Collinear laser spectroscopy was performed on stable isotopes of neutral Fe-56 and Mn-55 in both the ground and excited electronic states. The experiments served as the groundwork for the planned study on the nuclear electromagnetic moments and charge radii of beta unstable Mn and Fe isotopes via laser probing methods at the National Superconducting Cyclotron Laboratory. Ion beams were generated in one of two sources; a commerical plasma ion source, which was used to generate ion beams from metallic and ionic salt charges, and an electron ionization source that produced ion beams from molecular fragmentaion of sublimated organometallic compounds. The ions were accelerated to an energy of 15 keV and co-propagated with single-mode continuous-wave laser light. The ion beam was neutralized via charge-exchange reactions with a Na vapor. Multiple atomic levels in the outgoing atomic beam were populated in the charge-exchange reactions. One transition in neutral 56Fe and two transitions in neutral Mn-55 were separately investigated via laser probing. The Fe transition was the 3d64s2 5D4 $ 3d64s4p 5F5 transition at 372 nm. The transitions investigated in Mn I were the 3d54s2 6S5/2 -> 3d54s4p 6P7/2 transition from the Mn I ground state at 403 nm, and the 3d54s4p 8Po 9/2 -> 3d54s4d 8D11/2 transition at 357 nm. The 8Po 9/2 state is a long-lived metastable state that was semi-resonantly populated in the charge-exchange process. Hyperfine spectra for the transitions were recorded by measuring laser-induced fluorescence from the atoms as a function of effective laser frequency. The frequency of the single resonance peak observed in the Fe-56 spectrum agreed with the accepted value. The hyperfine spectra obtained from the two transitions in Mn-55 I were each analyzed by simultaneously fitting all observed peaks for each transition, and the A and B hyperfine coupling constants were deduced. The respective A and B constants were determined to be -72.2(2) MHz and 2(1) MHz for the 3d54s2 6S5/2 ground state, and 428.9(1) MHz and 60(1) MHz for the 3d54s4p 6P7/2 state, and were found to agree with the literature values. For the 3d54s4p 8Po 9/2 and 3d54s4d 8D11/2 levels, the constants were determined to be A = 455.3(4) MHz and B = 71(6) MHz, and A = 409.4(8) MHz and B = -52(7) MHz, respectively, an order of magnitude more precise than the previously reported values, where available.
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