China plans to build world's most powerful particle collider

China plans to build world's most powerful particle collider with a circumference of 50 to 100 kilometres, bigger than any particle accelerator on Earth to allow a more precise understanding of universe.
"We have completed the initial conceptual design and organised international peer review recently and the final conceptual design will be completed by the end of 2016," Wang Yifang, director of the Institute of High Energy Physics, Chinese Academy of Sciences, told state-run China Daily.
The project was expected to be built between 2020 and 2025, the report said.
The institute has been operating major high-energy physics projects in China, such as the Beijing Electron Positron Collider and the Daya Bay Reactor Neutrino experiment.

Now scientists are proposing a more ambitious new accelerator with seven times the energy level of the Large Hadron Collider (LHC) in Europe.
In July 2012, the European Organisation for Nuclear Research, also known as CERN, announced that it had discovered the long sought-after Higgs boson-the "God particle", regarded as the crucial link that could explain why other elementary particles have mass-on LHC.

The discovery was believed to be one of the most important in physics for decades. Scientists are hopeful that it will further explain nature and the universe we live in.
With a circumference of 50 to 100 kilometres, however, the proposed Chinese accelerator Circular Electron Positron Collider (CEPC) will generate millions of Higgs boson particles, allowing a more precise understanding.

"The technical route we chose is different from LHC. While LHC smashes together protons, it generates Higgs particles together with many other particles," Wang said.
"The proposed CEPC, however, collides electrons and positrons to create an extremely clean environment that only produces Higgs particles," he said.
The Higgs boson factory is only the first step of the ambitious plan.
A second-phase project named SPPC (Super Proton-Proton Collider) is also included in the design-a fully upgraded version of LHC.
LHC shut down for upgrading in early 2013 and restarted in June with an almost doubled energy level of 13 TeV, a measurement of electron volts. LHC has a circumference of 27 kilometres.

"LHC is hitting its limits of energy level, it seems not possible to escalate the energy dramatically at the existing facility," Wang said.
The proposed SPPC will be a 100 TeV proton-proton collider. If everything moves forward as proposed, the construction of the first phase project CEPC will start between 2020 and 2025, followed by the second phase in 2040.