I've expanded my TCSY glitch investigation to include L1 TCS signals.  The attached plots recreate my H1 plots in alog 41039, and now include the corresponding L1 TCS signals.  Most noteable in the L1 TCS LASERTEMPERATURE signals is a noise pattern on top of the DC temperature signal, and in H1 TCSX has regular noise glitches, both directions, and TCSY appears to have the same glitches, just constantly.   The FLOWRATE signals in H1 and L1 are very similar.  The QPD B SEG4 INMON signals in H1 show instantaneous level changes, and some downward spikes, and the L1 signals show some upward spikes, but no level changes.  All plots show raw data, each is about 10 minutes in duration, H1 signals in blue, L1 signals in red.

Kyle, Dave:

The regen overtemp interlock is still bad, we are bypassing cell phone alarms for this channel for a futher 24 hours (expire Wed Mar 21 11:41:33 PDT 2018)

   Added 150ml water to PSL crystal chiller. Diode chiller water level is OK. No changes in the filters. 

(Gray, Radkins)

BACKSTORY: 

After the major balancing & floating of the HAM6 ISI (due to adding the new OPO to HAM6) last Thurs, we have not been able to isolate HAM6.  The thought is there is a mechanical issue (i.e. cable pulling on system?).  Another symptom (related?) is related to the Capacitive Position Sensors (CPS).  This is relegated primarily to Corner 3's horizontal (H3) CPS; it has a large value on the order of -13000 counts (roughly an order of magnitude more than normal).

YESTERDAY'S ACTIVITIES:

Before working in the chamber Hugh did some electrical checks:

• Power cycled the CPS portion of interface chasis for Corner 3 (which also turns of the sattelite rack) in the CER.
• Reseated cards at the Corner 3 satellite rack (at HAM6)
• Jiggled Corner 3 CPS cables at flange (in-vac & in-air side) at HAM6

Saw some minor change with the cable jiggling at the flange.  But for the most part no change.  This is when Hugh went in to look at possible cables pulling the system & to also clean up/remove the spools of newly-added Squeezer Silver cables.  The Squeezer cables were removed from the ISI and tie-wrapped to the wall tabs of the HAM6 chamber).  Since these cables were pulled off the ISI, we will need to add weight to the table and then re-balance.

After removing the cables above, unfortunately still saw the large H3 CPS values.  So this remains an issue.  This is where we ended the day on Monday.

TO DO LIST:

• Continue to investigate the issue with H3 CPS. 
• Add weight (due to Squeezer cables were pulled off) & rebalance the table.

NikoL, RickS

With the removal of the ETM camera relay mirrors from the Pcal periscopes, the Pcal ETM cameras are no longer useable.

Thus, we removed these systems from the A7 Adapter ports at both end stations.

Before/after photos attached.

Note that the red-anodized gates (guillotines) for the viewport protectors are still in place.  These have round pieces of black glass glued in rececces in the side facing the viewport.

This morning I got a little bit of time to try some more debugging of ZM1. Jeff Kissel's last alog (lhoalog41034) showed a big feature in the Y to Y measurement and a possible issue with the LL flag/magnet. After team SEI was done with their work and locked up the table, Corey and I checked all around the the suspension for anything that might look or feel wrong. I looked all around the LL OSEM for anything that might cause a problem but didn't find anything. I recentered the OSEMs on  their flags and then we ran the measurements again. No change.

During a lunchtime talk with Betsy, she suggested that I try to run the Y to Y measurement with the top OSEMs backed out and not actuating, and then do the same with the bottom. When I tried it, it looked like the lower frequency feature was much smaller when the top OSEMs were backed out (see attached). I got excited and tried this for pitch as well, but didn't notice much of a difference. This ended my day in HAM6 as I had other teams nipping at my heels.

16:45 JeffB transition LVEA to laser safe
17:00 Hugh & Corey to HAM6 for CPS work
17:00 PeterK & Ed to PSL enclosure
17:30 TJ to HAM6
17:45 JeffB to LVEA
17:45 Betsy & Travis to EX
19:30 Sheila found sqz and isct6 lasers still on after morning laser safe transition
20:15 Betsy & Travis to EX
20:15 M&M to HAM6
21:30 Peter to PSL
21:30 TJ to HAM6
22:00 Fil to LVEA
22:15 RickS Niko to EX, EY to remove PCAL Camera
22:15 M&M to HAM6

22:45 Sheila transition LVEA to Hazard
 

Laser Status:
SysStat is good
Front End Power is -0.003262W (should be around 30 W)
HPO Output Power is -0.04724W
Front End Watch is RED
HPO Watch is RED

PMC:
It has been locked 0 days, 0 hr 0 minutes (should be days/weeks)
Reflected power = 0.008512Watts
Transmitted power = -0.02508Watts
PowerSum = -0.01657Watts.

