Plain silicon grating reveals a hidden 'twist' in light from electron beams
In 1953, two physicists showed that an electron beam skimming past a grating emits light whose color depends only on the electron's speed and the grating's spacing. Known as Smith-Purcell radiation, this phenomenon has become a useful tool for building compact, tunable light sources and tracking particle beams without touching them.
We haven't written up this one. Phys.org has the full story — the link below goes straight to it.
