We are in the process of preparing a cleaning of ETMY. Even so, it is not conclusive, ETMY has a clear problem as indicated by the green ring type absorption pattern which is thought to be due to first contact material left behind. At least 2 of the bright spots are extended and do not look like single point defects. A vent in EY is planned to start Monday next week. The opening of HAM1 has been delayed to next week as well to allow us to keep working with the Y-arm this week. Since we do not want to "bake" contaminants to the TMs, we decided to postpone any locking attempts and instead concentrate on a couple of task which previously had second priority.
Here is the list of commissioning task for the next 7-14 days:
Y-arm loss investigation:
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Make another wider scan on ETMY.
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Make a similar scan on ETMX.
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Try to understand the ITMY scan.
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Ring down measurements.
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Mode matching measurements.
Seismic:
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Investigate why the LHO performance is still lagging behind the LLO one.
Length team:
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Characterize PRMI power build-ups.
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RFAM measurements (including a EOM bias voltage).
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Measurement of the Schnupp asymmetry using the aux. laser on IOT2R.
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A good set of RFAM length measurements.
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Commission updated tidal compensation/length relief strategy.
Alignment team:
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DMRI WFS: add SRM alignment loops.
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Make EY green WFS work again.
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Add triggers to the auto-centering system, so it can be engaged automatically.
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Add a "bleed" feature to the auto-centering system, so it automatically resets when it looses the beam.
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Commission an arm alignment controls topology which can be used for initial alignment.
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Integrate green WFS into initial alignment.
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Revise initial alignment scheme.
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Investigate the temperature dependence of the TM orientation (T step in EX with cavity locked).
Miscellaneous:
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Fine tune Michelson contrast defect using ITMY TCS/CO2 laser.
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Set up the HWS to check the thermal lens.
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Investigate the long-term alignment stability of the mode cleaner ISS.
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Add an "ISS engaged" state to the IMC guardian.
RF:
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Revive the EOM driver.
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Make an assessment of RF cross talk into the IMC AOM.
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Investigate EMI radiation by the VCOs and the fixed frequency OCXO.