Monochromateur de vitesse pour macroions

1976 ◽  
Vol 54 (18) ◽  
pp. 1833-1838 ◽  
Author(s):  
Réal Paquin ◽  
Marcel Baril
Keyword(s):  
Energy Distribution ◽  
General Expression ◽  
Drift Tube ◽  
Linear Acceleration ◽  
Energy Spread ◽  
Cesium Ions

We propose the use of a dynamic monochromator to reduce the energy spread of a macroion source. It is shown that the energy aberration can be corrected using linear acceleration after the particles are separated in a field free drift tube. We give a general expression for the resolution of the monochromator. We verify experimentally that the energy distribution of a beam of cesium ions of 160 eV mean energy could be reduced from 20 eV to 4.5 eV, giving an improvement of 4.3. with this monochromator which has an efficiency of 6%. Two suggestions to improve the transmission of the monochromator are also given.[Journal translation]

scholarly journals The dispersion of a light pulse by a prism

1914 ◽  
Vol 90 (618) ◽  
pp. 298-312
Keyword(s):  
Energy Distribution ◽  
General Expression ◽  
Light Pulse ◽  
Focal Plane ◽  
Definite Function ◽  
Initial Pulse ◽  
Initial Form ◽  
First Time

This investigation is a continuation of a former one in which an expression was derived for a light pulse with an energy distribution given by Wien's law. The first three paragraphs are supplementary to the former paper; the rest of the investigation deals with the passage of the same pulse through a prism and its separation into the different colours in the focal plane of a telescope. The general principles according to which this must take place are, of course, known, but here the actual disturbance at every point in the focal plane is given for the first time as a definite function of the time and as a result it is possible to state how many waves there are in the trains, which the single initial pulse gives rise to in the various parts of the spectrum. §1. My general expression for the initial form of a light pulse was cos ( n + ½) θ /( x 2 + h 2 ) (2 n +1)/4 , where tan θ = x/h . I did no notice until after the former paper was communicated, that this expression is 1/Г ( n + ½) ∫ ∞ 0 e - ha cos αx α n -½ dα .

scholarly journals Modeling the influence of electron beam energy distribution on quality of radiation processing

2018 ◽  
Keyword(s):  
Electron Beam ◽  
Energy Distribution ◽  
Beam Energy ◽  
Computer Experiments ◽  
International Standards ◽  
Energy Spread ◽  
Electron Beam Energy ◽  
Radiation Processing ◽  
Empirical Formulas ◽  
Depth Dose

The obtained values of most probable energy and practical range have been compared to values calculated according to the formula proposed by the internationally recognized documents. The presented results of the study are focused on the issue of the influence of electron beam energy spread on the depth dose distribution and practical range of electron beam in the irradiated material. The computational experiments have been performed using the Monte-Carlo simulation method for modeling the electron beam energy spectra and depth dose distributions of electrons in aluminum target. Obtained values of most probable energy Ep and practical range Rp have been compared to the values calculated according to formula proposed by the internationally recognized report. The value of a practical range of electrons Rp strongly depends on electron beam energy spread, even in case when value of most probable energy Ep of electrons in the beam is unchanged. Results of computer experiments show that in case of a large energy spread, and presence of asymmetry of electron energy distribution, the electrons energy can’t be determined properly by empirical formulas included to the international standards.

Practical Picture Processing

1974 ◽  
Vol 32 ◽  
pp. 338-339
Author(s):  
T. A. Welton
Keyword(s):  
Radiation Damage ◽  
Coherence Length ◽  
Spatial Information ◽  
State Of The Art ◽  
Coherent Radiation ◽  
The State ◽  
Energy Spread ◽  
Electron Micrograph ◽  
Picture Processing ◽  
Molecular Skeleton

Various authors have emphasized the spatial information resident in an electron micrograph taken with adequately coherent radiation. In view of the completion of at least one such instrument, this opportunity is taken to summarize the state of the art of processing such micrographs. We use the usual symbols for the aberration coefficients, and supplement these with £ and 6 for the transverse coherence length and the fractional energy spread respectively. He also assume a weak, biologically interesting sample, with principal interest lying in the molecular skeleton remaining after obvious hydrogen loss and other radiation damage has occurred.

