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Title: High density turbulent plasma processes from a shock tube. Final performance report

Technical Report ·
DOI:https://doi.org/10.2172/418475· OSTI ID:418475

A broad-based set of measurements has begun on high density turbulent plasma processes. This includes determinations of new plasma physics and the initiation of work on new diagnostics for collisional plasmas as follows: (1) A transient increase is observed in both the spectral energy decay rate and the degree of chaotic complexity at the interface of a shock wave and a turbulent ionized gas. Even though the gas is apparently brought to rest by the shock wave, no evidence is found either of prompt relaminarization or of any systematic influence of end-wall material thermal conductivities on the turbulence parameters. (2) Point fluorescence emissions and averaged spectral line evolutions in turbulent plasmas produced in both the primary and the reflected shock wave flows exhibit ergodicity in the standard turbulence parameters. The data show first evidence of a reverse energy cascade in the collisional turbulent plasma. This suggests that the fully turbulent environment can be described using a stationary state formulation. In these same data, the author finds compelling evidence for a turbulent Stark effect on neutral emission lines in these data which is associated with evidence of large coherent structures and dominant modes in the Fourier analyses of the fluctuations in the optical spectra. (3) A neutral beam generator has been assembled by coupling a Colutron Ion Gun to a charge exchange chamber. Beam-target collisions where the target species is neutral and the beam is either singly charged or neutral have been performed using argon as the working gas. Spectral analysis of the emission shows specific radiative transitions characteristic of both Ar I and Ar II, indicating that some ionization of the target gas results. Gas and plasma parameters such as density, pressure, temperature and flow velocity and their fluctuations can now be followed in real time by spectroscopic analysis of carefully chosen radiative emissions.

Research Organization:
Florida Agricultural and Mechanical Univ., Tallahassee, FL (United States). Dept. of Physics
Sponsoring Organization:
USDOE Office of Energy Research, Washington, DC (United States)
DOE Contract Number:
FG05-94ER54288
OSTI ID:
418475
Report Number(s):
DOE/ER/54288-T1; ON: DE97001778; TRN: 97:002287
Resource Relation:
Other Information: PBD: [1997]
Country of Publication:
United States
Language:
English