Gun lens theory for nonparaxial trajectories by canonical mapping transformation: Characterization of general skewed rays inside electron guns by electron gun focal length

2006 ◽  
Vol 24 (4) ◽  
pp. 1891 ◽  
Author(s):  
Shin Fujita ◽  
Hiroshi Shimoyama
Keyword(s):  
Focal Length ◽  
Electron Gun ◽  
Canonical Mapping ◽  
Electron Guns

Characterization of a long-focal-length polycapillary optic for high-energy x-rays

2000 ◽  
Author(s):  
Padiyar Cari ◽  
Suparmi ◽  
Sushil D. Padiyar ◽  
Walter M. Gibson ◽  
Carolyn A. MacDonald ◽  
...  
Keyword(s):  
Focal Length ◽  
High Energy ◽  
X Rays

Characterization of THz radiation generated by ultra-short bunch from energy chirping cell attached RF electron gun

2014 ◽  
Vol 75 ◽  
pp. 184-189 ◽  
Author(s):  
Y. Koshiba ◽  
K. Sakaue ◽  
M. Mizugaki ◽  
M. Washio ◽  
R. Kuroda ◽  
...  
Keyword(s):  
Electron Gun ◽  
Thz Radiation

Novel Fabrication and Characterization of Diaphragm Micromirror Using ‘Bulk Lithography’

2012 ◽  
Author(s):  
Prasanna Gandhi ◽  
Shital Kamble ◽  
Kiran Bhole
Keyword(s):  
Adaptive Optics ◽  
Focal Length ◽  
Laser Doppler Vibrometer ◽  
Single Layer ◽  
Layer By Layer ◽  
Micro Fabrication ◽  
Wavefront Correction ◽  
Fabrication And Characterization ◽  
First Time

Adaptive optics is being explored actively for several applications such as wavefront correction in biomedical imaging (retinal surgery), variable focal length lenses, and adaptive zoom micromirrors. Diaphragm micromirrors have several advantages such as continuity in image and ease of fabrication. This paper investigates, for the first time to the best of our knowledge, fabrication of diaphragm micromirror using a recently proposed novel process of ‘Bulk Lithography’. In contrast to classical microstereolithography (MSL) processes of 3D layer-by-layer micro fabrication, bulk lithography fabrication is done by scanning of laser beam over the photopolymer resin of unconstraint depth in a single layer scan. The process has capability to fabricate smoothly varying thickness diaphragms for micromirrors. However, as a first step, this paper demonstrates fabrication of uniform thickness micromirrors coated with aluminum. Micromirrors are fabricated with air trapped beneath them which contributes to enhanced stiffness and low damping. Further fabricated micromirror is characterized using laser doppler vibrometer.

scholarly journals Uncertainty Analysis and Characterization of the SOFAST Mirror Facet Characterization System

2011 ◽  
Author(s):  
Nolan S. Finch ◽  
Charles E. Andraka
Keyword(s):  
Uncertainty Analysis ◽  
Focal Length ◽  
Input Parameter ◽  
Fringe Analysis ◽  
Development Partner ◽  
Input Parameters ◽  
Deviation Measurement ◽  
Facet Surface ◽  
Setup Variables

Sandia Optical Fringe Analysis Slope Tool (SOFAST) is a mirror facet characterization system based on fringe reflection technology that has been applied to dish and heliostat mirror facet development at Sandia National Laboratories and development partner sites. The tool provides a detailed map of mirror facet surface normals as compared to design and fitted surfaces. In addition, the surface fitting process provides insights into systematic facet slope characterization, such as focal lengths, tilts, and twist of the facet. In this paper, a preliminary analysis of the sensitivities of the facet characterization outputs to variations of SOFAST input parameters is presented. The results of the sensitivity analysis provided the basis for a linear uncertainty analysis which is also included here. Input parameters included hardware parameters and SOFAST setup variables. Output parameters included the fitted shape parameters (focal lengths and twist) and the residuals (typically called slope error). The study utilized empirical propagation of input parameter errors through facet characterization calculations to the output parameters, based on the measurement of an Advanced Dish Development System (ADDS) structural gore point-focus facet. Thus, this study is limited to the characterization of sensitivities of the SOFAST embodiment intended for dish facet characterization. With reasonably careful setup, SOFAST is demonstrated to provide facet focal length characterization within 0.5% of actual. Facet twist is accurate within ± 0.03 mrad/m. The local slope deviation measurement is accurate within ± 0.05 mrad, while the global slope residual is accurate within ± 0.005 mrad. All uncertainties are quoted with 95% confidence.