Energy Distribution in Electron Beams

1972 ◽  
Vol 30 ◽  
pp. 568-569
Author(s):  
Tamotsu Ohno
Keyword(s):  
Electron Beam ◽  
Energy Distribution ◽  
Cross Section ◽  
Integral Curve ◽  
Electron Beams ◽  
Electron Gun ◽  
Angular Divergence ◽  
Apparent Increase ◽  
Integral Width ◽  
The Cross

The energy distribution in an electron; beam from an electron gun provided with a biased Wehnelt cylinder was measured by a retarding potential analyser. All the measurements were carried out with a beam of small angular divergence (<3xl0-4 rad) to eliminate the apparent increase of energy width as pointed out by Ichinokawa.The cross section of the beam from a gun with a tungsten hairpin cathode varies as shown in Fig.1a with the bias voltage Vg. The central part of the beam was analysed. An example of the integral curve as well as the energy spectrum is shown in Fig.2. The integral width of the spectrum ΔEi varies with Vg as shown in Fig.1b The width ΔEi is smaller than the Maxwellian width near the cut-off. As |Vg| is decreased, ΔEi increases beyond the Maxwellian width, reaches a maximum and then decreases. Note that the cross section of the beam enlarges with decreasing |Vg|.

Principle and practice of high-resolution imaging with a field-emission TEM

1992 ◽  
Vol 50 (1) ◽  
pp. 138-139
Author(s):  
Max T. Otten ◽  
Wim M.J. Coene
Keyword(s):  
High Resolution ◽  
Field Emission ◽  
Incidence Angle ◽  
Temporal Coherence ◽  
Energy Spread ◽  
High Resolution Imaging ◽  
Major Improvement ◽  
High Resolution Images ◽  
Resolution Imaging

High-resolution imaging with a LaB6 instrument is limited by the spatial and temporal coherence, with little contrast remaining beyond the point resolution. A Field Emission Gun (FEG) reduces the incidence angle by a factor 5 to 10 and the energy spread by 2 to 3. Since the incidence angle is the dominant limitation for LaB6 the FEG provides a major improvement in contrast transfer, reducing the information limit to roughly one half of the point resolution. The strong improvement, predicted from high-resolution theory, can be seen readily in diffractograms (Fig. 1) and high-resolution images (Fig. 2). Even if the information in the image is limited deliberately to the point resolution by using an objective aperture, the improved contrast transfer close to the point resolution (Fig. 1) is already worthwhile.

Magnetic energy distribution in polycrystalline sputtered CoCr magnetic thin films

2008 ◽  
Vol 42 (2) ◽  
pp. 125-128
Author(s):  
J. F. Al-Sharab ◽  
J. E. Wittig ◽  
G. Bertero ◽  
T. Yamashita ◽  
J. Bentley ◽  
...  
Keyword(s):  
Thin Films ◽  
Energy Distribution ◽  
Magnetic Energy ◽  
Magnetic Thin Films

MEASUREMENT OF THE ELECTRON ENERGY DISTRIBUTION IN A CO2LASER PLASMA

1979 ◽  
Vol 40 (C7) ◽  
pp. C7-385-C7-386
Author(s):  
S. Bourquard ◽  
J. M. Mayor ◽  
P. Kocian
Keyword(s):  
Energy Distribution ◽  
Electron Energy ◽  
Electron Energy Distribution

PRECISE MEASUREMENT OF ENERGY DISTRIBUTION IN Ga LMIS

1987 ◽  
Vol 48 (C6) ◽  
pp. C6-141-C6-146 ◽  
Author(s):  
M. Komuro ◽  
T. Kato
Keyword(s):  
Energy Distribution ◽  
Precise Measurement
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