Physicists, start your engines.

Officials at CERN, the European Center for Nuclear Research, outside Geneva, announced Thursday that their new particle accelerator, the world’s largest, would begin operation on Sept. 10. On that date, the physicists and engineers will make the first attempt to circulate a beam of protons around a 17-mile-long super-cooled underground racetrack known as the Large Hadron Collider.

The collider, 14 years and $8 billion in the making, has been built to smash together protons that have been accelerated to energies of 7 trillion electron volts, and examine the remains for clues to the origin of mass and new forces and particles in the universe.

But the collisions will not happen immediately. The first step on the journey to new physics will happen this weekend, when engineers test their method of injecting high-energy protons, which are produced in a separate accelerator, the Super Proton Synchrotron, into the collider by sending a batch through one part of the racetrack.

In September, the first protons to circle the entire ring will have a relatively modest energy of 450 billion electron volts. Once the physicists and engineers have learned to drive their new machine and had a few collisions at that energy, they will ramp up the energy as fast as they can to 5 trillion electron volts  unexplored territory.