Suppression of ³He superfluidity in small cylindrical pores.
| Main Author: | |
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| Other Authors: | , , |
| Format: | Thesis Book |
| Language: | English |
| Published: |
1987.
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| Subjects: | |
| Online Access: | Link to OAKTrust copy Link to ProQuest copy |
| Abstract: | The suppression of ³He superfluidity in 1800 Å radius pores has been observed using a torsional oscillator cell and nuclepore membrane. The measured amount of B-phase suppression is less than half the amount calculated by Kjäldman, Kurkijärvi, and Rainer for perfectly diffuse scattering boundary conditions. The data fits the theory well for a fitted pore radius of approximately 2550 Å. The AC technique employed generates very low flow velocities and provides a high sensitivity to the pressure variation across the membrane. This permits the observation of a superfluid velocity which is two to three orders of magnitude smaller than usually measured and which does not obey the usual (depairing) temperature dependence. The critical velocity manifests a low dissipation state in ³He not previously observed in less sensitive experiments. In the A-phase a greater amount of transition temperature suppression is measured. Likewise there is a low velocity critical phenomenon which occurs for mass currents much smaller than in the B-phase. |
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| Item Description: | Typescript (photocopy). Vita. |
| Physical Description: | x, 115 leaves : illustrations ; 29 cm |
| Bibliography: | Includes bibliographical references (leaves 101-104). |