Equation of State for Hydrodynamic Compression in Turbulent Z-Pinch

这个项目调查了在湍流涡流中储存能量，然后突然释放这种能量的推测可能性。当气体被压缩时，它的温度会升高。然而，如果有其他自由度吸收能量，温度的上升可能会较小。例如，假设气体能量主要存在于旋涡中，而不是完全随机运动。我们提出的问题是，是否存在压缩气体可能会增加涡流能量的条件。这个问题的意义在于，涡流中的能量与随机能量的作用不同，因为相邻的分子往往朝着同一方向移动。这意味着气体分子发生高撞击正面碰撞的次数将会减少。核聚变等重要过程依赖于这种相对运动，因此在能量存在于旋转涡流而不是随机热运动的气体中，聚变反应会更少。如果这是真的，那么人们可能还会推测，这种效应可以有利地用于控制高度压缩的等离子体中的核聚变。这个项目研究了储存能量然后突然释放出来的可能性，这些能量可以沉积在等离子体中的湍流涡流中。据推测，在可以忽略粘性的时间尺度压缩下，这种涡旋的能量可能会增加。此外，如果能量存在于流体动力涡流中，而不是离子温度中，这意味着电子无法通过碰撞获得能量。因此，这种能量不容易被电子捕获和辐射。如果压缩增加的涡动能量大于随机能量，则可能提出一种在高度压缩的等离子体中存储能量的新范式，即在非辐射等离子体中压缩时能量含量增加，然后在粘性耗散下突然释放能量。为了验证这些推测，将进行粒子模拟来描述压缩湍流涡流，从Z-Pinch实验中获得指导，这些实验似乎已经显示出湍流无粘等离子体的某些特征。这项工作将涉及普林斯顿大学和以色列魏茨曼科学研究所之间的合作，并将在美国国家科学基金会和美国-以色列双国科学基金会之间的研究合作谅解备忘录的框架下进行。该项目由美国国家科学基金会物理部和国际科学与工程办公室共同发起。

This project investigates the speculative possibility of storing energy in turbulent fluid eddies, and then suddenly releasing this energy. When gas is compressed, its temperature increases. However, the increase in temperature might be less if there are other degrees of freedom that absorb the energy. Suppose, for example, that the gas energy resides mainly in whirling eddies, rather than in completely random motion. We ask the question whether there are conditions under which compression of the gas might increase this eddy energy. The significance of this question is that energy in eddies acts differently than random energy because neighboring molecules tend to move in the same direction. That means that there would be fewer times that gas molecules would make high-impact head-on collisions. Important processes such as nuclear fusion depend on this relative motion, so the fusion reactions would be fewer in gases where the energy resides in whirling eddies rather than in random thermal motion. If this were true, then one might also speculate that the effect could be used advantageously in controlling nuclear fusion in a highly compressed plasma. This project investigates the possibility of storing and then suddenly releasing the energy that can be deposited into turbulent fluid eddies in a plasma. It is conjectured that, under compression on a time scale in which viscosity may be neglected, the energy in such eddies might increase. Also, if the energy resides in hydrodynamic eddies rather than ion temperature, it means that it is unavailable to electrons through collisions. Thus, this energy cannot be easily captured by electrons and radiated. If the compression increases eddy energy more than the random energy, a new paradigm for storing energy in a highly compressed plasma might be advanced in which the energy content is increased under compression in a non-radiating plasma, and then suddenly released under viscous dissipation. To test these speculations, particle-in-cell simulations will be performed to describe compressing turbulent eddies, with guidance obtained from Z-pinch experiments that already appear to exhibit certain features of a turbulent inviscid plasma. This work will involve a collaboration between Princeton University and the Weizmann Institute of Science in Israel, and will be performed under the umbrella of the Memorandum of Understanding on Research Cooperation between NSF and the US-Israel Binational Science Foundation. This project is co-sponsored by the NSF's Physics Division and the Office of International Science and Engineering.