Colliding Beams Focus Displacement Caused by Seismic Events

The Earth surface inclinations recorded by the Precision Laser Inclinometer have been transformed to vertical oscillations using a specifically developed method. A method to calculate the space displacement of collider beams focuses is proposed to evaluate the effects of the surface waves propagation, taking into account: the length of the region of the beam focusing for collisions, the seismic wave frequency and the wave speed dependence on the frequency. It is shown that the beams focus divergence is measurable: for the LHC, with a 40-m long beam focusing path for collisions, in the frequency range above 1 Hz for the seismic surface wave; for the CLIC (first stage), with a 1.9-km long beam focusing path for collision, in the frequency range [0.1 Hz, 0.5 Hz], typical range of the micro-seismic peak. The data obtained shows the necessity of monitoring the seismic activity by using a network of Precision Laser Inclinometers.