Investigation of the angular distribution of neutrons from an isotropic source beyond lead and iron barriers

1969 ◽  
Vol 26 (5) ◽  
pp. 521-521
Author(s):  
A. I. Kiryushin ◽  
Yu. P. Sukharev
Keyword(s):  
Angular Distribution ◽  
Isotropic Source

scholarly journals Open water camouflage via ‘leaky’ light guides in the midwater squid Galiteuthis

2016 ◽  
Vol 13 (119) ◽  
pp. 20160230 ◽  
Author(s):  
Amanda L. Holt ◽  
Alison M. Sweeney
Keyword(s):  
Angular Distribution ◽  
Open Water ◽  
Light Environment ◽  
Cross Sectional ◽  
Isotropic Source ◽  
Vertical Range ◽  
Light Guides

Galiteuthis , a midwater squid, has photophores on the ventral surfaces of its eyes. These photophores emit bioluminescence to counter-illuminate the shadows cast by the eyes in downwelling sunlight, thereby hiding the eyes from upward-looking predators. The photophores consist of laminated fibre-like cells with semi-coaxial protein-dense layers around axial cytoplasm. These cells have been suggested to function as light guides: bioluminescence is an isotropic process used to hide in an anisotropic light environment, so any emission must be reshaped to be effective. We found a wide variation in cross-sectional geometries of photophore cells; some were more efficient at light guiding than others. We used a set of optical models to place these photophores in the context of the radiance where Galiteuthis lives and discovered a possible adaptive reason for this variation. In Galiteuthis 's horizontal and vertical range, ocean radiance is also quite variable. For complete camouflage, photophores must reproduce this variation in radiance using an isotropic source. Our models show that variation in the geometry of the photophore light guides reproduces the predicted variation in ocean radiance experienced by this species. By selectively activating geometrically distinct populations of photophore cells, the animal may reproduce the angular distribution of light at all positions in its habitat.

Nonstationary angular distribution of optical field radiance from an isotropic source in sea water

2020 ◽  
Vol 59 (20) ◽  
pp. 6046
Author(s):  
Alexander G. Luchinin ◽  
Mikhail Yu. Kirillin ◽  
Lev S. Dolin
Keyword(s):  
Angular Distribution ◽  
Sea Water ◽  
Optical Field ◽  
Isotropic Source

Electron Scattering in Solids

1990 ◽  
Vol 48 (2) ◽  
pp. 4-5
Author(s):  
Ryuichi Shimizu ◽  
Ze-Jun Ding
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Angular Distribution ◽  
Elastic Scattering ◽  
Electron Scattering ◽  
Cross Sections ◽  
Expansion Method ◽  
Electron Excitation ◽  
Partial Wave Expansion ◽  
Backscattered Electrons

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.

Radiation of Charge Moving Between Two Planar Periodic Wire Structures

2020 ◽  
Vol 23 (1) ◽  
pp. 66-71
Author(s):  
E. A. Gurnevich ◽  
I. V. Moroz
Keyword(s):  
Angular Distribution ◽  
Charged Particle ◽  
Research And Development ◽  
High Power ◽  
Free Electron ◽  
Radiation Intensity ◽  
Free Electron Lasers ◽  
Radiation Sources ◽  
Power Radiation ◽  
High Power Radiation

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.

Experimental investigation and modelling of light scattering in a-Si:H solar cells deposited on glass/ZnO:Al substrates

2002 ◽  
Vol 715 ◽  
Author(s):  
J. Krc ◽  
M. Zeman ◽  
O. Kluth ◽  
F. Smole ◽  
M. Topic
Keyword(s):  
Surface Roughness ◽  
Experimental Investigation ◽  
Solar Cells ◽  
Angular Distribution ◽  
Light Scattering ◽  
Optical Model ◽  
Distribution Functions ◽  
Interface Roughness ◽  
Scattering Parameters ◽  
Good Agreement

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.

UGR CALCULATION BASED ON THE LUMINANCE SPATIAL-ANGULAR DISTRIBUTION

2020 ◽  
Vol 2020 (4) ◽  
pp. 25-32
Author(s):  
Viktor Zheltov ◽  
Viktor Chembaev
Keyword(s):  
Monte Carlo ◽  
Angular Distribution ◽  
Monte Carlo Method ◽  
Visual Task ◽  
New Method ◽  
Lighting System ◽  
Preliminary Assessment ◽  
System A ◽  
The Monte Carlo Method

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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