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The French-Italian interferometric gravitational wave detector VIRGO is currently being commissioned. Its principal instrument is a Michelson interferometer with 3 km long optical cavities in the arms and a power-recycling mirror. This paper gives an overview of the present status of the system. We report on the presently attained sensitivity and the(More)
We report the case of an 8-year-old boy, suffering from nocturnal pain localized on the left groin and presenting as a limp over several months. Examination revealed diminished strength of the left leg, atrophy of the thigh and calf, and a diminished deep tendon reflex. The pain could be intense and the patient had found an analgesic position by pushing on(More)
(Affiliations can be found after the references in the electronic version) ABSTRACT Aims. A transient astrophysical event observed in both gravitational wave (GW) and electromagnetic (EM) channels would yield rich scientific rewards. A first program initiating EM follow-ups to possible transient GW events has been developed and exercised by the LIGO and(More)
In the search for binary systems inspiral signal in interferometric gravitational wave detectors, one needs the generation and placement of a grid of templates. We present an original technique for the placement in the associated parameter space that makes use of the variation of size of the isomatch ellipses in order to reduce the number of templates(More)
We describe a model evaluating changes in the optical isolation of a Faraday isolator when passing from air to vacuum in terms of different thermal effects in the crystal. The changes are particularly significant in the crystal thermal lensing (refraction index and thermal expansion) and in its Verdet constant and can be ascribed to the less efficient(More)
PURPOSE To compare radiation dose and image quality between a slot-scanning system (SSS) and a dynamic flat-panel detector (DFD) in assessing scoliosis in children. METHODS An experimental study was first performed with a phantom to assess the quality of each device. The clinical part included a prospective observational dosimetric and qualitative(More)
In the search for binary systems inspiral signal in interferometric gravitational waves detectors, one needs the generation and placement of a grid of templates. We present an original technique for the placement in the associated parameter space, that makes use of the variation of size of the isomatch ellipses in order to reduce the number of templates(More)
In-vacuum Faraday isolators (FIs) are used in gravitational wave interferometers to prevent the disturbance caused by light reflected back to the input port from the interferometer itself. The efficiency of the optical isolation is becoming more critical with the increase of laser input power. An in-vacuum FI, used in a gravitational wave experiment(More)
We report an application of Kalman filtering to the inverted pendulum (IP) of the Virgo gravitational wave interferometer. Using subspace method system identification techniques, we calculated a linear mechanical model of Virgo IP from experimental transfer functions. We then developed a Kalman filter, based on the obtained state space representation, that(More)