Aligning the World’s Largest Gas Electron Multipliers (GEMs) Rotator at Thomas Jefferson National Accelerator Facility

Gas Electron Multipliers (GEMs) are sensors originally developed at CERN, which measure precise positional data of passing electrons. Thomas Jefferson National Accelerator Facility (Jefferson Lab) will install the world’s largest GEM rotator in Experimental Hall A for the MOLLER experiment. The GEM sensors must be aligned around the beam line, requiring six degrees of freedom (6DOF). This paper details the engineering design of the GEM rotator alignment system using Siemens NX. The alignment system is then structurally analyzed using ANSYS Finite Element Analysis. Our GEM rotator alignment system achieved 6DOF and met structural integrity standards. Finally, a drawing package was created to specify the design before manufacturing.