partowhâ-ye X-e saxt (#)
Fr.: rayons X durs
The short wavelength, high energy end of the → electromagnetic spectrum. Hard X-rays are typically those with energies greater than around 10 keV. The dividing line between hard and → soft X-rays is not well defined and can depend on the context.
partowhâ-ye iks-e narm
Fr.: rayons X mous
X-ray photons with energies between about 0.1 to 10 keV. → hard X-rays.