A PULSED LIGHT SOURCE WITH RADIATION SIMILAR TO THE RADIATION OF AN ABSOLUTELY BLACK BODY AT A TEMPERATURE OF APPROXIMATELY 40,000K,

Abstract : The unique properties of a high-intensity flash discharge with a limited diameter of the discharge channel were utilized in designing an EV-39 high-temperature light source calibrated by luminance. The test results show that: (1) in the region of 1900-8000 A the source emits a uniform continuous spectrum, (2) the central part of the discharge channel with a diameter of 1 mm has a constant luminance within an accuracy of plus or minus 2% and that the luminance decreases at the edge of the aperture, (3) the radiation source is square shaped and that the form and duration of the light source do not vary with the wavelength, (4) the brightness temperature of the source in the spectral region 4000-6000 A does not vary with the wavelength and amounts to 39000 plus or minus 40000 K, and (5) the spectral density measurements are within an accuracy of plus or minus 7%. The EV-39 light source was designed on the basis of an electrical circuit developed by the authors and described in the present article. These types of light flash sources are currently used in high-speed photography and gas pyrometry, as well as for obtaining plasma absorption spectra and studying gas dynamics.