Optical absorption spectrum of the silver dimer ion: temperature dependence measured by photodissociation and photon-trap spectroscopy

The optical absorption spectrum is reported for the silver dimer cation, Ag2+, which is temperature-controlled by buffer-gas cooling in an ion trap. The measurement is performed by two methods, photodissociation and photon-trap spectroscopy. The temperature of the trapped ions is estimated from the profiles of the spectrum. The spectrum is further analyzed to evaluate the bond length, re, the vibrational frequency, ωe, and the anharmonic constant, ωexe, in the first excited electronic state based on the molecular parameters reported for the ground state. Absorption and dissociation cross sections are compared as well.