Electron Probe Micro-Analysis of Minerals for Light Elements : Carbon and Nitrogen

Electron probe microanalysis (EPMA) of the wavelength-dispersive (WD) type offers some advantage in each quantitative analysis of carbon and nitrogen in non-conducting minerals coated with a thin film of Al-metal and carbon, respectively. The crystal of W/Si evaporated multilayers for long-wavelength WD spectrometry is used to cover the routine wavelength range for these elements. Both opening of the slit and accumulation of the intensity by reiterative measurements at several analytical points adjoining each other have improved the accuracy in the low count rates of 'soft' X-rays from canbon and nitrogen.