In this note, we address the beam performance (particle content, rates) with
emphasis on the momentum determination and particle identification methods for
the new H2-VLE (Very Low Energy) beam line that will serve the double phase
ProtoDUNE experiment (also known as WA105), in the framework of the CENF
project. The proposed instrumentation is configured to achieve an optimal
pi/K/proton separation over the full spectrum of provided beam energies, from
0.4 GeV up to 12 GeV, as well as precise momentum measurement to a percent
level, if required by the experiment. This note focuses on the H2-VLE beam line
for the Double Phase ProtoDUNE experiment, however the same approach can be
implemented for the H4-VLE beam, since the design of the two beam lines is very
similar