aLIGO LHO Logbook

H1 DetChar (DetChar)

ethan.payne@LIGO.ORG - posted 11:10, Wednesday 06 November 2019 - last comment - 11:49, Monday 11 November 2019(53047)

Air compressor scattering still present after isolation

Ethan, Adrian, Sheila

A few minutes before Nov 01 2019 20:41:42 UTC, the instrument air compressor was put on isolation springs in order to mitigate scattering in DARM at 35 Hz (see alog 52879). The first attached plot shows when the compressor was placed on springs. The horizontal red line in the figure it set slightly above 35 Hz.

Following up on this a few days later (Nov 6), we see there is still some scattering at 35 Hz that is consistent with the behaviour of the air compressor. This seen in the second attached figure.

Some work could be undertaken to better isolate the compressor and/or locate the coupling site.

Images attached to this report

Comments related to this report

jeffrey.kissel@LIGO.ORG - 09:23, Thursday 07 November 2019 (53059)FMP, ISC, PEM, SEI

Link

Tagging Facilities, ISC, SEI, and PEM for the folks whom'd likely be modifying the seismic isolation.

Now associated with FRS Ticket 13809.

chandra.romel@LIGO.ORG - 11:49, Monday 11 November 2019 (53157)

Link

Improved isolation was added to the instrument air compressor this morning. See aLOG 53151.