Authors:Z. En, J. Brenizer, B. Hosticka, and D. Becker
The paper is devoted to determination of boron and nitrogen in metallic materials by nuclear track techniques for the case of high background in radiograms. The method is based on the detection of the 10B(n,)7Li and 14N(n,p)14C reaction products with plastic track detectors exposed to a neutron flux in a close contact with the samples analyzed. When determining boron, high background can arise due to fast neutron interactions with hydrogen existing in the detector material and with matrix elements of the sample. In the case of nitrogen determination, high background is usually associated with a presence of boron in metals and alloys, alpha tracks of which strongly interfere with proton tracks from the 14N(n,p)14C reaction. The feasibility for measurement of micro-concentrations of boron as well as nitrogen determination in the presence of boron has been studied.
Authors:Z. En, J. Brenizer, B. Hosticka, J. Gao, and D. Becker
A method utilizing plastic track detectors was developed to determine the nitrogen distribution and concentration in the presence
of boron in metals. Experiments were performed at the UVAR (cadmium ratio ≈25) and the NIST Reactor (cadmium ratio ≈3000).
The minimum detectable concentration of nitrogen at a given concentration of boron has been estimated using the detector’s
response to10B(n,α)7 Li reaction products in terms of track size distribution. The capability of the technique to detect nitrogen in the presence
of boron has been demonstrated using 316L stainless steel with a nitrogen concentration of ≈560 ppm and a boron concentration
of ≈0.86 ppm.
Authors:H. Kim, Z. En, J. Ho, J. Jang, N. Jurneav, and M. Usmanova
The neutron induced microscopic radiography is a suitable method to detect boron content and distribution in metallic materials. For the research reactor KRR-2, the optimum thermal neutron fluence for various amount of boron content, the background effect due to fast neutron and -ray to the minimum detection limit of boron content, as well as the optimum-etching condition of the solid state nuclear track detector were determined.