Shock ionization of gases

Since the appearance of Vol 4, relatively little has been published on ionization in detonation waves, or ionization in shocked condensed media. However, there is considerable new information on shock ionization of gases. We discuss these phenomena below... 

Shock Ionization of Gases. If temperatures behind a shock front are in. the range of 15000-20000°K the gas through which the shock is moving will be appreciably ionized. 

The ionization process is quite complex, and to avoid even further complications, the following discussion will be limited entirely to the shock-ionization of monatomic gases. 

There are no direct measurements of the degree of ionization of strongly shocked noble gases. Thus the validity of the above discussion can only be tested indirectly by comparing computed shock temperatures (which contain... 

If ionization occurs from excited and metastable states, as suggested by Benson to account for the ionization of the inert gases in shock tubes, the expression must be replaced by a suitably weighted summation over these states. 

Eq 8 immediately tells us that the degree of ionization depends strongly on the shock velocity U. For strong shocks p constant 0.9 (see Fig 6 of Ref 2) for all monoatomic or even polyatomic gases. Thus the only important shock parameter is U. Similarly the only important gas parameters are the molecular weight M and the first Ionization potential 1,... 

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