Lifetime of electronic states of CO2+

Photon–electron coincidence experiments at synchrotron radiation facilities with arbitrary bunch modes

“…The retrieved binding energy E El, bind = (18.16 ± 0.07) eV shows good agreement with the already published data of E (Lit) El, bind = 18.1 eV. [81][82][83] While, in the present case, the radiative lifetime was obtained by the fitting procedure of the convoluted signal, for short lifetimes, it may be determined directly using the dark gap in the hybrid fill pattern. We estimate an upper boundary of this radiative lifetime determination of τmax ≈ 40 ns for the 200 ns dark gap in the hybrid mode of BESSY II.…”

“…The obtained lifetime τ = (149.5 ± 0.5) ns agrees with the range of reported lifetimes of the CO + 2 B state based on coincidence measurements from 118 to 150 ns. 82,83 In the next step, the obtained coincidence signal was smoothed using a weighted moving average approach [Fig. 5(a), dotted line].…”

“…The obtained radiative lifetime τ = (149.5 ± 0.5) ns and the electron binding energy E El, bind = (18.16 ± 0.07) eV are in good agreement with literature values. [81][82][83] The presented approach is applicable to arbitrary excitation patterns and may stimulate efforts to include photon detection to other coincidence experiments, increasing both physical information obtained in an experiment and versatility of coincidence spectrometers. For more complex physical processes, the deconvolution of the measured signal might be replaced by the convolution of simulated signals in combination with optimization algorithms.…”

Fluorescence efficiencies of the A-X and B-X systems of CO+2 in comets

“…Einstein A coefficients for the v states of the A-X band and the entire B-X band were measured and updated by Herran et al (1983). Individual Einstein A coefficient for each vibrational transition, A v v , was calculated using the F-C factors of McCallum and Nicholls (1971).…”

Simultaneous Ionization and Excitation of Molecules by Positron Impact

“…These, and the total ionization cross section (Q t i ), were measured simultaneously, ensuring consistent normalization. The lifetimes of the A 2 Å u and B 2 AE þ u states of CO þ 2 are 115 AE 5 ns and 126 AE 3 ns, respectively [20], and that of the B 2 AE þ u state of N þ 2 is 61:5 AE 1:1 ns [21], i.e., less than 1% of the ion extraction times (typically, $20 s), thus resulting in negligible loss of signal.…”