GENEVA (AP) — Scientists behind the world's largest atom smasher have laid out their multibillion-euro vision to build an even bigger one, in hopes of unlocking even more secrets of matter and the universe in the coming decades.

Officials at CERN, the European Organization for Nuclear Research, presented Tuesday their study for a "Future Circular Collider" inside a 100-kilometer circumference tunnel which could start operating in 2040.

It would sit next to the current 27-kilometer (17-mile) circumference Large Hadron Collider near Geneva, which is perhaps best known for helping confirm the subatomic Higgs boson in 2012.

Officials hope for a decision by CERN's 22 member states within the next few years about the project that would debut with an electron-positron collider at an estimated cost of 9 billion euros ($10.25 billion).