scholarly journals OPTICAL DESIGN WITH ROTATIONALLY SYMMETRIC NURBS

2002 ◽  
Author(s):  
Holden Chase
Keyword(s):  
Optical Design ◽  
Rotationally Symmetric

A high resolution multi-turn TOF mass analyzer

2019 ◽  
Vol 34 (36) ◽  
pp. 1942005 ◽  
Author(s):  
Vyacheslav Shchepunov ◽  
Michael Rignall ◽  
Roger Giles ◽  
Ryo Fujita ◽  
Hiroaki Waki ◽  
...  
Keyword(s):  
High Resolution ◽  
Mirror Symmetry ◽  
Rotational Symmetry ◽  
Optical Design ◽  
Resolving Power ◽  
Mass Analyzer ◽  
Rotationally Symmetric ◽  
Mass Resolving Power ◽  
Operational Modes ◽  
Drift Direction

An ion optical design of a high resolution multi-turn time-of-flight mass analyzer (MT-TOF MA) is presented. The analyzer has rotationally symmetric main electrodes with additional mirror symmetry about a mid-plane orthogonal to the axis of symmetry. Rotational symmetry allows a higher density of turns in the azimuthal (drift) direction compared to MT-TOF MAs that are linearly extended in the drift direction. Mirror symmetry about a mid-plane helps to achieve a high spatial isochronicity of the ions’ motion. The analyzer comprises a pair of polar-toroidal sectors S1 and S3, a pair of polar (trans-axial) lenses, and a pair of conical lenses for longitudinal and lateral focusing. A toroidal sector S2 located at the mid-plane of the analyzer has a set of embedded drift focusing segments providing focusing and spatial isochronicity in the drift direction. The ions’ drift in the azimuthal direction can be reversed by using dedicated reversing deflectors. This gives the possibility of several operational modes with different numbers of turns and passes in the drift direction. According to numerical simulations, the mass resolving power of the analyzer ranges from [Formula: see text]40 k (fwhm) at small (typically below ten) numbers of turns to [Formula: see text]450 k (fwhm) at 96 turns.

scholarly journals Non-Rotationally Symmetric Field Mapping for Back-Scanned Step/Stare Imaging System

2020 ◽  
Vol 10 (7) ◽  
pp. 2399
Author(s):  
Qiang Fu ◽  
Xin Zhang ◽  
Jianping Zhang ◽  
Guangwei Shi ◽  
Shangnan Zhao ◽  
...  
Keyword(s):  
Optical System ◽  
Imaging System ◽  
Optical Design ◽  
Mapping Method ◽  
Focal Plane Arrays ◽  
Image Motion ◽  
Field Point ◽  
Field Mapping ◽  
Symmetric Field ◽  
Rotationally Symmetric

Step/stare imaging with focal plane arrays (FPAs) has become the main approach to achieve wide area coverage and high resolution imaging for long range targets. A fast steering mirror (FSM) is usually utilized to provide back-scanned motion to compensate for the image motion. However, the traditional optical design can just hold one field point relatively stable, typically the central or on-axis field point, on the FPA during back-scanning; all other field points may wander during the exposure due to imaging distortion characteristics of the optical system, which reduces the signal to noise ratio (SNR) of the target. Aiming toward this problem, this paper proposes a non-rotationally symmetric field mapping method for the back-scanned step/stare imaging system, which can make all field points stable on the FPA during back-scanning. First of all, the mathematical model of non-rotationally symmetric field mapping between object space and image space is established. Then, a back-scanned step/stare imaging system based on the model is designed, in which this non-rotationally symmetric mapping can be implemented with an afocal telescope including freeform lenses. Freeform lenses can produce an anamorphic aberration to adjust distortion characteristics of the optical system to control image wander on an FPA. Furthermore, the simulations verify the effectiveness of the method.

scholarly journals An Inverse Model for Two-dimensional Reflectors With Scattering

2021 ◽  
Vol 255 ◽  
pp. 02003
Author(s):  
Vì C.E. Kronberg ◽  
Martijn J.H. Anthonissen ◽  
Jan H.M. ten Thije Boonkkamp ◽  
Wilbert L. IJzerman
Keyword(s):  
Light Scattering ◽  
Energy Conservation ◽  
Optical Design ◽  
Integral Relation ◽  
Isotropic Scattering ◽  
Two Dimensional ◽  
Convolution Integral ◽  
Surface Light Scattering ◽  
Novel Approach ◽  
Rotationally Symmetric

We present a novel approach of modelling surface light scattering in the context of freeform optical design. Using energy conservation, we derive an integral relation between the scattered and specular distributions. This integral relation reduces to a convolution integral in the case of isotropic scattering in the plane of incidence for cylindrically and rotationally symmetric problems.

scholarly journals Efficient representation of freeform gradient-index profiles for non-rotationally symmetric optical design

2020 ◽  
Vol 28 (10) ◽  
pp. 14788
Author(s):  
Tianyi Yang ◽  
Nick Takaki ◽  
Julie Bentley ◽  
Greg Schmidt ◽  
Duncan T. Moore
Keyword(s):  
Optical Design ◽  
Gradient Index ◽  
Rotationally Symmetric ◽  
Efficient Representation

Use of the Magnetostatic Analogue In Electromagnetic Lens Engineering

1970 ◽  
Vol 28 ◽  
pp. 360-361
Author(s):  
John W. Coleman
Keyword(s):  
Boundary Conditions ◽  
High Performance ◽  
Force Fields ◽  
Optical Design ◽  
Direct Conversion ◽  
Design Engineering ◽  
Design Data ◽  
Scalar Potentials ◽  
Geometric Elements ◽  
At Will

In the design engineering of high performance electromagnetic lenses, the direct conversion of electron optical design data into drawings for reliable hardware is oftentimes difficult, especially in terms of how to mount parts to each other, how to tolerance dimensions, and how to specify finishes. An answer to this is in the use of magnetostatic analytics, corresponding to boundary conditions for the optical design. With such models, the magnetostatic force on a test pole along the axis may be examined, and in this way one may obtain priority listings for holding dimensions, relieving stresses, etc..The development of magnetostatic models most easily proceeds from the derivation of scalar potentials of separate geometric elements. These potentials can then be conbined at will because of the superposition characteristic of conservative force fields.

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