Prototype for an undulator-based source for polarised positrons
The full exploitation of the physics potential of a future Linear Collider requires the development of polarised positron beams. A very promising scheme for the technical realisation is the use of helical undulators, generating circular polarised photons of several MeV which are then converted in a thin target to longitudinally polarised positrons. The experiment E-166 tests this scheme. It uses the low-emittance 50-GeV electron beam at the Final Focus Test Beam (FFTB) at SLAC, passing through a 1 meter-long helical undulator. The flux and polarisation of the undulator photons as well as the properties of the positrons will be measured and will be compared with simulations.
PACS: 12.60.-i Models beyond the standard model – 13.88.+e Polarization in interactions and scattering – 29.27.Hj Polarized Beams – 95.75.Hi Polarimetry