Effect of⁸⁷Sr hyperfine structure on the isotope selective excitation of⁸⁹Sr and⁹⁰Sr isotopes in collinear resonance ionization spectroscopy

Abstract

The 87Sr isotope has an extremely complex hyperfine structure (HFS) as a consequence of simultaneous mixing of the 3F2, 3F3, 3F4 and 1F3 fine structure components in the 5s32f state. The resultant hyperfine spectrum of the 5s4d 3D3-5s32f 3F4 (364 nm) transition consists of 74 hyperfine components. HFS constants A, B for both upper and lower levels have been derived from the single-electron contribution factors a5s, a4d3/2, a4d5/2, b4d3/2 and b4d5/2 using Breit-Wills formalism. Isotope ratio enhancement factors have been computed for the 5s5p 3P2-5s21s 3S1 (325 nm), 5s4d 3D3-5s32f 3F4 (364 nm) and the 5s2 1S0-5s5p 3P1 (689.7 nm) transitions for isotope selective excitation/ionization of 89Sr and 90Sr isotopes in collinear fashion. The results obtained are comparable to that of the experimental results reported earlier. Simulations have been carried out for various laser linewidths and acceleration potentials considering appropriate abundances, HFS of the odd isotope and mass shifts of the constituent isotopes. This method can be used for optimization of experimental configurations with respect to acceleration potentials and appropriate laser linewidths in order to obtain better selectivities for the 89Sr and 90Sr isotopes which allows the long term monitoring of these isotopes in the environment. The present study shows that the HFS of the 87Sr isotope has a significant effect on the isotope selective excitation of 89Sr and 90Sr isotopes.

Theoretical and Experimental Understanding of the Anomalous Odd-to-Even Isotope Ratios of Tin in a 1 + 1 Single-Colour Resonance Ionization Mass Spectrometry: Revisited

“…The theoretical approach adopted for the isotopic selectivity calculations is the spectral simulation (SS) method developed by our group [14][15][16][17]. In this approach the atomic line profile is generated assuming a Lorentzian profile taking into account the appropriate abundances, isotope shifts of the constituent isotopes and hyperfine structure of the odd isotopes.…”

“…The laser linewidth and the laser line shape are incorporated in the computation. Further details of this theoretical model have been discussed in our previous publications, and hence it is not elaborated here [14][15][16][17].…”

Investigation of Optical Ionization of Strontium via 5s21S0 ⟶ 5s5p 3P1° ⟶ 5s5d 3D2 ⟶ 4dnp (or 4ndf, n = 39) for Isotope Selectivity Enhancement

“…e isotope shift, particularly, is one of the dominant factors in achieving isotopic selectivity and is required to be optimized for each excitation transition by identi cation. e isotope selectivity can be de ned as below [17][18][19]:…”