HV1600-10 pressure + RGA

Recording pressures and RGA scans weekly with HV1600-10 activated at EY. H2 reduction is most significant change.

PT-428 = 1.62e-7 Torr (NEG housing hot cathode gauge)

PT-410 = 1.21e-7 Torr (BSC 10 main volume cold cathode gauge)

 

FIBOX issues at vault and MID X

In an effort to complete work at the vault and vault power room prior to the dry season we have been pushing hard to get the readbacks for the Seismic and LEMI channels in the vault operational.  Many issues impede this work, including but not limited to bugs, mice and their biproducts, bees, goat heads, snakes, dirt, weather, spotty communication to the control room, etc...  Currently the seismic reset resides inside of a bees nest.

The FIBOX is a system that can read in an audio signal (seismic and magnetic LEMI signals) and transmit them via multi mode fiber over long distances.  Our system has three Seismic channels, X, Y, and Z, and two LEMI channels X and Y.

Over the past week we have tried resetting the FIBOX's, replacing them with freshly calibrated units, we carried everything back to the lab and tested it, carried everything to MID X and tested the throughput.  After testing the FIBOX's at MID X with a local fiber, I can report that all of the channels are working as designed in this controlled environment.  The ADC inputs also work when a signal is injected into them.

When the FIBOX's are placed in the vault the seismic channels look bad, I assume it is because we cannot reset the seismic system (reset located in bees nest).  The LEMI signals also look bad.  Next step will be to read the signals directly with an oscilloscope and inject signals directly with a function generator out in the vault.

Everything is reconnected in the vault as of 3:00pm PDT.

Bubba is aware of and working on a resolution to the bees. 

Ops Day Shift Summary

TITLE: 05/14 Day Shift: 15:00-23:00 UTC (08:00-16:00 PST), all times posted in UTC
STATE of H1: Planned Engineering
INCOMING OPERATOR: None
SHIFT SUMMARY: Work today including: ISC team in HAM6 investigating AS_C and viewports, EX PCAL checks, ETMX prep for AMDs later in the week, PEM PSL testing. 
LOG: See attached

 

WHAM4 HEPI Unlocked

HAM4 HEPI is unlocked and the Chamber went to fully isolated with out issue.

Ran Range of Motion tests of 600 micro units on X Y & RX RY.  See attached for the local sensor response:  First is the X & Y.  On this one I've taken the absolute to show the over lap better.  Can't really explain why they don't overlap on the smaller X drive excursions when it can do the larger Y.  This would appear to not be an interference issue but must be some force problem.  Again, can't explain at this point.  The second plot shows the tilting offsets  and suggests the vertical motion of the greater RY excursion starts to run into something, note: I dod not take the absolute value this time.  I'll look into the details to see if it guides me to a particular spot.  Meanwhile, there is plenty of range available for operation.

Add 100ml to Crystal Chiller

   Added 100ml cooling water to PSL crystal chiller. Did not add any water to diode chiller. Both filters are clean and clean. No noted debris or discoloration. 

  Should read "Both filters are clean and clear" 

Measurements of single-bounce OMC mismatch due to SR3 heater

Alexei, TVo

Ran a measurement OMC mismatch from of single-bounce beam (off of ITMX) as a function of SR3 heater temperature.

The power to the SR3 heater was gradually ramped from 0 W to 5 W (corresponding to a temperature range of 25 C to 70 C) over the course of several hours to account for the SR3 time constant (about 15 minutes according to G1501373)

The OMC was scanned by applying a sawtooth ramp voltage to PZT2_EXC with a period of 20 seconds and amplitude of [0,120] counts.
There were also some OMC alignment loops that were closed during the scan (AS_A, and AS_B?) (I'm sure TVo will correct me if I'm wrong).

The mismatch was computed by measuring the ratio of the second order peak to the zeroth order peak. The mismatch data was taken by an OMC scan analyzer tool that I've been developing, which tries to track the zerorth and second order peaks
in time by essentially plotting the PZT2_EXC channel against the AS_DCPD channel. I will upload the tool on gitlab and pypi hopefully sometime soon when it can be used without needing me to watch over it.

