1965 Volume 14 Issue 3 Pages 212-217
Neutron absorptiometry for analysing of boron contents in borosilicate glass and frit was investigated. A Ra+Be of 4.81 mg Ra fast neutron source and the paraffin were used to slow down the fast neutrons to thermal velosity. The neutron detector was a ZnS (Ag) -B polyester scintillator of 2 inches diameter and 5/8 in thickness. The relations between the intensity of slow neutrons produced and the size of paraffin were studied, and then a neutron howitzer suitable for neutron absorption analysis was prepared. The measurements of neutron transmittanee of borosilicate glasses and frits of known boron contents were performed. The accuracy of boron determination is highest in the case of σnx=2, where σ is cross section per atom, n is the number of atoms in cm3, and x is the thickness of sample material to be tested. The relative error of boron determination was estimated as about ±9% in 10 minutes counting for a sample when B2O3 content was 5% for frit sample of 1.75 g/cm2 thickness.