Preliminary Selection of Device Materials to Locally Transform Thermal into SFR Neutron Spectrum

Table 2

Selected isotopes and their densities.

Element	Density (g/cm^3)
^36S	1.96
^39K	0.86
^40K	0.86
^48Ca	1.55
^138Ba	3.51
^139La	6.15
^197Au	19.30