A series of gamma-sources with activity from 0.08 to 0.93 GBq was prep
ared from isotopically pure metallic americium-241. These sources were
prepared by condensation on the tantalum or stainless steel support o
f highly pure metallic americium, which was obtained by thermal decomp
osition of long-stored Pu-241-Am-241 alloy in a high vacuum.