Deflection angle
The deflection angle is a term from classical physics .
One designates with it
- in optics the change in the direction of propagation of a light beam and
- in kinematics the change in the direction of movement of a mass body .
- for the cathode ray tube the achievable angular deflection of the electron beam , see deflection system .
interaction
The deflection is the result of an interaction that influences the propagation , i.e. it does not happen spontaneously: According to the law of inertia (the lex prima of the three laws of motion of Isaac Newton ), a mass body, on which no external force acts, does not change its state of motion, i.e. it rests or moves rectilinearly uniform.
A light beam behaves accordingly according to Huygens' principle : it always spreads in a straight line in a vacuum. By refraction , diffraction , scattering or reflecting it may be to change the direction of propagation of the light beam coming. The same applies to the mass body, namely that it changes its speed in magnitude and / or direction as soon as forces act on it, which do not neutralize each other in their effect ( resultant ).
The angle between the directions of propagation (direction of the velocity vector ) before and after the interaction is the deflection angle. To characterize picture tubes , however, twice the maximum deflection angle is specified as the deflection angle.
Individual evidence
- ^ Walter Greiner: Classical electrodynamics (= theoretical physics ). 7th edition. German, Frankfurt am Main 2008, ISBN 978-3-8171-1818-2 , pp. 422 ( limited preview in Google Book search).
- ↑ Peter Schneider: Introduction to the extragalactic astronomy and cosmology . Springer Verlag, Berlin, Heidelberg 2006, ISBN 3-540-30589-0 , pp. 67 ( limited preview in Google Book search).
- ↑ Deflection Prism . In: Lexicon of Optics . Spectrum of Science Verlag, Heidelberg 1999 ( Spektrum.de [accessed on January 19, 2018]).