  The $\nuebar$ flux and spectrum have been measured at a distance of about 800
m from the reactors of the Palo Verde Nuclear Generating Station using a
segmented Gd-loaded liquid scintillator detector. Correlated positron-neutron
events from the reaction $\nuebar$p$\to$e^+n were recorded for a period of 200
d including 55 d with one of the three reactors off for refueling. Backgrounds
were accounted for by making use of the reactor-on and reactor-off cycles, and
also with a novel technique based on the difference between signal and
background under reversal of the e^+ and n portions of the events. A detailed
description of the detector calibration, background subtraction, and data
analysis is presented here. Results from the experiment show no evidence for
neutrino oscillations. $\nuebar\to\bar\nu_x$ oscillations were excluded at 90%
CL for $\dm>1.12\times10^{-3}$ eV^2 for full mixing, and $\sinq>0.21$ for large
$\dm$. These results support the conclusion that the observed atmospheric
neutrino oscillations does not involve $\nu_{\rm e}$.
