DarkSide-50: researchers at the Gran Sasso Laboratories have begun to chase the dark side of the Universe
An internationally important project that could revolutionize our knowledge of the Universe has started at Gran Sasso National Laboratories of the National Institute of Nuclear Physics. DarkSide-50 is the most advanced dark matter detector ever designed and will address one of the crucial challenges of contemporary physics since it uses highly advanced technologies located under 1400 meters of mountain rock sheltered from cosmic radiation.
An amount of matter that is five times greater than the one that we know escapes our understanding: we don’t know what its nature is and we are not able to detect its presence, but we have rather solid evidence that it does exist since it holds the galaxies together by its gravitational attraction. An unprecedented chase of the “dark side” of the Universe has begun with the DarkSide-50 project at the Gran Sasso National Laboratories (LNGS) of the National Institute of Nuclear Physics (INFN). This is an international project carried out with the fundamental contribution of the Italian INFN, the U.S. National Science Foundation (NSF) and Department of Energy, with the participation of research teams from France, Poland, Ukraine, Russia and China, under the coordination of INFN and the University of Princeton.
“Our multi-year efforts have been crowned by the beginning of DarkSide-50. The tests performed before starting had already shown that the DarkSide technology is perfectly suited for a programme of complete exploration of zero-background dark matter”, said Cristian Galbiati, one of the coordinators of DarkSide-50, during the inauguration of the experiment held at the Gran Sasso National Laboratories. This international event featured prominent figures of the scientific, institutional and industrial world, including Fernando Ferroni, President of INFN, John Philips, U.S. ambassador to Italy, Stefano Ragazzi, Director of LNGS, and Ken Havens from Kinder Morgan, the provider of the radio-pure argon needed for the experiment.
The heart of DarkSide-50 is a cylindrical detector filled with 153 Kg of extremely pure liquid argon: if a particle of dark matter hit a single nucleus of this noble gas, very weak light flashes would be emitted and immediately captured by the myriad of photo-sensors located around the nucleus. However, to detect these very weak signals, that have never been observed till now, it is necessary to minimize the “background noise” of cosmic radiation. For this reason, the heart of DarkSide is encased inside a steel “matryoshka” filled with 30 tons of liquid scintillator material – shielding neutrons – and 1000 tons of ultra-pure water. The whole system is located under a mountain rock of 1400 meters, inside the Gran Sasso National Laboratories, an ideal and unique place where to perform scientific experiments in a condition very close to “cosmic silence”.
“DarkSide is a big leap in quality in the field of frontier research on dark matter” explained Gioacchino Ranucci, a researcher of the INFN section in Milan and coordinator of the project with Galbiati. “With its ultra-pure argon core surrounded by a sophisticated system of vetoes against the possible sources of disturbance, the system is able to conduct its investigation in an ideal situation of almost complete absence of background noises, that is a necessary condition to identify, in an absolutely clear way, the elusive and evasive particles of dark matter”.
After the initial testing, the “chase” has begun and the DarkSide-50 technologies will allow to investigate the presence of dark matter with energies inaccessible until now, making these Laboratories an international centre of excellence for research in the field of “new” physics. This result has started to produce a direct impact also in other sectors, e.g. medicine, since the new technologies that have resulted into the development of this experiment could soon lead to new developments in diagnostic technologies for the fight against cancer and neurodegenerative diseases.