  Liquid argon time projection chamber technology is an attractive choice for
large neutrino detectors, as it provides a high-resolution active target and it
is expected to be scalable to very large masses. Consequently, it has been
chosen as the technology for the first module of the DUNE far detector.
However, the fiducial mass required for "far detectors" of the next generation
of neutrino oscillation experiments far exceeds what has been demonstrated so
far. Scaling to this larger mass, as well as the requirement for underground
construction places a number of additional constraints on the design. A
prototype 35-ton cryostat was built at Fermi National Acccelerator Laboratory
to test the functionality of the components foreseen to be used in a very large
far detector. The Phase I run, completed in early 2014, demonstrated that
liquid argon could be maintained at sufficient purity in a membrane cryostat. A
time projection chamber was installed for the Phase II run, which collected
data in February and March of 2016. The Phase II run was a test of the modular
anode plane assemblies with wrapped wires, cold readout electronics, and
integrated photon detection systems. While the details of the design do not
match exactly those chosen for the DUNE far detector, the 35-ton TPC prototype
is a demonstration of the functionality of the basic components. Measurements
are performed using the Phase II data to extract signal and noise
characteristics and to align the detector components. A measurement of the
electron lifetime is presented, and a novel technique for measuring a track's
position based on pulse properties is described.
