aLIGO HAM-ISI, Test Report, Phase I: Assembly Validation, LHO Unit #2

Document #:

LIGO-E1000311-v9

Document type:

E - Engineering documents

Abstract:

This unit was first assembled and tested in 2010, until September 24th 2010. Following the discovery of un-authorized repairs, the unit was disassembled. Testing done before disassembly can be seen under v3 of this document. The unit was re-assembled and tested early 2012. The assembly was validated on February 16th 2012.

Particularities:
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-Every GS13 was removed prior to storage. No GS13 stored with the ISI.
-Production GS13s have to be installed, and tested, before in-chamber installation of the unit.
-One test-GS13 was used as H3. The production pods used as H1 and H2 were pulled out before storage. They are now installed on Unit #4.
-No L4C

Complementary inquiries:
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-Extraction of GS13 frequency responses is order to explain discrepancies observed on TFs, between corners
-Confirmation of the need, and functionality, of symmetrization filters
-Comparison of extracted responses with huddle test for the instrument that has its resonance frequency shifted. The instrument already had this feature when huddle-tested. Hence, the resonance frequency shift was not caused by handling/shipping. Attention will be kept on this matter to make sure that no resonance frequency shift occurs post huddle-testing.

Minor issues that don’t imply further work:
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-CPS gap measurement with a jig was waived to avoid scratching targets
-Blade #1 spring profile slightly out of requirements
-Excessive STD measured on CPSs is associated to ground motion

Minor issues that imply further work:
---------------------------------------------------
-Actuators linearity is within requirement. However the average slope deviation is out of spec. It seems to correlate with the cable+actuator resistance measurements. This observation needs to be correlated with the final measurements made with the in-field cables.

Files in Document:

• E1000311-v8_HAM_Unit_2_Testing_Phase_I_Report-v9.pdf (8.8 MB)

Other Files:

• E1000311-v8_HAM_Unit_2_Testing_Phase_I_Report-v9.docx (4.9 MB)

Topics:

• Seismic Isolation
• Final Design

Authors:

• Hugo Paris
• Fabrice Matichard
• Jim Warner
• Hugh Radkins
• Mitchell Robinson
• Corey Gray
• Greg Grabeel
• Eric Allwine
• Vincent Lhuillier

Keywords:

HAM -ISI Assembly Validation Unit #2

Notes and Changes:

Corrested the GS13 status: Every GS13 was removed prior to storage. No GS13 stored with the ISI.

Related Documents:

Referenced by:

• LIGO-E1100996: aLIGO HAM-ISI, Phase I Testing Reports