|
Size: 1996
Comment:
|
Size: 1440
Comment:
|
| Deletions are marked like this. | Additions are marked like this. |
| Line 1: | Line 1: |
| == Arm Cavity Finesse == We will change the transmission of the ITMs from 0.5% to 1.4% to match the new AdvLIGO design. |
## page was renamed from Upgrade 08/Overview = Purpose of the upgrade = == Demonstration of the AdvLIGO interferometer technologies == === Prototyping of AdvLIGO LSC === * '''Lock acquisition''' * "Prove AdvLIGO LSC actually works" * '''Green laser locking''' * "Realize lock of the arms independently from the main beam" * "Achieve semi-deterministic lock & smooth handing off" * '''Noise mechanisms / DC readout''' * "Discover and/or confirm by a model RSE specific noise couplings" |
| Line 4: | Line 13: |
| We will also replace the MOS (with 1.25 kg masses) with SOSs. This is to increase the effect of radiation pressure. | === Tuned / Detuned RSE comparison === * "Address advantage and disadv. of the tuned/detuned configuration" * "Demonstrate smooth transition" |
| Line 6: | Line 17: |
| We will not fine-tune the coatings of the ITMs for cool dichroic properties unless some coating place gives us a <4 month lead time. | === RGC based digital control system === * "Demonstrate complicated LSC code on the connected multiple systems" * "Establish rapid prototyping methods with simulated plants on the processors" |
| Line 8: | Line 21: |
| == Modulation Frequencies == We will change the modulation frequencies from f1=33 MHz and f2 = 166 MHz to f1 = 9 MHz and f2 = 45 MHz. We will increase the length of the MC to accomodate this. |
== To do anything useful to make the AdvLIGO easier / faster == === DC&Dither technologies === * Offset lock and handoffs * AF WFS technique * "Develop and characterize various new useful techniques" |
| Line 11: | Line 27: |
| == Recycling Cavities == We will increase the length of the RCs to handle the lower modulation frequency. This will require 2 tip/tilt mirrors per cavity. These will be imperial, eddy current damped versions of the ANU tip/tilt mirrors. |
=== Interferometer Diagnosis === Cavity characterization using aux. laser injection "Provide a method of precise in-situ characterization of the interferometer" |
| Line 14: | Line 31: |
| Should we get new PR and SR or use what we have? (curvature, reflectivity). Maybe we should match the AdvLIGO Gouy phases. We will make the tip/tilts so that we can have a POP signal. We also keep POX & POY. == Mach Zender == We will not use a Mach Zender. We will use 2-3 EOMs in series or a UF Trimod if it shows up. == Control System Computers == We will have a big multi-core box to run all of the front ends. It will have fast fiber links to remote ADC/DACs. == Multi-wavelength Locking == Make wedges and coatings to accomodate multi-color locking if the lead time is reasonable. The beam from the end should not see the corner. == Optical Levers == Make a fiber based OL delivery scheme. Try to also make 40m long OLs by putting turning mirrors into the vacuum system. == Analog Electronics == === Suspensions === No change of the suspension analog electronics. We will have interface cards/connectors to go from new style ADC/DACs into the old analog electronics. === LSC === New RFPDs for the 9 & 45 MHz as well as 3*f1 (27 MHz). Maybe DD as well. == Cameras == We'll have GigE cameras and an all GigE backbone for all CDS connections. |
- Development / test bench of advanced technologies GigE CCD WFS technique Adaptive noise cancellation "Demonstrate how it works" "Understand and improve its limitations" |
Purpose of the upgrade
Demonstration of the AdvLIGO interferometer technologies
Prototyping of AdvLIGO LSC
Lock acquisition
- "Prove AdvLIGO LSC actually works"
Green laser locking
- "Realize lock of the arms independently from the main beam"
"Achieve semi-deterministic lock & smooth handing off"
Noise mechanisms / DC readout
- "Discover and/or confirm by a model RSE specific noise couplings"
Tuned / Detuned RSE comparison
- "Address advantage and disadv. of the tuned/detuned configuration"
- "Demonstrate smooth transition"
RGC based digital control system
- "Demonstrate complicated LSC code on the connected multiple systems"
- "Establish rapid prototyping methods with simulated plants on the processors"
To do anything useful to make the AdvLIGO easier / faster
DC&Dither technologies
- Offset lock and handoffs
- AF WFS technique
- "Develop and characterize various new useful techniques"
Interferometer Diagnosis
- Cavity characterization using aux. laser injection "Provide a method of precise in-situ characterization of the interferometer"
- Development / test bench of advanced technologies
- GigE CCD WFS technique Adaptive noise cancellation "Demonstrate how it works" "Understand and improve its limitations"