# Wavelength of X-rays in a tube

If I increase the accelerating potential in an X-ray tube the wavelength of the characteristic X-rays do not change.

Is this because when an electron beam strikes the target in an X-ray tube, part of its kinetic energy is converted into X-ray energy?

• Actually, the wavelength of xrays produced is a function of the energy electrons have when hitting the anode. Perhaps you are seeing secondary re-emissions? – Olin Lathrop Jan 30 '15 at 14:48

So changing the energy of the incident photons may well change the intensity of the fluorescence peak, but it will not change the wavelength. Typically a commercial X-ray tube, e.g. for use in a diffractometer, will have the electron energy tuned to maximise the intensity of the required fluorescence peak (usually the $K^\alpha$.