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H1 General

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edmond.merilh@LIGO.ORG - posted 04:18, Sunday 01 December 2019 - last comment - 12:16, Monday 02 December 2019(53599)

Mid-Shift Summary

So, at my last mention of Initial Alignment, a lot has transpired.

WFS kept driving ALSY out of lock
- DOF 2 off stoppped that and allowed me to step TMS back in pitch to the zero crossin where I re-enabled the DOF 2 WFS which just screwed it up again
- I, then , manually locked ALSY and offloaded the green WFS in order to attempt another IA

10:04 I ran Initial Alignment

10:18 I attempted to re-lock

10:20 FSS trouble started
- it became unlocked and despite my efforts I couldn't get it nor the IMC re-locked
- 10:30 I succumbed to call Jason and he helped me to resolve the issue

10:43 back to attempting to re-lock

IFO still in SEI_CONF = USEISM

10:57 Lockloss at TURN_ON_BS_STAGE2

11:00 Attempt #2

Lockloss @ CARM_OFFSET_REDUCTION

11:14 Attempt #3

made it to INCREASE_POWER . As I was investigating why the power increase wasn't happening I acidentally clicked a button on the laser power guardian. grrrrrrr

11:47 Attempt #4

Lockloss @ CARM_OFFSET_REDUCTION
Got rid of nagging LASER_PWR notification by executing te Search for Home on the Rotation Stage MEDM screen

Comments related to this report

edmond.merilh@LIGO.ORG - 04:20, Sunday 01 December 2019 (53600)

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On another note:

Snow Flurries beginning to Appear on Cameras 12:15UTC (4:15 PST)

edmond.merilh@LIGO.ORG - 05:03, Sunday 01 December 2019 (53602)

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As a matter of discovery:

I noticed that the request of 2W yielded a number of 2.8W in the rotation stage MEDM screen
@ DOWN, I requested 1W and the rotation read.9W- It seemed to be an ~ 1W correction from the previous 2W request
- Also, there would be no IMC lock at .9W (rotation stage)
@ re-request of 2W rotation returned to a nominal value of 1.9W
- This seemed more normal to me

thomas.shaffer@LIGO.ORG - 12:16, Monday 02 December 2019 (53623)GRD, OpsInfo, PSL

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A note on the 2.8W and searching for home:

The LASER_PWR node was complaining because it had to bootstrap the power too much (requesting 2.7W to get 2W => ~35% difference). Searching for home was the correct move here, and we haven't done this in quite some time. After searching for home via the medm, not the Guardian node, the node became confused. Requesting a different power and then back to 2W, as Ed did, is one way to solve this. The other to use the Search_For_Home state in LASER_PWR to aliviate some of the confusion.

Perhaps we should set up a consistent schedule to search for home on the rotation stage.