Ginger Status Report

The GINGER project is based on ring lasers and is under construction at the underground Gran Sasso laboratories, as part of the underground geophysical obser- vatory of Gran Sasso (UGGS). Large frame ring lasers are top sensitivity instruments to measure angular rotation rate, in particular when attached to the Earth crust they can measure with very high precision the Earth angular velocity. This kind of measurements when the precision is of the order of 1 part in 109, are certainly relevant for geophysics and geodesy, for instance to measure the fast variation of the length of Day (LoD), but are also relevant for fundamental physics, since are affected by de Sitter and Lense-Thirring effects and can be used to investigate Lorentz’s violations. Ring lasers ensure long-term continuous operation with record sensitivity. The limit of 1 part in 109 of the Earth’s rotation rate has already been demonstrated, and recent sensitivity study has shown that the ring laser shot noise limit is at least a factor 10 better than expected. GINGER and its status report will be described.