1. A resonant mass detector is characterized by those eigenmodes having the appropriate
(quadrupole) symmetry
cylindrical bar
only one quadrupole mode interacts strongly with GWs
The cross section is dependent on the wave propagation
direction. The single output is a (unknown) combination
of the components (same for an interferometer)
sphere
five degenerate quadrupole modes (described using the basis of the
five spherical harmonics Y2m with m=±2,±1,0;
the same basis can be used to express hij in the equivalent
spherical components hm)
The cross section is omnidirectional
The five outputs determine the five parameters:
h+ hx H hs
Xylophone in its own (all spheroidal modes have high cross section)

2. Spherical detectors Transducer arrangement and deconvolution technique
Study of the coupling of resonant transducers with the sphere modes
on a realistic scale (miniGrail)
Fast cooling (miniGrail)
Study of the effect of cosmic rays at the Dafne Beam Test Facility (RAP)
Determination of the welding technique
Optimization of read-out
Study of the observatory capability

3. Large Spherical Detector
GOAL:
Large Spherical Detector
Detecting collapses and
200Mpc
Determining
Source direction
Chirp mass
A chirp signal excites the two
modes at different times.
This double passage technique
determines the chirp mass.

gw~ 10-9

4. Goal: Large hollow sphere
HOLLOW SPHERES
Can be realized in large dimensions - 4 to 6 meters diameter
Hz frequency
Ideal detector for coincidences and stochastic background searches with the advanced interferometer
Xylophone in its own (all spheroidal modes have high cross section)
Goal: Large hollow sphere
Collapses and
200Mpc
gw~ 10-9
D = 4.8 m;
f1=300 Hz;
f2=1000 Hz;
SQL