Continuous spectrum and characteristic X-Rays?

When energetic electrons bombard atoms in a metal target (for ex. tungsten) an electron may be ejected from innermost K-shell, the atom then is in exited state and is unstable. If an electron from L-shell now moves to vacancy in K-shell , the energy of atom is decreased and simultaneously there is emission of radiation. If E is the change in energy when electron moves from L-shell to K-shell then ,
E=hν where h is the plank's constant and ν is the frequency of radiation.
Thus , ν=E/h and for high energies , wavelength of the radiation is short and is of the order of 10-8cm for X-Rays.
When we study X-Rays from a target it is observed to be a continuous spectrum with intense lines. These intense lines depends on the metal used as target and these are called characteristic X-Rays. The continuous spectrum depends on applied potential difference , current flowing in the filament and atomic number of target.

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