翻訳と辞書 Words near each other ・ Sokratis Malamas ・ Sokratis Papastathopoulos ・ Sokratis Petrou ・ Sokratis Psaropoulos ・ Sokratis Skartsis ・ Sokratis Tsoukalas ・ Sokrogbo ・ Sokrogbo-Carrefour ・ Soksom ・ Soku ・ Soku hi ・ Soku, Suluova ・ Soku-no-Kumi ・ Sokolovsky (rural locality) ・ Sokolovsky gypsy choir ・ Sokolov–Ternov effect ・ Sokolow ・ Sokolow et al v. Palestine Liberation Organization et al ・ Sokolowski ・ Sokolska planina ・ Sokolski Monastery ・ Sokolsko ・ Sokolsko, Kardzhali Province ・ Sokolsky ・ Sokolsky (inhabited locality) ・ Sokolsky District ・ Sokolsky District, Nizhny Novgorod Oblast ・ Sokolsky District, Vologda Oblast ・ Sokolsky horse ・ Sokolsky Opening Dictionary Lists mini英和辞書 mini和英辞書 Webster 1913 Latin-English FOLDOC Wikipedia English ウィキペディア

翻訳と辞書　辞書検索 [ 開発暫定版 ] スポンサード リンク Sokolov–Ternov effect ： ウィキペディア英語版 Sokolov–Ternov effect The Sokolov–Ternov effect is the effect of self-polarization of relativistic electrons or positrons moving at high energy in a magnetic field. The self-polarization occurs through the emission of spin-flip synchrotron radiation. The effect was predicted by Igor Ternov and the prediction rigorously justified by Arseny Sokolov using exact solutions to the Dirac equation. ==Theory== An electron in a magnetic field can have its spin oriented in the same ("spin up") or in the opposite ("spin down") direction with respect to the direction of the magnetic field (which is assumed to be oriented "up"). The "spin down" state has a higher energy than "spin up" state. The polarization arises due to the fact that the rate of transition through emission of synchrotron radiation to the "spin down" state is slightly greater than the probability of transition to the "spin up" state. As a result, an initially unpolarized beam of high-energy electrons circulating in a storage ring after sufficiently long time will have spins oriented in the direction opposite to the magnetic field. Saturation is not complete and is explicitly described by the formula〔 Section 21.3 for the theory and section 27.2 for experimental verifications of the Sokolov–Ternov effect.〕 :$\backslash xi(t)=A\backslash Bigl(1\; -e^\}\backslash Bigr)$ where $\backslash scriptstyle\; A\; \backslash ;=\backslash ;\; 8\backslash sqrt/15\; \backslash ;\backslash approx\backslash ;\; 0.924$ is the limiting degree of polarization (92.4%) and $\backslash scriptstyle\; \backslash tau$ is the relaxation time, :$\backslash tau\; =\; A\backslash Bigl(\backslash Bigr)^2\backslash Bigl(\backslash Bigr)^3$ Here $\backslash scriptstyle\; A$ is as before, $\backslash scriptstyle\; m$ and $\backslash scriptstyle\; e$ are the mass and charge of the electron, $\backslash scriptstyle\; c$ is the speed of light, $\backslash scriptstyle\; H\_0\; \backslash ;\backslash approx\backslash ;\; 4.414\; \backslash ,\backslash times\backslash ,\; 10^\; \backslash ,\; \backslash text$ is the Schwinger field, $\backslash scriptstyle\; H$ is the magnetic field, and $\backslash scriptstyle\; E$ is the electron energy. The limiting degree of polarization $A$ is less than one due to the existence of spin-orbital energy exchange which allows for transitions to the "spin up" state (with probability 25.25 times less than to the "spin down" state). Typical relaxation time is on the order of minutes and hours. Thus producing a highly polarized beam requires a long enough time and the use of storage rings. The self-polarization effect for positrons is similar, with the only difference that positrons will tend to have spins oriented in the direction parallel to the direction of the magnetic field.〔 Section 6.2.〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Sokolov–Ternov effect」の詳細全文を読む スポンサード リンク 翻訳と辞書 : 翻訳のためのインターネットリソース Copyright(C) kotoba.ne.jp 1997-2016. All Rights Reserved.