Storage rings as detectors for relic gravitational-wave background ?

We argue that storage rings can be used for the detection of low-frequency gravitational-wave background. Proceeding from the measurements by Schin Date and Noritaka Kumagai (Nucl. Instrum. Meth. A421, 417 (1999)) and Masaru Takao and Taihei Shimada (Proceedings of EPAC 2000, Vienna, 2000, p.1572) of variations of the machine circumference of the SPring-8 storage ring we explain the systematic shrinkage of the machine circumference by the influence of the relic gravitational-wave background. We give arguments against a possibility to explain the observed shrinkage of the machine circumference of the SPring-8 storage ring by diastrophic tectonic forces. We show that the forces, related to the stiffness of the physical structures, governing the path of the beam, can be neglected for the analysis of the shrinkage of the machine circumference caused by the relic gravitational-wave background. We show the shrinkage of the machine circumference can be explained by a relic gravitational-wave background even if it is treated as a stochastic system incoming on the plane of the machine circumference from all quarters of the Universe. We show that the rate of the shrinkage of the machine circumference does not depend on the radius of the storage ring and it should be universal for storage rings with any radii.