U.S.-Germany Cooperative Research on the Homogeneous Nucleation of Metal Vapors

该奖项支持约翰·霍普金斯大学的约瑟夫·L·卡茨与德国马尔堡菲利普斯大学的弗里德里希·亨塞尔教授在化学工程方面的合作研究。他们正在合作进行一项研究，该研究涉及使用向上的热扩散室来测量铯和其他金属蒸气的均匀成核。他们的研究计划利用了两个研究小组的互补优势。亨塞尔博士领导的德国研究小组以金属-绝缘体转变和金属蒸气的其他性质的研究而闻名。他们拥有最先进的设备，积极研究过饱和水银蒸气。卡茨博士和他的团队是使用扩散云室和核化理论的专家。他们有一个非常活跃的计划，使用向上热扩散云室来研究均匀和其他核化。大部分实验工作将在马尔堡完成，一些数据分析和其他支持将在马里兰州进行。两个研究小组成员的互访将促进这项联合工作。成核过程在自然界和实验室中都极为普遍。然而，我们预测导致成核的条件以及它在典型过程中发生的速度的能力几乎是不存在的。液体从其过饱和蒸汽中均匀成核特别适合于理论和实验研究。金属的形核性质与非金属的形核性质有很大的不同，随着生产和使用新合金或以新方式使用已知金属的技术的发展，它们变得越来越重要。

This award supports Joseph L. Katz of Johns Hopkins University for collaborative research in chemical engineering with Professor Friedrich Hensel of Phillips University in Marburg, Germany. They are cooperating in a study that involves the use of upward thermal diffusion chambers to measure the homogeneous nucleation of cesium and other metal vapors. Their research plan exploits the complementary strengths of the two research groups. The German group led by Dr. Hensel is well known for their research on the metal-insulator transition and other properties of metal vapors. They have state-of-the-art facilities where they are actively studying supersaturated mercury vapor. Dr. Katz and his group are expert in the use of the diffusion cloud chamber and in nucleation theory. They have a very active program using upward thermal diffusion cloud chambers for the study of homogeneous and other nucleations. Most of the experimental work will be done in Marburg, with some data analysis and other support going on in Maryland. Reciprocal visits of members of the two research groups will facilitate this joint work. Nucleation processes are extremely widespread in the natural world as well as in the laboratory. However, our ability to predict the conditions that cause nucleation and the rate at which it occurs in typical processes is almost non-existent. Homogeneous nucleation of a liquid from its supersaturated vapor is particularly amenable to theoretical and experimental study. The nucleation properties of metals are quite different from those of non-metals, and they are of growing importance as technologies develop to produce and use novel alloys or to use known metals in novel ways.