Atomic energy level diagrams

Californium energy level diagram

Energy levels and transitions of neutral californium (Cf I): 55 levels and 65 classified lines below 2 µm taken from the cited literature, each line with its vacuum wavelength and frequency. The NIST Atomic Spectra Database lists only the ground level and the ionisation limit of californium, so the level energies on this page are those of the literature sources named below.

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Californium energy level diagram with transition wavelengths and dipole matrix elements

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Key transitions of californium

Transitionλ vac (nm)λ air (nm)ν (THz)|⟨J‖er‖J′⟩| (ea₀)A (s⁻¹)Γ/2π up. (MHz)branch (%)Use
5I8 – (8,1)°9359.9797359.8770832.8038––––first step of Mainz resonance ionization scheme F
5I8 – (8,1)°8366.3741366.2698818.2687––––first step of Mainz resonance ionization scheme E
5I8 – (8,1)°7378.6688378.5612791.7011––––first step of Mainz resonance ionization scheme D
5I8 – (15/2,5/2)°7410.0277409.9120731.1517––1.234–first step of Mainz scheme C / III
5I8 – (8,2)°7416.7595416.6420719.3417––0.2274–first step of Mainz scheme B / II
5I8 – (15/2,5/2)°9419.9177419.7994713.9315––0.08992–first step of Mainz two-step resonance ionization scheme…

λ, ν from the level energies of the cited literature (NIST lists no excited levels) unless a measured frequency for this isotope is available. A: measured value or NIST. Γ/2π: natural linewidth of the upper level, 1/(2πτ).

253Cf hyperfine structure (I = 7/2)

LevelA (MHz)B (MHz)Shift of each F level from the centre of gravity (MHz)
5I8-127(3)2640(200)F=9/2: +4941.00 F=11/2: +3749.86 F=13/2: +2464.71 F=15/2: +1146.86 F=17/2: -133.00 F=19/2: -1294.71 F=21/2: -2248.71 F=23/2: -2896.00
(15/2,5/2)°9-109(3)11100(850)F=11/2: +7623.82 F=13/2: +4793.27 F=15/2: +2071.35 F=17/2: -308.72 F=19/2: -2082.66 F=21/2: -2955.11 F=23/2: -2599.57 F=25/2: -658.50
(8,2)°7-28.6(7)-1130(90)F=7/2: +378.60 F=9/2: +453.46 F=11/2: +496.17 F=13/2: +477.47 F=15/2: +362.75 F=17/2: +112.11 F=19/2: -319.69 F=21/2: -983.20
(15/2,5/2)°7-170(4)3430(260)F=7/2: +6041.54 F=9/2: +4658.65 F=11/2: +3116.54 F=13/2: +1504.04 F=15/2: -73.85 F=17/2: -1495.96 F=19/2: -2625.00 F=21/2: -3307.50

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

Isotope shifts

Transitionλ vac (nm)IsotopesShift (MHz)
5I8 – (15/2,5/2)°7410.028249-250-5921(12)
5I8 – (15/2,5/2)°7410.028251-2505013(12)
5I8 – (15/2,5/2)°7410.028252-25011265(14)
5I8 – (15/2,5/2)°7410.028253-25015230(75)
5I8 – (8,2)°7416.760249-2506250(12)
5I8 – (8,2)°7416.760251-250-5274(12)
5I8 – (8,2)°7416.760252-250-11887(14)
5I8 – (8,2)°7416.760253-250-16052(20)
5I8 – (15/2,5/2)°9419.918249-250-6812(12)
5I8 – (15/2,5/2)°9419.918251-2505721(14)
5I8 – (15/2,5/2)°9419.918252-25012944(14)
5I8 – (15/2,5/2)°9419.918253-25017470(50)

Shift = ν(first isotope) − ν(second isotope).

Closed and nearly closed transitions of californium

Transitionλ vacuum (nm)Lower levelA (s⁻¹)Leak per scattered photonPhotons before a leakWhere the leak goes
5I8 → (8,1)°9541.0360ground–closed–no other level can be reached by electric-dipole decay

A transition is closed when its upper level can decay only to the level it was excited from, so the atom keeps scattering photons. “closed”: among the levels NIST lists, no other level below the upper level has the opposite parity and |ΔJ| ≤ 1, so no other electric-dipole decay exists. Otherwise the leak is the sum of the branching ratios of the other decay lines of the upper level (or 1 − branching ratio where that of the line itself has been measured), and the number of photons is 1 / leak. “≥” and “≤”: at least one possible decay path has no listed rate, so the leak is a lower limit. These numbers are derived from the branching ratios, lifetimes and rates of this page, not measured as such; the tag names the weakest of the inputs, * marks theory and ≈ a model or semi-empirical calculation. Listed: lines that start on the ground level or on a metastable level and leak at most 10 %, unless more than three possible decay paths have no listed rate. Fine-structure levels only: hyperfine and Zeeman dark states and forbidden decays without a listed rate are not considered. Select a line in the diagram for the full list of its leak channels.

