Electron concentration behind a sphere of an aluminum-magnesium alloy in a hypersonic flow

Results of microwave measurements of the electron concentration and the frequency of electron-neutral particle collisions in the wakes behind models of an aluminum-magnesium alloy flying in air- xenon mixtures at Mach numbers of 10–15 are reported. For comparison, similar measurements for models without and with aluminum decomposition are presented. The burn-up of Mg particles in the wake is found to change the form of the distribution and to increase appreciably the electron concentration in the wake. The attachment coefficients for electrons in the experiment with Al entrainment and in previous studies are shown to be in good agreement.