Simulation of Gravitational Radiation Antennas

The large complexity associated with the design of spherical resonant mass <A HREF=http://www.wins.uva.nl/research/pscs/projects/ Grail.html>gravitational radiation</A> antennas, necessitates the use of reliable simulation tools, that can accurately predict consequences of specific design choices. For this purpose, we have implemented three different methods; an analytical solution for the displacement field in spherical homogeneous objects, a method utilizing a polynomial expansion of this same displacement field, which is suitable for more complex shaped objects, and a finite element simulation. It is shown that the latter method is best suited to answer critical design issues, whereas the first two can serve as a calibration for the finite element simulation. Since the computational complexity of the finite element kernel requires significant computing power, it has been tailored for execution on <A HREF=http://www.wins.uva.nl/research/pscs/>parallel</A> computer systems. The simulation program is used to model the influences on the frequency spectrum of the antenna, resulting from varying important design parameters, like the size, material, suspension system and read-out system. Furthermore, we simulate the antenna's response to seismic and thermal noise, cosmics and gravitational radiation.