  We perform next-to-leading order calculations of the single-diffractive and
non-diffractive cross sections for dijet production in proton-antiproton
collisions at the Tevatron. By comparing their ratio to the data published by
the CDF collaboration for two different center-of-mass energies, we deduce the
rapidity-gap survival probability as a function of the momentum fraction of the
parton in the antiproton. Assuming Regge factorization, this probability can be
interpreted as a suppression factor for the diffractive structure function
measured in deep-inelastic scattering at HERA. In contrast to the observations
for photoproduction, the suppression factor in proton-antiproton collisions
depends on the momentum fraction of the parton in the Pomeron even at
next-to-leading order.
