The Scattering Cross Section of Spheres for Electromagnetic Waves

1949 ◽  
Vol 20 (11) ◽  
pp. 1110-1125 ◽  
Author(s):  
L. Brillouin
Keyword(s):  
Cross Section ◽  
Electromagnetic Waves ◽  
Scattering Cross Section ◽  
Scattering Cross

Scattering of electromagnetic waves by anomalous fluctuations of a magnetized plasma

1990 ◽  
Vol 43 (2) ◽  
pp. 165-172 ◽  
Author(s):  
V. N. Pavlenko ◽  
V. G. Panchenko
Keyword(s):  
Cross Section ◽  
Electromagnetic Waves ◽  
Pump Wave ◽  
Density Fluctuations ◽  
Scattering Cross Section ◽  
Magnetized Plasma ◽  
Lower Hybrid ◽  
Scattering Cross ◽  
Parametric Decay ◽  
Ion Acoustic

Fluctuations and scattering of transverse electromagnetic waves by density fluctuations in a magnetized plasma in the presence of parametric decay of the pump wave are investigated. The spectral density of electron-density fluctuations is calculated. It is shown that the differential scattering cross-section has sharp maxima at the ion-acoustic and lower-hybrid frequencies when parametric decay of the lower-hybrid pump wave occurs. We note that scattering at the ion-acoustic frequency is dominant. When the pump-wave amplitude tends to the threshold strength of the electric field the scattering cross-section increases anomalously, i.e. there is critical opalescence.

Mass Determination by Direct Measurement of Electron Scattering

1975 ◽  
Vol 33 ◽  
pp. 240-241
Author(s):  
M. K. Lamvik ◽  
A. V. Crewe
Keyword(s):  
Cross Section ◽  
Electron Scattering ◽  
Mass Density ◽  
Variable Mass ◽  
Scattering Cross Section ◽  
Mass Determination ◽  
Number Density ◽  
Cross Sectional ◽  
Thin Slice ◽  
Scattering Cross

If a molecule or atom of material has molecular weight A, the number density of such units is given by n=Nρ/A, where N is Avogadro's number and ρ is the mass density of the material. The amount of scattering from each unit can be written by assigning an imaginary cross-sectional area σ to each unit. If the current I0 is incident on a thin slice of material of thickness z and the current I remains unscattered, then the scattering cross-section σ is defined by I=IOnσz. For a specimen that is not thin, the definition must be applied to each imaginary thin slice and the result I/I0 =exp(-nσz) is obtained by integrating over the whole thickness. It is useful to separate the variable mass-thickness w=ρz from the other factors to yield I/I0 =exp(-sw), where s=Nσ/A is the scattering cross-section per unit mass.

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