Study On Transient Atomic/Molecular Absorption Spectra Of Iodine Vapor

Through the glow discharge of a mixture?I₂:He?1:40?of iodine vapor?I₂?and helium?He?,transient iodine molecular ion?I₂⁺?and iodine atom?I I?were generated.The Ti-sapphire laser was used as the light source to obtain near-infrared absorption spectra of transient iodine molecular ion and iodine atom of iodine vapor.The absorption spectra of iodine molecular ion in the range of 11 860 cm^-1-12100 cm^-1 were obtained using the optical heterodyne-velocity modulation spectroscopy?OH-VMS?technique.After integration with the spectra from the previous experiment in the range of 12 060 cm^-1-13 100 cm^-1,the spectra in the range of 11 860 cm^-1-13 100 cm^-1 was obtained and fitted.A total of 5 759 transition lines of 31 vibration bands in the A²?_3/2-X²?_3/2 system of iodine molecular ion were fitted.Dimensionless fundamental physical constants,such as?and?,may change over time and space.Seven vibration bands were analyzed for the first time.I₂⁺is a very promising candidate to mesure the variation of constants?and?.The forbidden transition of I₂⁺has an enhancement sensitivity factor for variation of?and?.The statistical uncertainty of the variation of?and?are??/?=2.42×10^-19/yr and??/?=1.13×10^-18/yr,respectively.It is proved that I₂⁺satisfies the requirement of measuring the constants?and?.Absorption spectra of iodine atom in the range of 11 300 cm^-1-13 000 cm^-1were measured by concentration modulation spectroscopy?CMS?,and the hyperfine structure?hfs?constants of 22 even levels and 32 odd levels of iodine atom were obtained by analyzing and fitting 50 transition lines.The hfs constants of 54 levels were obtained,of which the constants of 12 levels were obtained for the first time.