Measurements of Energy Spectra and Doses in Liquid Air of Neutrons from a Californium-252 Source

To provide data for testing nitrogen and oxygen cross-section sets, transport of neutrons from a ²⁵²Cf source was investigated in a large volume of liquid air. Neutron energy spectra and doses were measured at distances between 30 and 230 cm from the source. Proton recoil proportional counters and NE-213 scintillation detectors were used to obtain energy spectra from 40 keV up to 10 MeV. Different computer programs were employed to unfold the pulse-height spectra. Dose measurements were made using a tissue equivalent ionization chamber and a GM counter. The results are compared with theoretical transport calculations performed with the ANISN code. In general, there is good agreement between the calculations and measurements up to the largest distances.