Simultaneous two-wavelength holographic interferometry ina superorbital expansion tube facility

Timothy J. McIntyre, Margaret J. Wegener, Alexis I. Bishop, Halina Rubinsztein-Dunlop

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A new variation of holographic interferometry has been utilized to perform simultaneoustwo-wavelength measurements, allowing quantitative analysis of the heavy particle and electron densities in a superorbital facility. An air test gas accelerated to 12 km/s was passed over a cylindrical model, simulating reentry conditions encountered by a space vehicle on a superorbital mission. Laser beams with two different wavelengths have been overlapped, passed through the test section, and simultaneously recorded on a single holographic plate. Reconstruction of the hologram generated two separate interferograms at different angles from which the quantitative measurements were made. With this technique, a peak electron concentration of (5.5 ± 0.5) × 1023 m−3 was found behind a bow shock on a cylinder.

Original languageEnglish
Pages (from-to)8128-8134
Number of pages7
JournalApplied Optics
Issue number31
Publication statusPublished - 1 Nov 1997
Externally publishedYes

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