Convection and Critical Dynamics in Helium Three            Superfluid Helium Four Mixtures
{'Code': '03070003', 'Directorate': {'Abbreviation': 'MPS', 'LongName': 'Direct For Mathematical & Physical Scien'}, 'Division': {'Abbreviation': 'DMR', 'LongName': 'Division Of Materials Research'}}
{'SignBlockName': 'Wendy W. Fuller-Mora', 'PO_EMAI': None, 'PO_PHON': None}
The proposed measurements, to be carried out using superfluid                   helium mixtures, will address a number of questions of                          considerable current interest.  Using a pioneering flow                         visualization technique exploiting the interaction of thermal                   neutrons and helium three, they will obtain the first images of                 flows near the onset of convection in liquid helium.  Additional                measurements will use the very high temperature resolution                      obtainable at low temperatures and a variable geometry technique                developed in this laboratory to further characterize these flows.               Superfluid mixtures have a unique and very interesting parameter                range in which the hydrodynamic instabilities of steady                         convection will change character.  Using appropriate geometries,                they will explore in detail these instabilities, the way they                   lead to chaos, and the way they are affected by the steady                      convection patterns.  In a second set of measurements using the                 neutron imaging technique, they will establish the helium three                 profiles which are caused by the flow of heat in a superfluid                   mixture.  By these measurements, they hope to understand recent                 data which show a striking violation of current theories                        describing the heat flow in these mixtures.  The importance of                  the theories involved--Two-fluid Hydrodynamics and Dynamic                      Renormalization Group Theory--requires a careful examination of                 the heat flow problem in mixtures using a direct, but non-                      perturbative technique such as the neutron probe.
{'FirstName': 'Robert', 'LastName': 'Behringer', 'PI_MID_INIT': 'P', 'PI_SUFX_NAME': None, 'PI_FULL_NAME': 'Robert P Behringer', 'EmailAddress': 'bob@phy.duke.edu', 'NSF_ID': '000236819', 'StartDate': '11/01/1987', 'EndDate': None, 'RoleCode': 'Principal Investigator'}
{'Name': 'Duke University', 'CityName': 'DURHAM', 'ZipCode': '277054640', 'PhoneNumber': '9196843030', 'StreetAddress': '2200 W MAIN ST', 'StreetAddress2': None, 'CountryName': 'United States', 'StateName': 'North Carolina', 'StateCode': 'NC', 'CONGRESSDISTRICT': '04', 'CONGRESS_DISTRICT_ORG': 'NC04', 'ORG_UEI_NUM': 'TP7EK8DZV6N5', 'ORG_LGL_BUS_NAME': 'DUKE UNIVERSITY', 'ORG_PRNT_UEI_NUM': None}
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{'Code': '1764', 'Text': 'LOW TEMPERATURE PHYSICS'}
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