Angular Distribution of Ly(alpha) Resonant Photons Emergent from Optically Thick Medium

2012 ◽  
Author(s):  
Yang Yang ◽  
Ishani Roy ◽  
Chi-Wang Shu ◽  
Li-Zhi Fang
2013 ◽  
Vol 772 (1) ◽  
pp. 3 ◽  
Author(s):  
Yang Yang ◽  
Ishani Roy ◽  
Chi-Wang Shu ◽  
Li-Zhi Fang

Author(s):  
Ryuichi Shimizu ◽  
Ze-Jun Ding

Monte Carlo simulation has been becoming most powerful tool to describe the electron scattering in solids, leading to more comprehensive understanding of the complicated mechanism of generation of various types of signals for microbeam analysis.The present paper proposes a practical model for the Monte Carlo simulation of scattering processes of a penetrating electron and the generation of the slow secondaries in solids. The model is based on the combined use of Gryzinski’s inner-shell electron excitation function and the dielectric function for taking into account the valence electron contribution in inelastic scattering processes, while the cross-sections derived by partial wave expansion method are used for describing elastic scattering processes. An improvement of the use of this elastic scattering cross-section can be seen in the success to describe the anisotropy of angular distribution of elastically backscattered electrons from Au in low energy region, shown in Fig.l. Fig.l(a) shows the elastic cross-sections of 600 eV electron for single Au-atom, clearly indicating that the angular distribution is no more smooth as expected from Rutherford scattering formula, but has the socalled lobes appearing at the large scattering angle.


Author(s):  
F. Shaapur ◽  
M.J. Kim ◽  
Seh Kwang Lee ◽  
Soon Gwang Kim

TEM characterization and microanalysis of the recording media is crucial and complementary to new material system development as well as quality control applications. Due to the type of material generally used for supporting the medium, i.e., a polymer, conventional macro- and microthinning procedures for thin foil preparation are not applicable. Ultramicrotorny (UM) is a viable option and has been employed in previous similar studies. In this work UM has been used for preparation of XTEM samples from a magneto-optical (MO) recording medium in its original production format.The as-received material system consisted of a 4-layer, 2100 Å thick medium including a 300 Å TbFeCo layer enveloped by silicon nitride protective layers supported on a 1.2 mm thick × 135 mm (5.25 in.) diameter polycarbonate disk. Recording tracks had an approximate pitch of 1.6 μm separated by 800 Å deep peripheral grooves. Using a Buehler Isomet low-speed diamond saw, 1 mm wide and 20 mm long strips were cut out of the disk along the recording tracks.


2020 ◽  
Vol 23 (1) ◽  
pp. 66-71
Author(s):  
E. A. Gurnevich ◽  
I. V. Moroz

The Smith-Purcell radiation of a charged particle moving in a periodic structure is analysed theoretically. The considered structure consists of two planar diffraction gratings with different periods which are formed by parallel conducting wires. The analytical expression for the spectral-angular distribution of radiation is obtained. It is shown that the angular distribution of radiation can be made narrower by using two gratings instead of one, and radiation intensity can be manipulated by parallel relative shift of gratings. The obtained results are of great importance for the research and development of high power radiation sources based on volume free-electron lasers.


2002 ◽  
Vol 715 ◽  
Author(s):  
J. Krc ◽  
M. Zeman ◽  
O. Kluth ◽  
F. Smole ◽  
M. Topic

AbstractThe descriptive scattering parameters, haze and angular distribution functions of textured ZnO:Al transparent conductive oxides with different surface roughness are measured. An approach to determine the scattering parameters of all internal interfaces in p-i-n a-Si:H solar cells deposited on the glass/ZnO:Al substrates is presented. Using the determined scattering parameters as the input parameters of the optical model, a good agreement between the measured and simulated quantum efficiencies of the p-i-n a-Si:H solar cells with different interface roughness is achieved.


2020 ◽  
Vol 2020 (4) ◽  
pp. 25-32
Author(s):  
Viktor Zheltov ◽  
Viktor Chembaev

The article has considered the calculation of the unified glare rating (UGR) based on the luminance spatial-angular distribution (LSAD). The method of local estimations of the Monte Carlo method is proposed as a method for modeling LSAD. On the basis of LSAD, it becomes possible to evaluate the quality of lighting by many criteria, including the generally accepted UGR. UGR allows preliminary assessment of the level of comfort for performing a visual task in a lighting system. A new method of "pixel-by-pixel" calculation of UGR based on LSAD is proposed.


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