Temperature and Emissivity of a Shocked Surface: A First Experiment

We have conducted an experiment in which the temperature and the wavelength dependent emissivity of a shocked surface has been measured. In the past, only the thermal emission from the shocked surface has been measured. The lack of knowledge of the emissivity as a function of wavelength leads to uncertainty in converting the measured emission spectrum into a surface temperature. We have developed a technique by which we are able to calculate both the emissivity of the shocked surface over a range of relevant wavelengths and the temperature of the surface. We use a multi-channel spectrometer in combination with a pulsed light source having a known spectrum of infrared radiation. Two separate techniques using a pulse of reflected radiation are employed and described. Both give the same result: An initially polished molybdenum surface that is shocked and partially released has a temperature of 1040 degrees Kelvin and a wavelength (λ) dependent emissivity of 0.16 (λ = 1.2 (micro)m), 0.10 (λ = 1.6 (micro)m), and 0.20 (λ = 2.3 (micro)m)