St. Pratt, ELECTRIC-FIELD EFFECTS IN THE NEAR-THRESHOLD PHOTOIONIZATION SPECTRUMOF NITRIC-OXIDE, The Journal of chemical physics, 98(12), 1993, pp. 9241-9250
Zero-kinetic-energy-photoelectron spectroscopy (ZEKE-PES) and time-of-
flight mass spectrometry are used to investigate the near-threshold, t
wo-color photoionization of NO via the A 2SIGMA+, v = 0 level. Pulsed-
field ionization of Rydberg states within 20 cm-1 of the ionization th
reshold is shown to proceed via a diabatic mechanism. Particular empha
sis is given to the effect of predissociation on the signal produced b
y delayed field ionization. A small (approximately 3 V/cm) dc electric
field is shown to produce a dramatic decrease in the field ionization
signal in both the NO+-ion and ZEKE-electron channels. This decrease
is thought to be due to an increase in the predissociation rate caused
by the dc electric field. The implications of these experiments for m
ass-analyzed threshold ionization are discussed.