Discharge with an external magnetic field is promising for various applications of low-temperature plasmas from electric propulsion to semiconductor processes owing to high plasma density. It is essential to understand plasma transport across the magnetic field because plasma confinement under the field is based on strong magnetization of light electrons, maintaining quasi-neutrality through the inertial response of unmagnetized ions. In such a partially magnetized plasma, different degrees of magnetization between electrons and ions can create instability and make the confinement and transport mechanisms more complex. Theoretical studies have suggested a link between the instability of various frequency ranges and plasma confinement, whereas experimental work has not been done so far. Here, we experimentally study the magnetic confinement properties of a partially magnetized plasma considering instability. The plasma properties show non-uniform characteristics as the magnetic field increases, indicating enhanced magnetic confinement. However, the strengthened electric field at the edge of the plasma column gives rise to the Simon–Hoh instability, limiting the plasma confinement. The variation of the edge-to-center plasma density ratio (h-factor) with the magnetic field clearly reveals the transition of the transport regime through triggering of the instability. Eventually, the h-factor reaches an asymptotic value, indicating saturation of magnetic confinement.

由于高的等离子体密度，对于从电推进到半导体工艺的低温等离子体的各种应用，利用外部磁场进行放电是有希望的。了解等离子体在磁场中的传输是必不可少的，因为磁场下的等离子体约束是基于光电子的强磁化，通过未磁化离子的惯性响应来维持准中性。在这种部分磁化的等离子体中，电子和离子之间的磁化程度不同会导致不稳定，并使限制和传输机制更加复杂。理论研究表明，各种频率范围的不稳定性与等离子体限制之间存在联系，而迄今为止尚未完成实验工作。这里，考虑到不稳定性，我们通过实验研究了部分磁化等离子体的磁约束性质。随着磁场的增加，等离子特性显示出不均匀的特性，这表明增强了磁约束。但是，等离子柱边缘的电场增强会引起Simon-Hoh不稳定性，从而限制了等离子约束。边缘中心等离子体密度比的变化（h因子）与磁场清楚地揭示了通过引发不稳定性而引起的传输形式的转变。最终，h因子达到一个渐近值，表明磁约束处于饱和状态。