Stabilization of predissociating nitric oxide Rydberg molecules using microwave and radio-frequency fields

Abstract

We present three techniques for suppressing predissociation of the nitric oxide Rydberg states normally excited in pulsed-field ionization zero-kinetic-energy photoelectron spectroscopy. By applying a combination of appropriate dc and microwave fields it is possible to inhibit predissociation by resonantly mixing Stark states of adjacent principal quantum number n, with similar parabolic quantum number k. Lifetime enhancement is also obtained by using an appropriate radio-frequency field to resonantly mix Stark states of the same n. Finally, in the absence of dc fields, microwaves are used to stabilize optically excited nf Rydberg states, by inducing transitions to higher angular momentum states with longer lifetimes, specifically to the n±1, l⩾4 states.