Compilation of Wavelengths, Energy Levels, and Transition Probabilities for Ba I and Ba II

Abstract

Energy levels, wavelengths, and transition probabilities for the first and second spectra of barium, Ba I and Ba II, have been compiled. Wavelengths of observed transitions and energy levels derived from those wavelengths have been obtained from a critical evaluation of the available literature. Measured and calculated transition probabilities for some of the observed transitions have been obtained from the recent compilation of Klose et al.

Measurement of the Landégfactor of the5D5/2state of Ba ii with a single trapped ion

“…Ab initio calculations are often not possible and require experimental input of atomic parameters. We present a precision measurement of the Landé g factor of the 5D 5/2 state of Ba II, which we find to differ significantly from the previously accepted value of 1.12, derived from astronomical observation [15][16][17][18]. Along with values for the g factors of the 6S 1/2 , 6P 1/2 , 6P 3/2 , and 5D 3/2 , this completes the measurement of g factors for all low-lying (infrared and visible) atomic states of Ba II [19,20].…”

An exacting transition probability measurement - a direct test of atomic many-body theories

“…The calculated values of the transition probabilities also reply on the vacuum wavelength indicated in eq. (9), and some of the theory values use calculated energy eigen values for the wavelength which are about 2–3% different from the NIST recommended values26. Therefore, it is now essential to understand the choice of initial wavefunction so as to improve the calculations such that the calculated eigenvalues and eigenfunctions can meet the 1% requirement of a parity violation experiment on barium ion.…”

Measurement of apparent temperature in post-detonation fireballs using atomic emission spectroscopy

“…The apparent temperature of both barium species can be calculated from the relative intensities of the respective emission lines in the difference spectrum. temperature of 2800Ϯ 400 K. Applying the same method to the Ba atom peaks at 554 and 706 nm, corresponding to levels 2.2 and 2.9 eV above the ground state, 14 we find an apparent temperature of 3600Ϯ 1000 K. The larger uncertainty of this value reflects the lower signal-to-noise ratio of the peak at 706 nm.…”

“…Since the associated energy levels, degeneracies, and Einstein A coefficients for each of these transitions are well known, 14 we can calculate the apparent temperature from the Boltzmann populations of the energy levels using the two-line method. 3,6,15 Examining the Ba + ion signals at 493 and 614 nm, which originate from states 2.5 and 2.7 eV above the ground state, respectively, 14 we obtain an apparent 2. ͑Color online͒ ͑a͒ Emission spectra collected following detonation of RDX and ͑b͒ RDX doped with 1% barium nitrate by weight. ͑c͒ The difference spectrum is also shown and exhibits strong signals from barium atom and barium ion emissions.…”