Jenne, SHeila, Patrick, Ketia

We are still not able to lock ALS for very long.  We tried locking only ALS COMM, and were able to stay locked for more than 10 minutes.  We have been sitting here watching signals from the green arms, and we see the same ALS glitches (in the Yarm) that are described in many old alogs: 31053 lists som.  

Keita Patrick and I followed Jenne's instructions in alog 30519 to lock the green laser to the arm directly by passing the PLL.  In this configuration we did not see the glitches, but now that we have swapped the cables back to the original configuration the glitches are bac.  So it seems likely that the PLL is somehow involved in these glitches. I am not sure if these glitches are the reason we cannot lock, but in the past they have prevented locking. 

Edited attachment with annotations to make it more clear. (ignore the grey smudge)  We had the green arm locked bypassing the PLL from about 6-2-2017 1:38 UTC to 1:44 UTC

The second screenshot shows a repeat of this test using a gain of 6dB instead of 10dB. I think that the loop was oscillating with the 10dB setting, so this setting is better. 

CP3 log file DOES NOT exist!
CP4 Fill completed in 300 seconds. Starting CP4 fill. LLCV enabled. LLCV set to manual control. LLCV set to 70% open. Fill completed in 300 seconds. LLCV set back to 40.0% open.

Chandra, Dave:

CP3 is under PID control and its level sensor started reading below 100.0% around 10am this morning. So CP3 auto overfill was cancelled, and CP4 proceeded as scheduled at 11:02 PDT.

I made some changes to cp4_fill.py to add the summary text and correct some indentation isues.

Richard, Dave:

We power cycled the h1iscey computer and IO Chassis as part of the ALS-EY glitch investigation. Sequence was:

h1iscey, stop all models, take FE out of Dolphin fabric, power down comuter

IO Chassis: power cycle

h1iscey, power on computer, models restarted automatically

We had a brief (5 minute) IRIG-B excursion on h1iopiscey. After this cleared, DAQ and IPC were working correctly.

2017_06_02 10:17 h1caley
2017_06_02 10:17 h1iopiscey
2017_06_02 10:17 h1iscey
2017_06_02 10:17 h1pemey
2017_06_02 10:18 h1caley
2017_06_02 10:18 h1iopiscey
2017_06_02 10:18 h1iscey
2017_06_02 10:18 h1pemey
2017_06_02 10:19 h1alsey

CP3's reservoir level is back on scale - reading around 97% full. I lowered the PID lower limit of LLCV to 15% open when it was ~99% full to measure percentage per hour to get a feel for how low the reservoir got over the weekend.

PID is programmed to hold the reservoir at 92% full. Once it drops to that level, PI will kick in.

The pneumatic regulator connected to the supply line for the cylinder on GV8 has failed. The cylinder was still getting enough pressure to hold the gate open.
 
The ball valve used to isolate the pneumatic regulator is up stream of both GV 7 & 8 so I mechanically locked out both valves.  I talked with Chandra and Kyle before I locked out the valves. 
I will fill out a FRS for to replace the regulator this morning and confer with Chandra before any pressure is applied. This also has ties to FRS 8259.

 

Sheila is working on ALSY and working in close proximity to BRS.

TITLE: 06/02 Day Shift: 15:00-23:00 UTC (08:00-16:00 PST), all times posted in UTC
STATE of H1: Planned Engineering
OUTGOING OPERATOR:
CURRENT ENVIRONMENT:
    Wind: 2mph Gusts, 0mph 5min avg
    Primary useism: 0.01 μm/s
    Secondary useism: 0.08 μm/s
QUICK SUMMARY:

H1 remains in a state of disrepair. Sheila is down at EY investigating ALS.

TITLE: 06/02 Eve Shift: 23:00-07:00 UTC (16:00-00:00 PST), all times posted in UTC
STATE of H1: Planned Engineering
INCOMING OPERATOR: None
SHIFT SUMMARY: Jenne, Sheila, Jeff K., Kiwamu and Keita investigating ALS, including glitches on the Y arm. Received a corner station instrument air alarm (see separate entry).
LOG:

23:14 UTC Kiwamu to end X to adjust ALS laser current to make it more stable.
23:28 UTC Dave and I restarted the ops teamspeak computer. It was not connecting to the wireless network, and we did not have administrative access to make it, but it did connect upon reboot. It is now connected to teamspeak again.
23:58 UTC Kyle to mid Y
00:08 UTC Kiwamu back. Jenne aborting measurement. Kiwamu attempting to lock x arm on green.
00:17 UTC Kyle back.

Trouble with ALS Y glitches the remainder of night. Leaving the ISC_LOCK guardian node in DOWN.

I received a corner station instrument air alarm. I called Bubba and per his instructions went out to look at the compressor in the chiller yard. One compressor had a green running light lit and the other did not. The belts on both motors were spinning. He said that this is indicative of a bypass valve failure on one of the pumps. He said as long as the other pump continued to run it should be fine and he will replace the valve in the morning. I called Chandra and left a message with her, because I believe some of the gate valves in the LVEA are controlled by this instrument air. I also called Kyle. He indicated that there is no danger to the vacuum and will make a separate alog entry.

3 hour trend attached.

Daniel (on phone), Peter, Jason, Keita, Sheila, Kiwamu,

Today we set the diode current of the X end laser to the factory setting of 1.95 A. It had been for some reason set to 1.8 A.

This was motivated by the power fluctuation issue that Jenne reported the other day (36550). As a result, the green laser power became more stable, although it doesn't look like it has fixed the recent ALS issue of being difficult going through the ALS states.

(Symptom)

The end X laser intermittently ran into a situation where the power fluctuated by a few 10 % for unknown reason as reported in 36550. Today we ran into the same situation and therefore we decided to investigate this issue. As we studied the behavior, it turned out that the green laser power had a dependency on the laser temperature. This may be an indication that the laser was close to some bad mode hop condition or some sort. The behavior was clearly repeatable as we went to back to the same frequency (or crystal temperature).

(Fix)

Earlier Peter noticed that the laser current had been set to a lower value. However, since we weren't sure whether it had been purposely set or not, we initially decided to change the crystal temperature to escape from the mode hop region. However, in the end this didn't really work out because when we shifted all three lasers (PSL and both end lasers) by +800 MHz, the end X laser went into a good region where the laser power didn't change as a function of the laser frequency while the end Y laser went into a bad region.

Consulting with Keita, Sheila and Daniel. We decided to try out the diode current setting as another knob to escape from the bad region. This actually worked pretty well. All three lasers are now set to back to their nominal frequencies.