Adv. LIGO Arm Length Stabilisation Design

Document #:

LIGO-T0900144-v2

Document type:

T - Technical notes

Abstract:

The design of the arm length fluctuation system. This system aids in the lock acquisition of the interferometer by stabilising the arm cavity length fluctuations to within ~1.3 nm.

Files in Document:

• T0900144_v2_ALS_Design.pdf (file is not accessible)

Topics:

• Conceptual Design
• Sensing and Control

Authors:

• Sam Waldman
• Daniel Shaddock
• Bram Slagmolen
• Peter Fritschel
• Adam Mullavey
• David McClelland

Notes and Changes:

1) Started appendix B ’Version History’.
2) Modified section 5.1 to reflect what is mentioned in the ALS Requirements Document (T0900095-v2).
3) Updated figures 1,7,8 with the latest fiber phase noise correction measurements.
4) Updated figure 3, include the mode matching telescope for the 532 nm beam and wavefront sensors.