LIGO III: Blue Concept
description
Transcript of LIGO III: Blue Concept
![Page 1: LIGO III: Blue Concept](https://reader036.fdocument.org/reader036/viewer/2022081513/56813bf1550346895da52807/html5/thumbnails/1.jpg)
LIGO III: Blue Concept
Rana Adhikari for the Blue TeamG1200573-v1
Where do we come from?What are we?
Where are we going?-- Paul Gauguin
Where do we come from?What are we?
Where are we going?-- Paul Gauguin
![Page 2: LIGO III: Blue Concept](https://reader036.fdocument.org/reader036/viewer/2022081513/56813bf1550346895da52807/html5/thumbnails/2.jpg)
2
![Page 3: LIGO III: Blue Concept](https://reader036.fdocument.org/reader036/viewer/2022081513/56813bf1550346895da52807/html5/thumbnails/3.jpg)
3
![Page 4: LIGO III: Blue Concept](https://reader036.fdocument.org/reader036/viewer/2022081513/56813bf1550346895da52807/html5/thumbnails/4.jpg)
“Advanced”LIGO
![Page 5: LIGO III: Blue Concept](https://reader036.fdocument.org/reader036/viewer/2022081513/56813bf1550346895da52807/html5/thumbnails/5.jpg)
LIGO IIIVirgo IIIKAGRA+
λ = 1.5-2.1 μm
![Page 6: LIGO III: Blue Concept](https://reader036.fdocument.org/reader036/viewer/2022081513/56813bf1550346895da52807/html5/thumbnails/6.jpg)
BNS horizon = 1.3 Gpc
![Page 7: LIGO III: Blue Concept](https://reader036.fdocument.org/reader036/viewer/2022081513/56813bf1550346895da52807/html5/thumbnails/7.jpg)
Design Elements FD Squeezing Input is the winner
Coatings: AlGaAs, AlGaP, AlGaN,
AlGaSb,...
Quad SUS w/ Si ribbons on last stage
120-160 kg mass: Si @ 119-121 K
Si: High power (3 MW in arms)
1555-2222 nm laser; P = 444 W
10-30x Newtonian Noise sub.
![Page 8: LIGO III: Blue Concept](https://reader036.fdocument.org/reader036/viewer/2022081513/56813bf1550346895da52807/html5/thumbnails/8.jpg)
Why Crystal Mirror Coatings?
Why a ratio of 104 in dissipation?Why a ratio of 104 in dissipation?
R.O. Pohl, et al., Rev. Mod. Phys. (2002)R.O. Pohl, et al., Rev. Mod. Phys. (2002)
2-level tunneling model2-level tunneling model
W.A. Phillips, Rep. Prog. Phys. (1987)W.A. Phillips, Rep. Prog. Phys. (1987)
- Nearly all high quality optical coatings use amorphous oxides.
- Nearly all amorphous materials have a (low Q) large internal friction.
- Nearly all high quality optical coatings use amorphous oxides.
- Nearly all amorphous materials have a (low Q) large internal friction.
![Page 9: LIGO III: Blue Concept](https://reader036.fdocument.org/reader036/viewer/2022081513/56813bf1550346895da52807/html5/thumbnails/9.jpg)
Xylophone Concept is
totally WrongXylophone Concept: (Cold / Low
Power / Low f) + (Hot / High Power / High f)
THE REAL high power limit is thermal distortion: limited by thermal conductivity (k)
ksilica = 1.4 ksilicon @ 120 K = 500
Low Radiation Pressure
Low Shot Noise
150 kg Silicon:- Sigg/Sidles: OK- PI: not so bad
- RPN: usual
150 kg Silicon:- Sigg/Sidles: OK- PI: not so bad
- RPN: usual
![Page 10: LIGO III: Blue Concept](https://reader036.fdocument.org/reader036/viewer/2022081513/56813bf1550346895da52807/html5/thumbnails/10.jpg)
R. Weiss,LIGO-T1200093-v1
![Page 11: LIGO III: Blue Concept](https://reader036.fdocument.org/reader036/viewer/2022081513/56813bf1550346895da52807/html5/thumbnails/11.jpg)
RadiativeCooling Onlyi.e. no fibercooling reqd
![Page 12: LIGO III: Blue Concept](https://reader036.fdocument.org/reader036/viewer/2022081513/56813bf1550346895da52807/html5/thumbnails/12.jpg)
Juicy Research Opportunities Develop Si ribbons & blades
Need reliable Absorption meas. @ 1500-2000 nm @
120 K
AlGaX coatings on Silicon are unproven
Develop a 500 W laser at 1500-2000 nm
Cryogenics for 77-130 K
Si: High power (3 MW in arms)
30x Newtonian Noise subtraction