Physicists call for new atom smasher
Hope linear particle collider will give better picture of moments after big bang
Scientists gathered at an international physics conference in Paris are hoping a new type of particle collider they expect to be built over the next 15 years will help provide a clearer picture of how the universe was formed.
The linear particle collider is to be a worldwide project funded and studied by a number of countries, including Canada. It will build on discoveries made at Switzerland's $10-billion Large Hadron Collider (LHC), which has captured the imagination of physicists and the general public since it began working last November.
The new collider will be even more complex. It will aim to collide electrons and positrons, which according to University of Alberta Prof. James Pinfold, will create a cleaner collision than the LHC and allow scientists a far clearer picture of what happened in the moments after the big bang.
"It is absolutely vital that we have that mode of operation, so that we can understand what we discover," said Pinfold, who has worked with the LHC.
Currently, the LHC spins two beams of protons in opposite loops around a 27-kilometre long tunnel that has been chilled to just above absolute zero, making it the coldest place on Earth. That method has been successful in moving protons at incredible speed, but the proton collisions give somewhat "dirtier" information than physicists want, Pinfold said.
The proposed new machine, which Pinfold said is likely 15 years away from its first collision, won't necessarily create discoveries but would give a clearer understanding of what is happening in the LHC.
"It's easy to get high speeds with [protons], but when you want to study the results, you need to collide electrons and protons," Pinfold said.
Nigel Lockyer, director of the Canadian subatomic physics laboratory Triumf, said his physicists are already working on developing a linear collider. Lockyer said Triumf has thrown its weight behind the ILC, one of two possible machines that will be built.
The other collider in consideration is known as a Compact Linear Collider (CLIC) and is being researched by the European Organization for Nuclear Research, known as CERN, which runs the LHC.
Only one of the machines will be built, Lockyer said, adding that each of the proposed machines operates at a different energy level.
"You're making such a big investment in science that you know you're only going to build one," he said.
The linear collider is estimated to cost $10 billion and is likely 15 years away from being operational, although Lockyer said the group developing it might have a funding proposal for governments ready in two years time.
"It's a challenge, but I think it's technologically feasible," Pinfold said.
"It would be of great importance to [Canadian scientists] to continue working on it."
Canada, however, is not likely to house the new collider. Lockyer said Japan, the U.S. or Switzerland are the most likely locations for the worldwide project.
"It's really an international project; where it gets located is secondary," Lockyer said.
Pinfold said he thinks the funding and political will to continue studying particle collision will need to be driven by discoveries made at the LHC. Currently, he said, physicists have seen "all the things we should have seen but nothing new."
That is likely to change this year, he said, as the collider, which had its first collision in March, continues to spin and collide protons.
"We've managed to get collisions; we're seeing real physics," Pinfold said.
Lockyer compared the LHC to a camera's exposure — the longer it's left open, the clearer things get. Still, he admits, the clearest picture of how the universe came to be will likely require a completely new machine.