Isotopic variations of Sm, Gd, Er and Yb found in planetary materials caused by neutron-capture reactions in nature

Journal of Analytical Science and Technology

Table 2 Comparison of the isotopic variations of (a) ¹⁶⁸Yb/¹⁷⁴Yb and (b) ¹⁷⁰Yb/¹⁷⁴Yb between measured and calculated values for seven of lunar regolith materials from the A-15 drill stem

Sample	Measured^a		Calculated^b		Calculated^c
Sample	¹⁶⁸Yb/¹⁷⁴Yb	ε_168Yb	Ψ_th	ε_168Yb	Ψ_th	Ψ_epi	ε_168Yb
(a) ¹⁶⁸Yb/¹⁷⁴Yb
STD	0.003956 ± 2	0	0	0	0	0	0
15001	0.003951 ± 8	− 13 ± 21	5.2	− 1.2	4.8	59	− 22
15002	0.003951 ± 7	− 13 ± 18	5.9	− 1.4	5.7	67	− 25
15003	0.003946 ± 5	− 25 ± 14	6.9	− 1.6	6.3	71	− 27
15004	0.003945 ± 3	− 28 ± 9	7.5	− 1.7	6.9	81	− 31
15005.14	0.003945 ± 5	− 28 ± 14	7.0	− 1.6	6.5	77	− 29
15005.79	0.003947 ± 5	− 23 ± 14	6.6	− 1.5	6.1	75	− 28
15006	0.003951 ± 5	− 13 ± 14	5.5	− 1.3	5.1	54	− 20

Sample	Measured^a		Calculated^b		Calculated^c
Sample	¹⁷⁰Yb/¹⁷⁴Yb	ε_170Yb	Ψ_th	ε_170Yb	Ψ_th	Ψ_epi	ε_170Yb
(b) ¹⁷⁰Yb/¹⁷⁴Yb
STD	0.094812 ± 2	0	0	0	0	0	0
15001	0.094814 ± 6	+ 0.21 ± 0.67	5.2	+ 0.29	4.8	59	+ 6.4
15002	0.094814 ± 6	+ 0.21 ± 0.67	5.9	+ 0.33	5.7	67	+ 7.3
15003	0.094815 ± 7	+ 0.32 ± 0.77	6.9	+ 0.39	6.3	71	+ 7.8
15004	0.094810 ± 4	− 0.21 ± 0.47	7.5	+ 0.42	6.9	81	+ 8.9
15005.14	0.094813 ± 5	+ 0.11 ± 0.57	7.0	+ 0.39	6.5	77	+ 8.4
15005.79	0.094809 ± 7	− 0.32 ± 0.77	6.6	+ 0.37	6.1	75	+ 8.2
15006	0.094811 ± 4	− 0.11 ± 0.47	5.5	+ 0.31	5.1	54	+ 5.9

STD means standard reference materials of Yb
^aThe data fromHidaka et al. (2020)
^bThe calculations were done under consideration of the contribution of Ψ_th only. The Ψ_th values (in 10¹⁶ n cm⁻² unit) were given by Hidaka et al. (2000)
^cThe calculations were done under consideration of the contributions of both Ψ_th and Ψ_epi. Both Ψ_th and Ψ_epi values (in 10¹⁶ n cm⁻² unit) were given by Hidaka et al. (2020)