We present experimental data providing evidence for the formation of transient ( ${\sim }20\ \mathrm {\mu }\textrm {s}$ ) plasmas that are simultaneously weakly magnetized (i.e. Hall magnetization parameter $\omega \tau > 1$ ) and dominated by thermal pressure (i.e. ratio of thermal-to-magnetic pressure $\beta > 1$ ). Particle collisional mean free paths are an appreciable fraction of the overall system size. These plasmas are formed via the head-on merging of two plasmas launched by magnetized coaxial guns. The ratio $\lambda _{\textrm {gun}}=\mu _0 I_{\textrm {gun}}/\psi _{\textrm {gun}}$ of gun current $I_{\textrm {gun}}$ to applied magnetic flux $\psi _{\textrm {gun}}$ is an experimental knob for exploring the parameter space of $\beta$ and $\omega \tau$ . These experiments were conducted on the Big Red Ball at the Wisconsin Plasma Physics Laboratory. The transient formation of such plasmas can potentially open up new regimes for the laboratory study of weakly collisional, magnetized, high- $\beta$ plasma physics; processes relevant to astrophysical objects and phenomena; and novel magnetized plasma targets for magneto-inertial fusion.

中文翻译：

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在磁化、弱碰撞状态下形成瞬态高 β 等离子体

我们提供的实验数据为瞬态的形成提供了证据（ ${\sim }20\ \mathrm {\mu }\textrm {s}$ ）同时被弱磁化的等离子体（即霍尔磁化参数 $\omega \tau > 1$ ) 并受热压（即热压与磁压之比）支配 $\beta > 1$ ）。粒子碰撞平均自由程是整个系统大小的一个可观的部分。这些等离子体是通过磁化同轴枪发射的两个等离子体的正面合并形成的。比例 $\lambda _{\textrm {枪}}=\mu _0 I_{\textrm {枪}}/\psi _{\textrm {枪}}$ 枪电流 $I_{\textrm {枪}}$ 施加的磁通量 $\psi _{\textrm {枪}}$ 是探索参数空间的实验旋钮 $\beta$ 和 $\欧米茄\tau$ . 这些实验是在威斯康星等离子体物理实验室的大红球上进行的。这种等离子体的瞬态形成可能为实验室研究弱碰撞、磁化、高 $\beta$ 等离子体物理学；与天体物理对象和现象相关的过程；和用于磁惯性聚变的新型磁化等离子体靶。