Work began by the Siberian Lake Baikal to create a unique gamma ray observatory, which will span 100 square kilometers in one of the world's cleanest places, researchers said on Sunday.

The Tunka experiment has been ongoing since 1990s, when the first array of photomultipliers began work in the Republic of Buryatia. It was expanded in 2009 to span 1 square kilometer, becoming the world's biggest Cherenkov radiation detector.

The Cherenkov radiation is caused by charged particles moving through the air, producing a faint luminescence that can be detected and analyzed for information on particles that generate it.

The experiment is conducted in Tunka valley, marked for extremely clear air that makes it easier to detect the light generated by the particles.

The new project, approved by the Russian Academy of Sciences earlier this year, will see the array expanded 100 times by 2022, prorector of science of the Irkutsk State University, Alexander Arguchintsev, said on Sunday.

The project has a budget of 1.5 billion rubles ($46 million) and is being carried out jointly by several research institutions, including the Moscow State University and the University of Hamburg, Arguchintsev said.

The expansion will make Tunka the only research center in the world to simultaneously study all kinds of cosmic high-energy gamma rays, including neutrinos, gamma quanta and atomic nuclei, Arguchintsev said. The information contributes to our understanding of the evolution of the Universe, he said.