Half-life measurements of stored fully ionized and hydrogen-like 122 I ions

Abstract

Abstract. The half-lives of fully ionized and hydrogen-like (H-like)122 I ions have been measured in a heavy-ion storage ring. The β + -decay constants for both charge states and the electron capture (EC) decay constant of H-like ions have been determined. The EC-decay constant in H-like 122 I ions λ H-like EC = 7.35(33) · 10 −4 s −1 is, within the uncertainty, the same as the one in neutral atoms. This result is in agreement with the estimates of recent theoretical considerations on the EC-decay of few-electron ions that explicitly take into account the conservation of the total angular momentum of the nucleus plus lepton(s) system and its projections. No firm confirmation could be concluded from our results on the predicted effect that allowed Gamow-Teller transitions become forbidden if the initial and final total angular momenta are not equal.

Hyperfine structure and nuclear magnetic moments of the praseodymium isotopes135,136,137Pr

“…Similar enhancement has been measured in hydrogen-like 142 Pm 60+ ions [9]. Suppression of the EC decay rate has been seen in hydrogen-like 122 I 52+ ions as compared to the helium-like charge state [10]. In the latter case the quantum numbers of the involved states confirm the hypothesis formulated in [6][7][8].…”

“…The Voigt profil shows a FWHM of w L = 54(1) MHz for the Lorentzian part and w G = 95(1) MHz for the Gaussian contribution. 1814 (10) [20]…”

Expanding Nuclear Physics Horizons with the Gamma Factory

“…This could be explained by conservation of the total angular momentum, since only particular spin orientations of the nucleus and of the captured electron can contribute to the allowed EC decay [47]. This selection rule leads to the acceleration of the allowed Gamow-Teller 1 + → 0 + decay in one-electron Pr 58+ and Pm 60+ ions, while it stalls 1 + → 2 + decays in one-electron 122 53 I ions [48]. Bound β decay, on the other hand, can only occur if vacancies in the atomic shell are available for the β − particle to occupy.…”

Expanding Nuclear Physics Horizons with the Gamma Factory

“…[ 47 ] This selection rule leads to the acceleration of the allowed Gamow–Teller $$1^+\rightarrow 0^+$$ decay in one‐electron Pr 58 + and Pm 60 + ions, while it stalls $$1^+\rightarrow 2^+$$ decays in one‐electron $$^{122}_{\nobreakspace 53}$$I ions. [ 48 ] Bound β decay, on the other hand, can only occur if vacancies in the atomic shell are available for the $$\beta ^-$$ particle to occupy. The process and corresponding nuclear lifetime are sensitive to the electronic environment.…”