Efficient propagation of the polarization from laser photons to positrons through Compton scattering and electron-positron pair creation

TL;DR

This paper reports the first experimental demonstration of producing highly polarized short-pulse positrons via a novel two-quantum process involving inverse Compton scattering and pair creation, achieving significant polarization levels.

Contribution

It introduces a new scheme for polarization transfer from laser photons to positrons using two-quantum processes, validated by experimental results.

Findings

Produced polarized positrons with 73% polarization.

Achieved positron intensity of 10^4 e+/bunch.

Demonstrated the scheme's feasibility for polarized positron generation.

Abstract

We 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 scatterings and electron-positron pair creations. Using a circularly polarized laser beam of 532 nm scattered off a high-quality electron beam with the energy of 1.28 GeV, we obtained polarized positrons with an intensity of 10^4 e+/bunch. Magnitude of positron polarizations was determined as 73+-15(sta) +-19(sys)% by means of a newly designed positron polarimeter.