Task M2 – Working group Auriga-LNL

1. Task M2 – Working group Auriga-LNL Sub-task: Construction of optical transducer Present state • Cryogenic Test facility • Operation temperature 0.02-300K • Mechanical Attenuation >180dB in the frequency range 200-1600 Hz • Optical readout (now available)

2. Task M2 – Working group Auriga-LNL Mode #1: 908 Hz Mode #2: 1479 Hz Read-out scheme Q-Measurements results at 4.2K • Mode#1 Q=106 • Mode#2 Q=5.3 x 106

3. Task M2 – Working group Auriga-LNL First 18 months (starting now) • Room temperature optical bench Snn<10-5 Hz2/Hz @1kHz • Motorized optics mounts for cryogenic alignment • Operation at cryogenic temperature Four years • Improvement of the mirrors properties: Finesse >105, Al2O3 mirrors • Achievement of goal sensitivity to gw (Shh ~10-22 Hz-1/2 )

4. Task M2 – Working group Auriga-LNL Sub-task: • k, Q measurements at low T • Construction of resonators of CuAl, SiC Be.. Present state • Cryogenic test facility • Optical readout for cryogenic Q-measurements First 18 months (starting now) • Design and construction of the resonators in the kHz region • Modification of the cryogenic suspensions to preserve Q • Measurements of Q and k at low T Last time (months 19-24) Conclude low temperature measurements

5. Task M2 – Working group Auriga-LNL Sub-task: Improving fabrication process Present state Cryogenic test facility and optical readout for the Q-measurements First 18 months (staring month 12) • Assembling transducer and resonators using different joining procedures as silicate bonding • Q-measurement after bonding (kHz region) beginning Last years (months 13-36) • Low temperature Q and k-measurement after bonding • Comparison of the results with the single piece machined resonators

6. Task M2 – Working group Auriga-LNL Other collaborations with the working groups of the task • IFN->Limiting bias electric field in the capacitive transducer and effect of dieletric coating on the thermal noise. • ROG,Leiden->Capacitive transducer. • All->writing up the final report.