FSS:
It has been locked for 0 days 0 hr and 0 min (should be days/weeks)
TPD[V] = 0.06625V (min 0.9V)

ISS:
The diffracted power is around 3.3% (should be 3-5%)
Last saturation event was 14 days 2 hours and 58 minutes ago (should be days/weeks)

Possible Issues:
Front End Power is Low
FSS TPD is low
LRA out of range, see SYSSTAT.adl
 

The HEPI trends script was broken this morning when I launched it from the weeklies screen. This was caused by the changes to the EX channel names from the switch over to Beckhoff at that station. I updated the channels to my best guess but it's a little hard to say because the new overview doesn't seem to give a good map compared to the old overview. 

Today, Betsy and I prepped the ETMx Quad for removal of the lower structure tomorrow.  We swung back ACB, locked down all optics and masses, and disconnected all cables and wire segment necessary for removal of the lower structure.  We are in good shape for extraction from chamber tomorrow morning.

Following the installation of the improved TEC controller for the SHG, we started tuning the loop.

Figure 1: A single pole at 0Hz, a zero at 100mHz and with 10mHz selected in the ugf box. There is a fair amount of overshoot and it takes a long time to settle.

Figure 2: The zero has been moved down to 10mHz.

Figure 3: The zero has been moved down to 5mHz.

Figure 4: The zero has been moved down to 7mHz. The overshoot is about 20%. We are sticking with this value for the zero.

Figure 5: Pole at 0Hz, zero at 7mHz, another pole at 1Hz, gain of -1, ugf box set to 30mHz.

Figure 6: Response measurement at 30mHz, indicating that the ugf is around this frequency.

70W install is ongoing

Gerardo noticed this.

Kyle, Dave:

Two changes to the Vacuum cell phone alarms:

H1CDS_ROC.adl MEDM improved to show alarm levels and current value. Red border follows these alarm levels.

   Transitioned the LVEA to laser safe. Locked the ISCT6 and Squeezer cabinets. No other issues noted. 

Recall that TC1 has an offset and that it is under-representing the actual temperature it is exposed to by 6C - 10C.  

Also while at Y-mid, I closed the exhaust valve on the turbo that is pumping CP4, closed the foreline isolation valves and opened the scroll ballast/purge plug.  This allowed room air to purge, under viscous conditions, any water that may have condensed between the scroll stages since stopping the UHP N2 purge gas the other day.  I restored the configuration after a minute or two of viscous purge.  

I used the hand-held TC meter to measure the underside of CP4's vacuum vessel (1 ft. radius around vent/purge nozzle represented by TC3) and found the average temperature to be around 65C.  It would be interesting to see if we could lessen the temperature striation we are experiencing (HOT air resides at high elevations cooler air found at lower elevations) by heating the inner LN2 reservoir using the regeneration system. 

Nutsinee Terry Daniel

OPO locking:

• With the ISI no longer locked the ~1kHz acoustic peak is a factor of a few lower and the OPO locking needs correspondingly less range. The lock also looks much better now.
• We copied the guardian from the SHG and updated it for the OPO. It seems to work.
• The power coupled through the fiber was increased by a few. We get just under 6mW onto the OPO REFL diode.
• OPO REFL Photodiode DC: Unlocked 5.8mW, Locked 2.2mW. The dip in reflection therefore is 62%

Fibers:

• We tried the waveplates in the green pump path and we are able to go as low as 0.7mW for the rejected light. The adjustment was somewhat cumbersome, since both waveplates needed to be rotated simultaneously to make further improvements towards the end.
• We also tried the manual waveplates in the seed path. We were able to get the rejected light up and down by about a factor of 4. It seems difficult to do better by hand.

Translation stage:

• We were able to move the lens translation stage using the PI controller.
• We didn't try the oven translation stage since we had no feedback, if it is moving.

Next:

• We need to realign the pick-off beam towards the homodyne detector,
• and find the red/green double resonance in the OPO.