In order to calculate the spin-observables defined in section
it is
necessary to measure the polarization of the incident proton flux as well
as that of the resulting neutrons. The data from the high-energy beamline
polarimeters described in section 4.1.3 was recorded as part of
the same
data stream as the information from the neutron polarimeter and was
analyzed separately for each run at the same time that the neutron data was
being analyzed. The weighted average beam polarization for each part of
the run is shown in table .
Table: Proton beam polarizations for the individual parts of experiments
E385 and E387. The uncertainties include both statistical uncertainties
and uncertainties in the analyzing power of the analyzing reaction,
.
The uncertainty indicated for the values of proton polarization are
dominated by the uncertainty in the analyzing power of the analyzing
reaction, 
, used in the beamline polarimeters.
Portions of the polarization replay and analysis were conducted at Ohio
University.