Listed Cf transitions below 2 µm

Lower levelUpper levelλ vacuum (nm)λ air (nm)ν (THz)Type|⟨J‖er‖J′⟩| (ea₀)A (s⁻¹)Branching (%)Source of matrix element / A
5I8(30311)°7329.9089329.8139908.7129E1––––
5I8(29818)°8335.3673335.2709893.9228E1––––
5I8(29471)°7339.3196339.2222883.5106E1––––
5I8(28719)°8348.2073348.1076860.9597E1––––
5I8(28309)°7353.2496353.1487848.6703E1––––
5I8(7,1)°7354.1993354.0981846.3948E1––––
5I8(8,1)°9359.9797359.8770832.8038E1––––
5F5(36245)°6360.6355360.5326831.2894E1––––
5I7(36755)°6361.3142361.2111829.7279E1––––
5I7(7,1)°7361.8518361.7486828.4952E1––––
5F5(6,1)°5366.0501365.9458818.9930E1––––
5I8(8,1)°8366.3741366.2698818.2687E1––––
5I8(7,0)°7374.0414373.9351801.4954E1––––
5I8(8,1)°7378.6688378.5612791.7011E1––––
5I7(33852)°6403.6592403.5451742.6871E1––––
5I8(15/2,5/2)°7410.0277409.9120731.1517E1––––
5I8(8,2)°7416.7595416.6420719.3417E1––––
5I8(15/2,5/2)°9419.9177419.7994713.9315E1––––
5I8(8,2)°8424.3577424.2383706.4617E1––––
5I8(8,2)°9433.0250432.9033692.3214E1––––
5I8(15/2,5/2)°8433.6444433.5225691.3325E1––––
5I8(8,1)°7517.5389517.3948579.2656E1––––
5I8(8,1)°8518.0524517.9082578.6913E1––––
5F5(5,1)°4521.9871521.8418574.3292E1––––
5I7(7,1)°7522.0693521.9240574.2388E1––––
(8,1)°8(38241)8528.0478527.9009567.7374E1––––
5I6(6,1)°7528.0493527.9024567.7357E1––––
5F5(5,1)°6532.1592532.0112563.3511E1––––
5I7(7,1)°8534.0656533.9171561.3401E1––––
5I8(8,1)°9541.0360540.8856554.1082E1––––
5I8(8,0)°8572.7636572.6047523.4139E1––––
(8,1)°8(8,1)7662.4671662.2842452.5394E1––––
(8,1)°7(8,1)7663.3088663.1256451.9652E1––––
(8,1)°9(8,1)8667.9726667.7882448.8096E1––––
(8,1)°9(8,1)9689.6495689.4592434.7027E1––––
(8,1)°7(8,1)8707.6382707.4431423.6522E1––––
(8,1)°8(8,1)9730.9880730.7866410.1195E1––––
(15/2,3/2)°9(15/2,3/2)9814.3538814.1299368.1354E1––––
(8,2)°8(8,1)7923.0942922.8410324.7691E1––––
(8,2)°9(33800)8934.0264933.7702320.9678E1––––
(8,2)°7(8,1)7961.2150960.9514311.8891E1––––
(8,2)°9(8,1)8965.2156964.9509310.5964E1––––
(8,2)°8(33800)8977.0716976.8037306.8275E1––––
5I7(8,1)°8978.0028977.7346306.5354E1––––
(8,2)°10(8,1)9988.4871988.2161303.2841E1––––
(8,2)°6(8,1)7997.8108997.5373300.4502E1––––
(8,2)°9(8,1)91011.14021010.8631296.4895E1––––
(8,2)°8(8,1)81011.25421010.9771296.4561E1––––
(8,2)°6(34074)71031.12401030.8414290.7434E1––––
(8,2)°7(8,1)81057.18531056.8957283.5761E1––––
(8,2)°8(8,1)91061.77911061.4882282.3492E1––––
5I85I71101.54661101.2450272.1559M1––––
(15/2,5/2)°8(15/2,3/2)81130.32991130.0204265.2256E1––––
(15/2,5/2)°10(15/2,3/2)91168.50281168.1830256.5612E1––––
(15/2,3/2)°8(15/2,1/2)81194.45841194.1316250.9861E1––––
(15/2,5/2)°9(15/2,3/2)81235.61211235.2741242.6267E1––––
(8,1)°7(27360)71244.08821243.7479240.9736E1––––
(15/2,3/2)°8(15/2,1/2)71279.08891278.7391234.3797E1––––
(8,1)°9(8,0)81336.66611336.3006224.2837E1––––
(15/2,3/2)°7(15/2,1/2)71347.81241347.4440222.4289E1––––
(28719)°8(8,0)81528.55651528.1389196.1278E1––––
(15/2,3/2)°6(15/2,1/2)71763.11491762.6335170.0357E1––––
(8,0)°8(22800)91872.38221871.8710160.1129E1––––
(8,1)9(8,0)°81907.39051906.8698157.1741E1––––
(8,1)°8(24410)81958.22901957.6945153.0937E1––––

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.

