resonators (DSRRs) making magnetic permeability negative and plasmas excited by a 2.45-GHz microwave. We launch the microwave at 100-200 W, modulated by a pulse wave at a low frequency and a low duty ratio to detect time evolutions of plasma parameters. We perform the measurements at different positions with varying distance from the supporting plate of the DSRRs, and find enhanced wave transmission in the composite with nonuniform profiles of electron temperature. To reinforce the measurements of electron temperature, we evaluate electron energy distribution function (EEDF) by deriving second deviation of electron current for which data smoothing methods are applied, and the estimated EEDF becomes spatially non-uniform with the similar profile to electron temperature. In terms of the validity of results on the enhanced wave transmission, one-dimensional electromagnetic particle simulations reveal sneaking microwaves inside the composite. In comparison with cases of the negative-permeability and the passive (positive-permeability) DSRRs, we confirm that the non-uniformity is attributed to the magnetic resonance of the DSRRs, which is a microscopic effect of the DSRRs to plasma generation, whereas their macroscopic effect makes permeability negative and enhances wave energy transfer inside the composite.

中文翻译：

---

宏观负渗透超材料在低压微波等离子体中局部破坏参数均匀性

等离子体参数和透射微波的测量是在双裂环谐振器 (DSRR) 的复合材料中进行的，该谐振器使磁导率为负，等离子体由 2.45 GHz 微波激发。我们以 100-200 W 的功率发射微波，通过低频和低占空比的脉冲波进行调制，以检测等离子体参数的时间演变。我们在距 DSRR 支撑板不同距离的不同位置进行测量，并发现复合材料中具有不均匀电子温度分布的增强波传输。为了加强电子温度的测量，我们通过推导应用数据平滑方法的电子电流的二次偏差来评估电子能量分布函数（EEDF），并且估计的 EEDF 在空间上变得不均匀，具有与电子温度相似的轮廓。就增强波传输结果的有效性而言，一维电磁粒子模拟揭示了复合材料内部的潜行微波。与负渗透率和被动（正渗透率）DSRR 的情况相比，我们确认不均匀性归因于 DSRR 的磁共振，这是 DSRR 对等离子体产生的微观效应，而它们的宏观效应使渗透率变为负值并增强复合材料内部的波能传递。