A bigger, bolder leap into high-energy particle physics
An EU-funded project is setting in motion the future exploration of the building blocks of the universe, contributing to plans for particle accelerators three times bigger and many times more powerful than the Large Hadron Collider.
© CERN, 2018
A four-year initiative at the heart of a globally coordinated study to design research infrastructure for Future Circular Colliders, is seeking solutions to key technical, scientific and economic challenges in order to vastly expand the frontiers of particle physics.
The EU-funded EUROCIRCOL project is primarily focusing on a planned proton-proton collider, known as FCC-hh, that would be built near the Large Hadron Colliders 27-km loop at CERN in Switzerland. With a 100-km tunnel, the FCC-hh would be capable of smashing particle beams together with a strength of up to 100 tera electron volts (TeV) equivalent to about 10 million lightning strikes and approximately seven times more powerful than the LHC.
It will allow physicists to study particles even heavier and more mysterious than the Higgs boson, the God particle discovered at the LHC in 2012 that underpins our fundamental understanding of the laws of nature. Just as the creation of the LHC led to major scientific and technical breakthroughs with commercial applications in fields as diverse as medicine, magnet technology, superconductivity and power distribution, the development of future particle accelerators will drive potentially even greater innovation between academia and industry.
After answering the question where is the Higgs boson?, particle physics is now faced with even more challenging questions: What is the rest of the 95 % of the universe made of? How can we reconcile what we observe at large scales with fundamental physics laws at the smallest scales?, says EUROCIRCOL coordinator Michael Benedikt at CERN. Going up to 100 TeV is a bold leap into completely uncharted territory that would probe new energy scales, where fundamental new physical principles might be at play: additional particles and interactions could account for dark matter, the puzzling masses of neutrinos and the observed abundance of matter over antimatter. This marks the beginning of a new era of experimental and theoretical exploration.
From super-strong magnets to socio-economic benefits
Like any great expedition, it begins with charting a course. The FCC study, to which EUROCIRCOL is contributing, is proposing the first steps, plotting a path from the LHCs ongoing experiments today to designing, building and turning on future colliders several decades from now. It is exploring a number of complementary approaches, from the ultra-powerful 100 TeV FCC-hh to a high-precision electron-positron collider FCC-ee that could be housed in the same 100 km tunnel, as well as planned upgrades to the LHCs infrastructure.
In the interim, many challenges will need to be overcome from engineering materials to withstand such high-energy processes to aligning particle beams and achieving acceleration efficiently in such a gigantic machine while ensuring the project remains economically viable.
The EUROCIRCOL team has conducted extensive research into the super-strong magnets that will be needed to bend high-energy charged proton particles into the designed orbit and focus them before collision points, working with industrial partners to develop and test commercially viable solutions for manufacturing innovative 16T dipole magnets with double the magnetic field strength of those used in the LHC.
For the high-energy version of the FCC, four times more magnets are needed compared to the LHC. This means that we need to ensure the cost of magnets goes down considerably over the next decade which could also revolutionise their use outside particle physics, for example in medical imaging and treatment, says EUROCIRCOL communication head Carsten Welsch at the University of Liverpool in the UK.
The team has also proposed novel superconductor material for high magnetic fields, innovative refrigeration solutions for the 100 km tunnel, a prototype beam screen system to maintain an ultra-high vacuum within the accelerator, and a prototype radio frequency system capable of boosting energy efficiency by up to 50 % compared to conventional technologies.
Building a machine like the FCC requires significant advancements of key technologies along with new large-scale manufacturing techniques to make these technologies affordable and increase their market potential outside particle physics says Welsch. Together with research institutes and industrial partners from all over the world we have launched a vibrant R&D programme that is not only finding new technical solutions for the FCC but ensuring they can be industrialised, allowing large-scale production that would have benefits for many other industries.
Given the long development and construction timeframe, it is likely a new generation of researchers will be switching on the FCC for the first time in perhaps 30 years. Hence EUROCIRCOL is also focusing on the need for training young researchers by ensuring the FCC project offers a physics programme that contributes to the attractiveness of the field for the budding physicists, engineers and technicians that will build and operate the machine.
The success of this project is based on international collaboration and, equally important, the training and involvement of young talent. One of the biggest socio-economic benefits of such large-scale hi-tech research facilities is the value of education and training it offers to thousands of young people, Benedikt says.