March 3rd, 2021

лошадь, диаграмма, Фейнман

Томичи и рентгеновский черенок

Observation of soft X-ray Cherenkov radiation in Be and Si foils:
S. R. Uglov, A.V.Vukolov
Currently, most of the Cherenkov phenomenon researches for the X-ray region are theoretical studies; there are only a few experiments in this area. Here the new experimental results on observation of X-ray Cherenkov radiation generated by 5.7 MeV electrons in the thin Be and Si foils are presented. The Cherenkov effect from Be was observed for the first time. The experimental results are compared with the calculations performed according to the theoretical model of transition radiation taking into account the oxide layer on the target output surface.
Comments: 13 pages, 10 figures
лошадь, диаграмма, Фейнман

Рассеяние волнового пакета

Очень клевая учебная статья: и квантЫ с диагонализацией, и рассеяние, и твердое тело...

Scattering Problems via Real-time Wave Packet Scattering:
M. Staelens, F. Marsiglio
In this paper, we use a straightforward numerical method to solve scattering models in one-dimensional lattices based on a tight-binding band structure. We do this by using the wave packet approach to scattering, which presents a more intuitive physical picture than the traditional plane wave approach. Moreover, a general matrix diagonalization method that is easily accessible to undergraduate students taking a first course in quantum mechanics is used. Beginning with a brief review of wave packet transport in the continuum limit, comparisons are made with its counterpart in a lattice. The numerical results obtained through the diagonalization method are then benchmarked against analytic results. The case of a resonant dimer is investigated in the lattice, and several resonant values of the mean wave packet momentum are identified. The transmission coefficients obtained for a plane wave incident on a step potential and rectangular barrier are compared by investigating an equivalent scenario in a lattice. Lastly, we present several short simulations of the scattering process which emphasize how a simple methodology can be used to visualize some remarkable phenomena.
Comments: 10 pages, 5 figures plus 4 animations
лошадь, диаграмма, Фейнман

Дозорщик на отдыхе

Я уже показывал уважаемым читателям дозорщика-императора в полете. Но однажды я его заштопал во время отдыха, дело было 24 июля, день был довольно ветреный, и он, в основном, сидел на кусте, отлетая ненадолго:

DSC_3062_дозорщик.jpg © qedqed.iMGSRC.RU

DSC_3073_дозорщик.jpg © qedqed.iMGSRC.RU