  Last year the COHERENT collaboration was able to measure for the first time
the Coherent Elastic Neutrino Nucleus Scattering (CE$\nu$NS). Neutrinos within
the right energy range can be produced in large quantities at accelerator
facilities via pion Decay At Rest ($\pi$DAR) and used to measure CE$\nu$NS.
This new channel opens several, interesting possibilities: studying the
CE$\nu$NS spectrum it will be possible, for example, to search for Physics
Beyond the Standard Model, looking for deviations from the predictions of the
electroweak theory; it can also give important inputs for the understanding of
core collapse supernovas, where neutrino-nucleus interactions and, more
generally, collective neutrino behavior play a crucial role. Using CE$\nu$NS it
is also possible to measure precisely the electroweak form factor for a large
number of different nuclei, extracting information on the neutron distribution
inside the nucleus as well. In this presentation I will focus on the last
aspect: I will calculated the precision that can be achieved in such kind of
experiment, investigating in particular the effects of the low-energy threshold
and the systematic errors on the quenching factor. The expected precision will
be calculated using the Helm model and also with a model-independent approach.
