Optical trap experiments pick up recoil of a single alpha particle blasting off

Despite the 125 years that have elapsed since Ernest Rutherford first figured out that the particles emitted during alpha decay amounted to a helium nucleus comprising two neutrons and two protons, researchers are still making new revelations about what happens during the decay process itself.

Researchers led by David Moore, a physicist at Yale University in the US, conducted experiments using optical traps where optical fields from a laser control the position of microparticles and are also exquisitely sensitive to the forces acting on it. They were able to use these optical traps to observe the mechanical recoil of a silica microparticle following the emission of a single alpha particle from a radioactive atom embedded in it.