Table 2. Properties of the sapphire backscattering monochromator used in this work to match the nuclear transition energy in ¹²¹Sb, ¹²⁵Te, ¹¹⁹Sn, ¹⁴⁹Sm and ¹⁵¹Eu.

For each reflection the table provides the measured resonance temperature T, the corresponding resonance energy E, the extinction length z, the variation of the reflection energy with the crystal temperature ΔE/ΔT, the thickness of the crystal along the beam d, the theoretical ΔE _th and measured ΔE _exp energy bandwidth (FWHM), the theoretical R _th and measured R _exp spectral efficiency, and the measured incident N _inc and reflected N _ref flux of the sapphire monochromator at 70 mA storage-ring current.

	Isotope
	121Sb	125Te	119Sn	149Sm	151Eu
Reflection	(8 16 40)	(9 1 68)	(4 4 45)	(5 10 22)	(3 2 43)
T (K)	236.8 (1)	219.5 (1)	192.8 (1)	251.5 (1)	289.1 (1)
E (keV)	37.1292 (5)	35.4920 (5)	23.8793 (5)	22.5015 (5)	21.5412 (5)
z (mm)	0.85	0.48	0.28	0.46	0.37
ΔE/ΔT (meV mK−1)	−0.156	−0.149	−0.084	−0.100	−0.122
d (mm)	1.9 (1)	1.1 (1)	1.1 (1)	2.1 (1)	1.1 (1)
ΔEth (meV)	0.39	0.70	0.95	0.52	0.77
ΔEexp (meV)	1.2 (1)	1.1 (1)	1.1 (1)	1.0 (1)	1.1 (1)
Rth (%)	59	60	75	59	55
Rexp (%)	10	16	65	20	43
Ninc	0.8 × 1012	1.5 × 1012	2.2 × 1012	2.7 × 1012	3.4 × 1012
Nref	3.9 × 107	7.7 × 107	7.7 × 108	4.4 × 108	7.4 × 108