ILC Positron Source Based on Laser Compton

Positron generation is one of the most difficult technical challenges among the ILC (International Linear Collider) subsystems. A positron source based on Laser Compton back scattering is an attractive and advanced option for the ILC positron source. Here, the positrons are generated, via the pair creation process, from high energy gamma rays which themselves are produced by Compton scattering of laser photons off a high‐energy electron beam. Polarized positrons can be generated by employing a circularly polarized laser. The positron polarization is easily controlled and switched by changing the laser polarity. The electron beam can be unpolarized. The required electron energy is only a few GeV (in contrast, the “undulator scheme”, another advanced option, requires at least 100 GeV or more) and the system can be prototyped and tested prior to the real construction. The laser Compton technology has many other applications like advanced X‐ray sources and a good synergy is expected. In addition, this technol...