KAGRA Logbook

PEM (Center)

tatsuki.washimi - 11:37 Monday 23 August 2021 (17980)

IXV electrical noise investigation

[YokozaWashimi]

To investigate the source of IXV glitch noise correlated to the room temperature (https://klog.icrr.u-tokyo.ac.jp/osl/?r=17912), we installed 4 rolled cables to

ADC1 CH28 : Cable rack (near the seismometer, originally located) [photo1, photo2]
ADC1 CH29 : Air cooler [photo3,photo4]
ADC1 CH30 : Cubicle [photo5, photo6]
ADC1 CH31 : In the IX2 rack [photo7]

Unfortunately, the temporal channels for PEM were removed from the real-time model.
So far we use IOP channels.
The noisy time was just before this work.

Images attached to this report

17980_1629686190_Screenshot from 2021-08-23 11-10-15.png

Comments to this report:

takaaki.yokozawa - 9:45 Sunday 29 August 2021 (18063)

IXV instruments(cooler, rack, electrical boxes) may be independent from IX photosensor glitch...

Images attached to this comment

18063_1630197947_Screenshot from 2021-08-29 09-41-39.png

takafumi.ushiba - 1:00 Monday 30 August 2021 (18065)

Thank you for checking.

As reported in the klog17876 and related post, the photosensor sometimes becomes noisy and it seems to occur periorodically.
Important point of this phenometa is that it is not a glitch but a noise which continues for a while, which seems to happen every 3 hours.
So, we need to check more longer period to confirm whether the noise invrease has a crrelation with IXV cryocoolers and so on.

Also, I would like to confirm that installed cables are enough sensitive to see any events occured at IXV (I cannot find this kind of information in the original post).
Do you have any data of new PEM channels when cryocoolers and so on are turning ON?

Note:
The sorce of photosensor glitch might be the trouble of photosensor itself, which I reported on the klog18057.