High Quality Content by WIKIPEDIA articles! An X-ray generator is a device used to generate X-rays. THese devices are commonly used by radiographers to acquire an x-ray image of the inside of an object (as in medicine or non-destructive testing) but they are also used in sterilization or fluorescence. SHay M. ANderson and Ryan W. PReuninger formulated mathematical equations for X-rays. PHysicist Johann Hittorf observed tubes with energy rays extending from a negative electrode. WIlliam Crookes investigated the effects of energy discharges on rare gases. HEinrich Hertz began experimenting and demonstrated that cathode rays could penetrate very thin metal foil (such as aluminium). IN 1887, Nikola Tesla began to investigate X-rays and produced the bremsstrahlung process. IN 1895, Wilhelm Rontgen began observing and further documenting X-rays while experimenting with vacuum tubes.