The [1+1] two-photon dissociation dynamics of mass-selected 79Br2 + has been studied in a cold ion beam using a cryogenic cylindrical ion trap velocity map imaging spectrometer. The quartet 14Σ- u;3=2 state of 79Br2 ...The [1+1] two-photon dissociation dynamics of mass-selected 79Br2 + has been studied in a cold ion beam using a cryogenic cylindrical ion trap velocity map imaging spectrometer. The quartet 14Σ- u;3=2 state of 79Br2 + is employed as an intermediate state to initiate resonance enhanced two-photon excitation to high-lying dissociative states in the 4.0-5.0 eV energy region above the ground rovibronic state. Total kinetic energy release (TKER) and the twodimensional recoiling velocity distributions of fragmented 79Br+ ions are measured using the technique of DC-slice velocity map imaging. Branching ratios for individual state-resolved product channels are determined from the TKER spectra. The measured photofragment angular distributions indicate that the dissociation of 79Br2 + occurs in dissociative Ω=3/2 state via ΔΩ=0 parallel transition from the 14Σ-u;3=2 intermediate state. Due to the considerable spin-orbit coupling effects in the excited states of 79Br2 +, higher-lying dissociative quartet states are likely responsible for the observed photodissociation processes.展开更多
基金This work was supported by the National Key R&D Program of China(No.2017YFA0303502)the National Natural Science Foundation of China(No.21773221 and No.21827804)the Fundamental Research Funds for the Central Universities of China(No.WK2340000078).
基金the National Natural Science Foundation of China(No.21773221 and No.21827804),the National Key R&D Program of China(2017YFA0303502),and Fundamental Research Funds for the Central Universities of China(WK2340000078).
文摘The [1+1] two-photon dissociation dynamics of mass-selected 79Br2 + has been studied in a cold ion beam using a cryogenic cylindrical ion trap velocity map imaging spectrometer. The quartet 14Σ- u;3=2 state of 79Br2 + is employed as an intermediate state to initiate resonance enhanced two-photon excitation to high-lying dissociative states in the 4.0-5.0 eV energy region above the ground rovibronic state. Total kinetic energy release (TKER) and the twodimensional recoiling velocity distributions of fragmented 79Br+ ions are measured using the technique of DC-slice velocity map imaging. Branching ratios for individual state-resolved product channels are determined from the TKER spectra. The measured photofragment angular distributions indicate that the dissociation of 79Br2 + occurs in dissociative Ω=3/2 state via ΔΩ=0 parallel transition from the 14Σ-u;3=2 intermediate state. Due to the considerable spin-orbit coupling effects in the excited states of 79Br2 +, higher-lying dissociative quartet states are likely responsible for the observed photodissociation processes.
