The world's most powerful particle accelerator, the Large Hadron Collider (LHC), has been switched off after scientists concluded a second run of experiments.
The entire accelerator complex in Geneva is undergoing upgrades, with the LHC set to be turned off for two years.
It was previously shut down temporarily two years ago when a weasel chewed through the £3.74bn machine's wiring.
The European Organisation for Nuclear Research (CERN), which runs the complex, said it had delivered "well beyond our objectives and expectations".
During the two-year break, the whole accelerator complex and its equipment will be upgraded for its next run in 2021.
Scientists hope the upgrades will produce four times more "God particles" a year and unlock further secrets about the universe's existence.
It has been six years since the LHC confirmed the existence of the Higgs boson, which along with an associated force field, allowed researchers to better understand where matter gets its mass from.
The revamp would boost the "luminosity" of proton-smashing experiments at the 17-mile ring beneath the Swiss-French border, and produce a clearer picture of the sub-atomic world, expert say.
Helping them achieve this are upgrades to critical components of the accelerator chain that feed the LHC with protons to produce more intense beams.
The first link in this chain is the linear accelerator known as Linac4, that replaces Linac2 which has been in service since 1978.
The linear accelerator (shortened to linac) is the first vital component of an accelerator chain, and took almost 10 years to build. It is inside of the linac that the particles are produced, and it is the linac which delivers the initial acceleration.
In 2013, British scientist Peter Higgs was jointly awarded the Nobel Prize for proposing the existence of the Higgs boson, which was subsequently confirmed by the LHC.
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CERN hopes that this will make it possible for the experiments to accumulate about 10 times more data over the period 2025 to 2035 than before.
The High-Luminosity LHC will provide more accurate measurements of fundamental particles and offer scientists the possibility of observing rare processes that occur beyond the machine's present sensitivity level.
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