China Building 62-Mile-Long 'Supercollider' to Produce a Million Higgs Bosons

China is building a particle collider almost four times bigger than the Large Hadron Collider (LHC) and it is expected to produce over one million Higgs boson particles in its first decade of operation.

Plans for the Circular Electron Positron Collider (CEPC)—a 62 mile long collider—were first announced in 2012, a few months after the Higgs boson particle was discovered at the LHC. Now, researchers working on the project have released two new design reports to show what they have been working on over the last six years, and what they are planning to do over the coming decades.

The report shows how the CEPC dwarfs the LHC, which has a circumference of just under 17 miles. It outlines how it can go beyond the LHC's capabilities in terms of the physics experiments that can be carried out—over 10 years, scientists say it will be able to produce one million Higgs bosons, 100 million W bosons and a trillion Z bosons.

china collider
Artist impression of what China's collider will look like. IHEP

Like the LHC, the CEPC is circular in shape. It will be located in an underground tunnel and consists of a linear accelerator, a damping ring, a booster, transport lines and a collider. It will be a double ring collider, with electron and positron beams circulating in opposite directions in seperate pipes.

The tunnel it sits in could also be used to host a Super proton proton Collider (SppC)—a proposal for which is currently under consideration. This 'supercollider' would reach energies far beyond the LHC—the LHC was designed to have a maximum collision energy of 14 TeV, while the SppC would operate with an energy of 70 TeV.

"The Conceptual Design Report signifies that we have completed the basic design of the accelerator, detector and civil engineering for the whole project," Professor Gao Yuanning, chair of the CEPC Institutional Board, said in a statement. "Our next step will focus on the research and development of key technologies and prototypes for the CEPC."

The design report was announced at a ceremony held by the Institute of High Energy Physics (IHEP) in Beijing.

Geoffrey Taylor of the University of Melbourne, chairman of the International Committee for Future Accelerators (ICFA) and the Asian Committee for Future Accelerators (ACFA), said: "This is a significant milestone along the road to such an important facility for fundamental physics. I have no doubt the international community looks forward to partnering in the development and operation of the CEPC and in the quest to better understand the basic constituents of matter."

Over the next five years, scientists will carry out extensive research, building prototypes of key technical components for the CEPC. The infrastructure for the collider will also be built. Construction of the CEPC is expected to begin in 2022 and it will be completed in 2030.

Should the CEPC prove successful, scientists are hoping the SppC supercollider could be operational at some point in the 2030s. "As an energy frontier machine, the SPPC could discover an entirely new set of particles," the new report says. "Dark matter remains one of the most puzzling issues in particle physics and cosmology. Weakly interacting massive particles (WIMPs) are still the most plausible dark matter candidates." The SppC, the researchers say, could be used to "substantially extend" the search for WIMPs, potentially providing answers to one of the biggest mysteries in the universe.