Terbium energy level diagram

Energy levels and transitions of neutral terbium (Tb I): the 13 strongest classified lines below 2 µm from the NIST Atomic Spectra Database and the 17 levels they connect, each line with its vacuum wavelength, frequency and, for 0 of them, the reduced dipole matrix element derived from the NIST transition rate. Measured lifetimes, transition rates, hyperfine constants and isotope shifts from the literature are included, each with its citation.

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Download: diagram (PDF) diagram (SVG) transitions (CSV) levels (CSV) source code

Key transitions of terbium

λ, ν from NIST level energies unless a measured frequency for this isotope is available. A: measured value or NIST. Γ/2π: natural linewidth of the upper level, 1/(2πτ).

¹⁵⁹Tb hyperfine structure (I = 3/2)

Measured A, B constants; sources in the data file.

Listed Tb transitions below 2 µm

Reduced dipole matrix elements follow the convention A = ω³|d|²/(3πε₀ħc³(2J′+1)), with J′ the upper level. Tags show where a number comes from: measured, NIST compilation, high-accuracy theory, or a model calculation.

Tb energy levels

Tb⁺ ionisation limit 47295.00 cm⁻¹ = 5.86383 eV (211.439 nm)

Sources

• Childs, Goodman, J. Opt. Soc. Am. 69, 815 (1979), Table II (laser-fluorescence values)
• Childs, Phys. Rev. A 2, 316 (1970) (atomic-beam magnetic resonance), as tabulated in Elan…
• NIST ASD level energies
• Stefanska, Elantkowska, Ruczkowski, Furmann, J. Quant. Spectrosc. Radiat. Transfer 189, 4…
• Stefanska, Furmann, private communication, as tabulated in Elantkowska, Ruczkowski, Sikor…
• earlier atomic-beam magnetic-resonance work (Childs, Phys. Rev. A 2, 316 (1970)), as quot…

159Tb is the only stable isotope (I = 3/2), so there are no isotope shifts between stable isotopes. Hyperfine constants: 94 levels now carry A (and mostly B). Sources actually opened: (1) Elantkowska et al., Eur. Phys. J. Plus 132, 455 (2017) (open access; PDF from the Wayback copy of the Springer file, saved as pdf/Tb_Elantkowska_2017.pdf) - its Table 3 compiles all measured A, B of even-parity levels with the original reference per row (Childs 1970; Childs & Goodman 1979; Childs 1992; Furmann et al. 2015, 2016; Stefanska et al. 2017; private communication); these are stored with method 'compilation'. (2) Childs & Goodman, J. Opt. Soc. Am. 69, 815 (1979) and Childs, J. Opt. Soc. Am. B 9, 191 (1992): the tables embedded in the publisher abstract pages, read from Wayback Machine copies (saved as pdf/Tb_Childs_1979.html, pdf/Tb_Childs_1992.html); values measured in those papers are 'experiment'. (3) Arnoult & Gerstenkorn 1966 and Childs et al. 1984, read on the publisher abstract pages in the first pass. Eight levels with hyperfine data from Childs & Goodman 1979 are odd-parity upper levels (17118.72, 17341.92, 17409.62, 18461.87, 19450.45, 19658.41, 21837.92, 22223.87). Sign convention: A, B in MHz as printed. Still no lifetime for Tb I (see not_found). Transition rates: 7 lines from Irvine et al. 2023 (laser-induced-breakdown Saha-Boltzmann estimates, low accuracy, see the note on each entry; 5 of them are lines the site draws); the lifetime x sum(A) check could not be run be

Atoms with measured data

• Lithium-632 levels, 85 lines
• Lithium-732 levels, 85 lines
• Beryllium-917 levels, 26 lines
• Sodium-2336 levels, 106 lines
• Magnesium-2418 levels, 61 lines
• Magnesium-2518 levels, 61 lines
• Potassium-3934 levels, 84 lines
• Potassium-4034 levels, 84 lines
• Potassium-4134 levels, 84 lines
• Calcium-4035 levels, 61 lines
• Calcium-4335 levels, 61 lines
• Chromium-5256 levels, 87 lines
• Chromium-5356 levels, 87 lines
• Rubidium-8536 levels, 94 lines
• Rubidium-8736 levels, 94 lines
• Strontium-8440 levels, 70 lines
• Strontium-8640 levels, 70 lines
• Strontium-8740 levels, 70 lines
• Strontium-8840 levels, 70 lines
• Cadmium-11115 levels, 21 lines
• Cadmium-11315 levels, 21 lines
• Cadmium-11415 levels, 21 lines
• Caesium-13331 levels, 79 lines
• Barium-13744 levels, 89 lines
• Barium-13844 levels, 89 lines
• Dysprosium-16139 levels, 55 lines
• Dysprosium-16239 levels, 55 lines
• Dysprosium-16339 levels, 55 lines
• Dysprosium-16439 levels, 55 lines
• Erbium-16673 levels, 90 lines
• Erbium-16773 levels, 90 lines
• Erbium-16873 levels, 90 lines
• Thulium-16972 levels, 73 lines
• Ytterbium-17118 levels, 26 lines
• Ytterbium-17318 levels, 26 lines
• Ytterbium-17418 levels, 26 lines
• Mercury-19927 levels, 47 lines
• Mercury-20127 levels, 47 lines
• Mercury-20227 levels, 47 lines

All elements: periodic table