Radiation from two-dimensional ''molecular'' bound states of electrons channeled in diamond

Axially channeled electrons are captured into bound states of the ''atomic-string'' potential. When two rows lie in close proximity as in the <110> direction of diamond, the potentials overlap, forming a saddle point between the rows. For 4-MeV electrons in the <110> diamond potential, the 2p level lies above the saddle point, and molecular states are formed. The observation of radiation arising from transitions of these states is reported. Spectral information is used to deduce electron-density enhancement in the C-C bond