J. Phys. IV France 03 (1993) C4-131-C4-133
Positron spur structure emulated by variable energy slow positron beamY. ITO1, H. ABE2 and Y. TABATA2
1 Research Center for Nuclear Science and Technology, The University of Tokyo, Tokai, Ibaraki 319-11, Japan
2 Faculty of Engineering, Tokai University, Japan
Variable energy slow positron beam was used to probe the positronic spur processes in polymers : low density polyethylene and a polyimide (Kapton). A fraction of the injected positrons was re-emitted as positron or positronium, whose fraction was dependent on the energy of injected positrons. The energy of the re-emitted positrons could become quite large, even larger than the band-gap energies of the substance. This was considered to be the result of charge-up effect. This effect may provide a new concept for a "field assisted slow positron moderator".
© EDP Sciences 1993