Vibration isolation for the KAGRA beam splitter and signal recycling optics

Document #:

JGW-G1910307-v1

Document type:

G

Submitted by:

Fabian E Pena Arellano

Updated by:

Fabian E Pena Arellano

Document Created:

11 Jun 2019, 09:41

Contents Revised:

11 Jun 2019, 09:41

DB Info Revised:

11 Jun 2019, 09:41

Abstract:

KAGRA is an underground interferometric gravitational wave detector currently under construction in Japan. It aims to detect gravitational radiation from astronomical sources including core collapse supernovae and binary mergers of either black holes, neutron stars or both. As illustrated by the first LIGO detection, this type of measurement requires a strain sensitivity of the order of $10^{-21}$ for certain astronomical events. Such a goal can only be achieved by using high performance vibration isolation systems for the main optical components. In KAGRA these suspensions come in three different configurations, of which the Type B is used for the beam splitter and signal recycling mirrors. The Type B suspension comprises the payload, three geometric anti-spring filters for vertical isolation and one inverted pendulum for horizontal isolation. The payload comprises the optic, its marionette and their recoil masses which hold local displacement sensors and coil magnet actuators used for damping the resonant modes of oscillation of the suspension itself. The payload also relies on an optical lever to monitor the tilt and the longitudinal displacement of the optic from the ground. This presentation describes the mechanical system and the current status of the Type B suspension towards the O3 observation campaign this year.

Files in Document:

• fabian_GWCC_brazil.pdf (12.4 MB)
• fabian_GWCC_brazil.pptx (30.4 MB)

Topics:

• Detector:Seismic Isolation
• Management:Workshop
• Activity:KAGRA

Authors:

• Fabian E Pena Arellano