Photon generation by laser-Compton scattering at the KEK-ATF

TL;DR

This study demonstrates photon generation via laser-Compton scattering at KEK-ATF, achieving high photon yields by synchronizing laser pulses with electron beams, advancing polarized positron source development for linear colliders.

Contribution

First successful synchronization and photon production using laser-Compton scattering at KEK-ATF with high repetition rate laser pulses.

Findings

Achieved 26 photons per electron-laser pulse crossing.

Produced 10^8 photons per second.

Enhanced laser power by up to 250 times in the optical cavity.

Abstract

We performed a photon generation experiment by laser-Compton scattering at the KEK-ATF, aiming to develop a Compton based polarized positron source for linear colliders. In the experiment, laser pulses with a 357 MHz repetition rate were accumulated and their power was enhanced by up to 250 times in the Fabry-Perot optical resonant cavity. We succeeded in synchronizing the laser pulses and colliding them with the 1.3 GeV electron beam in the ATF ring while maintaining the laser pulse accumulation in the cavity. As a result, we observed 26.0 +/- 0.1 photons per electron-laser pulse crossing, which corresponds to a yield of 10^8 photons in a second.