On the Interaction of a Weak-R Type Ionization Front and a Contact Discontinuity

A numerical solution is given to the problem of a weak R type ionization front approaching a contact discontinuity across which the density increases. During the interaction it is found that there are three possible configurations produced; the weak-R type ionization front becomes (a) weak-R type but slower for QI/QO < 1.15, (b) strong-D type for 1.15 < QI/QO < 3.4 or (c) weak-D type for QI/QO > 3.4, where the original ionization front travels through a region of initial density go and across the contact discontinuity the density becomes £>i. A fine spacial mesh length is chosen so that the structures of the resulting ionization fronts and shock waves may be identified clearly at any time.