MEASUREMENT OF THE 235U(n,f) REACTION FROM THERMAL TO 1 keV
National Bureau of Standards
Gaithersburg, MD 20899, USA
The neutron induced fission cross section for 235U has been measured from .02 to 1000 electron volts at the NBS electron LINAC facility. This cross section, especially the integrals from 7.8 to 11 eV and from 100 to 1000 eV, is widely used as a standard to normalize shape experiments. A special ion chamber incorporating both the 235U foils and the 10B foils used to monitor the neutron beam was built. The geometry of the chamber and the data taking system are designed to give the effect of a common environment and flight path so as to reduce or eliminate background and energy assignment problems. The shape measurements were normalized at thermal. Results are compared to other recent measurements and ENDF/B-V.
KEYWORDS: fission, 235U, cross section, integrals, 10B, time-of-flight, neutron