Fast Ion Beam Laser Spectroscopy of13CO+2Laser Induced Fluorescence of theÃ2Πu–X2ΠgElectronic Transition

Laser induced fluorescence of a fast ion beam has been applied to13CO+2for its (0, 0, 0)Ã2Πu–(0, 0, 0)X2ΠgUV electronic transition. The high resolution (0.005 cm−1) of the FIBLAS method, due to a highly reduced Doppler broadening, allows us to evaluate the isotopic shift, to appreciate the contribution of the central atom when determining molecular parameters, and, for the first time, to determine the influence of the central atom on hyperfine structure. Absolute calibration of the13CO+2spectra is obtained by means of a12CO+2–13CO+2spectrum, allowing calibration via FT spectra of12CO+2.