Combining Equations of State in Kull

Ulitsky, M ; Zimmerman, G ; Renard, P

Lawrence Livermore National Laboratory

关键词: Thermodynamics;    Plastics;    Diffusion;    Tritium;    Implementation;   

DOI  :  10.2172/929185
RP-ID  :  UCRL-TR-224230
RP-ID  :  W-7405-ENG-48
RP-ID  :  929185

美国|英语

来源: UNT Digital Library

【 摘 要 】

For ICF applications, the temperatures are hot enough that materials can transition to an atomic state or plasma. If we are simulating an ICF capsule, then either thru ALE, physical diffusion, transmutation by nuclear reactions, a mix model, or numerical diffusion (if we are running an Eulerian code), we will generate zones that contain multiple materials. It may be desired to treat certain mixtures of materials or mixed zones as atomic mixtures rather than as chunk mixtures. For example, suppose we have a deuterated material that is initially separated from a tritiated material. As these quantities come into contact at the atomic level, high energy neutrons will be generated from the D + T reaction. However, if we had a chunk of deuterium and a chunk of tritium in the same computational zone, then the D + T reaction would not take place. In dealing with atomic mixtures, two topics that immediately come to mind are mixed equations of state and mixed opacities. This report will only focus on the equation of state (EOS) aspect and its implementation in the Kull code. Imagine we have a zone that contains an atomic mixture of plastic and steel. If we know the density, temperature, and isotopics of this mixture, then a natural question is how will we compute the pressure and specific internal energy of the mixture as well as the derivatives of these quantities with respect to density and temperature. Let's consider the case where we have tabular thermodynamic data for plastic and steel (as a function of density and temperature), and our goal is to determine how to use these tables to compute the thermodynamic quantities of interest.