A 100 KV Transmission Scanning Microscope

1971 ◽  
Vol 29 ◽  
pp. 22-23
Author(s):  
A. V. Crewe
Keyword(s):  
Focal Length ◽  
Electron Gun ◽  
Objective Lens ◽  
Scanning Microscope ◽  
Parallel Beam ◽  
Condenser Lens ◽  
Focal Length Lens ◽  
Short Focal Length ◽  
Pass Through ◽  
Correction System

A 100 kv transmission scanning microscope is now being constructed which should have a point resolution of 2.5 to 3 Å. The design of this microscope is similar to the design of our existing 30 kv 5 Å microscope, but there are several significant changes which are based upon some difficulties and sources of inflexibility of that microscope.A field emission electron gun of our usual design will be used as the source of electrons, the only difference being that the spacing between the anodes has been increased from 2 to 3 cm. The electron beam will then pass through a condenser lens which will produce a parallel beam of electrons. This parallel beam will then be focused onto the specimen by means of a short focal length lens (approximately 1 mm focal length). The reason for using a condenser lens to produce the parallel beam of electrons is that in the future a quadrupole-octupole correction system will be installed in this section of the microscope in order to attempt to correct the spherical aberrations of the objective lens and thereby improve its resolution.

Investigation of the throughput of the dosing device gas leak for gas discharge electron gun

2012 ◽  
Vol 16 (5) ◽  
pp. 25-30
Author(s):  
I.V. Mel'nik ◽  
S.B. Tugaj
Keyword(s):  
Experimental Data ◽  
Mathematical Model ◽  
Glow Discharge ◽  
High Voltage ◽  
Beam Current ◽  
Electron Gun ◽  
Technological Equipment ◽  
Gas Leak ◽  
Electron Guns ◽  
Empirical Coefficients

Model of capacity of valve with conic rod, which is used for control of beam current of high voltage glow discharge electron guns, is considered. Because of complicity of valve details geometry, mathematical model of dozed item is improved by suitable choosing of empirical coefficients and its approximation. On the base of modeling and experimental data analyzing of dependence of valve exploitation characteristics from geometry parameters of dozed item is provided. Obtained results can be used for simulation of stability of operation of high voltage glow discharge electron guns inconsisting of technological equipment

Simple method for manufacturing and optical characterization of tapered optical fibres

2016 ◽  
Vol 24 (4) ◽  
Author(s):  
A. Zakrzewski ◽  
A. Pięta ◽  
S. Patela
Keyword(s):  
Focal Length ◽  
Fdtd Method ◽  
Single Mode ◽  
Photonic Devices ◽  
Optical Fibres ◽  
Simple Method ◽  
Spot Diameter ◽  
Small Spot ◽  
Edge Method

AbstractPhotonic devices often use light delivered by a single-mode telecommunication fibre. However, as the diameter of the core of the optical fibre is of 10 microns, and the transverse dimensions of the photonic waveguides are usually micrometer or less, there is an issue of incompatibility. The problem may be solved by application of tapered optical fibres. For efficient light coupling, the taper should be prepared so as to create a beam of long focal length and small spot diameter in the focus. The article describes the design, fabrication and characterization of tapered optical fibres prepared with a fibre-optic fusion splicer. We modelled the tapers with FDTD method, for estimation of the influence of the tapered length and angle on the spot diameter and the focal length of an outgoing beam. We fabricated tapers from a standard single mode fibre by the Ericsson 995 PMfi- bre-optic fusion splicer. We planned the splicing technology so as to get the needed features of the beam. We planned a multistep fusion process, with optimized fusion current and fusion time. The experimental measurements of best tapered optical fibres were carried out by the knife-edge method.

Multifractal and optical bandgap characterization of Ta2O5 thin films deposited by electron gun method

2020 ◽  
Vol 52 (2) ◽  
Author(s):  
Reza Shakoury ◽  
Sahar Rezaee ◽  
Fredrick Mwema ◽  
Carlos Luna ◽  
Koushik Ghosh ◽  
...  
Keyword(s):  
Thin Films ◽  
Optical Bandgap ◽  
Electron Gun

scholarly journals Electron beam characterization of a combined diode rf electron gun

2010 ◽  
Vol 13 (9) ◽  
Author(s):  
R. Ganter ◽  
B. Beutner ◽  
S. Binder ◽  
H. H. Braun ◽  
T. Garvey ◽  
...  
Keyword(s):  
Electron Beam ◽  
Electron Gun ◽  
Beam Characterization

scholarly journals Evaluation and Optimization of a MOEMS Active Focusing Device

Micromachines ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 172
Author(s):  
Ulrich Mescheder ◽  
Michael Lootze ◽  
Khaled Aljasem
Keyword(s):  
High Performance ◽  
Focal Length ◽  
Silicon On Insulator ◽  
Dynamical Response ◽  
Experimental Characterization ◽  
Long Term Stability ◽  
Detailed Evaluation ◽  
Reflective Coatings

In this paper we present a detailed evaluation of a micro-opto-electromechanical system (MOEMS) for active focusing which is realized using an electrostatically deformed thin silicon membrane. The evaluation is done using finite element methods and experimental characterization of the device behavior. The devices are realized in silicon on insulator technology. The influence of internal stress especially resulting from the high compressive buried oxide (BOX) layer is evaluated. Additionally, the effect of stress gradients in the crystalline device layer and of high reflective coatings such as aluminum is discussed. The influence of variations of some important process steps on the device performance is quantified. Finally, practical properties such as focal length control, long-term stability, hysteresis and dynamical response are presented and evaluated. The evaluation proves that the proposed membrane focusing device is suitable for high performance imaging (wavefront errors between λ/5–λ/10) with a large aperture (5 mm).

Sign in / Sign up

Export Citation Format

Share Document