Transcript No Slide Title

STREGA kick-off meeting, 11-12 May 2004, Cascina
Introduction
T3 Development of selective read out schemes
T3 considers two aspects of the thermal noise
•The problem of the interrogation area of the test mass.
Small interrogation area means large fluctuations
because of the higher modes contribution
An average over higher order modes is needed
==> Wide area transducers
•The problem of the rejection of the non quadrupolar
modes.
These modes do not carry signal information but can
spoil the detector bandwidth
•Suitable arrangement and connections of the transducers
on the detector can reduce these effects
•Techniques to achieve a fine balancing of the sensitivity
of the transducers are needed.
STREGA kick-off meeting, 11-12 May 2004, Cascina
Introduction
T3 Development of selective read out schemes
DUAL resonant mass detector concept
Nested high cross section resonators
spheres or cylinders
M. Cerdonio et al., Phys. Rev. Lett. 87 (2001) 031101
M. Bonaldi et al., Phys. Rev. D 68 (2003) 102004
STREGA kick-off meeting, 11-12 May 2004, Cascina
Introduction
T3 Development of selective read out schemes
DUAL resonant mass detector concept
No resonant transducers
measurement of the differential motion
of the resonators
STREGA kick-off meeting, 11-12 May 2004, Cascina
Introduction
T3 Development of selective read out schemes
DUAL resonant mass detector concept
Selective read out
measured quantity: X = x1+x2-x3-x4
STREGA kick-off meeting, 11-12 May 2004, Cascina
Introduction
T3 Development of selective read out schemes
DUAL resonant mass detector concept
Mechanical amplifier
F
F
Displacement Gain Factor >10
First internal resonance > 5 kHz
Optical or Capacitive or Microwave readout
STREGA kick-off meeting, 11-12 May 2004, Cascina
Introduction
T3 Development of selective read out schemes
The T3 issues will be faced by
•studying, designing and if possible
realizing transducer prototypes based on
three displacement transduction methods:
optical, capacitive, and microwave.
•evaluating, also with FEM analysis, the
noise of a DUAL detector which employs
one or more of these transduction
methods
Groups involved
•CNRS (LKB Paris)
•IFN (Trento)
•INFN (AURIGA LNL Legnaro, PACO
Genoa, LENS Florence)