Aircraft Signature Studies Using Infrared Cross Section and Infrared Solid Angle

2021 ◽  
pp. 1-11
Author(s):  
Shripad P. Mahulikar ◽  
Pallavi Rastogi ◽  
Ashish Bhatt
Keyword(s):  
Cross Section ◽  
Solid Angle

An Algorithm for the Description of White and Characteristic Tube Spectra (11 ≤ Z ≤ 83, 10keV ≤ Eo ≤ 50keV)

1991 ◽  
Vol 35 (B) ◽  
pp. 721-726 ◽  
Author(s):  
H. Ebel ◽  
H. Wiederschwinger ◽  
J. Wernisch ◽  
P.A. Pella
Keyword(s):  
Kinetic Energy ◽  
Cross Section ◽  
Atomic Number ◽  
Solid Angle ◽  
Electron Interaction ◽  
X Rays ◽  
X Ray ◽  
The Cross ◽  
Spectral Responses ◽  
The Continuum

Kramers described the cross section of electron interaction with target atoms of atomic number Z bywhere Eo is the kinetic energy of impinging electrons, and E o S) the energy of x-ray photons of the continuum, Smith et al modified this equation, introducing an exponent x, so thatWe applied the cross-section σS, E to the evaluation of experimental results. The evaluation of the measured spectral responses of the x-ray signals nE was performed bywhere f(deff) describes the absorption of x-rays of energy E in the target, RE accounts for backscattering of electrons, DE quantifies the efficiency of x-ray detection within the solid angle Ω.

η PHOTO-PRODUCTION ON THE DEUTERON AT LNS, TOHOKU UNIVERSITY

2010 ◽  
Vol 19 (12) ◽  
pp. 2393-2399 ◽  
Author(s):  
T. Ishikawa
Keyword(s):  
Total Cross Section ◽  
Cross Section ◽  
Systematic Uncertainty ◽  
Cross Sections ◽  
Energy Region ◽  
Solid Angle ◽  
Total Cross Sections ◽  
Nuclear Science ◽  
Electro Magnetic ◽  
Photo Production

The differential and total cross sections were measured for the γp → ηp and γd → ηpn reactions at Eγ ≤ 1150 MeV by using an electro-magnetic (EM) calorimeter SCISSORS II at the Laboratory of Nuclear Science (LNS), Tohoku University. The total cross section on the deuteron shows a bump around Eγ = 1 GeV , while no bump is observed in the same energy region of that on the proton. This bump is attributed to be a nucleon resonance excited from the neutron, and it is a candidate of anti-decuplet penta-quark baryons with hidden strangeness. It was difficult, however, to detect all the γ's coming from η decay since the solid angle of SCISSORS II was only 12.6% in total. Statistics of the detected η produced events is poor and systematic uncertainty of the obtained cross section is not small due to low acceptance. A new EM calorimeter complex called FOREST with a solid angle of about 4π sr has been constructed. The spin and parity of the relevant resonance are expected to be determined by the experiments with FOREST.

scholarly journals Electron scattering in helium. Absolute measurements at 90° and 45°

1933 ◽  
Vol 139 (837) ◽  
pp. 113-129 ◽  
Keyword(s):  
Form Factor ◽  
Cross Section ◽  
Electron Scattering ◽  
Unit Volume ◽  
Solid Angle ◽  
Potential Difference ◽  
X Rays ◽  
Scattered Intensity ◽  
Atomic Form Factor ◽  
Absolute Measurements

The scattering formula of Rutherford gives an expression for the number n 1 d Ω of electrons in a gas which are scattered from a beam of electrons over the solid angle d Ω by impacts with atoms, which are to be found along a certain length l of this beam. If + Z e is the charge of the nucleus of the atoms, — e and m the charge and the mass of the electron, V the potential difference through which the electrons are accelerated, N the number of atoms in unit volume and n 0 the total number of electrons which pass a certain cross-section of the beam, we have the well-known formula: n 1 d Ω = n 0 N l (Z e /4V) 2 d Ω/sin 4 ½Θ, (1) where Θ is the angle of scattering. When n 0 = 1, N = 1, and l = 1 the scattering is usually expressed by I θ d Ω, where I θ is the so-called “scattered intensity.’’ According to Rutherford’s formula we get for the classical scattering due to the nucleus: I θ = ( e /4V) 2 Z 2 /sin 4 ½Θ. (2) Taking into consideration the electrons around the nucleus Mott and Bethe find: I θ = ( e /4V) 2 (Z -F) 2 /sin 4 ½Θ, (3) where F is the atomic form factor, known from the scattering of X-rays, and also a function of (V sin 2 ½Θ). The values calculated for helium by James have been used for F in this paper.

