vitmog

….. Next

Ueki 3-layer shielding experiment (Type 3)

A californium-252 neutron source of intensity $5.33 \cdot 10^8$ n/s is placed into a conic paraffin collimator. The goal is computation of neutron and secondary (capture) gamma dose rates behind 3-layered shield of steel (25 cm) - polyethylene (15 cm) - steel (10 cm) slabs.

Figure 1: Cross-section of the model

Computed flux functional - rates of equivalent dose ANSI 77 [2].

Thicknesses of volumetric detectors are equal to 2 cm. Results of a 2 h 52 min long computation are performed in Figures 2 and 3 (see details in [3]).

Figure 2: Neutron dose rates plot, μSv/h

Figure 3: Secondary gamma dose rates plot, μSv/h

….. Next

References

1. K. Ueki, A. Ohashi, Nobuteru Nariyama, S. Nagayama, T. Fujita, K. Hattori, and Y. Anayama. Systematic evaluation of neutron shielding effects for materials. Nuclear Science and Engineering, 124:455-464, 10 1996.
2. American National Standard: neutron and gamma-ray ux-to-dose rate factors. American Nuclear Society, United States, 1977.
3. V.G. Mogulian. An approach to radiation shielding evaluations using estimators by expected scoring. 2025. doi:10.5281/zenodo.16781416.

_{Copyright © 2025 Vitaly Mogulian}