Low energy positron beam studies

Measurements of positrons interacting with atoms and surfaces indicate surface structure and scattering dynamics. The positron beam has an energy range from about 1 to 900 eV, an expected polarization of about 20{\%} and intensity of 1000 counts/sec in a 10 mm radius on a microchannel plate detector used in retarding potential mode. A W(100) single crystal at 10 $^{-10}$ mbar supports the growth of Fe thin films. Results indicate the elastic and inelastic scattering of positrons, generation of secondary electrons, re-emission of thermalized positrons normal to different surfaces and various scattering mechanisms.