Measurement of the plasma sources spectral radiance

Бедрин А.Г., Гурьев А.П., Громовенко В.М., Жилин А.Н., Миронов И.С. Измерение спектральной плотности энергетической яркости плазменных излучателей // Оптический журнал. 2023. Т. 90. № 7. С. 76–85. http://doi.org/10.17586/1023-5086-2023-90-07-76-85

Bedrin A.G., Guryev A.P., Gromovenko V.M., Zhilin A.N., Mironov I.S. Measurement of the plasma sources spectral radiance [in Russian] // Opticheskii Zhurnal. 2023. V. 90. № 7. P. 76–85. http://doi.org/10.17586/1023-5086-2023-90-07-76-85

Alexander G. Bedrin, Alexander P. Guryev, Valentin M. Gromovenko, Aexander N. Zhilin, and Ivan S. Mironov, "Measurement of the spectral radiance of plasma sources," Journal of Optical Technology. 90(7), 399-404 (2023). https://doi.org/10.1364/JOT.90.000399

Subject of study. Plasma emitters generating high-power light pulses of a second duration: an open discharge of an erosion type controlled by a magnetic field — a magnetically pressed discharge and a large-format lamp panel based on tube gas-discharge lamps. The aim of the work is to develop a methodology for measuring the absolute values of spectral density of radiance of these sources using a spectrometer of USB4000 type. Research method. The measurement procedure includes measuring the light pulse using a pyroelectric detector (or calorimeter) installed at a certain distance from the radiation source, determining the irradiance and integrated luminance in the selected spectral interval and registering the source spectrum. Then the measured spectral dependence is adjusted for the spectrometer sensitivity and the exposure time to obtain a value proportional to the spectral density of the radiance. By integration of the found dependence in Excel in a graphic form with due regard for integrated luminance in the selected spectral interval, the absolute values of spectral density of the radiance of the source are determined. Main results. The technique of absolute radiometric calibration of the spectrometer USB4000 has been developed and applied, which allows the accuracy and reliability of the results obtained with simultaneous expansion of the spectral range from 220 to 900 nm to be increased. The technique is based on the use of two mutually complementary certified radiation sources with different spectral composition. To measure spectral density of the radiance of the radiation sources, the measurement scheme based on a pre-calibrated spectrometer is supplemented with a calorimeter (or a non-selective pyroelectric receiver) with band-pass light filters to find the irradiance in the selected spectral interval. The absolute values of spectral density of the radiance of the magnetically pressed discharge radiation in the spectral range 220–400 nm and lamp panel in the range 400–900 nm are determined. Practical use. Absolute calibration of spectrometers in the visible and infrared spectral regions presents no special problem due to the availability of standardized calibrated radiation sources. In the ultraviolet range, this is the problem for the lack of adequate equipment. The use of the developed method makes it possible to obtain absolute values of spectral radiance of plasma sources, including in the ultraviolet range of the spectrum.

The authors are grateful to V.G. Dokuchaev, who carried out the metrological calibration of the spectrometer, and A.F. Aushev for help with calibration and measurements.