Interference Effects in Hyperfine Induced 2s2p³P₀,³P₂→ 2s²¹S₀Transitions of Be-like Ions

Abstract

Interference effects in hyperfine induced AbstractThe hyperfine induced 2s2p 3 P 0 , 3 P 2 → 2s 2 1 S 0 E1 transition probabilities of Be-like ions were calculated using grasp2K based on multi-configuration Dirac-Fock method and HFST packages. It was found that the hyperfine quenching rates are strongly affected by the interference for low-Z Be-like ions, especially for 2s2p 3 P 0 → 2s 2 1 S 0 transition. In particular, the trends of interference effects with atomic number Z in such two transitions are not monotone. The strongest interference effect occurs near Z = 7 for 2s2p 3 P 0 → 2s 2 1 S 0 E1 transition, and near Z = 9 for 2s2p 3 P 2 → 2s 2 1 S 0 E1 transition.

Storage-ring measurement of the hyperfine-induced2s2p3P0→2sSchippers1, Bernhardt2, Müller3 et al. 2012Phys. Rev. A362300View full textAdd to dashboardCite

“…No significant influence of the magnetic field in the storage-ring bending magnets on our result has been found. The origin of the discrepancy between our previously measured HFI rate for 47 Ti 18 [26] and the latest calculations [8][9][10] still remains unclear.…”

“…In particular, Marques et al [6] disregarded the mixing of the 2s 2p 1 P 1 level with the 2s 2p 3 P 1 level. This mixing was included in the later calculations of HFI transition rates in Be-like ions [7][8][9][10]. The comparison of the available theoretical results with the present experimental result for 33 S 12+ strongly suggests that the additional computational effort of the later calculations is indeed required for arriving at more accurate HFI transition rates.…”

“…There is sufficient time for its decay since the ions are stored for much longer than the longest predicted S 12+ (2s 2p 3 P 0 ) HFI lifetime of about 28 s [6,[8][9][10].…”

“…This drastically increases the ns np 3 P 0 → (ns) 2 1 S 0 transition rate. Such hyperfine-induced (HFI) decay rates have been calculated theoretically for berylliumlike (n = 2) [6][7][8][9][10], magnesiumlike (n = 3) [7,[11][12][13], and zinclike (n = 4) ions [14][15][16]. Calculations have been carried out also for divalent heavier atoms [17,18] and singly charged ions [19], where the long isotope-dependent lifetimes are attractive systems for obtaining ultraprecise optical frequency standards [20,21].…”

“…The only theoretical value [6], that was available at the time of the experiment, was significantly smaller (Table I). This first laboratory measurement of a HFI-induced transition rate in a Be-like ion has triggered new theoretical calculations not only for Be-like ions [8][9][10] but also for Mg-like ions [12,13] and Zn-like ions [15]. Table I compares the experimental HFI 2s 2p 3 P 0 → 2s 2 1 S 0 transition rate for Be-like 47 Ti 18+ with all presently available theoretical values.…”