LIGO Document E1400113-v1

L1 SUS MC3 HSTS Acceptance Document

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Document type:
E - Engineering documents
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L1 SUS MC3 HSTS Acceptance Document

For General Acceptance Documentation common for all HSTS refer to aLIGO SUS HSTS Acceptance Documentation.

Calum Torrie signed March 26th 2014. Punch-list items listed below. All closed and accounted for.

Punch list item - need excel spreadsheet with input data from build.

Punchlist items and their resolution will be tracked in T1400181. They will not be updated on this Acceptance Document filecard.

Files in Document:
Notes and Changes:
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: aLIGO SUS HAM2-L1, XYZ Local CS for HSTS (MC3) Sub-Assy

ICS Assembly #:
- ICS Assembly Load:

Acceptance document:
This filecard serves as the acceptance document for L1-MC3.
For common material for all HSTS suspensions, see

ICS inventory

The electronics for L1 SUS MC3 can be found in the racks

Test results:
- Calibrated, M1toM1 Transfer Functions (DAMPING OFF/ON):

- Calibrated, M2toM2 Transfer Functions (DAMPING OFF/ON):

- Calibrated, M3toM3 Transfer Functions (DAMPING OFF/ON):

- Calibrated, M3toM3 Transfer Functions (DAMPING OFF/ON):

- Calibrated OSEM Sensor ASDs, All Stages (DAMPING OFF/ON):

- B&K Hammer Cage Resonance Transfer Functions:

- Coil Driver Noise:
- Coil Driver Response in all states:

- Violin Mode Frequencies and Q
Measured violin mode Qs are used to estimate wire losses (structural and thermo-elastic) and hence expected thermal noise at lower frequencies. Results for MC2 at LLO (see link) tie up well with our model and provide evidence that double prism technique appears to be doing its job. We confirmed that we are only requiring one example for each type of suspension.

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 HSTS, we measured violin mode Qs on L1 MC2, see links above.
See also reviewer comments on MC2 acceptance page at E1201042
Note that double prism technique is also used for the HLTS and BS.

Channel/Signal List and Calibrations
For latest measurements of OSEM Sensor's Open Light Current, See
Otherwise calibrations are assumed to be as shown in HSTS Control Design Description,
with a roughly 20% uncertainty (determined by the worst discrepancy seen between modeled and measured transfer functions across all DOFs and many HSTSs). The following channels are calibrated into [um] or [urad]:

L1:SUS-MC2_M1_ISIWIT_{L,T,V,R,P,Y}_DQ (Susp Point)
L1:SUS-MC2_M1_DAMP_{L,T,V,R,P,Y}_IN1_DQ (Top Mass)
L1:SUS-MC2_M2_WIT_{L,P,Y}_DQ (Middle Mass)
L1:SUS-MC2_M3_WIT_{L,P,Y}_DQ (Optic)

(For coordinate system definition, see

III. General notes and action items:

Referenced by:

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