Transition radiation can be emitted by neutral‐charge structures, such as atoms, crossing the interface between dielectric media. Intensities in excess of 103photons/sec, in the energy range 1–50 keV, may be obtained from high‐power (≳100 kV, ≳1 A) beams of neutral hydrogen isotopes incident on foils. This effect may have practical implications for constructing energy‐sensitive monitors for intense neutral beams.