Studies On Equation Of State And Opacity Of H₂,D₂,and Their Mixtures

In this dissertation, the equation of state (EOS) and opacity of shocked H2, D2 and their mixture are studied, but with emphasis on EOS. The content includes two parts: (a) The Hugomot data, shock temperature and opacity of gaseous D2 and H2+D2 equimolar mixture are measured by using instantaneous optical pyrometer and magneto-flier velocity system. The thermodynamic statistical theory is adopted to theoretically analyze the experimental data with considering the dissociation and ionization influence for the shocked H2, D2 and H2+D2 mixture with comparative systematicness; (b) Using the fluid perturbation variational theory with quantum correction, the EOS and the molecular interaction of liquid H2, D2, H2+D2 and He+H2 mixture are theoretically investigated, and compared with the experiments that have been published in literatures. The main results can be summarized as follows: 1. The Hugoniot data, shock temperature,TH, spectral absorption coefficient, K(2), and the reflection coefficient, R(2), of the shocked base-plate surface of gaseous D2 (with initial temperature 296K and initial pressure 0.6MPa.) and H2+D2 mixture (with initial temperature 285Kand two initial pressures 0.6MPa and I .2MPa.) are measured. The results show: the experimental EOS is in agreement with the calculations by Saha model on the whole; The value of R(2) is nearly a constant of 0.34?.41, approximately decreasing to half of its initial value of 0.82?.85. 2. With the use of thermodynamic statistical theory, we formulate the dissociation and ionization equilibrium equations for gaseous hydrogen, deuterium and their mixtures, and use the gradient method and Fortran77 for coding program (mol- saha.for). The particle number density, n, vs shock temperature relation is first calculated, and then to compute the shock pressures, H, the shock wave velocity, D, and the particle velocity, u. In comparison to the Sesame database, it can be found: (a) under shock compression condition, the main process occurring in H2 (or D2) is of dissociation when the temperature is below 4000K, forming two-element mixture of H2, H (or D2 and D); with increasing temperature, the dissociation, and so does the ionization, degree increases, and gradually transforms to a five-element mixture of H2, H, H, H2, and e (or D2, D, D, D2 and e); While TH up to 7000K or higher, most of H2(or D2) are dissociated [See Chinese Journal of High Pressure Physics, 14(3), (2000) p.168 (in Chinese)]. The situation of the shocked gaseous H2+D2 mixture is analogue to that of the shocked gaseous H2, i.e. when below 4000K, the main transformations is of dissociation, forming a four-element mixture of H2, D-,, H, and D; With increasing temperature, the dissociation, and so does the ionization, degree increases, and then the mixture gradually transform to a nine- element mixture of H2, H, H, H2, e, D2, D, D, D2 in final; While T up to 7000K or higher, most molecules in the mixture are dissociated; (b) The model calculations for shock compression behavior of the gaseous H2, D2, and H22 equimolar mixture are all analogue to with each other. The isotopic effect is mainly responsive to the value of C0in shock velocity relation D = C0 + 2u.It demonstrates that the value of C0 is basically proportional to the negative square root of density (i.e.C0p 2), but not for the values of 2 which remains a constant in the main; (c) The model calculations for shocked H2+D, equimolar mixture is in accord with the exper...