  Context: The determination of the magnetic field vector in quiescent solar
prominences is possible by interpreting the Hanle and Zeeman effects in
spectral lines. However, observational measurements are scarce and lack high
spatial resolution. Aims: To determine the magnetic field vector configuration
along a quiescent solar prominence by interpreting spectropolarimetric
measurements in the He I 1083.0 nm triplet obtained with the Tenerife Infrared
Polarimeter installed at the German Vacuum Tower Telescope of the Observatorio
del Teide. Methods. The He I 1083.0 nm triplet Stokes profiles are analyzed
with an inversion code that takes into account the physics responsible of the
polarization signals in this triplet. The results are put into a solar context
with the help of extreme ultraviolet observations taken with the Solar Dynamic
Observatory and the Solar Terrestrial Relations Observatory satellites.
Results: For the most probable magnetic field vector configuration, the
analysis depicts a mean field strength of 7 gauss. We do not find local
variations in the field strength except that the field is, in average, lower in
the prominence body than in the prominence feet, where the field strength
reaches 25 gauss. The averaged magnetic field inclination with respect to the
local vertical is 77 degrees. The acute angle of the magnetic field vector with
the prominence main axis is 24 degrees for the sinistral chirality case and 58
degrees for the dextral chirality. These inferences are in rough agreement with
previous results obtained from the analysis of data acquired with lower spatial
resolutions.
