UMass Amherst physicist Andrea Pocar AMHERST, Mass. – University of Massachusetts Amherst physicist Andrea Pocar is among the international team of scientists recently awarded the European Physical Society’s Giuseppe and Vanna Cocconi Prize. The team, known as the Borexino Collaboration, has spent more than a decade unlocking the secrets of how the sun produces its energy. The Cocconi prize goes to researchers who have made “an outstanding contribution to particle astrophysics and cosmology in the last fifteen years, in an experimental, theoretical or technological area.” The Borexino Collaboration was awarded the Cocconi prize “for their ground-breaking observation of solar neutrinos from the proton-proton and carbon-nitrogen-oxygen chains that provided unique and comprehensive tests of the sun as a nuclear fusion engine.” These measurements were made possible by an instrument called the Borexino detector, which is buried half a mile beneath the Apennine Mountains in Italy. The detector features a giant nylon balloon, almost 30 feet across, filled with 300 tons of an ultra-pure aromatic hydrocarbon. The balloon is itself housed in a 45-foot diameter, spherical vessel filled with a similar hydrocarbon and surrounded by ultra-pure water.