Isotopic variation of experimental lifetimes for the lowest 1Π u states of N 2

Abstract

Lifetimes of several 1Π u states of the three natural isotopomers of molecular nitrogen, N214, N14 N15, and N215, are determined via linewidth measurements in the frequency domain. Extreme ultraviolet (XUV) +UV two-photon ionization spectra of the b 1Π u (v=0-1,5-7) and c3 1Π u (v=0) states of N214, b 1Π u (v=0-1,5-6) and c3 1Π u (v=0) states of N14 N15, and b 1Π u (v=0-7), c3 1Π u (v=0), and o 1Π u (v=0) states of N215 are recorded at ultrahigh resolution, using a narrow band tunable XUV-laser source. Lifetimes are derived from the linewidths of single rotationally resolved spectral lines after deconvolution of the instrument function. The observed lifetimes depend on the vibrational quantum number and are found to be strongly isotope dependent. © 2005 American Institute of Physics.