This paper presents experimental investigations of the diffraction of plane strong shocks by several cones, a cylinder, and a sphere. The diffraction pattern, in particular the loci of Mach triple points and the shape of the diffracted shocks are compared with theoretical results obtained from a diffraction theory proposed by Whitham (1957, 1958, 1959). The agreement between theory and experiment is shown to be good. Also given are extensive numerical results supplementing Whitham's papers, and theortical considerations applying Whitham's theory to very blunt bodies.

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Using the glow discharge shock tube developed in this laboratory, we measured the temperature and density dependence of the β, γ, and δ bands for the NO recombination afterglow. We also determined the absolute rate constants for each of the vibrational transitions of the three bands at room temperature. Our results for the total band intensities are Iβ = 3.09 × 10−34(T / 300)−1.40[N][O][N2] photons / cm3·sec, Iγ = 1.18 × 10−17(T / 300)−0.35[N][O] + 2.12 × 10−34(T / 300)−1.24[N][O][N2] photons / cm3·sec, Iδ = 6.75 × 10−18(T / 300)−0.35[N][O] photons / cm3·sec. The results are critically reviewed and compared with previous experiments in the final part of the paper.

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