PROMPT GAMMA-RAY ANALYSIS OF BORON WITH COLD AND THERMAL-NEUTRON GUIDED BEAMS

Nondestructive determination of trace amounts of boron in various mate rials was carried out using neutron induced prompt gamma-ray analysis. A 100-250 mg sample was irradiated with cold or thermal guided neutro ns of JRR-3M, and the Doppler-broadened 478 keV prompt gamma-rays were measured. To determine the B content accurately, analytical condition s such as the sample size, the hydrogen content of the sample, and any interferences due to other elements were examined. Nanogram to microg ram per gram levels of B were determined in reference materials, inclu ding rocks, botanical samples, coal and coal fly ash, various types of sediments, animal tissue, environmental samples, and reactor material s, with accuracy and precision of better than 20%. The detection limit s varied depending on the type of sample: 12-22 ng/g for graphite and Be; 120-260 ng/g for marine environmental materials, coal fly ash, and pepperbush; and 57-98 ng/g for the other materials.