Neutrinos are the most elusive known particles in the universe. In order to observe these particles very large detectors with several tons (even thousands of tons) of active material have been built. On the other hand, a neutrino-interaction process with a much larger cross-section, called neutrino-nucleus coherent scattering (CEnNS), was predicted more than 40 years ago. In this process the neutrino interacts with the atomic nuclei as a whole instead than with the individual protons and neutrons (or quarks). In this case, the total cross-section for this process is proportional to the square of the number of neutrons resulting in cross-sections that are ~1e4 times larger for large nuclei such as xenon or cesium.
The counter part of this process is that it can only be observed for relatively low energy neutrinos (<30-40 MeV) and, more important, the energy deposited in the detector is incredibly small, near 1 keV.
For this reason, new detector technologies have to be developed to observe and study this process that could open a new window to understand these elusive particles.
In the GanESS project we are developing the high-pressure gas TPC technology to be applied in the search of CEnNS at the European Spallation Source (ESS) that will produce neutrinos as a residue of the neutron production. The high-pressure gas TPC has the advantage of allowing for amplification of the electrons produced by neutrino interactions which should allow for an important energy threshold reduction with respect to current technologies. In addition, the technology also allows operation in the same detector with different gases enlarging the physics potential of this technology.
