General considerations for effective thermal neutron shielding in detector applications

EPJ Techniques and Instrumentation

Table 1 Summary of materials used, showing their molecular composition, weight distribution, enrichment level, and average atomic number densities N̄. Materials implemented as standard Geant4 materials are marked with asterisks, while materials implemented using NCrystal are marked with daggers. Note that for personnel safety reasons, the amount of gamma rays produced from the neutron absorption reactions in the materials should be considered

Material	Composition	wt%	Enrichment [at%]	N̄ [cm⁻³]
Elements
Cadmium^∗	Cd	100		4.63401⋅10²²
Aluminum^†	Al	100		6.02325⋅10²²
Molecules
Gadolinium oxide^∗	^natGd₂O₃	100		6.15251⋅10²²
Boron carbide (natural)^†	^natB₄C	100	¹⁰B/B: 20	1.36702⋅10²³
Boron carbide (enriched)^†	B₄C	100	¹⁰B/B: 99	1.36712⋅10²³
Lithium fluoride (natural)^†	^natLiF	100	⁶Li/Li: 8	1.23396⋅10²³
Lithium fluoride (enriched)^†	LiF	100	⁶Li/Li: 99	1.23392⋅10²³
Epoxy^†	C₅₄H₆₀O₉	100		1.02462⋅10²³
Polyethylene^†	C₂H₄	100		1.18497⋅10²³
Compounds
Epoxy – Gadolinium oxide^∗	C₅₄H₆₀O₉	50		9.68366⋅10²²
(50 – 50)	^natGd₂O₃	50		9.68366⋅10²²
Epoxy – Gadolinium oxide^∗	C₅₄H₆₀O₉	35		9.30040⋅10²²
(35 – 65)	^natGd₂O₃	65		9.30040⋅10²²
Epoxy – Boron carbide^†	C₅₄H₆₀O₉	50		1.13422⋅10²³
(natural)	^natB₄C	50	¹⁰B/B: 20	1.13422⋅10²³
Epoxy – Boron carbide^†	C₅₄H₆₀O₉	50		1.13861⋅10²³
(enriched)	B₄C	50	¹⁰B/B: 99	1.13861⋅10²³
MirroBor^∗	^natB₄C	80	¹⁰B/B: 20	7.95206⋅10²²
	C	14
	O	5
	H	1
Boral^†	Al	90		6.83984⋅10²²
(90 – 10)	^natB₄C	10	¹⁰B/B: 20	6.83984⋅10²²
Boral^†	Al	33		1.12700⋅10²³
(33 – 67)	^natB₄C	67	¹⁰B/B: 20	1.12700⋅10²³