SWGO, the Cherenkov water detector observatory for the extreme gamma-ray sky.
The Southern-hemisphere Wide-field Gamma-ray Observatory (SWGO) is a ground-based observatory for very and ultra high energy gamma rays, with a close 100% duty cycle and order steradian field of view, located in the Atacama desert, Chile (4770 meters altitude). The SWGO is an array that will measure the Extensive Air Showers (EAS) generated by primary photons from space, incident on the atmosphere, of energy from hundreds of GeV up to the PeV scale.
Access to the Galactic Centre and complementary with the major facility CTA-South, are key motivations for such a EAS gamma-ray observatory in the southern hemisphere. There is also significant potential for charged cosmic ray studies, including anisotropy. Fundamental physics such as Lorentz invariance violation at such energies will be tested, and the muon content in EAS at the PeV scale investigated. The large field of view is crucial for transient and variable multi-wavelength and multi-messenger phenomena in the sky.
SWGO is mainly based on thousands of, Cherenkov-effect, water detectors, arranged in an array covering a circular area of several kilometers, having a high fill-factor core detector with area considerably larger than the HAWC observatory, and significantly better sensitivity, and completed by a low density array of outer detectors.
The team of INFN Roma Tor Vergata is working on production and test of Resistive Plate Chamber (RPC) prototype (120x180cm) for SWGO. Activities and developments include a new read-out system for the RPC, new front-end electronics and mechanical frame, simulations and events reconstruction for the array, performance studies and hadron separation methods. The front-end electronics will be tested on small chambers, with novel read-out layout, and tested also in climatic chamber, followed by the integration onto the double layer cylindrical tanks.