We report the measurement result of the degree to which X-rays from a
conventional X-ray generator in the energy range up to 60 keV are line
arly polarized. The X-ray generator we used in which the accelerated e
lectrons hit the water-cooled metal head is widely used commercially.
We measured the degree of linear polarization by employing a Thomson s
cattering process. We found that the degree of linear polarization dep
ends only on the ratio between the X-ray energy from 20 keV to 60 keV
and the applied voltage to the electron. The higher the ratio is, the
higher the degree of linear polarization we obtain, whereas the weaker
the X-ray intensity is. By selecting an appropriate combination betwe
en the applied voltage and the X-ray energy: we confirmed that we woul
d obtain a mono-energetic highly linear polarized X-ray beam with enou
gh intensity for practical use.