Demagnetization Correction Method by Using Inverse Analysis Considering Demagnetizing Field Distribution

It is significant to note field aberrations (chromatic field aberration, coma, astigmatism and blurring due to curvature of field, defined by Glaser's aberration theory relative to the Blenden Freien System) of the objective lens in connection with the following three points of view; field aberrations increase as the resolution of the axial point improves by increasing the lens excitation (k2) and decreasing the half width value (d) of the axial lens field distribution; when one or all of the imaging lenses have axial imperfections such as beam deflection in image space by the asymmetrical magnetic leakage flux, the apparent axial point has field aberrations which prevent the theoretical resolution limit from being obtained.

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Field Distribution of Strongly Excited Magnetic Lenses

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100114323 ◽

1975 ◽

Vol 33 ◽

pp. 140-141

Author(s):

M. Strojnik

Keyword(s):

Flux Density ◽

Field Distribution ◽

Optical Axis ◽

Operating Point ◽

Pole Piece ◽

Partial Saturation ◽

Axial Flux ◽

The Stability

Magnetic lenses operating in partial saturation offer two advantages in HVEM: they exhibit small cs and cc and their power depends little on the excitation IN. Curve H, Fig. 1, shows that the maximal axial flux density Bz max of one of the lenses investigated changes between points (3) and (4) by 5% as the excitation varies by 40%. Consequently, the designer can relax the requirements concerning the stability of the lens current supplies. Saturated lenses, however, can only be used if (i) unwanted fields along the optical axis can be controlled, (ii) 'wobbling' of the optical axis due to inhomogeneous saturation around the pole piece faces is prevented, (iii) ample ampere-turns can be squeezed into the space available, and (iv) the lens operating point covers a sufficient range of accelerating voltages.

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Imposition of sinusoidal flux by feedback for analogue and digital computation of the field distribution in a.c.-magnetised ferromagnetic laminas

Proceedings of the Institution of Electrical Engineers ◽

10.1049/piee.1969.0292 ◽

1969 ◽

Vol 116 (9) ◽

pp. 1613

Author(s):

Sanda Mastero

Keyword(s):

Field Distribution ◽

Digital Computation

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Reliability Inverse Analysis Method of X80 Pipeline Parameter Design

ICPTT 2011 ◽

10.1061/41202(423)83 ◽

2011 ◽

Author(s):

Lisong Zhang ◽

Xiangzhen Yan ◽

Xiujuan Yang

Keyword(s):

Inverse Analysis ◽

Parameter Design ◽

Analysis Method ◽

Inverse Analysis Method

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Ortho-k lenses fitting in patients with “non-typical” corneas

The Eye ◽

10.33791/2222-4408-2020-1-22-29 ◽

2020 ◽

Vol 22 (129) ◽

pp. 22-29

Author(s):

Svetlana Kravchuk ◽

Olga Zhabina

Keyword(s):

Correction Method ◽

Diameter Ratio ◽

Corneal Curvature ◽

Individual Approach ◽

Fitting In ◽

Corneal Diameter ◽

Clinical Cases

We described two clinical cases of ortho-k lenses fitting in patients with “non-typical” corneal curvature/diameter ratio. The main goal was to acknowledge effective and safe use of this myopia correction method in patients with corneal diameter greater than 11 mm. Individual approach to each patient is the key to a successful and safe ortho-k lenses fitting.

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