Fig. 3: Vibronic spectra measured for different isotopologues of RaF.

Measured vibronic absorption spectra for the A2Π1/2 ← X2Σ+ transition are shown for the isotopologues 223RaF, 224RaF, 225RaF, 226RaF and 228RaF. Wavenumber values are relative to the transition (0, 0) of 226RaF.