Hyperfine structure investigations in atomic iodine

Experimental results of the hyperfine structure (hfs) constants of levels of the iodine atom are reported. The absorption spectra of 50 transitions in the near infrared spectral region were observed using concentration modulation technique with a tunable single-mode cw Ti:Sapphire laser. Magnetic dipole hfs constants A and electric quadrupole hfs constants B for 54 levels were determined, out of which for 10 levels were examined for the first time, the constants were confirmed for 44 levels.