Accelerator Physics LCRD 2.37

Undulator Based Production of Polarized Positrons for Linear Colliders (SLAC Experiment E-166) S. Berridge, W. Bugg, Y. Efremenko, T. Handler, Y. Kamychkov, S.Spanier,

University of Tennessee

C. Lu, K.T.McDonald.

Princeton University

• E-166 uses the 50 GeV FFTB beam in conjunction with a 1 m-long, helical undulator (  = 2.4 mm, ID = 0.9 mm) to make 10-MeV polarized photons.

Concept: Balakin and Mikhailichenko (1978) •These photons are converted in a ~ 0.5 rad. len. Thick target into e+ (and e-) with ~ 50% polarization.

•The polarization of the positrons and photons will be measured.

• E-166 scheduled to run in Oct. 2004.

Hardware: Silicon calorimeters (U.Tennessee), Aerogel Cerenkov, Positron transport magnets (Princeton).