Nucleation Processes in Liquid Helium

液氦中的成核过程

• 批准号: 9703529
• 负责人: Humphrey Maris
• 金额: $ 27万
• 依托单位: Brown University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-08-15 至 2000-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9703529&HistoricalAwards=false
• 关键词: Nucleation; Processes; Liquid; Helium

w:\awards\awards96\num.doc 9703529 Maris Experimental research will be performed to study nucleation processes in liquid helium. The first project is an investigation of the nucleation of bubbles in helium liquid which is subjected to a negative pressure. We plan to study how this nucleation process is influenced by the presence of electrons and quantized vortices. The goal of the second project is the detection of the nucleation of solid helium at pressures above the normal freezing pressure of the liquid. The third experiment is to look for the nucleation of bubbles at the interface between liquid helium and a solid wall. As part of this last experiment, we will attempt to measure the equation of state of liquid helium at negative pressure. %%% The way in which bubbles form in liquids is important in many technologically important applications. These include ink-jet printers, ship propellers, and liquid pumps. Bubble formation can occur even in clean liquids but is often greatly influenced by impurities or solid particles in the liquid. Studying bubbles in liquid helium is worthwhile because the liquid can be made much purer than any other liquid, and hence it is easier to perform experiments which are unaffected by the influence of impurities. *****

Maris将进行实验研究，以研究液氦的成核过程。第一个项目是研究负压下氦液体中气泡的成核。我们计划研究这种成核过程如何受到电子和量子化漩涡的影响。第二个项目的目标是在高于液体正常冷冻压力的压力下探测固体氦的成核。第三个实验是在液氦和固体壁之间的界面上寻找气泡的成核。作为最后一个实验的一部分，我们将尝试测量液氦在负压下的状态方程。气泡在液体中形成的方式在许多技术上重要的应用中是重要的。这些设备包括喷墨打印机、船舶螺旋桨和液体泵。气泡的形成即使在干净的液体中也会发生，但通常会受到液体中的杂质或固体颗粒的很大影响。研究液氦中的气泡是值得的，因为这种液体可以比任何其他液体纯净得多，因此更容易进行不受杂质影响的实验。＊＊＊＊＊