Siberian scientists have created the airgel particle detectors

Siberian scientists have created the world's first multi-layer airgel, which enables to record accurately measure the speed of elementary particles, for example, in the experiments at the Large Hadron Collider, told RIA Novosti senior researcher at the Institute of Nuclear Physics of SB RAS Budker Evgeny Kravchenko.

Aerogel — the least dense of all solid materials. It is 99.8% air and 0.2% — of nanosized silica fibers. Equipment using airgel works in accelerators or in the open space: on board the space station "Mir" airgel used to capture micrometeorites, and the American probe Stardust with it "caught" millions of tiny particles from the tail of comet Wild (81P/Wild 2) These samples and delivered to the Earth. The program BESS, which was conducted in 2004 and 2007, the years in Antarctica, an international collaboration under the auspices of NASA, the equipment with a radiator of the airgel was raised to the stratosphere into the upper atmosphere to detect charged particles from outer space.

  • Silicon photomultiplier detector for particle "charm-tau factory"
  • Silicon photomultiplier detector for particle "charm-tau factory"


"When a charged particle — electron, muon, proton or nucleus of antimatter — passes through the airgel faster than the speed of light in this matter, it makes it a flash of Cherenkov radiation directed at a certain angle from the line of motion of the particle. Direction of the radiation in combination with other settlement data to determine the velocity of a particle on the basis of which it can be identified. For measurements of airgel blocks set matrix of silicon photomultipliers, and the units themselves playing the role of the radiator which emits photons at this matrix. more photons, the more accurate the information, "- explained Kravchenko.

Head of the group of airgel materials of the Institute of Catalysis SB RAS Alexander Danyluk explained that the production of airgel is very expensive, and its consumers, are the main scientific organizations. Therefore, mass produce it only two laboratories in the world that could get this stuff with the best optical parameters — the Japanese company Matsushita and the Institute of Catalysis, high-end transparency and size of the blocks of airgel. Technology of production of multi-layer airgel — Siberian fully develop. System with its use was called FARICH — focusing airgel Cherenkov detector particles.

Each layer thickness of 5-7 millimeters airgel has a density and refractive index of light.

"It is necessary that all photons are born to last through the airgel particles fall into one area on the matrix of silicon photomultiplier and giving record accuracy for speed, without increasing the width of the light ring that is not" smearing "the image matrix," — said Kravchenko.

He noted that at high speeds to determine the type of particles requires a very high accuracy. For example, if the momentum of the muon exceeds 0.6 GeV at the speed of light in a vacuum (GeV / c), it can not be distinguished from pions with hitherto existing methods.

"Multi-layer airgel would" recognize "a particle with momentum up to 1.6 GeV / c. Emitting photons in the same area, each layer increases the accuracy of the measurements. Four layers of airgel give a fourfold increase in accuracy," — said the scientist.

Kravchenko said detectors FARICH INP proposed for the "super-tau charm factory" — is an electron-positron collider, which enables highly accurate measurement of the parameters of the particles produced in the energy range from 1 to 2.5 GeV. First of all, they include the tau lepton and the "enchanted" (charm) quark.

"Factory" became one of the six scientific megaustanovok that receive government support for broad-based international participants.

Area airgel radiator in it is 17 square meters, and the photon detector — 21 square meters, or one million pixels of the silicon photomultiplier. For comparison, the scale: a matrix of photomultipliers used today contain dozens or hundreds of pixels. The desire to participate in the creation of super-tau charm factory in Novosibirsk expressed such major research centers like CERN, the European, the Japanese laboratory KEK, the Italian Institute for Nuclear Physics (INFN) and others.

"To bring such a flood of information needed thousand desyatigigabitnyh optical links, and to process it will be a powerful supercomputer center, so this mega project will give a powerful impetus to the development of parallel computing technology, transmission and storage of large volumes of data and the development of highly specialized chips and processors under our objectives" — said Kravchenko.

Together with a group of physicists from the Institute of Nuclear Research, Russian Academy of Sciences (Moscow), Institute of Nuclear Physics has developed a project for the modernization of the system FARICH ALICE detector at the Large Hadron Collider at the European Organization for Nuclear Research (CERN). Experiment with the four airgel at CERN is scheduled for June 2012.

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