Results of a Feasibility Study for High Pressure Electron Beam Diagnostics in the AFFDL High Temperature Facility.

摘要

Results of an unsuccessful attempt to determine the feasibility of making electron beam measurements of nitrogen vibrational temperature in hypersonic air flows at high static pressures (greater than 5 Torr) are presented. A flat plate and cylindrical blunt body were used to generate the higher pressure test gas. In the case of the flat plate, reflection of secondary electrons from the plate surface caused spurious excitation of the, nitrogen molecules negating the theory underlying the interpretation of the monitored fluorescence. In the case of the solid cylinder, the generated test gas was at too high a static temperature, causing serious Overlapping of the bands used in making the measurements and thus making interpretation of the data impossible. An encouraging result was that the electron beam can easily penetrate flows of 40 mm static pressure.