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NIST Atomic Spectra Database Lines Data

He I: 37 Lines of Data Found
Z = 2, He isoelectronic sequence 
Example of how to reference these results:
Kramida, A., Ralchenko, Yu., Reader, J., and NIST ASD Team (2023). NIST Atomic Spectra Database (ver. 5.11), [Online]. Available: https://physics.nist.gov/asd [2024, May 18]. National Institute of Standards and Technology, Gaithersburg, MD. DOI: https://doi.org/10.18434/T4W30F
BibTex Citation (new window)
 
No explicit information on uncertainties of observed wavelengths is available in ASD for this selection of lines.
Showing results for transitions involving level 1s3d 1D2 at 23.07407479777 eV only.
λ in: vacuum
Highest relative intensity: 200
Some data for neutral and singly-charged ions are available in the Handbook of Basic Atomic Spectroscopic Data

Primary data sources
Query NIST Bibliographic Databases for
He I (new window)
Energy Levels:  Drake 2023, Kandula et al. 2010, Martin 1973     The energy level data refer to the isotope 4He. The excitation energies of the 1snl levels with n ≤ 10 were determined here by subtracting the theoretical ionization energy listed by Drake 2023 from the experimental ionization energy of the ground level reported by Kandula et al. 2010 . The energies of the higher levels below the ionization limit were determined by fitting the extended Ritz quantum-defect expansion formula (Eq. 12.54 of Drake 2023 ) to the adjusted theoretical energies of the same 1snl SLJ series listed here as prescribed by Eqs. (12.55) through (12.57) of Drake 2023 . Uncertainties are specified relative to the ionization limit. To find uncertainties of excitation energies, combine the given uncertainties in quadrature with the uncertainty of the ground level. The 1s2p 3P° levels are given with excessive number of decimal figures required to reproduce the splittings between them, which are known very precisely. The current values of these splittings are from the calculations of Pachucki et al. 2017 . There exist many experimental reports on these splittings. No attempt has been made here to evaluate them. The doubly-excited levels above the ionization limit require a significant update. Those given here are quoted from the old compilation of Martin 1973 . There are 364 papers on energy levels of He I published between 1974 and October 2023. About half of them are devoted to core-excited levels. NIST lacks the workforce required to process such a large number of publications. The present data set was prepared by A. Kramida for the release of ASD v.5.11 in October, 2023. He I Energy Levels
Lines:  Martin 1960  He I Line Wavelengths and Classification
Transition Probabilities:  Wiese and Fuhr 2009  He I Transition Probabilities

 Observed 
 Wavelength 
 Vac (nm) 		  Ritz 
 Wavelength 
 Vac (nm) 		  Unc. 
 (nm) 		  Rel. 
 Int. 
(?) 		 Aki
 (s−1) 		  Acc.   Ei 
 (eV) 		    Ek 
 (eV) 		  Lower Level 
 Conf., Term, J 		  Upper Level 
 Conf., Term, J 		  Type   TP
Ref.		  Line
Ref.
                                   
  53.7331180   0.0000003      1.299e+03    AA [0.00000000]     -  [23.07407479777]     1s2   1S   0   1s3d   1D   2  E2 T7378  
  504.34934585  0.00000013     1.022e+02    AA [20.615774823]    -  [23.07407479777]     1s2s   1S   0   1s3d   1D   2  E2 T7378  
  587.60620344  0.00000007     4.310e+03    AA [20.96408688908]  -  [23.07407479777]     1s2p   3P°   2   1s3d   1D   2  T8636c73  
  587.60884228  0.00000007     1.232e+04    AA [20.96409636464]  -  [23.07407479777]     1s2p   3P°   1   1s3d   1D   2  T8636c73  
667.9995      667.9995639   0.0000003    100  6.3705e+07    AAA [21.2180227112]   -  [23.07407479777]     1s2p   1P°   1   1s3d   1D   2  T8636c73 L366
                                   
  899.99904827  0.00000007     1.2389e+04    AAA [23.07407479777]  -  [24.451678459372]    1s3d   1D   2   1s10p   1P°   1  T8636c73  
  900.22070373  0.00000006     2.8406e+05    AAA [23.07407479777]  -  [24.4513392610240]   1s3d   1D   2   1s10f   1F°   3  T8636c73  
  900.22084511  0.00000006     7.516e+04    AA [23.07407479777]  -  [24.4513390447263]   1s3d   1D   2   1s10f   3F°   3  T8636c73  
  921.25769865  0.00000008     1.7331e+04    AAA [23.07407479777]  -  [24.419889314325]    1s3d   1D   2   1s9p   1P°   1  T8636c73  
  921.57568882  0.00000006     3.9961e+05    AAA [23.07407479777]  -  [24.4194249403235]   1s3d   1D   2   1s9f   1F°   3  T8636c73  
                                   
