Figure 1

Simplified energy level diagrams of Ca (a) and ${\text{Ca}}^{+}$ (b) of relevance to the experiments. The straight arrows indicate laser driving transitions, while the wavy arrow symbolizes spontaneous emission. In (a), the solid line beneath the hatched region indicates the ionization limit.Reuse & Permissions

Figure 2

(a) Schematics of the experimental setup with an inset showing a side view of the imaging system. For the optical elements in the figure, the following notation has been used: M, mirror; DM, dichroic mirror; PBS, polarization beam splitter; and $\lambda ∕2$, half-wave-plate. (b) The linear Paul trap electrodes with applied rf voltages. The $z$ axis defines the trap axis. The middle sections are $5.4\text{mm}$ long and the end pieces are $20\text{mm}$ each. The diameter of the electrodes is $8.0\text{mm}$ and the minimum distance to the trap axis is $3.5\text{mm}$.Reuse & Permissions

Figure 3

Image of a pure ${}^{40}\mathrm{Ca}^{+}$ Coulomb crystal consisting of $\sim \mathrm{10\hspace{0.17em}000}$ ions.Reuse & Permissions

Figure 4

Image of a ${}^{40}\mathrm{Ca}^{+}$ (fluorescing)–${}^{44}\mathrm{Ca}^{+}$ (nonfluorescing) two-component crystal of $\sim 1500$ ions before (a) and after (b) exposure to the atomic beam which leads to the electron transfer as described in the text. The white line indicates the outer boundary of the crystal.Reuse & Permissions

Figure 5

Semilogarithmic plot of the production rate of ${\text{Ca}}^{+}$ ions as a function of the frequency detuning of the spectroscopy laser from the ${}^{40}\mathrm{Ca}$ resonance. The data points presented are the results of three frequency scans made at slightly different temperatures [$\left(\Delta \right)$ $T_{\mathit{oven}}=612°\mathrm{C}$, $(∎)$ $T_{\mathit{oven}}=630°\mathrm{C}$, and $(◻)$ $T_{\mathit{oven}}=602°\mathrm{C}$]. The full line indicates a Voigt profile fit to the ${}^{40}\mathrm{Ca}$ resonance within the frequency range $\sim [-1300;700]\text{MHz}$.Reuse & Permissions

Figure 6

Plot of the values $[A^{\prime }40∕(A^{\prime }-40\left)\right]\delta {\nu }_{RIS}^{40A^{\prime }}$ derived from the measurements as a function of $[A^{\prime }40∕\left(A^{\prime }-40\right)]\delta {⟨r^2⟩}^{40A^{\prime }}$ for the $4s^2$ ${}^{1}S_0\to 4s5p$ ${}^{1}P_1$ transition in Ca. The dashed line is a weighted linear regression fit to determine the coefficients $M_{SMS}$ and $F$ from the relation given in Eq. (4).Reuse & Permissions