High-resolution absorption spectrum of Ne i in the region of 565–595 Å

The absorption spectrum of Ne i was observed photographically in the wavelength region of 565–595 Å with the high-resolution spectrograph at the Photon Factory in Japan. From the observed term values, the first ionization potentials I(2p5 2P3/2) and I(2p5 2P1/2) were found to be 173 930.0 ± 0.2 and 174 710.4 ± 0.2 cm−1, respectively. Furthermore, the five-channel quantum-defect theory is applied to the analysis of the present experimental term values. It is found that the multichannel quantum-defect theory describes well the absorption spectrum of Ne i observed in the present measurement.