<P> X-rays with high photon energies ( above 5 -- 10 keV , below 0.2 -- 0.1 nm wavelength ) are called hard X-rays , while those with lower energy are called soft X-rays . Due to their penetrating ability , hard X-rays are widely used to image the inside of objects , e.g. , in medical radiography and airport security . The term X-ray is metonymically used to refer to a radiographic image produced using this method , in addition to the method itself . Since the wavelengths of hard X-rays are similar to the size of atoms they are also useful for determining crystal structures by X-ray crystallography . By contrast , soft X-rays are easily absorbed in air ; the attenuation length of 600 eV ( ~ 2 nm ) X-rays in water is less than 1 micrometer . </P>
<P> X-rays with high photon energies ( above 5 -- 10 keV , below 0.2 -- 0.1 nm wavelength ) are called hard X-rays , while those with lower energy are called soft X-rays . Due to their penetrating ability , hard X-rays are widely used to image the inside of objects , e.g. , in medical radiography and airport security . The term X-ray is metonymically used to refer to a radiographic image produced using this method , in addition to the method itself . Since the wavelengths of hard X-rays are similar to the size of atoms they are also useful for determining crystal structures by X-ray crystallography . By contrast , soft X-rays are easily absorbed in air ; the attenuation length of 600 eV ( ~ 2 nm ) X-rays in water is less than 1 micrometer . </P>
range of energy used in diagnostic x rays
range of energy used in diagnostic x rays
above 5 -- 10 keV , below 0.2 -- 0.1 nm wavelength
above 5 -- 10 keV , below 0.2 -- 0.1 nm wavelength