Quantum Vortex Events in the Critical Flow of Superfluid Helium-4 Through Microscopic Apertures

9403522 Zimmermann这是低温凝聚态物理领域的研究成果。 该项目将研究超流氦-4通过亚微米和微米大小的孔在亚微米厚度的独立薄膜中流动的临界速度和相滑移。 这项工作的目的是了解基本的量子涡旋过程中所涉及的第一次发病的耗散超流体流动的速度从零开始增加。 使用高Q超流体谐振器来激励通过孔的超流体的振荡流，并感测耗散的开始。 %这是低温物理领域的研究成果。 该项目涉及超流氦的研究，它不像普通流体那样传递热能。 在这样的系统中，热能需要产生类似于烟圈的漩涡，当超流体移动通过微观孔时，可以产生漩涡。 这项研究将研究超流氦-4中涡旋产生和能量耗散的基本方面。 这项工作是具有根本意义的，但也可能有技术上的重要性，在一般领域的流体动力学。 该项目包括在实验观测下对流体动力学进行计算机建模。

9403522 Zimmermann This is a research effort in the area of low temperature condensed matter physics. The project will investigate critical velocities and phase-slip in the flow of superfluid helium-4 through submicron and micron-size apertures in thin, free-standing films of submicron thickness. The aim of the work is to understand fundamental quantum vortex processes involved in the first onset of dissipation in superfluid flow as the velocity is increased from zero. Use is made of a high-Q superfluid resonator to excite oscillatory flow of the superfluid through the aperture and to sense the onset of dissipation. %%% This is a research effort in the area of low temperature physics. The project involves the study of superfluid helium, which does not transport heat energy as ordinary fluids. The heat energy in such systems requires generation of vortices, analogous to smoke rings, that can by generated as the superfluid moves through microscopic apertures. The research will study fundamental aspects of vortex generation and energy dissipation in superfluid helium-4. The work is of fundamental significance but may as well have technical importance in the general field of fluid hydrodynamics. The project includes computer modeling of the fluid hydrodynamics under experimental observation.