Supernova-creating particle accelerators will make the biggest bangs we have ever known

Every inch of your body – as well as the screen you are reading, the chair you are sitting on and the entire world around you – is made up of a combination of fewer than 100 basic chemical building blocks. These will be familiar to every student who has seen the periodic table hanging on a classroom wall: they are the elements, the various atoms that make up the universe around us.

The periodic table is meant to be an authoritative list, but scientists believe there are a few elements missing. Well, not exactly a few – more likely between 3,500 and 7,000. And now they are preparing to build a series of giant new machines to find them. This new breed of atom-smashers, billed as the successors to the Large Hadron Collider (LHC) at Cern in Geneva, will recreate some of the most extreme conditions found in the universe, creating miniature supernovae (huge explosions triggered when stars collapse), neutron stars and even the mysterious vampire stars right here on planet Earth.

Inside the replicas of these cataclysmic cosmic explosions, scientists expect to find atoms that have never been seen before winking in and out of existence. It is a search for what nuclear physicists describe as terra incognita, an unknown land of atomic science.

"Nobody knows exactly how many elements are out there waiting to be discovered," explains Professor Guenther Rosner, a physicist at Glasgow University who sits on the committee at the European Science Foundation that has just published the long-term plan for a new generation of giant experimental facilities. "The estimate is that there are at least another 4,000 or 5,000. They are thought to be generated in supernova explosions, so we are sure they are out there. Unfortunately, these atoms are also going to be extremely short-lived, lasting just a trillionth of a trillionth of a second before disappearing.

While the 16-mile LHC has been searching for the elusive subatomic particles that make up atoms and give them mass, these new experiments will aim to answer fundamental questions about atoms themselves by revealing how they are created.

After the Big Bang, just a handful of elements were brought into existence, namely the lightest and simplest atoms like hydrogen and helium. It was not until these were subjected to the furnaces of the first stars and the massive heat of supernovae, which explode with temperatures in excess of 180 billion degrees Fahrenheit (100 billion Kelvin), that larger atoms began to emerge.

Under the plans set out by the European Science Foundation's Nuclear Physics Collaboration Committee, two "next-generation" super-accelerators have now been approved to reproduce these extreme conditions.

The first, the Facility for Antiproton and Ion Research (Fair), which is to be sited in Darmstadt in Germany, will accelerate atoms inside a double ring with a circumference of more than 3,000 feet before smashing them into a fixed target that causes them to fragment. The fragments will then be accelerated and smashed into a second target to produce temperatures more than a million times hotter than the centre of the Sun. Scientists say the intense and dense explosions generated will produce conditions thought to exist inside neutron stars – the remnants of massive stars that have collapsed under their own gravity during an supernova explosion.

"Fair will generate matter that is about 10 times denser than is possible at the LHC, so that it resembles the matter at the centre of neutron stars," says Prof Rosner. "We don't know what the interior of a neutron star is, but it is probably not normal matter – it will be strange and very exciting."

The £1 billion facility will also be able to produce beams of antimatter that can be collided with ordinary matter to produce entirely new types of particles. Among the exotic objects they will be looking for are bizarre balls of energy that behave like particles known as "glueballs". These hypothetical particles are made up of gluons, one of the elementary particles thought to hold the nucleus of atoms together.

"We will be able to address a very broad spectrum of science that will answer some really fundamental questions," explains Professor Martin Freer, a nuclear physicist at Birmingham University who is involved in one of the experiments at Fair. "Things like how atoms first formed, what happens to terra incognita elements and what sits at the heart of neutron stars that we have only been able to see at the centre of echoes left behind by supernova explosions."

Read more at The Telegraph