A conventional positron source for International Linear Collider
  A possible solution to realize a conventional positron source driven by a several-GeV electron beam for the International Linear Collider is proposed. A 300 Hz electron linac is employed to create positrons with stretching pulse length in order to cure target thermal load. ILC requires about 2600 bunches in a train which pulse length is 1 ms. Each pulse of the 300 Hz linac creates about 130 bunches, then 2600 bunches are created in 63 ms. Optimized parameters such as drive beam energy, beam size, and target thickness, are discussed assuming a L-band capture system to maximize the capture efficiency and to mitigate the target thermal load. A slow rotating tungsten disk is employed as positron generation target. 
Tsunehiko Omori, Tohru Takahashi, Sabine Riemann, Wei Gai, Jie Gao,   Shin-ichi Kawada, Wanming Liu, Natsuki Okuda, Guoxi Pe...
physics.acc-ph