  921.57589016  0.00000006     1.095e+05    AA [23.07407479777]  -  [24.4194246464065]   1s3d   1D   2   1s9f   3F°   3  T8636c73  
  952.70455021  0.00000011     2.5364e+04    AAA [23.07407479777]  -  [24.375466697350]    1s3d   1D   2   1s8p   1P°   1  T8636c73  
  953.18779781  0.00000006     1.697e+05    AA [23.07407479777]  -  [24.3748069170618]   1s3d   1D   2   1s8f   3F°   3  T8636c73  
953.188       953.18749503  0.00000006   1  5.8976e+05    AAA [23.07407479777]  -  [24.3748073302369]   1s3d   1D   2   1s8f   1F°   3  T8636c73 L366
  1 002.59462782  0.00000015     3.9418e+04    AAA [23.07407479777]  -  [24.31070817873]     1s3d   1D   2   1s7p   1P°   1  T8636c73  
                                   
  1 003.39050903  0.00000007     2.866e+05    AA [23.07407479777]  -  [24.3097272911601]   1s3d   1D   2   1s7f   3F°   3  T8636c73  
1 003.391       1 003.39001702  0.00000007   2  9.2892e+05    AAA [23.07407479777]  -  [24.3097278970701]   1s3d   1D   2   1s7f   1F°   3  T8636c73 L8200
  1 090.5194664   0.0000003      6.6614e+04    AAA [23.07407479777]  -  [24.21100267716]     1s3d   1D   2   1s6p   1P°   1  T8636c73  
  1 092.00566253  0.00000008     8.195e+01    AA [23.07407479777]  -  [24.209455342828]    1s3d   1D   2   1s6f   3F°   2  T8636c73  
  1 092.00615815  0.00000008     5.518e+05    AA [23.07407479777]  -  [24.209454827529]    1s3d   1D   2   1s6f   3F°   3  T8636c73  
                                   
1 092.009       1 092.00525574  0.00000008   3  1.6083e+06    AAA [23.07407479777]  -  [24.2094557657828]   1s3d   1D   2   1s6f   1F°   3  T8636c73 L885
  1 109.8899855   0.0000009      4.515e-01    AA [23.07407479777]  -  [24.1911602752]      1s3d   1D   2   1s6s   1S   0  E2 T7378  
  1 275.9177829   0.0000005      1.2754e+05    AAA [23.07407479777]  -  [24.04580040653]     1s3d   1D   2   1s5p   1P°   1  T8636c73  
  1 279.40078158  0.00000011     1.732e+02    AA [23.07407479777]  -  [24.043155012649]    1s3d   1D   2   1s5f   3F°   2  T8636c73  
  1 279.40200739  0.00000011     1.320e+06    AA [23.07407479777]  -  [24.043154084167]    1s3d   1D   2   1s5f   3F°   3  T8636c73  
                                   
1 279.407       1 279.39994220  0.00000011   20  3.2475e+06    AAA [23.07407479777]  -  [24.043155648442]    1s3d   1D   2   1s5f   1F°   3  T8636c73 L885
  1 323.0058800   0.0000018      7.4166e-01    AAA [23.07407479777]  -  [24.0112149898]      1s3d   1D   2   1s5s   1S   0  E2 T7378  
  1 856.0640144   0.0000024    1  2.9630e+05    AAA [23.07407479777]  -  [23.74207006880]     1s3d   1D   2   1s4p   1P°   1  T8636c73 L366
1 870.234       1 870.23181137  0.00000024   200  8.9780e+06    AAA [23.07407479777]  -  [23.737009722091]    1s3d   1D   2   1s4f   1F°   3  T8636c73 L885
  1 870.23452352  0.00000024     5.235e+02    AA [23.07407479777]  -  [23.737008760725]    1s3d   1D   2   1s4f   3F°   2  T8636c73  
                                   
  1 870.24003537  0.00000024     4.852e+06    AA [23.07407479777]  -  [23.737006806968]    1s3d   1D   2   1s4f   3F°   3  T8636c73  
  1 956.149673    0.000003       1.150e+02    AA [23.07407479777]  -  [23.7078923433]      1s3d   1D   2   1s4p   3P°   1  T8636c73  
  1 956.153115    0.000003       2.354e+01    AA [23.07407479777]  -  [23.7078912279]      1s3d   1D   2   1s4p   3P°   2  T8636c73  
  2 068.141261    0.000009       1.3064e+00    AAA [23.07407479777]  -  [23.673570590]       1s3d   1D   2   1s4s   1S   0  E2 T7378  
  8 063.62276     0.00020        1.2492e-03    AAA [22.920317359]    -  [23.07407479777]     1s3s   1S   0   1s3d   1D   2  E2 T7378  
                                   
  18 505.40092     0.00024        2.317e+00    AA [23.0070758719]   -  [23.07407479777]     1s3p   3P°   1   1s3d   1D   2  T8636c73  
  95 787.057       0.006          1.5281e+02    AAA [23.07407479777]  -  [23.08701852960]     1s3d   1D   2   1s3p   1P°   1  T8636c73  

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