Diagnostics of nonstationary distribution of charged particles using 2D images: inverse problem approach

Рассматривается проблема математического моделирования и синтеза нанооптических элементов, формирующих двумерные изображения для автоматического контроля их подлинности. Обратная задача синтеза ставится в скалярном волновом приближении Френеля. Задача сводится к решению нелинейного операторного уравнения Фредгольма первого рода, для решения которого предлагаются эффективные численные методы. Разработанные нанооптические элементы при их освещении когерентным излучением формируют двумерные изображения, используемые для автоматизированной идентификации. Предложенная процедура идентификации инвариантна относительно поворота и сдвига изображения. С использованием электронно-лучевой литографии изготовлены образцы нанооптических элементов для излучения с длиной волны 650 нанометров. Технология нанолитографии позволяет формировать микрорельеф с точностью до 20 нанометров. Разработанные оптические элементы устойчивы к частичному повреждению микрорельефа и могут быть использованы для идентификации банкнот, документов и др. This paper deals with the mathematical modeling and the synthesis of nano-optical elements for the forming of 2D images used for automated identification. The inverse problem of synthesis is considered in Fresnel's scalar wave approximation. The problem is reduced to the solution of a nonlinear Fredholm operator equation of the first kind. Some efficient numerical iterative methods are developed to solve the inverse problem. When illuminated by a coherent light, the designed nano-optical elements produce 2D images used for the automated identification. The proposed identification procedure is invariant with respect to rotations and shifts of images. The electron beam lithography was used to produce samples of nano-optical elements for the case of 650 nm wavelength. The microfabrication technology allows forming a microrelief with 20 nm accuracy. Such nanooptical elements are resistant against the damage of microreliefs and can be used for the verification of banknotes, documents, etc.

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Inverse problem of the potential scattering of charged particles at fixed orbital angular momentum and energy

Theoretical and Mathematical Physics ◽

10.1007/bf01017500 ◽

1985 ◽

Vol 63 (3) ◽

pp. 550-555 ◽

Cited By ~ 2

Author(s):

M. N. Popushoi

Keyword(s):

Inverse Problem ◽

Angular Momentum ◽

Orbital Angular Momentum ◽

Charged Particles ◽

Potential Scattering

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The Jovian ring

International Astronomical Union Colloquium ◽

10.1017/s0252921100101174 ◽

1984 ◽

Vol 75 ◽

pp. 203-209

Author(s):

Joseph A. Burns

Keyword(s):

Equatorial Plane ◽

Charged Particles ◽

Dynamical Evolution ◽

Main Band ◽

Small Grains ◽

Three Components

ABSTRACTLying in Jupiter's equatorial plane is a diaphanous ring having little substructure within its three components (main band, faint disk, and halo). Micron-sized grains account for much of the visible ring, but particles of centimeter sizes and larger must also be present to absorb charged particles. Since dynamical evolution times and survival life times are quite short (≲102-3yr) for small grains, the Jovian ring is being continually replenished; probably most of the visible ring is generated by micrometeoroids colliding into unseen parent bodies that reside in the main band.

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Atomic orientation effects in proton stopping at low velocity

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100077116 ◽

1983 ◽

Vol 41 ◽

pp. 708-709

Author(s):

Kin Lam

Keyword(s):

Polycrystalline Material ◽

Charged Particles ◽

Target Material ◽

Stopping Power ◽

Low Velocity ◽

Electronic Density ◽

Interatomic Distances ◽

Frame Work ◽

Image Position ◽

Atomic Orientation

The energy of moving ions in solid is dependent on the electronic density as well as the atomic structural properties of the target material. These factors contribute to the observable effects in polycrystalline material using the scanning ion microscope. Here we outline a method to investigate the dependence of low velocity proton stopping on interatomic distances and orientations.The interaction of charged particles with atoms in the frame work of the Fermi gas model was proposed by Lindhard. For a system of atoms, the electronic Lindhard stopping power can be generalized to the formwhere the stopping power function is defined as

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Inelastic scattering at surfaces and interfaces

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100143560 ◽

1986 ◽

Vol 44 ◽

pp. 392-393

Author(s):

R. H. Ritchie ◽

A. Howie

Keyword(s):

Inelastic Scattering ◽

Surface Properties ◽

Correlation Energy ◽

Condensed Matter ◽

Charged Particles ◽

Condensed Matter Physics ◽

Optical Phonons ◽

Exchange Correlation ◽

Surfaces And Interfaces ◽

Inelastic Interactions

An important part of condensed matter physics in recent years has involved detailed study of inelastic interactions between swift electrons and condensed matter surfaces. Here we will review some aspects of such interactions.Surface excitations have long been recognized as dominant in determining the exchange-correlation energy of charged particles outside the surface. Properties of surface and bulk polaritons, plasmons and optical phonons in plane-bounded and spherical systems will be discussed from the viewpoint of semiclassical and quantal dielectric theory. Plasmons at interfaces between dissimilar dielectrics and in superlattice configurations will also be considered.

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