Atomic transition probabilities for Tm I and Tm II

Atomic transition probabilities for 376 spectral lines of neutral thulium and for 146 spectral lines of singly ionized thulium are reported. Branching fractions, measured with the 1.0-m Fourier-transform spectrometer at the National Solar Observatory on Kitt Peak, Tucson, Arizona, are combined with recently published radiative lifetimes, measured with time-resolved laser-induced fluorescence on a slow atomic beam, to determine these transition probabilities. Typical uncertainties are less than or equal to ±10%.