摘要
In the recent years, the idea for undulator based positron source had became a current design for internationallinear collider (ILC). This design is that the beam from the electron main linac passes through a long helical undu-lator to generate a highly polarized and multi-Mev photon beam which hits a thin metal rotating target to generateshowers of positron[1]. In this progress, the multi-Kev energy deposition will heat target and then damage therotating target system[2].
