Exit positions of beam were calculated as a function of the injected ones. For an example, the non-linear effect took effect at larger injected offset than 350um (about 11 sigmax). Such large offset could be realized in a beam halo (dark current etc.).
There were suggestions as follows; The k2 should be distributed with a Gaussian-sigma of k2/k1= 0.001/Ro. Results should be presented in a phase space for various beam halos.
(2) Beam dump ( T. Tauchi and N. Delerue )
Tauchi and Nicolas investigated the beamstrahlung photon dump with a separated beam dump. Characteristics of beamstrahlung photons have been analyzed by CAIN. Total energy is the largest in case of collisions with large offsets between two beams, which is +/- 6 ~ 10 sigmay. So, the photons would be produced even if luminosity is practically zero. The dump must be designed with this largest energy deposit (1.5 times of head-on collision's energy) and beam energy of 500GeV.