Dose estimates when electrons strike a copper absorber during injection at the Canadian Light Source

Dose estimates are undertaken when injected electrons strike a tapered copper absorber of the insertion device beamline during injection at the Canadian Light Source (CLS). A model consisting of a tapered copper absorber, a wiggler vessel, a stainless steel beam pipe and a concrete ratchet and side wall is constructed. The doses immediately behind the ratchet wall are estimated by calculating the energy depositions in a water phantom that encloses the entire structure. Also estimated are the doses along the side wall and near the inner edge of the ratchet wall. The accumulated doses are calculated assuming various injection efficiencies to the storage ring and the number of electrons lost at the tapered copper absorber during injection. From these values, the dose rates are obtained with or without a local shield.