We have studied events with a high-xF antiproton and two central
jets in CDF, with ppbar collisions at sqrt s = 630 and 1800 GeV.  These events
are expected to be dominated by diffraction (pomeron exchange).  The jet E_T
spectra are very similar to those of non-difficulty produced jets but slightly
steeper; their azimuthal difference Delta phi is more peaked at 180^0.