Hyperfine structure constants of atomic bromine (Br I)

•Doppler-limited absorption spectrum of atomic Br was observed around 800 nm.•Hyperfine structures of 45 lines were analyzed for Br I.•HFS constants A of 33 levels were reported for the first time.•HFS constants B were reported for the first time.

The absorption spectrum of the neutral bromine (Br I), lying in the region from 11,300 cm−1 to 12,600 cm−1 has been investigated using concentration modulation absorption spectroscopy with a tunable Ti:Sapphire laser. The bromine atoms were excited by discharging the mixture of Helium and bromine vapour in a hollow discharge glass tube. The hyperfine structure spectra of 45 lines were analyzed. Hyperfine structure constants A and B were derived for 20 even and 27 odd levels amongst which constants for 12 even and 21 odd levels were newly reported.