strawman red caltech - physics.gla.ac.uk
TRANSCRIPT
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Overview
Stefan Hild Slide 2 Strawman Caltech, Jan 2012
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Task description
Stefan Hild Slide 3 Strawman Caltech, Jan 2012
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Some working assumptions
Stefan Hild Slide 4 Strawman Caltech, Jan 2012
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To avoid misunderstandings …
Stefan Hild Slide 5 Strawman Caltech, Jan 2012
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Suspension Thermal Noise
Boosted aLIGO Quad with 1.2m long last stage and 160kg test masses.
Stefan Hild Slide 6 Strawman Caltech, Jan 2012
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Suspension Thermal Noise
Stefan Hild Slide 7 Strawman Caltech, Jan 2012
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Suspension R&D
Stefan Hild Slide 8 Strawman Caltech, Jan 2012
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Newtonian Noise
Stefan Hild Slide 9 Strawman Caltech, Jan 2012
Used seismic from:
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Newer data from LLO
Stefan Hild Slide 10 Strawman Caltech, Jan 2012
New data from LLO seem to suggest that Strawman red underestimates the GGN level by about a factor 2. Work in progress!
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Seismic barrages
2D finite-difference time-domain simulations for barrages of 40x40m.
Attenuation of seismic by about a factor 2.
Stefan Hild Slide 11 Strawman Caltech, Jan 2012
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Coating Brownian noise
Stefan Hild Slide 12 Strawman Caltech, Jan 2012
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Increasing the beam size
Assume an increase of beam size by a factor 1.6.
Keep aspect ratio of test masses as it is => 160kg.
Stefan Hild Slide 13 Strawman Caltech, Jan 2012
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Optical coatings with reduced thermal noise
Continued improvement of tantala coatings. Loss related to local atomic structure of material
High-temperature annealing of coatings. Heat treatment in the range of 500-1000 degrees centigrade
Amorphous silicon as a high-index coating material n=3.5 => quarter-wave layer is thinner. In addition need fewer layers. Potential improvement = 4.6 Requires change of laser wavelength
Crysatalline coatings (AlGaAs)
Stefan Hild Slide 14 Strawman Caltech, Jan 2012
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Khalili cavities
Stefan Hild Slide 15 Strawman Caltech, Jan 2012
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Khalili cavities
Extremely hardware intensive.
Lots of technical challenges: Thermal lensing Cavity stability Control
Stefan Hild Slide 16 Strawman Caltech, Jan 2012
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Thermal lensing in K-cavity
Stefan Hild Slide 17 Strawman Caltech, Jan 2012
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Waveguide mirrors
Stefan Hild Slide 18 Strawman Caltech, Jan 2012
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Quantum noise
Stefan Hild Slide 19 Strawman Caltech, Jan 2012
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Squeezing losses
Stefan Hild Slide 20 Strawman Caltech, Jan 2012
= 9% in total
Cavity losses in literature
Assuming losses are independent of cavity length
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Speedmeter an alternative?
Stefan Hild Slide 21 Strawman Caltech, Jan 2012
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Strawman Red Costs
Stefan Hild Slide 22 Strawman Caltech, Jan 2012
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Stefan Hild Slide 23 Strawman Caltech, Jan 2012
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Stefan Hild Slide 24 Strawman Caltech, Jan 2012
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Overview
Stefan Hild Slide 25 Strawman Caltech, Jan 2012
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For details please see document on the DCC:
https://dcc.ligo.org/cgi-bin/private/DocDB/ShowDocument?docid=78100
Stefan Hild Slide 26 Strawman Caltech, Jan 2012