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 Helicity Amplitudes for Generic Multibody Particle Decays Featuring Multiple Decay Chains

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Daniele Marangotto
Keyword(s):  
General Expression ◽  
Spin States ◽  
Full Generality ◽  
Final Particle ◽  
Particle Spin ◽  
Helicity Amplitudes ◽  
Definition Of ◽  
First Time ◽  
Particle Decays ◽  
Exact Definition

We present the general expression of helicity amplitudes for generic multibody particle decays characterised by multiple decay chains. This is achieved by addressing for the first time the issue of the matching of the final particle spin states among different decay chains in full generality for generic multibody decays, proposing a method able to match the exact definition of spin states relative to the decaying particle ones. We stress the importance of our result by showing that one of the matching methods used in the literature is incorrect, leading to amplitude models violating rotational invariance. The results presented are therefore relevant for performing numerous amplitude analyses, notably those searching for exotic structures like pentaquarks.

The Reliability of Measurements on Electron Energy Distribution Function in Silane rf Glow Discharges

2003 ◽  
Vol 762 ◽  
Author(s):  
Kuixun Lin ◽  
Xuanying Lin ◽  
Linfei Chi ◽  
Chuying Yu ◽  
Yunpeng Yu ◽  
...  
Keyword(s):  
Distribution Function ◽  
Energy Distribution ◽  
Electron Energy ◽  
Electron Energy Distribution Function ◽  
Energy Distribution Function ◽  
Second Derivative ◽  
Electron Energy Distribution ◽  
Amplifying Effect ◽  
Smoothing Process ◽  
First Time

AbstractElectron energy distribution function (EEDF) is directly proportional to the second derivative of the probe I-V characteristics. Because of an amplifying effect of unavoidable noises in the experimental probe I-V curves on the derivation process, the experimental I-V curves should be smoothed before performing the numerical derivation. This article investigates the effect of adjustable factors used in the smoothing process on the deduced second derivative of the I-V curves, and an optimum group of the adjustable factors is selected to make the rms deviation of the smoothed I-V curves from the measured ones less than 1 %. A simple differentiation circuit is designed and used to measure the EEDF parameter straightforwardly. It is the first time, so far as we know, to measure the EEDF parameters simultaneously by means of both numerical and circuit derivative methods under the same discharge conditions and on the same discharge equipment. The deviation between two groups of mean electron energy (E) and electron density (ne) obtained by the above different methods is within about 7 %. This apparently improves the reliability of the measurements on the EEDF parameters.

Energy distribution on the focal plane of a parabolic cylindrical concentrator with angular defocusings

2007 ◽  
Vol 43 (1) ◽  
pp. 30-33
Author(s):  
A. V. Vardanyan ◽  
K. A. Pogosyan ◽  
G. S. Aloyan ◽  
Z. S. Ovsepyan
Keyword(s):  
Energy Distribution ◽  
Focal Plane

Numerical Simulation for Focal Region Characterization in a New Solar Concentrator

2014 ◽  
Vol 13 (05n06) ◽  
pp. 1460006
Author(s):  
Leilei Wang
Keyword(s):  
Energy Distribution ◽  
Focal Plane ◽  
Focal Spot ◽  
Specular Reflection ◽  
Position Error ◽  
Focal Region ◽  
Solar Concentrator ◽  
Absolute Value ◽  
Pointing Error ◽  
New Type

Considering the sun light nonparallelism, Monte Carlo ray tracing method and specular reflection law are employed to simulate the effects of focal plane position error, pointing error to spot shape and energy distribution on focal plane of a new type of space solar concentrator. The results show that: with the absolute value of focal plane position error increasing, focal spot radius increases and peak energy flux value on focal plane decreases; when absolute value of focal plane position error is same, focal spot shape and energy distribution is almost the same; with pointing error increasing, the deviation of focal spot from the focal plane center increases and round focal spot becomes oval focal spot gradually. This will provide a reference for the new space solar concentrating and absorbing system design.

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]

Binary Optics Microlens Arrays in CdTe.

