Ramsauer-Townsend effect in the electron loss from H0 colliding with heavy atoms.

The emission pattern of loosely bound projectile electrons is strongly dependent on the target species. For 0.5 MeV hydrogen colliding with krypton we observe large variations in the intensity of these electrons as a function of emission angle. There are also large changes in the energy and width of the electron loss peak associated with these intensity variations. These features are closely related to the Ramsauer-Townsend scattering of free electrons and can be interpreted within the electron impact approximation, a model which successfully combines free electron scattering by the heavy target with the Compton profile of the initially bound projectile electron.