Improving LIGO calibration accuracy by tracking and compensating for slow temporal variations

Document #:

LIGO-P1600063-v9

Document type:

P - Publications

Abstract:

Calibration of the second-generation LIGO interferometric gravitational-wave detectors employs a method that uses injected periodic modulations to track and compensate for slow temporal variations in the differential length response of the instruments. These detectors utilize feedback control loops to maintain resonance conditions by suppressing differential arm length variations. We describe how the sensing and actuation functions of these servo loops are parameterized and how the slow variations in these parameters are quantified using the injected modulations. We report the results of applying this method to the LIGO detectors and show that it significantly reduces systematic errors in their calibrated outputs.

Files in Document:

• pdf (P1600063-09_tdep.pdf, 1.8 MB)

Topics:

• Calibration

Authors:

• Darkhan Tuyenbayev
• Sudarshan Karki
• Joseph Betzwieser
• Craig Cahillane
• Evan Goetz
• Kiwamu Izumi
• Shivaraj Kandhasamy
• Jeffrey Kissel
• Gregory Mendell
• Madeline Wade
• Alan Weinstein
• Richard Savage

Notes and Changes:

Submitted to CQG on Aug 8.