Orateur
Jonathan Dumas
(LPSC)
Description
Recently, the nuclear and high-energy physics communities have shown a growing interest in the availability of high current, highly-polarized positron beams. The Polarized Electrons for Polarized Positrons (PEPPo) experiment planned at the Jefferson Lab (JLab) aims to measure the transfer of polarization from a low energy (< 10 MeV) highly spin polarized electron beam to positrons.
A sufficiently energetic polarized photon or lepton incident on a target may generate, via bremsstrahlung and pair creation processes within a solid target foil, electron-positron pairs that should carry some fraction of the initial polarization. This approach has been successfully tested using polarized photons created with a multi-GeV un-polarized electron beam, resulting in positrons with polarization ~80%. Although the pair creation yield is reduced at low energy, recent advances in high current (> 1 mA) spin polarized electron sources at Jefferson Lab offer the perspective of creating polarized positrons from a low energy electron beam. A successful demonstration of this technique would provide an alternative scheme to produce low energy polarized positrons and information useful to optimize the design of polarized positron sources using sub-GeV electron beams.
An overview and status of the PEPPo experiment will be presented, along with some of the motivations in the context of the JLab physics program.
Auteur principal
Jonathan Dumas
(LPSC)
