Statehyphen;selective ionization of nitrogen in theXthinsp;2Sgr;+gv+=0 andv+=1 states by twohyphen;color (1+thinsp;1) photon excitation near threshold

摘要

Efficient generation of N+2Xthinsp;2Sgr;+g(v+=0,1) is demonstrated by an extremehyphen;ultraviolet +visible (1+1) photon excitation scheme. Thecrsquo;4thinsp;1Sgr;+u(vrsquo;=0,1) Rydberg states are used as intermediates. The N2molecules are ionized near thev+=0 andv+=1 ionization thresholds. The autoionizingnddgr;gthinsp;1Dgr;gRydberg series with the rotational quantum numbersN=4, 5, and 6 (in the limit ofluncoupling) are observed for the first time. Extrapolation of theN=4 series yields an ionization energy of N2of 125thinsp;666.959(67) cmminus;1.