Numerical Simulations to Evaluate the Performance of CERN PS Dummy Septum to Reduce Irradiation for the Multi-Turn Extraction

The losses created by the proposed Multi-Turn Extraction (MTE) at the CERN PS induce high activation of the magnetic extraction septum due to the de-bunched longitudinal beam structure requested to transfer the beam to the SPS. A mitigation measure is under study aiming at localizing the losses in a well-shielded area by shadowing the magnetic extraction septum thanks to a septum-like passive device. Such a solution is based on a so-called dummy septum, a blade which absorbs particles during the rise time of the extraction kickers for MTE beams. The efficiency of the scheme is presented in this paper. The quantitative estimate is based on detailed simulations that analyze the beam-matter interaction and provide a determination of the shadowing effect of the dummy septum.