1990 ◽  
Vol 216 ◽  
Author(s):  
M.B. Stem ◽  
W.F. Delaney ◽  
M. Holz ◽  
K.P. Kunz ◽  
K.R. Maschhoff ◽  
...  
Keyword(s):  
Focal Plane ◽  
Ion Beam ◽  
Spot Size ◽  
Detector Plane ◽  
Optical Elements ◽  
Microlens Arrays ◽  
Ion Beam Etching ◽  
Binary Optics ◽  
Infrared Materials ◽  
First Time

ABSTRACTArrays of miniature focusing optics located at the focal plane can improve the performance of focal plane systems. By more completely collecting the light at the focal plane and concentrating it into a smaller spot size on the detector plane, the photodetector area can be substantially reduced. Increased gamma radiation hardening and noise reduction result from the decrease in photodetector surface area. Binary optics technology, a process for fabricating large arrays of diffractive optical elements, is especially attractive for infrared materials. In this paper, diffractive Fresnel microlens arrays containing over six thousand F/0.9 lenslets are patterned in the surface of CdTe substrates by successive photolithographic and Ar+ ion-beam-etching steps. Results on smaller arrays of monolithically integrated binary-optics lenslets with II-VI detectors, demonstrating enhanced photodetector responsivities, are presented for the first time.

Selected-Area Epitaxy of CdTe on GaAs with A Cantilever Shadow Mask

1992 ◽  
Vol 263 ◽  
Author(s):  
N.K Dhar ◽  
P. Boyd ◽  
M. Martinka ◽  
J.D. Benson ◽  
J.H. Dinan ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Focal Plane ◽  
Side Wall ◽  
Auger Spectroscopy ◽  
Focal Plane Arrays ◽  
Shadow Mask ◽  
Wall Growth ◽  
First Time ◽  
Scanning Electron

ABSTRACTA cantilever shadow masking technique has been used for the first time to grow CdTe in recesses of GaAs wafers. The use of this technique eliminated the deleterious effects of side wall growth. Scanning electron microscopy, electron channeling, Auger spectroscopy and photoluminescence were used to characterize these structures. An application to planar monolithic infrared focal plane arrays is discussed.

DETERMINATION OF THE DENSITY VALUE SPECIFICALLY AT THE FOCAL POINT OF THE MIRROR CONCENTRATING SYSTEM

2019 ◽  
Vol 6 (4) ◽  
pp. 49-55
Author(s):  
Yuldash Begzhanovich Sobirov ◽  
Rustam Khakimovich Rakhimov ◽  
Shakhriyor Abdujabbarovich Abdurakhmanov
Keyword(s):  
Energy Distribution ◽  
Focal Plane ◽  
Focal Point ◽  
Angular Size ◽  
Analytical Calculation ◽  
Radiant Flux ◽  
The Sun ◽  
Partial Shading ◽  
Focal Zone ◽  
Reflective Surfaces

When designing mirror concentrating systems, it is necessary to determine in advance the optical-geometric and optical-energy characteristics of the installation. One is required to choose the mirrors with a reflection coefficient to satisfy the expected energy distribution in the focal area and to pay attention to the accuracy of the reflective surfaces of the mirrors, to the accuracy of the tracking system of the heliostats to the trajectory of the apparent motion of the Sun, to the partial shading to the reflective surfaces, etc. Based on these data, it is necessary to calculate the irradiance distribution in the focal zone of the installation. During installation and utilization of the equipment it is necessary to measure and monitor these parameters and, if necessary, to recalculate the energy distribution taking into account the new parameters.The methods for calculating the density distribution of the radiant flux in the focal zone of mirror-concentrating systems have been developed in parallel with the requirements of exploitation. They do not always correctly reflect the true picture formed in the focus of the heliostat. In this paper, the analysis presents the existing methods for calculating paraboloid concentrators based on the Gaussian distribution of energy in the focal plane. Developing the method of fallen and reflected elementary cone beam and on the basis of generated scattered optical images of the Sun and of the visible angular size (2γо = 32 angle of minutes) of the Sun, which shows non-Gaussian nature of the resulting distribution in the focal plane due to the influence of aberration of the optical paraboloidal surface depending on the change of the aperture angle 2U, we obtained an analytical calculation formula to determine the value of the concentrated radiant flux specifically at the focal point of a paraboloid mirror concentrating system.

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