A "new era" in science is expected to dawn in two week's time as scientists re-start the world's biggest and most powerful atom-smasher after a two-year upgrade.
Scientists in charge of the Large Hadron Collider revealed that last weekend test beams of proton particles were successfully sent into the machine's 27km of circular tunnels.
They hope to start circulating the beams in earnest as the gradual process of building up energy begins.
But it is likely to be another two months before the target energy level of 13 tera electron volts (TeV) is reached.
Two years ago the LHC team at CERN, the European Organisation for Nuclear Research, astounded the world with the discovery of the Higgs boson, an elementary particle that gives other particles mass.
This time their sights are set on an even more exotic prize, dark matter - the invisible, undetectable material that makes up 84% of the mass of the universe and binds galaxies together, yet whose nature is unknown.
One theory that could be tested suggests that the Higgs boson can give birth to particles of dark matter.
According to a "new physics" model of the universe called supersymmetry, the Higgs might disintegrate into a photon - a packet of light - and a dark matter particle.
Speaking at a news briefing at CERN in Geneva, close to where the LHC straddles the Swiss and French borders, the organisation's director general Professor Rolf Heuer said: "We're really excited because we're entering a new phase of the LHC after two years of heavy maintenance and heavy improvement.
"It will start some time this month - I hope in maybe two weeks we will see that we get the first protons circulating, but it will take some time. We have learned to be patient.
"When this new window opens, we don't know. It's in the hands of nature."
The LHC smashes streams of protons - the hearts of atoms - and electrically charged particles of lead together at energies never attained before.
The collisions, taking place in four giant detectors, spark the creation of new particles and allow scientists to peer deep into the fundamental building blocks of nature.
In accordance with Albert Einstein's famous equation E = MC2, energy can be converted into mass. And the more energy, the more massive the particles that can be created.
After its re-fit, the LHC should be able to reach an energy level of almost double the 8TeV that produced the Higgs boson.
British scientist Professor David Charlton, from the University of Birmingham, who heads the Atlas detector team, said: "We're heading for unexplored territory. It's going to be a new era for science.
"There's a whole set of questions we're trying to answer."
Besides looking for dark matter, the scientists will want to learn more about the Higgs boson, he said.
"We know very little about it," Prof Charlton added. "We need to study it in a lot more detail. It may be there will be further Higgs bosons to be found."
The search for dark matter involves stepping outside the Standard Model, the all-encompassing theory that describes the particles and forces of nature and has stood firm for the past 50 years.
Supersymmetry predicts that every known particle has a more massive partner - and one of these elusive supersymmetry particles might be the source of dark matter.
Prof Heuer said: "There's a direct possibility that we will produce particles with higher mass. There could be a chance, if nature is kind to us, that we could find such a particle. That would be a huge discovery. It would be fantastic.
"I have a dream. I want to see the first light in the dark universe."
The second run of the LHC is due to last three years, before the machine is shut down for another "MOT" check. It has a planned working life of around 20 years.
Prof Charlton said: "We don't know if we're going to find dark matter this year. It could be that dark matter is in a place where we can start to see it this year. It could be we will only start to see it with more data; it could take 20 years. We don't know."
The scientists stressed the importance of carrying out thorough checks and increasing the energy of the vast machine step by step.
During the final commissioning phase in 2008, the LHC was severely damaged by a leak of helium coolant which shut it down for a year.
Prof Heuer said: "It is practically a new machine. You have to be very careful about switching on such a high- power laser, so to speak, because there's enough power to melt one tonne of copper, and I don't want to do that."
During the upgrade, 18 of the LHC's superconducting magnets, which steer the particle beams, were replaced and more than 10,000 electrical connections between the magnets strengthened.
Frederick Bordry, CERN's director of accelerators and technology, said the system of injecting protons into the LHC's beam tunnels - the "transfer line" - was successfully tested at the weekend.
Pilot beams of protons were sent into the tunnels in both directions, without colliding.
The LHC cost around €6 billion to build and has an operating cost of almost €1 billion per year, according to financial information agency Forbes.
But Prof Heuer said the money was well-spent, pointing out that Cern's budget was about the same as that of large university and the LHC had spawned around 3,000 doctorates.
"When mankind stops paying at least a small amount of money for educating people, especially concerning science, technology, engineering and mathematics, I don't think the Earth can evolve," he said.
