Physicists plan to seek antimatter

Researchers are focusing on transforming this elusive material between laboratories and using it to study the bizarre effects of rare radionuclides.

is a very elusive substance, but physicists have learned how to control it with a tool that was first used. In the PUMA (anti-Proton Unstable Matter Annihilation) project that started in January 2018 at CERN, researchers turned antimatter in a truck and used it to study the strange effects of radionuclides. rare. This study aims to bring deeper insights into the basic processes within the atomic nucleus and to help astrophysicists study the inner parts of these, which are states the most dense in the universe.

The antiparticle proton appears in a unique way to study the radioactive elements made at the ISOLDE, CERN experiment.

'People have been studying antimatter for a long time and now it is enough to start using knowledge about it [in] a physical detector' , physicist Alexandre Obertelli (university Technical Darmstadt, Germany) and project manager said.

CERN created antiparticles of protons - a mirror image of protons - by firing a beam of protons into a metal stele, then the antiparticles appeared sluggish and could be used for experiments. . Obertelli and his colleagues plan to use magnetic fields and electric fields to trap a cloud of proton particles in a vacuum device. Next they would put that "trap" on a truck and transport it to another experimental site a few hundred meters away named ISOLDE , to produce rare radioactive nuclear atoms that decay process. usually takes place very quickly to be able to transport them anywhere. "Transporting antiparticles with a truck is really a science fiction story , " Charles Horowitz, a nuclear theory physicist at Indiana University, Bloomington, said, "this is a great idea."

Unique detector

Because the lifetime of the proton antiparticles is very short, with both protons and neutrons, there is only one unique way to study the unusual shapes of radionuclides. While the atomic nucleus holds protons and neutrons at roughly the same level, the radioisotopes are loaded with more neutrons. This imbalance can lead to strange effects, including a "skin" surface thickened by neutrons rather than protons. By observing how the antiproton particles annihilate the same proton pair and a neutron, the team will be able to understand the relative density of particles at the nucleus's surface. And because this annihilation process is very fast, the measurement time must be fast enough to observe the phenomenon, even if the nucleus life is very short. 'This is an experiment that we have never been able to perform before to recognize new problems, many strange nuclei have very interesting structures , ' Horowitz said.

In order to find the surface structure of atomic nuclei, physicists transferred the ion beam of rare radioactive isotopes into a tubular device 700milimet long, where they were destroyed along with proton particle antiparticles. trap.

The radionuclide acts as a microscopic world for researchers to learn about neutron stars, objects whose mass is roughly equivalent to the mass of the sun but the size is only one wall. city. This knowledge will be a key factor in understanding how heavy elements in the universe are formed. Not only are these super-dense cores still full of mysteries, but their structure is also shaped from lesser known effects and creates bizarre phenomena in neutron-rich nuclei . "It is important to understand the neutron surfaces and corona, because most astronomical observations can be made , " said Panagiota Papakonstantinou, a nuclear physicist at the Institute of Scientific Research. basically in Daejeon (South Korea) said.

Obertelli and colleagues created a trap that could contain 1 billion anti-proton particles - a new record, more than 100 times the amount of antiparticle protons contained in any experiments performed earlier. Another difficulty is that each time the experiment is performed, it is necessary to keep them in the trap for weeks, while keeping a few dozen antiparticles at a time is far away. That means keeping them at 4 degrees Celsius and in a vacuum environment similar to interstellar space."This is a challenging project but I think it's feasible , " commented Chloé Malbrunot, a physicist who studies antimatter at CERN.

Developing and testing the technology to create a portable trap will take about 4 years with the initial measurements scheduled for 2022. If this method is implemented, physicists can transfer More antiparticle antiparticle, thereby allowing other researchers, although not involved in the six experiments conducted at the antiparticle counterpart, can also study and use this elusive material.

"They can perform one billion proton experiments and keep them for several weeks as soon as possible so that more such experiments will be deployed and there will be more researchers with new ideas involved. I think that could help usher in a new field of research , " Malbrunot predicted.