Cf energy levels

LevelEnergy (cm⁻¹)JParityLifetimegJHyperfine A (MHz)Hyperfine B (MHz)Lifetime sourceHyperfine source
5I80.0008evenstable1.215-1272640–Weber, Albrecht-Schoenzart, Allehabi, Berndt, Block, et al., 'Nuclear moments and isotope…
5F58516.3805even–1.22––––
5I79078.1457even–1.155––––
5I611074.3906even–1.135––––
(15/2,3/2)°816909.5358odd–1.301––––
(15/2,3/2)°717308.1707odd–1.298––––
(8,0)°817459.2108odd–1.277––––
(8,1)°918483.0609odd–1.25––––
(15/2,3/2)°619055.8206odd–1.405––––
(8,1)°819303.0658odd–1.164––––
(8,1)°719322.2207odd–1.22––––
(15/2,3/2)°919907.4709odd–1.255––––
(22800)922800.0009even––––––
(8,2)°1022866.71010odd–1.28––––
(15/2,5/2)°823060.3708odd–1.233––––
(8,2)°923093.3559odd–1.25––––
(8,2)°823565.0258odd–1.225––––
(15/2,5/2)°1023629.18510odd––––––
(15/2,5/2)°923814.1909odd1.77 µs measured1.21-10911100Weber, Albrecht-Schoenzart, Allehabi, Berndt, Block, et al., 'Nuclear moments and isotope…Weber, Albrecht-Schoenzart, Allehabi, Berndt, Block, et al., 'Nuclear moments and isotope…
(8,2)°723994.6557odd700 ns measured1.19-28.6-1130Weber, Albrecht-Schoenzart, Allehabi, Berndt, Block, et al., 'Nuclear moments and isotope…Weber, Albrecht-Schoenzart, Allehabi, Berndt, Block, et al., 'Nuclear moments and isotope…
(8,2)°624376.2156odd–1.15––––
(15/2,5/2)°724388.5957odd129 ns measured1.286-1703430Weber, Albrecht-Schoenzart, Allehabi, Berndt, Block, et al., 'Nuclear moments and isotope…Weber, Albrecht-Schoenzart, Allehabi, Berndt, Block, et al., 'Nuclear moments and isotope…
(24410)824409.7208even––––––
(15/2,1/2)724727.6007even––––––
(15/2,1/2)825281.5308even––––––
(8,1)°726408.3057odd–1.25––––
(7,0)°726735.0107odd–1.205––––
(8,1)°827294.5058odd––––––
(5,1)°627307.7506odd–1.29––––
(27360)727360.2357even––––––
(5,1)°427673.9404odd––––––
(8,1)°927779.3459odd–1.2––––
(7,1)°827802.4358odd–1.22––––
(7,1)°728232.6907odd–1.175––––
(28309)°728308.5957odd–1.2––––
(28719)°828718.5258odd–1.24––––
(29471)°729470.7407odd–1.22––––
(29818)°829818.0558odd–1.3––––
(6,1)°730012.0157odd––––––
(30311)°730311.4007odd–1.275––––
(15/2,3/2)831907.3458even––––––
(15/2,3/2)932187.1459even–1.28––––
(8,1)932983.1809even–1.3––––
(8,1)833453.7358even–1.21––––
(33800)833799.6908even–1.18––––
(33852)°633851.5206odd–1.185––––
(34074)734074.3707even––––––
(8,1)734398.1557even–1.135––––
(8,0)835260.6458even–1.195––––
(6,1)°535835.0455odd–1.14––––
(36245)°636245.2106odd–1.2––––
(7,1)°736713.7707odd–1.16––––
(36755)°636754.8906odd–1.17––––
(8,0)°838225.9458odd––––––
(38241)838240.7458even––––––

Cf⁺ ionisation limit 50666.76 cm⁻¹ = 6.28188 eV (197.368 nm)

Sources

energy_cm values are 249Cf energies from the archived Laboratoire Aime Cotton database (compilation); three-decimal values +-0.010 cm^-1, two-decimal +-0.05 cm^-1. Isotope shifts are nu(A) - nu(250). Negative shift for lighter isotope in the 420 and 410 nm lines (5f -> 6d jump), positive in the 417 nm line (7s -> 7p). relative_intensity is 9 for every line of the source table (strongest lines only; 'R' = self-reversed), so it carries no ranking. Even levels above 30 000 cm^-1 are included because the strongest red / infrared Cf I lines end on them. The M1 line at 9078.145 cm^-1 is inside the ground configuration.

Atoms with measured data

All elements: periodic table