Fig. 2: Spectroscopy of AcF.
From: Laser spectroscopy and CP-violation sensitivity of actinium monofluoride
a, Two-step laser resonance ionization scheme used to search for electronic transitions in AcF. b, Spectrum of the measured vibronic transitions from the ground state in AcF, and simulation based on the contour-fitted molecular constants. c, Assigned vibronic transitions observed in the spectrum shown in b. d, Fortrat diagrams for the measured vibronic transitions, showing the evolution of the P, Q and R branches along the diagonal vibrational progression. e, Ion count rate as a function of the wavenumber of the first excitation laser across the full scanning range. A cubic Savitzky–Golay de-noising filter with a ten-point window length is applied to the raw data to assist in the visualization of data trends. The complete spectrum is constructed from multiple shorter scans. A vertical offset is applied to each scan to compensate for their different background rates owing to long-term variations in the beam intensity. The y axis is thus in arbitrary units. The red band marks the region of the spectrum in b and the grey bands mark regions investigated and excluded as resonant features. f, Comparison of excitation wavenumbers with different electronic states calculated with FS-RCC27 and the upper state in the spectrum of b. The error bars correspond to the theoretical uncertainty in the excitation wavenumber calculations, as reported in ref. 27.
