OPTIMIZATION OF THE ee OPTION FOR THE ILC

The e−e− running mode is one of the interesting physics options at the International Linear Collider (ILC). The luminosity for e−e− collisions is reduced by the beam-beam effects. The resulting beamstrahlung energy loss and beambeam deflection angles as function of the vertical transverse offset are different compared to the ee collisions. In this paper, the dependence of these observables with the offset for different beam sizes has been analyzed to optimize performances for the e−e− mode, taking into account the requirements of the beam-beam deflection based intra-train feedback system. A first study of the implications for the final focus and extraction line optics is also presented for the cases of the 20 mrad and 2 mrad ILC base line crossing angle geometries.