Stability of shock waves in high temperature plasmas

Journal Article · Sat Oct 15 00:00:00 EDT 2011 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.3653253· OSTI ID:22036754

Das, Madhusmita ^[1]; Bhattacharya, Chandrani; Menon, S V. G. ^[2]

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1. Department of Physics, Indian Institute of Technology, Bombay, Powai-400076 (India)
2. Theoretical Physics Division, Bhabha Atomic Research Centre, Mumbai-400085 (India)

The Dyakov-Kontorovich criteria for spontaneous emission of acoustic waves behind shock fronts are investigated for high temperature aluminum and beryllium plasmas. To this end, the Dyakov and critical stability parameters are calculated from Rankine-Hugoniot curves using a more realistic equation of state (EOS). The cold and ionic contributions to the EOS are obtained via scaled binding energy and mean field theory, respectively. A screened hydrogenic model, including l-splitting, is used to calculate the bound electron contribution to the electronic EOS. The free electron EOS is obtained from Fermi-Dirac statistics. Predictions of the model for ionization curves and shock Hugoniot are found to be in excellent agreement with available experimental and theoretical data. It is observed that the electronic EOS has significant effect on the stability of the planar shock front. While the shock is stable for low temperatures and pressures, instability sets in as temperature rises. The basic reason is ionization of electronic shells and consequent increase in electronic specific heat. The temperatures and densities of the unstable region correspond to those where electronic shells get ionized. With the correct modeling of bound electrons, we find that shock instability for Al occurs at a compression ratio {approx}5.4, contrary to the value {approx}3 reported in the literature. Free electrons generated in the ionization process carry energy from the shock front, thereby giving rise to spontaneously emitted waves, which decay the shock front.

• OSTI ID: 22036754
• Journal Information: Journal of Applied Physics, Vol. 110, Issue 8; Other Information: (c) 2011 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
ALUMINIUM
BERYLLIUM
BINDING ENERGY
COMPRESSION RATIO
ELECTRON TEMPERATURE
ELECTRONIC SPECIFIC HEAT
ELECTRONS
EQUATIONS OF STATE
FERMI STATISTICS
HOT PLASMA
ION ACOUSTIC WAVES
ION TEMPERATURE
IONIZATION
MEAN-FIELD THEORY
PLASMA DENSITY
PLASMA INSTABILITY
PLASMA PRESSURE
SHOCK WAVES
STABILITY
THERMODYNAMICS