Glossary - X

X band
1: frequency band from 7 to 11.2 GHz
(communications)

X band
2: frequency band from 8 to 12 GHz
(radar)

X rays
a form of electromagnetic radiation between gamma rays and ultraviolet in the electromagnetic spectrum; X rays have a wavelength between about 10 pm and 10 nm and an energy between 100 eV and 100keV
(physics)