Long term ground movement of TRISTAN synchrotron

The long-term ground movement was estimated in a geological survey done in connection with the siting of the TRISTAN-MR (main ring). The movement of the synchrotron magnet mainly results from the structure of the tunnel. If the movement of an individual magnet exceeds a certain threshold limit, it exerts a significant influence on the particle behavior in a synchrotron. The height of the quadrupole magnets was observed periodically during the past two years at the TRISTAN-MR, and the height differences along the 3-km circumference of the accelerator ring were expanded into the Fourier components depicting the causes of the movements. Results show the movement of the tunnel foundation, which was also observed from the simultaneous measurement of both magnets and fiducial marks on the tunnel wall.<>