The final plot ( m_vs_temp_1_2.png ) is the summary of the measurement, which is a combination of two sets taken about an hour apart. The mean mismatch managed to drop by about a 1% over a 40 C change, with a fluctuation of about 1% for any given temperature. I'm not really sure why the mismatch data is so noisy (I confirmed that the tool was correctly tracking the heights of the peaks). I was also unsure what temperature load the SR3 heater could sustain ( G1501373 says that either 10 W (emitted?) or 87 C is the max).

I will investigate the single-bounce models of the IFO to see if the mismatch change is what we expect.

PSL Weekly Report - 10 Day Trends FAMIS #6200

Morning Meeting Minutes

ISC

    - Beam to HAM6, AS AIR check, AS_C, and lock DRMI

    - SRM AWC testing on going. SR3 heater measurements happened over the weekend

PSL

    - "Wrap up" this week

SUS

    - Zero ITM OpLevs and run ITM TFs

VAC

    - MY work continues

    - Ion pump installs not till next week

EX

    - TMS and ETMX work continues

    - AMD install end of the week

    - PCAL baffle install this week

Other

    - HAM6 Door will be coming off this week

    - Access control work will be in LSB today

Tuesday Maintenance

    - RF balun investigation

PSL Weekly Report

FAMIS7490

Laser Status:
SysStat is good
Front End Power is -0.003303W (should be around 30 W)
HPO Output Power is 0.7854W
Front End Watch is GREEN
HPO Watch is RED

PMC:
It has been locked 3 days, 15 hr 28 minutes (should be days/weeks)
Reflected power = 16.46Watts
Transmitted power = 51.93Watts
PowerSum = 68.39Watts.

FSS:
It has been locked for 3 days 15 hr and 28 min (should be days/weeks)
TPD[V] = 1.073V (min 0.9V)

ISS:
The diffracted power is around 1.8% (should be 3-5%)
Last saturation event was 3 days 15 hours and 28 minutes ago (should be days/weeks)

Possible Issues:
Front End Power is Low
ISS diffracted power is Low
LRA out of range, see SYSSTAT.adl

 

---

 

This script definitely needs to be updated. I will talk to the PSL crew.

SRM heater at HAM5

Thomas, Dan Brown

This morning we wheeled out the SRM heater to the north side of HAM5. The CO2 laser cannot be switched on currently until the SOP is complete, the controller for the CO2 is on Thomas' desk. The goal today was to try and align the table to the two steering mirrors and the holes in the SRM baffle. We managed to center on the ZnSe viewport and the first steering mirror. Changing pitch and yaw there we could trace the beam around the edge of the first baffle hole, we were unable to do the same on the output baffle hole. When we believed we were centered correctly the alignment beam could be clearly seen on the baffle on the HR side of the SRM, we're currently unsure whether that should be the case or not. We also do not have a good view of the beam dump from the north side which makes trying to align into it difficult. We still have some alignment work to do here before we are ready.

The north HAM5 door area is now sectioned off with screens between the squeezer table and the clean room, pictures of the area are attached. 

 

SRM heater beam shape

Alexei, Dan Brown

We did some beam profiling measurements of the SRM heater to determine how far away the table should be positioned from the ZnSe viewport and if the beam sizes are correct. To take beam profiles of the CO2 we used a knife edge and a power meter. The measurements were compared to a simple model of the setup which matches up well. The aim was to get around a 5mm radius at the SRM, which we can achieve if we position the table so the top of the periscope is about 1m from viewport.

Measurements and analysis can be found in:

https://git.ligo.org/IFOsim/Finesse_playground/blob/master/daniel_brown/LHO/CO2_knife_edge.ipynb

AS DC Centering and OMC ASC Loops closed, AS_C missing

Daniel, Jenne, Fil, TVo

In preparation for this weekend's work to try to do an OMC Scan measurement while varying SR3 RoC, I decided to try to make sure our new alignment of the IMC could make it down to HAM6.  I was able to get light on AS_A_DC and AS_B_DC and close the centering loops but I noticed that AS_C had no light on it which is very odd.  

