Calibration of the VIRGO central interferometer

Abstract

This paper describes the calibration procedures developed for the commissioning of the VIRGO central interferometer, as well as their main results obtained during the engineering runs that occurred during that phase. The issue of the detector response monitoring is also addressed, and a preliminary test to produce reconstructed data is reported.

Status of VIRGO

“…Several investigating groups have worked on specific data analysis issues: calibration [20], locking [21], alignment and suspension performance [17], environmental noises [22], laser noises, photodiode readout noise, glitch identification [23], line noise characterization [24], noise stationarity and Gaussianity [25]. These activities helped to better characterize the instrument [26], and also contributed inputs and feedback for the development of the collaboration analysis tools.…”

Measurements of Superattenuator seismic isolation by Virgo interferometer

“…The integration time of all the experiments is the second column of Tables 1 and 2. The Virgo calibration which allows to translate the photodiode signal (in W) into the differential mirror displacement (in m) has an uncertain not exceeding 10% in the entire detection band [26,27]. A similar error affects the calibration of the Inertial Damping accelerometers, used to measure the top stage displacement.…”

Data quality studies for burst analysis of Virgo data acquired during Weekly Science Runs

“…When the reconstruction [7] of the calibrated gravitational channel (h) fails because the calibration lines are too weak, then the h signal, used by the detection algorithm, is missing; so we have holes in the data to be analyzed. • During white noise injections (for calibration purposes) h is not reconstructed.…”