A spectroscopic investigation of the ionisation and dissociation decay dynamics of Rydberg states of NO

• Published in: Molecular physics Vol. 112; no. 13; pp. 1808 - 1815
• Main Authors: Minns, R.S., Lazenby, D.T.C., Hall, F.H.J., Jones, N.J.A., Patel, R., Fielding, H.H.
• Format: Journal Article
• Language: English
• Published: Abingdon Taylor & Francis 03.07.2014; Taylor & Francis Ltd
• Subjects: autoionisation; Channels; Decay; Dynamic tests; Extreme values; Molecular physics; Monitors; predissociation; Rydberg states; Spectroscopy; Spectrum analysis
• ISSN: 0026-8976; 1362-3028
• DOI: 10.1080/00268976.2013.865809

Double-resonance spectroscopy has been employed to characterise the autoionising and predissociating Rydberg states of NO converging to the υ + = 0 and υ + = 1 levels of the X 1 Σ + ground state of NO + . Below the lowest ionisation limit, we monitor the formation of the N( 2 D) predissociation product and observe a spectrum dominated by the p(N + = 0) series, with smaller contributions from the p(2) and f(2) series. Many of the lineshapes can be fit to a simple Fano line profile. Upon vibrational excitation, a competing autoionisation channel is opened and we monitor the products of both the dissociation and ionisation channels. The υ + = 1 predissociation spectrum appears much more complex than the predissociation spectrum, with significant contributions from the p(0), f(2), p(2), s(1) and d(1) series. In contrast, the υ + = 1 ionisation spectrum is dominated by the p(0) and f(2) Rydberg series, with much weaker contributions from s(1), d(1) and p(2) series. The lineshapes in the υ + = 1 predissociation and autoionisation spectra are perturbed and cannot be fit to simple Fano line profiles. In some extreme cases, these perturbations result in the complete disappearance of peaks from either the autoionisation or predissociation spectrum.