Channeling radiation on quartz stimulated by acoustic waves

The stimulation of channeling radiation by acoustic waves excited in the single crystal has been predicted in early works of the 1980's. Based on quantum calculations, the described experiment aimed at verification of theoretical considerations. Making use of the reverse piezoelectric effect, hypersonic waves of frequency 12 GHz, which corresponds to a dedicated transition between bound states of planar channelled relativistic electrons, were excited in a single-crystal quartz plate. The spectrum of channeling radiation measured under the influence of acoustic waves reveals enhanced radiation intensity. The obtained results are discussed and may be phenomenologically understood assuming electron diffraction on an acoustic superlattice.