1964 Volume 13 Issue 1 Pages 13-19
Radioactivation analysis of manganese was studied with a low-level neutron source, (1c) Pu+Be, and the procedure designed was applied to the nondestructive analysis of the element in some mineral samples.
Paraffin was used as moderator, and the distribution of thermal neutron was measured by using In foil, MnO2 and Au foil. The maximum thermal neutron flux of 3×103n/cm2⋅sec. was obtained with 1-2.1 em thick paraffin.
The self-shielding effect and self-absorption effect were also studied; the both effects were observed when the amounts of sample exceeded 250 mg.
Two hundred and fifty milligrams of powdered sample (Ca. 200 mesh) was irradiated for 17 hours at the distance of 2.5 cm from the neutron source, and after cooling for 10 min, activity was measured with G-M counter.
The decay curve and the gamma scintillation spectrum indicated that the activity obtained was attributed to the decay of 56Mn. The constituents of minerals such as O, Na, Mg, Al, Si, Ca, Fe etc., did not give any effect, when manganese content was more than 2 %. Manganese in minerals can be determined within the relative error of 5%.