Experiments on Rayleigh Scattering of 145 keV and 317 keV Photons

1981 ◽  
Vol 36 (6) ◽  
pp. 595-599 ◽  
Author(s):  
S. de Barros ◽  
J. Eichler ◽  
. Gonçalves ◽  
M. Gaspar
Keyword(s):  
Form Factor ◽  
Energy Dependence ◽  
Cross Section ◽  
Cross Sections ◽  
Differential Cross ◽  
Rayleigh Scattering ◽  
Solid Angle ◽  
Differential Cross Sections ◽  
Strong Energy ◽  
Collimated Beam

Abstract Elastic differential cross sections for scattering of photons with 145 keV and 317 keV were measured for Pb, W, Sn, Cd, Ag, Mo and Cu for angles from 5° to 40°. For measuring the strong energy dependence of the cross section at small angles, a well collimated beam (±0,5°) and a small detecting solid angle were used. For the energies and angles studied, agreement between experiment and form factor calculations is found. The results are compared with recent measurements of other authors, which found disagreement with form factor calculations

A coincidence method of measuring a flux of fast neutrons

1948 ◽  
Vol 44 (1) ◽  
pp. 96-113 ◽  
Author(s):  
B. B. Kinsey ◽  
S. G. Cohen ◽  
J. Dainty
Keyword(s):  
Cross Section ◽  
Ionization Chamber ◽  
Unit Area ◽  
Solid Angle ◽  
Fast Neutrons ◽  
Proton Scattering ◽  
Coincidence Method ◽  
Γ Rays ◽  
Thick Layers

A method is described in which the rate at which fast neutrons cross unit area is measured by counting protons projected into a small solid angle in the forwards direction from thin and thick layers of polythene. The protons are detected by triple coincidences between three proportional counters mounted coaxially behind the hydrogenous layers. The method is applicable to neutrons of energies from 1 MeV. upwards, and can be used in the presence of intense γ-rays. The flux of these neutrons is calculated in terms of the rate of detection of the protons, the solid angle for proton collection, the mass per unit area of the polythene layer, and the neutron-proton-scattering cross-section. A study of the behaviour of proportional co-axial counters, used in this manner, has been made. A determination of the angular distribution of fast neutrons produced by a deuteron-deuterium source has been made by our coincidence method, and the results compared with those obtained by the ionization chamber method by Bretscher and French. Absolute values agree to within 10%.

scholarly journals Installation of NEOPTOLEMOS, the new sum spectrometer for cross section measurements of capture reactions at the ΤANDEM Accelerator Laboratory of NCSR “Demokritos”

2019 ◽  
Vol 24 ◽  
pp. 134
Author(s):  
V. Lagaki ◽  
V. Michalopoulou-Petropoulou ◽  
M. Axiotis ◽  
V. Foteinou ◽  
A. Lagoyannis ◽  
...  
Keyword(s):  
Cross Section ◽  
Large Volume ◽  
Solid Angle ◽  
Nuclear Astrophysics ◽  
Nuclear Level ◽  
Level Densities ◽  
Γ Rays ◽  
Integrated Cross Section ◽  
The University

Cross-section measurements of capture reactions are of key importance in understanding the contribution of the uncertainties of nuclear properties, such as the nucleon-nucleus potential and the nuclear level densities, entering in astrophysics abundance calculations. During the recent years, the Nuclear Astrophysics group of NCSR “Demokritos” has been conducting angle-integrated cross-section measurements using a large-volume NaI(Tl) detector installed at the Dynamitron Tandem Laboratory of the University of Bochum in Germany. Thanks to LIBRA funds a brand new cylindrically shaped NaI(Tl) detector, coined NEOPTOLEMOS, was acquired that is axially segmented in two, covering a solid angle of almost 4π for γ rays emitted at its center.

XUV Absorption Spectra of Carbon Ions

1988 ◽  
Vol 102 ◽  
pp. 71-73
Author(s):  
E. Jannitti ◽  
P. Nicolosi ◽  
G. Tondello
Keyword(s):  
Absorption Spectra ◽  
Cross Section ◽  
Theoretical Calculations ◽  
Photoionization Cross Section ◽  
Carbon Ions

AbstractThe photoabsorption spectra of the carbon ions have been obtained by using two laser-produced plasmas. The photoionization cross-section of the CV has been absolutely measured and the value at threshold, σ=(4.7±0.5) × 10−19cm2, as well as its behaviour at higher energies agrees quite well with the theoretical calculations.

Elastic Scattering in Electron Microscopy

1973 ◽  
Vol 31 ◽  
pp. 252-253
Author(s):  
J. Langmore ◽  
M. Isaacson ◽  
J. Wall ◽  
A. V. Crewe
Keyword(s):  
Electron Microscopy ◽  
Elastic Scattering ◽  
Cross Section ◽  
Quantum Noise ◽  
Dark Field ◽  
Elastic Cross Section ◽  
Biological Molecules ◽  
Dark Field Microscopy ◽  
Field Systems ◽  
Effects Of Radiation

High resolution dark field microscopy is becoming an important tool for the investigation of unstained and specifically stained biological molecules. Of primary consideration to the microscopist is the interpretation of image Intensities and the effects of radiation damage to the specimen. Ignoring inelastic scattering, the image intensity is directly related to the collected elastic scattering cross section, σɳ, which is the product of the total elastic cross section, σ and the eficiency of the microscope system at imaging these electrons, η. The number of potentially bond damaging events resulting from the beam exposure required to reduce the effect of quantum noise in the image to a given level is proportional to 1/η. We wish to compare η in three dark field systems.

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