What potassium abundance in the Earth does the Borexino experiment admit?

The results of analysis for the single events energy spectrum obtained in phase III of Borexino detector operation are considered. The experimental spectrum was fitted by a set of standard single events sources with the addition of events from potassium geo-antineutrinos (40K-geo-v) scattering on electrons. The addition of 40K-geo-v events makes it possible to improve the agreement of the experimental and fitted spectra. Experimental results indicate the presence of a significant amount of potassium in the Earth.