Task M2 – Working group Auriga-LNLTask M2 – Working group Auriga-LNL

• Operation temperature 0.02-Operation temperature 0.02-300K300K

• Mechanical Attenuation Mechanical Attenuation >180dB in the frequency range >180dB in the frequency range 200-1600 Hz200-1600 Hz

Sub-task: Construction of optical transducer

Present statePresent state

•Cryogenic Test facilityCryogenic Test facility

•Optical readout (now Optical readout (now available)available)

Task M2 – Working group Auriga-LNLTask M2 – Working group Auriga-LNL

Q-Measurements results at Q-Measurements results at 4.2K4.2K

Mode #1: 908 HzMode #1: 908 Hz

Mode #2: 1479 HzMode #2: 1479 Hz

Read-out schemeRead-out scheme

•Mode#1 Q=106

•Mode#2 Q=5.3 x 106

Task M2 – Working group Auriga-LNLTask M2 – Working group Auriga-LNL

First 18 months (starting First 18 months (starting now)now)

Four yearsFour years

1. Room temperature optical bench S<10-5 Hz2/Hz @1kHz

2. Motorized optics mounts for cryogenic alignment

3. Operation at cryogenic temperature

1. Improvement of the mirrors properties: Finesse >105, Al2O3 mirrors

2. Achievement of goal sensitivity to gw (Shh ~10-22 Hz-1/2 )

Task M2 – Working group Auriga-LNLTask M2 – Working group Auriga-LNL

Sub-task:

Present statePresent state

1. k, Q measurements at low T

2. Construction of resonators of CuAl, SiC Be..

1. Cryogenic test facility

2. Optical readout for cryogenic Q-measurements

First 18 months (starting now)First 18 months (starting now)1. Design and construction of the resonators in the kHz region

2. Modification of the cryogenic suspensions to preserve Q

3. Measurements of Q and k at low T

Last time (months 19-24)Last time (months 19-24)

Conclude low temperature measurements

Task M2 – Working group Auriga-LNLTask M2 – Working group Auriga-LNL

Sub-task: Improving fabrication process

Present statePresent state

First 18 months (staring month First 18 months (staring month 12)12)

Last years (months 13-36)Last years (months 13-36)

Cryogenic test facility and optical readout for the Q-measurements

1. Assembling transducer and resonators using different joining procedures as silicate bonding

2. Q-measurement after bonding (kHz region) beginning

1. Low temperature Q and k-measurement after bonding

2. Comparison of the results with the single piece machined resonators

Task M2 – Working group Auriga-LNLTask M2 – Working group Auriga-LNL

Other collaborations with the working groups of the task1. IFN->Limiting bias electric field in the capacitive

transducer and effect of dieletric coating on the thermal noise.

2. ROG,Leiden->Capacitive transducer.

3. All->writing up the final report.