title: Efficient propagation of polarization from laser photons to positrons through compton scattering and electron-positron pair creation.
abstract: We have demonstrated for the first time the production of highly polarized short-pulse positrons with a finite energy spread in accordance with a new scheme that consists of two-quantum processes, such as inverse Compton scattering and electron-positron pair creation. Using a circularly polarized laser beam of 532 nm scattered off a high-quality, 1.28 GeV electron beam, we have obtained polarized positrons with an intensity of 2 x 10(4) e+ /bunch. The magnitude of positron polarization has been determined to be 73 +/- 15(stat) +/- 19(syst)% by means of a newly designed positron polarimeter.
authors.affiliation: KEK: High Energy Accelerator Research Organization, Tsukuba-shi, Ibaraki 305-0801, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Omori
authors.forename: M
authors.initials: M
authors.lastname: Fukuda
authors.forename: T
authors.initials: T
authors.lastname: Hirose
authors.forename: Y
authors.initials: Y
authors.lastname: Kurihara
authors.forename: R
authors.initials: R
authors.lastname: Kuroda
authors.forename: M
authors.initials: M
authors.lastname: Nomura
authors.forename: A
authors.initials: A
authors.lastname: Ohashi
authors.forename: T
authors.initials: T
authors.lastname: Okugi
authors.forename: K
authors.initials: K
authors.lastname: Sakaue
authors.forename: T
authors.initials: T
authors.lastname: Saito
authors.forename: J
authors.initials: J
authors.lastname: Urakawa
authors.forename: M
authors.initials: M
authors.lastname: Washio
authors.forename: I
authors.initials: I
authors.lastname: Yamazaki