Optimization of a high-intensity positron source

The positron source of a future high-energy e+e- collider is challenging due to the high luminosity requests. Therefore CLIC as well as the International Linear Collider (ILC) have a design for an undulator based positron source, using an helical undulator and producing a high number of circularly polarized photons. However such a high number of photons generate a high thermic stress on the target material producing the required high number of positrons. This talk is about a mathematical study on the radiation behaviour of a helical undulator based on the equation for the radiated synchrotron energy spectral density per solid angle per electron in the relativistic, far field and pointlike charge approximation. From this starting point the resulting following undulator properties were examined: the deposited power in the undulator vessel, which can disrupt the functionality of the undulator's electromagnets, the protective property of a mask on this disturbance and the number of positrons produced by the synchrotron radiation in a Ti-6%Al-4%V target. Those quantities were calculated for various values for parameters like the undulator period, undulator length and the magnetic flux.