Comparison of 14 MeV neutron activation analysis and competitive methods for determination of oxygen, nitrogen, silicon, fluorine and other elements

Conference · Wed Jan 01 04:00:00 EST 1986

OSTI ID:7252609

Bild, R W

14 MeV neutron activation analysis (14 MeV NAA) makes use of small particle accelerators to produce 14 MeV neutrons from the D-T reaction. The neutrons produce radioactive isotopes in samples by the reactions (n,p), (n,2n) and (n,..cap alpha..). Gamma rays emitted are counted to determine the amount of the target element present. Major applications have been determination of total O, N or Si in solid and liquid matrices, but the technique can also be applied to determine concentrations of about 30 other elements including F, Cl, Al, P and Mg. Detection limits are a few micrograms in the best cases and milligrams for most others. The method has advantages of being nondestructive, fast and insensitive to sample inhomogeneities. It lends itself especially well to sequential analysis of the same sample by several techniques and to samples that are difficult to dissolve. Portable generators have been applied to industrial situations and to well logging. Major disadvantages are the necessity to house a radiation producing instrument, the cost of the equipment and the lack of useful neutron reactions for some important elements. Accuracy (typically +-7 to 10% relative) and precision (+-1 to 5% relative) are comparable to competing techniques. For determination of low levels of O and N in most metals inert gas fusion is more rapid and sensitive; elemental analyzer is more sensitive for O and N in organics. Wet chemical methods rarely have any advantage over 14 MeV NAA for solid samples when concentrations are in the detection limit range of the 14 MeV NAA methods. Future developments in the field will come in the areas of simpler, more portable and higher neutron output generator designs. 66 refs.

• Research Organization: Sandia National Labs., Albuquerque, NM (USA)
• DOE Contract Number: AC04-76DP00789
• OSTI ID: 7252609
• Report Number(s): SAND-86-2315C; CONF-8610149-3; ON: DE87001734
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400101* -- Activation
Nuclear Reaction
Radiometric & Radiochemical Procedures
ACTIVATION ANALYSIS
BARYON REACTIONS
CHEMICAL ANALYSIS
ENERGY RANGE
FLUORINE 19 TARGET
GAMMA SPECTRA
HADRON REACTIONS
MEV RANGE
MEV RANGE 10-100
NEUTRON REACTIONS
NITROGEN 14 TARGET
NUCLEAR REACTIONS
NUCLEON REACTIONS
OXYGEN 16 TARGET
SILICON 28 TARGET
SPECTRA
TARGETS