| We present and discuss results from a measurement of the hyperfine a constant of the 1s22s 22p63p P122 excited state in 25Mg+ and the linewidth of the same state in 24Mg +. We trapped a single ion in a linear Paul trap and laser-cooled it using the S122 →P32 2 transition (in the case of 25Mg +) and the S122 →P12 2 transition (in the case of 24Mg +). We optically pumped the ion into the (F = 3, mF = +/-3) ground states and weakly probed it with a tunable fibre laser that was scanned to drive the ion from the ground state to the F' = 3 and F' = 2 manifolds of the P122 state. The final state of the ion was determined by counting fluorescence (or the reduction therein) from the S122 (F = 3, mF = +/-3) → P322 (F'' = 4, m''F = +/-4) cycling transition with a photomultiplier module. We determined that the hyperfine a constant is 102.16 +/- 0.16 MHz and the natural linewidth is 42.4 +/- 1.2 MHz.. |
