Portuguese reach technological advancement. A “historical result”, an unprecedented sensitivity in the detection of dark matter.
A technological advance that is described as “Historical Result” in scientific research.
Concerned is a system with a level of unprecedented sensitivity in the detection of dark matter.
And there is a Portuguese touch: the team is from the Instrumentation Laboratory, Biomedical and Physics Engineering of Radiation (Libphys) of the Faculty of Science and Technology of the University of Coimbra (FTUC).
The Best Purification of the Radioactive Isotope 222 of Radão (222RN) of history. It lowered its concentration to 430 atoms per ton of liquid xenon target, a value 5 times lower than other experiences that use the same technology.
This investigation emerges within the international experience Xnies, created for direct detection of dark matter. The project is installed in the Gran Sasso underground laboratory (Italy), under 1300 meters of rock – to reduce cosmic radiation levels dramatically compared to those on the surface of our planet. The system uses six tons of ultra-popular xenon.
“Radiation as it passes through the target can generally produce tiny signs of light and load. The overwhelming majority of these signs (over 99.99%) are due to known origin radiations, allowing scientists to greatly calculate the number of expected events,” describes José Matias-Lopes, coordinator of the Portuguese team, in a statement sent to ZAP.
The most important requirement for measuring events as rare as those of neutrinos and from dark matter is that the target has the lower level possible level of radiation (background radiation), so that it can distinguish what is intended to measure.
In order to achieve such a technically demanding goal, all types of radiation sources count, including to the present at Xenon’s own target and to the materials that the Detection System (Xenonnt) is built.
José Matias-Lopes explained that Xenonnt was able to reduce the level of contamination of the 222RN isotope to unprecedented levels-thanks to a distillation column with an innovative cryogenic heat pump systemespecially developed for this purpose by the experts involved.
“All materials used in Xenonnt have been carefully selected (even the smallest of the screws) to have the lowest possible level of radiation,” the researcher continues.
Xenonnt targets the site of planet Earth with the lowest background radiation in the whole history of humanity. And the beginning of a new era in the detection of dark matterbecause it initiates the detection of neutrinos fog, where they coexist with dark matter, which, because they are almost indistinguishable, makes it difficult to detect.
The extraordinarily low radiation level reached in this system also allows study a large number of particularly rare phenomena: Interaction of dark matter in the form of solar axions, axion analogous particles, neutrinos with anomalous magnetic moment and detection by neutrino-nucleus coherent elastic dispersion.
Researcher José Matias-Lopes explains that, through these conditions, Xenonnt “may Perform neutrin measurements with high precision and research of extremely rare eventsas the double beta decay of Xénon isotopes 124 and 126.
In addition, it may continue to “test the existence of an extended number of dark matter candidatesincluding massive particles of very weak interaction, to the limit of neutrinos fog. ”
