Laser interferometer for the precise alignment of a linear accelerator

Since the beam spot size reaches nanometers at a final focusing region in future linear colliders, vibration displacement must be suppressed to the order of nanometers, which will be called dynamic alignment hereafter. A technique involving laser interferometers allows such precise measurements of the displacements of accelerator components. In the alignment of linear accelerators, the most important quantity to be measured is transverse to the laser direction, which defines a reference line. In order to realize it, the possibility of using phase conjugate mirrors with a laser interferometer was investigated