Discrete spectra of them are produced by electron transitions between the normally-filled lower electron levels of atoms.  Continuous spectra of them commonly result from bremsstrahlung, or "braking" radiation.  In the work of Laue and Bragg, a beam 
Discrete spectra of them are produced by electron transitions between the normally-filled lower electron levels of atoms.  Continuous spectra of them commonly result from bremsstrahlung, or "braking" radiation.  In the work of Laue and Bragg, a beam of them were diffracted by a crystal lattice.  Slightly less energetic than gamma rays, FTP, identify this form of electromagnetic radiation commonly used to provide images of internal body structures and first observed by Wilhelm Roentgen.
Discrete spectra of them are produced by electron transitions between the normally-filled lower electron levels of atoms.  
X-rays