A MEASUREMENT OF THE NEUTRON-PROTON CAPTURE CROSS-SECTION

Journal Article · Sun Nov 30 23:00:00 EST 1958 · Proc. Roy. Soc. (London)

DOI:https://doi.org/10.1098/rspa.1958.0260· OSTI ID:4309972

Baker, A R

Measurements have been made of the neutron density as a function of distance from a polonium-beryllium source in effectively infinite tanks of water and aqueous boric acid. The ratio of the thermal-neutron capture cross sections of boron and hydrogen was found to be 2317 plus or minus 27. The cross section of hydrogen calculated from this result, using the known cross section of Harwell standard boron, 769 plus or minus 4 barns (at a neutron velocity of 2200 m/s.), and the known cross section of the boron used relative to Harwell standard boron, 0:.985 plus or minus 0.002, was 0.327 plus or minus 0.004 barn (at 2200 m/s.) which is consistent with other recent accurate values. In preliminary experiments, it was shown that flux measurements reproducible to better than 3% were possible with the disks of Ilford C2 nuclear research photographic emulsion used as detectors. The main source of error in the result was the statistical error for a total count of 200,000 tracks. The only corrections necessary were 1.6% for recoil proton background, and 0.7% for the disturbance of the neutron density by the detectors. (auth)

• Research Organization: Cambridge Univ., Eng.
• Sponsoring Organization: USDOE
• NSA Number: NSA-13-003323
• OSTI ID: 4309972
• Journal Information: Proc. Roy. Soc. (London), Journal Name: Proc. Roy. Soc. (London) Vol. Vol: A248
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

ACIDS
BACKGROUND
BERYLLIUM
BORON
BORON COMPOUNDS
CAPTURE
CROSS SECTIONS
DENSITY
EXCITATION
FISSION
HYDROGEN
MEASURED VALUES
NEUTRON DETECTION
NEUTRON FLUX
NEUTRON SOURCES
NEUTRONS
NUCLEAR EMULSIONS
NUMERICALS
PARTICLE TRACKS
PHYSICS AND MATHEMATICS
POLONIUM
PROTONS
SOLUTIONS
STANDARDS
THERMAL NEUTRONS
VELOCITY
WATER