Monolayer Physics

w：\awards\awards96\*. doc 9623395 Vilches 本项目主要研究H2、HD、D2、3He和4He中的表面和界面现象。 将对低于5.7K（有记录以来的最低三相点）的液相H2进行搜索。如果在2K左右的温度下观察到液相，那么超流体性质是可以预期的。H2-D2膜混合物中冻结和可能的相分离的仔细调查（和比较 3He-4He混合物的研究）将 被 完了 将测量微孔内冷凝的H2的冻胀压力，其中H2的表面熔融层应通过维持非常大的压力梯度来响应沿着样品的温度梯度。中子和X射线散射测量各种氢同位素将测量 结构和输运性质。 研究生 和本科生都参与了项目的各个方面。 %本项目将探索，使用不同的条件 和技术，可能存在的液氢薄膜，以非常低的温度。在特殊固体基质上形成的氢膜和在多孔材料内冻结的氢可产生液体膜，其将具有不寻常的新流体流动、热传输和/或压力梯度特性。 该项目的技术方面将通过测量液体和固体性质， 热， 压力梯度， 中子， 和 氢、氘、氢化氘及其混合物稳定分子的x射线实验。比较实验将使用已知是流体的氦同位素进行。 研究生和本科生参与了这个项目的各个方面。 ***

w:\awards\awards96\*.doc 9623395 Vilches This project is concerned with the study of surface and interface phenomena in H2, HD, D2, 3He, and 4He. A search for a liquid phase of H2 below 5.7K, the lowest triple point on record, will be conducted. Should a liquid phase be observed down to 2K or so, superfluid properties are expected. A careful survey of freezing and possible phase separation in H2-D2 film mixtures (and comparison studies with 3He-4He mixtures) will be done. Measurements of the frost heave pressure of H2 condensed inside micropores, where a surface melted layer of H2 should respond to a temperature gradient along the sample by sustaining a very large pressure gradient, will be performed. Neutron and X-ray scattering measurements on the various hydrogen isotopes will measure structure and transport properties. Graduate and undergraduate students are involved in all aspects of the project. %%% This project will explore, using different conditions and techniques, the possible existence of liquid hydrogen films to very low temperatures. Films of hydrogen formed on special solid substrates and hydrogen frozen inside porous materials may yield liquid films which will have unusual new fluid flow, heat transport, and/or pressure gradient properties. The technical side of the project will measure liquid and solid properties through thermal, pressure gradient, neutron, and X-ray experiments on the stable molecules of hydrogen, deuterium, and deuterium hydride, and their mixtures. Comparison experiments will be done using helium isotopes which are known to be fluid. Graduate and undergraduate students are involved in all aspects of this project. ***