BREMSSTRAHLUNG IN ALPHA-DECAY OF PO-210 - DO ALPHA-PARTICLES EMIT PHOTONS IN TUNNELING

Emission probability of bremsstrahlung in the ct decay of Po-210 was m easured in alpha-gamma coincidence measurements with Si and Ge detecto rs. It was found that the bremsstrahlung yields are much smaller than those predicted by a Coulomb acceleration model, in which gamma rays a re emitted during acceleration outside the barrier. This suggests that the radiation amplitude in the barrier cannot be neglected, and the d iscussion based on a quasiclassical approach is given.