EXPERIMENTAL INVESTIGATIONS OF NORMAL IONIZING SHOCK WAVES,
Abstract
Experiments were conducted on normal ionizing shock waves produced in a coaxial electromagnetic shock tube. Steady shock velocities were measured as a function of initial gas pressure, drive current, and applied axial magnetic field. The speeds agreed well with theoretical values. Shocks propagating at transAlfvenic speeds were studied. Measurements were made of the upstream transverse electric field and the switch-on magnetic field. Further support for this theory was provided by the measured compression ratio across the shock front. It was concluded that transAlfvenic normal ionizing shocks exhibited Chapman-Jouguet behavior with current flow in the shock front, and no separation of shock and drive currents. In contrast, superAlfvenic shocks appear to be gas dynamic in nature. Spectroscopic measurements and shock reflection studies demonstrated the presence of a nonluminous front and shock heated gas preceding the drive current. The luminosity front acts as a contact surface separating the unequilibrated shock from the luminous current. Finite transverse electric fields and switch-on behavior were observed at superAlfvenic shock speeds. Both of these effects were attributed to the finite conductivity of the plasma. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1967
- Accession Number
- AD0663212
Entities
People
- Leslie S. Levine
Organizations
- Columbia University