Showing papers by "T. Kuhl published in 1994"
TL;DR: The first direct observation of a hyperfine splitting in the optical regime is reported, and should allow a novel test of ED corrections in the previously unexplored combination of strong magnetic and electric fields in highly charged ions.
Abstract: The first direct observation of a hyperfine splitting in the optical regime is reported. The wavelength of the $M1$ transition between the $F=4$ and $F=5$ hyperfine levels of the ground state of hydrogenlike $^{209}\mathrm{Bi}^{82+}$ was measured to be ${\ensuremath{\lambda}}_{0}=243.87(4)$ nm by detection of laser induced fluorescence at the heavy-ion storage ring ESR at GSI. In addition, the lifetime of the laser excited $F=5$ sublevel was determined to be ${\ensuremath{\tau}}_{0}=0.351(16)$ ms. The method can be applied to a number of other nuclei and should allow a novel test of QED corrections in the previously unexplored combination of strong magnetic and electric fields in highly charged ions.
213 citations
TL;DR: The quadrupole moment and isomer shift were determined for the first time as well as a precise value and the sign of the magnetic dipole moment.
Abstract: The complete hyperfine spectrum in the optical transition 5${\mathit{d}}^{2}$6${\mathit{s}}^{2}$ $^{3}$${\mathit{P}}_{2}$\ensuremath{\rightarrow}5d6${\mathit{s}}^{2}$6p $^{1}$${\mathit{P}}_{1}$ of $^{178}\mathrm{Hf}^{\mathrm{m}2}$ was recorded by collinear laser spectroscopy using nanogram amounts of samples. The quadrupole moment and isomer shift were determined for the first time as well as a precise value and the sign of the magnetic dipole moment. The change in nuclear mean-square charge radius between the isomeric state $^{178}\mathrm{Hf}^{\mathrm{m}2}$ and the ground state $^{178}\mathrm{Hf}^{\mathit{g}}$ was evaluated as \ensuremath{\delta}〈${\mathit{r}}^{2}$${\mathrm{〉}}^{178.178\mathrm{m}2}$=-0.059(9) ${\mathrm{fm}}^{2}$. From the hyperfine A and B factors the magnetic moment ${\mathrm{\ensuremath{\mu}}}_{\mathit{I}}^{178\mathrm{m}2}$=+8.16(4) nuclear magnetons and the spectroscopic quadrupole moment ${\mathit{Q}}_{\mathit{s}}^{178\mathrm{m}2}$=+6.00(7) b were were extracted.
49 citations
TL;DR: Two-step resonant laser-stimulated recombination of highly charged ions was performed for the first time and provides access to detailed Rydberg spectroscopy in an electron beam environment.
Abstract: Two-step resonant laser-stimulated recombination of highly charged ions was performed for the first time. Nd:YAG laser pulses overlapped with an Ar[sup 18+] beam in the electron cooler of the ESR storage ring at GSI induced transitions from the continuum to the [ital n]=81 state of hydrogenlike Ar[sup 17+]. To avoid reionization in the bending magnet before reaching the detector, the [ital n]=81 population was transferred to a state well below the reionization threshold by a Ti:sapphire laser. Tuning of this laser yielded the [ital n]=81 to 36 and 37 transition-line profiles. The two-step method provides access to detailed Rydberg spectroscopy in an electron beam environment.
28 citations