Hyperfine structure measurements on singly ionized atomic iodine (I II) using fourier transform spectroscopy

Highlights: • Observation of 141 hfs spectral transitions in the Near IR and Visible spectral regions. • Hfs investigations on 73 spectral transitions. • Hfs constants A and B were reported for 29 even and 32 odd levels. • Hfs constants A and B for 26 even and 27 odd levels for the first time. Hyperfine structure (hfs) investigations were performed on singly ionized atomic iodine (I II) in the spectral region 12,000 - 24,000 cm⁻¹, utilizing microwave discharge method in combination with high resolution Fourier Transform Spectroscopy (FTS). Electrodeless discharge lamps (EDL) were used to generate the iodine plasma. In the present work, 141 hyperfine spectral transitions are reported. Hfs measurements were carried out on 73 well resolved spectral lines and derived the magnetic dipole constant (A) and electric quadrupole constant (B) for 61 energy levels (29 even parity and 32 odd parity). Further, a magnetic dipole transition (14,366 cm⁻¹) and a blended line (20,611 cm⁻¹) have been observed.