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P. Marsili

Publications and source records attributed to P. Marsili.

3 recordsLinked to original sources

First results of a high sensitivity and transportable Ring Laser Gyroscope

Within the GINGER project, aimed at installing an array of large frame ring laser gyroscopes for fundamental physics tests and as part of a geophysics observatory located in the underground laboratory at Gran Sasso, Italy (LNGS-INFN), we are developing a ring laser gyroscope design to reduce spurious rotation of instrumental origin and the ability to extend the cavity side length from 1.5 up to 5 m, thanks to the implementation of suitable spacers. The new design led to a prototype, called TRIO, with a side length of 1.52 m, conceived as a transportable instrument. The present paper reports on several preliminary measurements of the Earth angular velocity carried out with TRIO. Results have the twofold objective to assess the instrument performance in the present geometrical configuration and to test validity of the design in view of the GINGER project. To this aim, data obtained with TRIO are compared with typical data acquired with other, previously made, gyroscope prototypes, including the large frame GINGERINO already in operation at the Gran Sasso underground site.

physics.ins-det

Overcoming 1 part in $10^9$ of Earth angular rotation rate measurement with the G Wettzell data

The absolute measurement of the Earth angular rotation rate with ground-based instruments becomes challenging if the 1 part in $10^9$ of precision has to be obtained. This threshold is important for fundamental physics and for geodesy, to investigate effects of General Relativity and Lorentz violation in the gravity sector and to provide the fast variation of the Earth rotation rate. High sensitivity Ring Laser Gyroscopes (RLG) are currently the only promising technique to achieve this task in the near future, but their precision has been so far limited by systematics related to the laser operation. In this paper we analyze two different sets of observations, each of them three days long. They were obtained from the G ring laser at the Geodetic Observatory Wettzell. The applied method has been developed for the GINGERINO ring laser in order to identify and extract the laser systematics. For the available data sets the residuals show mostly white noise behavior and the Allan deviation drops below 1 part in $10^9$ after an integration time of about $10^4$~s.

physics.geo-ph

A high sensitivity tool for geophysical applications: A geometrically locked Ring Laser Gyroscope

This work demonstrates that a middle size ring laser gyroscope (RLG) can be a very sensitive and robust instrument for rotational seismology, even if it operates in a quite noisy environment. The RLG has a square cavity, $1.60\times 1.60$ m$^2$, and it lies in a plane orthogonal to the Earth rotational axis. The Fabry-Perot optical cavities along the diagonals of the square were accessed and their lengths were locked to a reference laser. Through a quite simple locking circuit, we were able to keep the sensor fully operative for 14 days. The obtained long term stability is of the order of 3~nanorad/s and the short term sensitivity close is to 2~nanorad/s$\cdot$Hz$^{-1/2}$. These results are limited only by the noisy environment, our laboratory is located in a building downtown.

physics.ins-det