測定器開発室セミナー

日時: 2013-03-20 08:30 - 10:00
場所: Seminar hall bldg. 3
会議名: HIGH ENERGY COSMIC RAY EXPERIMENTS
連絡先: Mibe (mibe_at_post.kek.jp)
講演者: Mostafa Miguel   (Colorado State Univ)
講演言語: 英語
URL: http://rd.kek.jp/seminar_01.html
アブストラクト: The so-called Cherenkov e ect refers to the electromagnetic radiation that is emitted when a charged particle passes through a dielectric medium at a speed greater than the phase velocity of light in that medium. These charged particles polarize the molecules of that medium, which then turn back rapidly to their ground state, emitting radiation in the process. Cherenkov radiation is commonly used in experimental particle physics for particle identi cation, and in nuclear reactors to detect high-energy charged particles (i.e., to measure the intensity of the reaction), and also to characterize the remaining radioactivity of spent fuel rods.

The Cherenkov e ect is also used in many di erent astrophysics experiments. When a high-energy photon or cosmic ray interacts with the Earth's atmosphere, it produces an extensive air shower of secondary particles with enormous velocities. The Cherenkov radiation (in air) from the secondary charged particles can be used to determine the incoming direction and energy of the primary cosmic ray or gamma ray. This is used by the Imaging Atmospheric Cherenkov Telescopes, such as VERITAS, HESS, MAGIC, and the future Cherenkov Telescope Array (CTA), to study very high energy gamma rays. Similar methods are used (in water and in ice) by very large neutrino detectors, such as the Super-Kamiokande, the Sudbury Neutrino Observatory, and IceCube. Other experiments, like the Pierre Auger and the High Altitude Water Cherenkov (HAWC) Observatories, use tanks lled with puri ed water to observe the Cherenkov radiation caused in water by the secondary muons, electrons, and positrons of the extensive air showers.

In this lecture I will discuss the main characteristics of the Cherenkov radiation, and its use in particle physics, nuclear reactors, and astrophysics experiments. In particular, I will concentrate on the Pierre Auger and HAWC Observatories, CTA, and IceCube.

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