Measuring the local density of light gases by characteristic X-rays

Until recently, the measurement of the local gas and plasma density through the intensity of the characteristic radiation induced by an electron beam was being carried out for argon only. The difficulty in applying this method to light gases, e.g., N₂ and O₂, resides in the necessity of resolving the low-energy (0.4–0.6 keV) spectral lines against the background of high-energy (15–50-keV) bremsstrahlung. X-ray and magnetic filters helped measure light-gas spectra under the given conditions. Deceased.