A PRECISE DETERMINATION OF THE THERMAL NEUTRON ABSORPTION CROSS SECTION OF V$sup 10$ AN NATURAL BORON BY TIME OF FLIGHT
The total cross section of B/sub 2/O/sub 3/ was measured from 0.006 to 0.082 ev with the BR-1 slow-chopper. Samples of natural boron with an isotopic abundance of (19.81 plus or minus 0.02) per cent B/sup 10/ atoms, and boron enriched up to (96.515 plus or minus 0.013) per cent were used for these measurements. From the accurate total cross-section values obtained, the ratio of the boron absorption cross section to the reciprocal of neutron velocity was calculated. This quantity remains a constant over the entire energy range covered and its mean value for natural boron is K = (1.674 plus or minus 0.0041) barns m/ mu sec and for the enriched boron K = (8.15 plus or minus 0.019) barns m/ mu sec. The deduced values for the boron absorption cross section at the reference neutron velocity of 2200 m/sec are for natural boron sigma /sub a/ = 760.8 plus or minus 1.9 barns and for the enriched boron sigma /sub a/ = 3703 plus or minus 8.9 barns. These values yield for the absorption cross section of the B/sup 10/ isotope at the reference velocity 3840 plus or minus 11 barns as deduced from the natural boron results, and 3837 plus or minus 9 barns from the enriched sample. (auth)
- Research Organization:
- Euratom, Geel, Belg.
- NSA Number:
- NSA-17-024425
- OSTI ID:
- 4707976
- Journal Information:
- J. Nucl. Energy, Pts. A and B, Vol. Vol: 17; Other Information: Orig. Receipt Date: 31-DEC-63
- Country of Publication:
- Country unknown/Code not available
- Language:
- English
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