High-Accuracy Ring Laser Gyroscopes: Earth Rotation Rate and Relativistic Effects

8th Symposium on Frequency Standards and Metrology 2015

Beverini, N.^1,2 ; Virgilio, A. Di^2 ; Belfi, J.^2 ; Ortolan, A.^3 ; Schreiber, K.U.^4 ; Gebauer, A.^4 ; Klügel, T.^5

Department of Physics, Università di Pisa, Largo Pontecorvo 3, Pisa

I 56127, Italy^1

INFN, Sezione di Pisa, Largo Pontecorvo 3, Pisa

I 56127, Italy^2

INFN, Laboratorio Nazionale di Legnaro, Legnaro

I 35020, Italy^3

Forschungseinrichtung Satellitengeodäsie, Techn. Universität München, Germany^4

Bundesamt für Kartographie und Geodäsie, GO Wettzell, Germany^5

关键词: General Relativity;    International system;    Lense-thirring effect;    Long term stability;    Monolithic structures;    Relativistic effects;    Ring laser gyroscope;    Underground laboratory;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/723/1/012061/pdf
DOI  :  10.1088/1742-6596/723/1/012061

来源: IOP

【 摘 要 】

The Gross Ring G is a square ring laser gyroscope, built as a monolithic Zerodur structure with 4 m length on all sides. It has demonstrated that a large ring laser provides a sensitivity high enough to measure the rotational rate of the Earth with a high precision of ΔΩE-8. It is possible to show that further improvement in accuracy could allow the observation of the metric frame dragging, produced by the Earth rotating mass (Lense-Thirring effect), as predicted by General Relativity. Furthermore, it can provide a local measurement of the Earth rotational rate with a sensitivity near to that provided by the international system IERS. The GINGER project is intending to take this level of sensitivity further and to improve the accuracy and the long-term stability. A monolithic structure similar to the G ring laser is not available for GINGER. Therefore the preliminary goal is the demonstration of the feasibility of a larger gyroscope structure, where the mechanical stability is obtained through an active control of the geometry. A prototype moderate size gyroscope (GP-2) has been set up in Pisa in order to test this active control of the ring geometry, while a second structure (GINGERino) has been installed inside the Gran Sasso underground laboratory in order to investigate the properties of a deep underground laboratory in view of an installation of a future GINGER apparatus. The preliminary data on these two latter instruments are presented.