Disclosed is a system for producing electromagnetic radiation with enhancement from a drift tube containing a cylindrical Smith-Purcell structure. The system includes a magnetically insulated linear oscillator. The oscillator includes a cylindrical resonant cavity having a traveling wave electron gun and a cooperating anode. The drift tube is formed of a hollow cylindrical conductive element that is positioned within a resonant cavity of the oscillator. The drift tube includes an inner surface and a pair of ends. The drift tube may be adapted such that the interaction between an electron beam, from the electron gun, passes through the inner space of the drift tube, and the internal grating, so as to produce RF radiation by the Smith-Purcell Effect. Spacing, face angle and shape of the grating, and the energy of the electron beam are determinants of the frequency of the RF radiation.

Controlling electromagnetic (‘EM’) radiation in a data center having a number EM sections, including: receiving, by an EM controller, a specification of preferred EM radiation characteristics for the data center; and setting, by the EM controller, a state of each EM section in accordance with the specification, where the state of each EM section may be one of: an absorption state in which the EM section absorbs EM radiation or a reflection state in which the EM section reflects EM radiation.