Russian charge emission detector for neutrinos registration (RED-100) is the main object in the Laboratory for Experimental Nuclear Physics of MEPhI. This device was made by a team of specialists led by Professor of the University of Tennessee and a research scientist of an Oak Ridge National Laboratory (USA) Yuri Efremenko. A Deputy scientific Director of the Laboratory for Experimental Nuclear Physics, MEPhI Professor Alexander Bolozdynya told about details of the project.
– Detector RED-100 is aimed at discovery of a rare effect of coherent scattering of neutrinos on heavy atomic nuclei, which was predicted in the Standard model about 40 years ago, but still was not observed experimentally due to the extreme complexity of registration, said A. Bolozdynya. – Installation, capable to detect coherent scattering of neutrinos on nuclei of xenon, is based on a principle of the emission registration of elemental particles, developed at MEPhI in the laboratory of a physicist Boris Dolgoshein. The experiment is planned to be conducted at the high-intensity neutrino source, such as nuclear reactors and some high-current accelerators; venue will be determined this year. The effect, that we try to observe, has important scientific value as a “tester” of new physics beyond the Standard model, for the development of theoretical models of the Universe's evolution and it also can be used for practical purposes, for example, for creation of a new generation of detectors for monitoring nuclear reactors. Coherent scattering of neutrinos on nuclei is a fundamental physical process that is supposed to happen according to the Standard model of electromagnetic, weak and strong interactions of elementary particles. Coherent scattering of neutrinos on nuclei plays an important role in the formation of the Universe and evolution of stars.
– “Tester” of a new physics should refute the Standard model, shouldn’t it?
– To check. This effect is very sensitive to uncertainties. If there are any inaccuracies in our understanding of how interaction of elementary particles is going on, then in this experiment it should reveal itself hundreds of times stronger than in the other experiments. Here the question can be about a major discovery. Neutrinos interact with the core and the core is an “ensemble” of protons and neutrons, which in turn consist of quarks. Coherent scattering is characterized by the fact that neutrinos of low energies interact not with the one quark but with one hundred of them. That is, if something goes off course, it will be hundreds of times more visible than, for example, at the Large Hadron Collider at CERN.
– There is another topic that physicists of the Laboratory of Experimental Nuclear Physics MEPhI are interested in – search for dark matter.
– 85 percent of what our world creates is unknown to us. It is abusive situation for theorists. In the twenty-first century we have to say that we have small knowledge of what the universe is made of.
This exciting, according to scientists, situation requires a solution. Experiments related to the search for dark matter, are conducted in many laboratories of the world. The most powerful of them for the next decade is called LZ, which is planned to be delivered in the American Homestake mine in South Dakota. The collaboration LZ comprise of 29 universities and scientific organizations of the USA, the UK, Portugal and Russia. MEPhI is the only Russian representative, which is a part of the collaboration along with famous research centers such as, Brookhaven National Laboratory, Fermi National Accelerator Laboratory, Lawrence Berkeley National Laboratory, Rutherford Appleton Laboratory, SLAC, University of Oxford, Yale University, Imperial College London, and others.
The LZ experiment aims to test the theoretical model, according to which dark matter consists of weakly interacting massive particles beyond the Standard model. It will use a technology of liquid xenon two-phase detectors proposed in MEPhI.
The US Department of Energy is the main donor of the LZ project, which will provide funding for research groups from the United States. Other members contribute by appointment. MEPhI, namely five members of the Laboratory for Experimental Nuclear Physics who are in this project from the Russian side, contribute mainly intellectual resources and also study elementary processes in liquid xenon affecting sensibility limits of the experiment.
In general, MEPhI experts are in demand in many international experiments. For example, a few years ago the deepest (2400 meters) in the world low-background laboratory Chinese Jin-Ping Underground Observatory was created and is now in rapid development in the Chinese province of Sichuan. In a short time it will concentrate low-background physics of the world. A strong team, headed by Professor of the Shanghai Jiao Tong University and the University of Maryland (USA) Shandong Ji is already formed there. They have invited us and we have already visited the laboratory and determined how we can contribute to this project. Russia could help China with the supply of xenon isotopes, its cleaning, and also in the creation of low-background (with a low content of natural radioactive isotopes) bodies of detectors.
– It turns out that your lab is mobile. How do you manage to always stay on the forefront of science, to work in different parts of the world?
– We try to use our potential to the maximum. In addition to the core staff we have 8 postgraduates and 10 students who receive skills of scientific work in modern laboratories and under the supervision of leading world scientists. We train students not at the desk, but real modern scientific installations, allowing them to expand their horizons and participate in solving physical problems. Now we are actively looking for new ways of development, including through the participation in large international projects. We want not only to survive as a modern experimental laboratory, but also help to return a former glory of the Russian fundamental experimental nuclear physics.
