Simulated Response of the MARIO SCHENBERG Detector to Gravitational Wave Signals with Noise

The Mario Schenberg gravitational wave detector has been constructed at its site in the Physics Institute of University of Sao Paulo as programmed by the Brazilian Graviton Project under full financial support from FAPESP (the Sao Paulo State Foundation for Research Support). We are ready to do a first test run of the spherical antenna at 4.2 K with three parametric transducers and an initial target sensitivity of h ∼ 10-21 Hz-1/2 in a 60 Hz bandwidth around 3.2 kHz. We have built a computer code for determining the source direction and the wave polarization (solution of the inverse problem) in real time acquisition for strong signal-to-noise ratio cases. The digital filter used is a simple bandpass filter. The 'data' used for testing our code was simulated, it had both the source signal and detector noise. The detector noise includes the antenna thermal, back action, phase noise, series noise and thermal from transducer coupled masses. The simulated noise takes into account all these noise and the antenna-transducers coupling. The detector transfer function was calculated for a spherical antenna with six two-mode parametric transducers. Finally, we were able to check at what distance Schenberg would detected some known sources. Here we present the results of these simulations