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Abstract

The heat capacity C(p) of UO(2) was measured in a laboratory experiment where sintered 0.5 to 1 mm diameter microspheres were heated by four tetrahedrally oriented laser beams in an autoclave filled with inert gas at pressures up to around 1000 bar. The sample, suspended by a tungsten needle, was heated to 8000 K during pulses of a few milliseconds duration. The experimental technique, the instrumentation, and the analytical method used to deduce C(p) from the experimental pulse-heating curves are described. Between the melting point T(m) and around 4000 K, the heat capacity decreases to a value close to that given by the Neumann-Kopp rule for a triatomic, harmonic lattice, i.e. 9R. Near 5000 K, however, the heat capacity again increases, and it appears to saturate at a value around 30 % higher by 8000 K. The new results are compared with published C(p) values for molten UO(2) (and other relevant materials) and are discussed briefly in light of the established temperature dependence of C(p) at T less than T(m) and the high-energy electronic structure of UO(2).

Additional information

Authors: RONCHI C, JRC Karlsruhe (DE);HIERNAUT J P, JRC Karlsruhe (DE);SELFSLAG R, JRC Karlsruhe (DE);HYLAND G J, University of Warwick, Department of Physics, Coventry (GB)
Bibliographic Reference: Article: Nuclear Science and Engineering, Vol. 113 (1993) pp. 1-19
Record Number: 199310369 / Last updated on: 1994-11-29
Category: PUBLICATION
Original language: en
Available languages: en