Increasing accuracy of X-ray radiometric determination of small contents of heavy elements in ores

X-ray fluorescence method for analyzing elements with Z≥47 was considered; the contribution of conditions of secondary radiation spectrum formation to device error was evaluated. Method for secondary radiation spectrum formation, enabling to decrease sufficiently the value of device error, related to instability of 'detector-amplifier' path, was suggested. X-ray fluorescence determination of tungsten in tungsten-containing ores was taken as an example to show, that the suggested method enabled to decrease 3-4 times its detection limit as compared to traditional method