Speaker
Description
In the context of the Physics Beyond Colliders Project, a QCD facility named AMBER/NA66 was developed as a successor of the COMPASS experiment. AMBER is located in the surface hall EHN2 in the CERN SPS North Area. The approved physics program of AMBER includes, amongst others, measurements of the pion-induced Drell-Yan process. This process shall be studied with a high-intensity 190 GeV/c pion beam impinging on a tungsten and several carbon targets followed by a 2.2 m-long absorber. A total of 3.07×10^14 pions on target per year shall be reached. This corresponds to a beam intensity increase by 68% with respect to the previous COMPASS Drell-Yan run. During the latter, the annual dose at a nearby environmental monitoring station close to the CERN fence reached 76% of the annual limit of 1 mSv. A radiation survey inside of the EHN2 hall and in its direct vicinity further allowed identifying several locations with elevated radiation levels.
To increase the beam intensity delivered to EHN2 while staying compliant with CERN’s radiation protection code regarding doses to personnel and members of the public, detailed studies for improving the shielding around the AMBER target area and along the M2 beam line were performed. These studies include the evaluation of the prompt dose rates in the accessible areas of EHN2 and next to it, at the CERN fence and at the surrounding publicly accessible places. In addition, the residual dose rates inside of the target area were evaluated for different cooling times to determine adequate access requirements. Finally, the air activation inside the EHN2 hall and the exposure of members of the public due to air releases into the environment were assessed. The studies were performed with the FLUKA Monte Carlo particle transport code and the ActiWiz Creator tool.