By utilizing a geometrically centered pulsed source internal to a large (B2g) ≈ 0.002) cylindrical H₂O system, the neutron flux was measured as a function of position and time. A least square fit of the data yielded the fundamental and five higher decay constants and amplitudes of the thermal neutron flux. Symmetrical and enhanced neutron densities were obtained as a result of the internal source. Long waiting times were unnecessary and data acquisition was accelerated.
The decay constants were found to be independent of position, pulse width, counting time and rates, method of normalization, or waiting time. The decay constants were related to the bucklings by an analysis of the amplitudes without variance of the size of the system.
This method gives Σav = (4759 ± 54) sec⁻¹, Do = (3.7084 ± 0.0897) x 10⁴ cm²/sec, L = (2.79 ± 0.05) cm, σaH = (323 ± 3) mb, and a mean neutron lifetime of (210 ± 2.4) µsec --Abstract, page ii
