7.7 Visualisation by Induced Light Emission
181
Fig. 7.22 Glow discharge visualisation of a shock-shock interference at Mach 10 (© DLR)
etc. Figure 7.22 shows a visualisation of the field produced by the intersection of
an oblique shock wave generated by a wedge and the shock forming in front of a
cylinder (experiments performed by DLR in the ONERA R5Ch wind tunnel).
7.7.2 Electron Beam-Induced Fluorescence (EBF)
This process, which uses light emitted by nitrogen molecules while de-energising
after intense electron beam bombardment (30 kV–0.1 mA), is also used for quantitative measurements (see Sect. 12.7). Figure 7.23 shows an EBF visualisation of a
Mach 10 flow past a Martian probe. The image of the field is obtained by scanning
the electron beam at a frequency of 50 Hz.
181
Fig. 7.22 Glow discharge visualisation of a shock-shock interference at Mach 10 (© DLR)
etc. Figure 7.22 shows a visualisation of the field produced by the intersection of
an oblique shock wave generated by a wedge and the shock forming in front of a
cylinder (experiments performed by DLR in the ONERA R5Ch wind tunnel).
7.7.2 Electron Beam-Induced Fluorescence (EBF)
This process, which uses light emitted by nitrogen molecules while de-energising
after intense electron beam bombardment (30 kV–0.1 mA), is also used for quantitative measurements (see Sect. 12.7). Figure 7.23 shows an EBF visualisation of a
Mach 10 flow past a Martian probe. The image of the field is obtained by scanning
the electron beam at a frequency of 50 Hz.