All the electronics were turned back on from our grounding loop searching from April 26-27 however, the attached trend shows that something dramatic happened to that QPD segments around Apr 27 2018 15:53:41 PDT which caused the individual segments to get much noisier and the sum to drop dramatically.  I'm pretty sure we were laser safe at the time so it wasn't like the a beam falling off the diode. So I thought this might be some sort of electronics problem like a disconnected cable in the midst of the madness, but everything in the rack to the chamber feed-through seemed to be connected properly, Fil and Daniel tested the in vacuum QPD chain from the outside with a multi-meter and confirmed that there is a connected diode in chamber.

So maybe we're just not seeing light? Again, this seems strange because we see light on both AS_A and AS_B.

In general, this won't deter our work this weekend but we might want to get this figured out before we open the doors early next week or put it on the task list for the chamber.  One method we haven't tried is looking for AS_AIR and seeing if that comes out of the viewport. Also, there is a picomotor we can actuate to steer the beam onto AS_C, but I'm holding off on this unless we know what is going on.

 

ETMY HEPI Y to RZ Decoupling

The two attached plots show before and after adding the final HEPI Y to RZ Cross Coupling factor.

This was first looked in alog 40106, 40117, & 40150 for ETMX.  I want to look at ETMX again as that was before I looked at the geometric consideration I posted earlier in 41955.

I feel pretty good about the solution here though now.

The optical lever out put during the HEPI length stroke is the sum of actual optic yaw plus the expected apparent yaw due to the OpLev Length to Yaw Cross Coupling: OLOutput = Actual + Expected.

So I want to minimize the Actual = Output - Expected.  Assume in this case the Actual is all caused by the HEPI Cross Coupling.  See the 40106 alog for the conversions and such to get the units, and the amplitudes of the OpLev Cross Coupling factors are from E1200836.  The signs of these corrections are subject to geometric analysis.

Anyway, with a CC factor for HEPI Y to RZ of 0.0065 in H1:HPI-ETMY_IPSALIGN_3_2 of the IPS Alignment Matrix, the residual is pretty much zero'd out as seen in the 2nd plot although I might be able to tweak it a little bit more.

This length drive on the ETMY HEPI is 0.8mm so a huge drive wrt anything we'd ever need to drive but why not get rid of it.

XBM Purge Air Butterfly Valve Replaced

The butterfly valve for the purge air on the X beam manifold was missing its stop pin, allowing it to turn freely (more than a 1/4 of a turn), removed it and replace it with a spare on hand.

Upon further inspection of the bad valve we found the rolled pin was sheared off, also noted one of the two screws missing that fasten the disc to the stem, I was not able to locate the missing screw.

Ops Day Shift Summary

 

TMSX SUS rotation complete (Corey, Travis, Keita)

Betsy and Travis told us that we can just use the top blade to rotate TMS is we're talking about O(100urad) instead of O(many mrad), so we did just that.

The procedure was: Remove ERM protection cover, adjust EX bias so the optic is centered in oplev, inject green laser, set the TMSX offset to get the retro-reflection on the table. Then loosen the blade (which makes TMS sag so no retro-reflection), turn the adjustment screw, tighten the blade, look where the beam goes, repeat.

It turns out that 1/4 turn of the adjustment screw took out 400-something urad, then Travis tried 1/16 of a turn and that took out the rest.

In the end TMSX alignment sliders were set to [P,Y]=[-74,5] urad, almost perfect for Y, and P is no worse than yesterday where it was [91,-585].

We also adjusted BOSEM depth. For F1, LF and RT we recently measured the open values and set the depth (41675) so didn't bother to remeasure open values but we reset the depth anyway as RT seemed to have drifted out.

For F2, F3 and SD, old and new offset as well as open value as of now are:

	Open today	New offset	Old offset	Reading before adjustment	Reading after adjustment
LF	NA	NA	-9350	~9.9k	~9k
RT	NA	NA	-13475	~16k	~12k
F1	NA	NA	-10515	~10.9k	~10.7k
F2	18.1k	-9050	-11164	~11k	~9k
F3	23.2k	-11600	-14150	~18.5k	~11.3k
SD	22.1k	-11050	-14372	~11k	~11.5k

 

Inventory info: S/N of F3 BOSEM is 296, F2 301.