LIGO Document E1300917-v1
- L1 SUS ITMY Acceptance Documentation
ACTION (Janeen) - Top Level Quad assembly, generic quad assembly and specific optic assembly all need work. This is now with Eddie Sanchez (and Janeen) ALL updates will be covered via DCN E1300970 and signed off by SUS and SYS.
Committee and committee chair calling this closed. Any remaining items / actions will be passed to punch list.
Punchlist items and their resolution will be tracked in T1400181. They will not be updated on this Acceptance Document filecard.
- I. Committee (* indicates review chair)
Rich Abbott, Alastair Heptonstall, Calum Torrie*, Jeff Lewis, Fabrice Matichard, Celine Ramet.
II. Documents for Review (against list from M1100282)
Top Assembly Name:
https://dcc.ligo.org/LIGO-D0900445 AdvLIGO SUS BSC1-L1, XYZ Local CS for ITMY
ICS Assembly #:
- ICS Assembly Load:
This filecard serves as the acceptance document for L1-ITMY.
For common material for all QUAD suspensions, see
The electronics for L1 SUS ITMY can be found in the racks
- Calibrated, M0toM0 Transfer Functions (DAMPING ON/OFF): https://alog.ligo-la.caltech.edu/aLOG/index.php?callRep=8625
- Calibrated, R0toR0 Transfer Functions (DAMPING ON/OFF): https://alog.ligo-la.caltech.edu/aLOG/index.php?callRep=8625
The ~1.45 Hz R0 Pitch mode is shifted from the model due to cable routing stiffening the suspension. L1ITMY has the ESD cables cut, whereas they remain intact for L1ITMX, likely attributing to the difference in the frequency shift of this pitch mode between L1 ITMs.
- Calibrated, L1toL1 and L2toL2 Transfer Functions (DAMPING ON/OFF): Lower stages are not in the scope of this acceptance review, therefore not included here.
- Good example of Calibrated OSEM Sensor ASDs, All Stages (DAMPING ON/OFF): https://alog.ligo-la.caltech.edu/aLOG/index.php?callRep=10154
- Bad example of Calibrated OSEM Sensor ASDs, due to ground loop induced noise, All Stages (DAMPING ON/OFF): https://alog.ligo-la.caltech.edu/aLOG/index.php?callRep=8625
- B&K Hammer Cage Resonance Transfer Functions: https://alog.ligo-la.caltech.edu/aLOG/index.php?callRep=7214
- Coil Driver Noise: https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=3748
- Coil Driver Response in all states: https://alog.ligo-la.caltech.edu/aLOG/index.php?callRep=4495
- ESD Driver Noise: Not in the scope of this acceptance review, therefore not included here. (n.b. ESD cable cut for CP rotation)
- Violin Mode Frequencies and Q
Measured violin modes: https://alog.ligo-la.caltech.edu/aLOG/index.php?callRep=8628
- Summary of modeled violin modes: https://dcc.ligo.org/LIGO-T1300876
Measured violin mode Qs are used to estimate wire losses (structural and thermo-elastic) and hence expected thermal noise at lower frequencies. Additional data will be taken and subsequent analysis is still to come, but this falls outside of the scope of the fabrication acceptance review.
Note added 5th Sept 2014 for clarification (NAR/CIT)
Predicted violin mode frequencies and Qs for all types of suspensions are given in T1300876. These can be compared to measured values.
Measuring Qs is not a requirement for SUS acceptance.
For Installation acceptance it has been agreed that we should measure Qs once for each major suspension type.
For quads we have measured Qs on L1 ITMY, see for example
including comments. The Qs are higher than seen at LASTI but results are plausible if surface loss has improved with time under vacuum.
There is ongoing commissioning work to investigate whether the quad violin modes are being rung up in some cases.
Channel/Signal List and Calibrations
For latest measurements of OSEM Sensor's Open Light Current, See https://dcc.ligo.org/LIGO-E1200343
Otherwise calibrations are assumed to be as shown in QUAD Control Design Description,
https://dcc.ligo.org/LIGO-T1100378 with a roughly 20% uncertainty
DCC Version 3.4.0, contact
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