Travis/Betsy
This morning, we staged to put the ETMy QUAD monolithic structure back together. We vacuumed as much of the structures as we could. I re-first-contact-cleaned the ERM-front surface since it had been exposed to the elements since the last vent and showed much particulate dispite blowing it with N2. The FC cleaning worked and the surface looked improved. We then removed the ETMy test mass HR First contact (which has been on since it left CIT) and attached the 2 lower structures. Using the Genie, w transfered the completed lower structure to the silver pallet jack + 5-axis lift table. We then maneuvered the LS into place and attached it to the upper structure already on the ISI table. We removed all of the lifting EQ from the QUAD and stowed everything in the unused welding cleanroom. All went well. We did not suspend the QUAD - we'll start that on Monday.
In the above alog I state that we removed the ETMy-HR First Contact sheet in order to mate the chains togther. This MUST be a typo as we always remove the TM-AR FirstContact (not the HR) when we mate the chains together.
Apollo – In LVEA working on nitrogen piping. Jim B. - 2 DAC restarts Apollo & Justin – On top of HAM2 installing the parking beam beam dump Betsy & Travis - At End-Y working on monolithic Corey & Filiberto – At End-Y working on TMS cable problem Doug – Moving survey equipment into LVEA Justin - Transition LVEA to Laser Safe Soil & Ground Water on site checking wells Betsy & Travis At End-Y working on monolithic Corey – At End-X TMS lab looking for parts Jeff K. - Running long TFs on PRM – needs Mode Cleaner PSL laser down
Opsws0. Should complete sometime early Saturday.
(Corey, Filiberto)
Went out during an open window for access at the Test Stand to perform an in-situ Hi-Pot cable test of our Seismically-Responsible TMS Beam Diverter Cable (D1000223 s/n S1104078); it was observed to have an electrical short in it. Unfortunately, the Hi-Pot tester was not able to run a measurement on the cable with it clamped on the ISI.
I removed the cable off the ISI and then Filiberto ran a Hi-Pot test, and it was confirmed that Pin#1 (Shield) is shorted to Pin#23.
We will either fix this cable or replace it with a D1000225 (different guage wire cable).
(Alexa, Sheila)
We wanted to compare our senstitivty to angular motion between HIFOX and Y. I used Seigman (Lasers, Chap 19) equation for the beam displacement from the optical axis as a function of mirror displacements. In my calculation, I used the following values
I found the ratio of HIFO X to HIFOY for...
11:50 - Bubba & Justin install parking beam beam dump cover on top of HAM2. Done 12:00
11:09 - Justin on top of HAM2 checking parking beam beam dump mount. Done 11:16
10:00 - Betsy and Travis at End-Y working on monolithic install.
09:25 - Mitch in LVEA West Bay working on ACB assembly. Done 12:10. 1:25 - Mitch in LVEA West Bay working on ACB assembly. Done 3:30.
Sebastien, Hugh
We investigated a little more on BSC-ITMX comb issue that we noticed yesterday (see Jeff's log).
Our guess what that the position sensors are cross talking with each other between the chambers at the corner station. To verify that, we turned off the CPSs of BSC-BS, to see if it makes the comb disappear.
In the plots attached, the red curves are the reference curve (BSC-BS ON). We can see a comb on the rotational DOFs, starting at 0.45Hz. When the CPSs of the BS are OFF (blue curves), the comb goes away. At this point, I think we can clearly assest that we have a CPS issue.
PS: the huge spike at 0.5Hz on X and Y seems unrelated with the CPS effect. We're still investigating to understand where it comes from. For now, we just installed a narrow notch at this frequency in our blend filters as a temporary solution.
Hugh gave me instructions for recovering from a HEPI and ISI trip on ETMx, which should work for the ITM:
1) turn off any large inputs from lsc to hepi, set a large ramp time for reengaging it later.
2) untrip watch dogs
3)isolate level 1
4) check RX +Ry (or all) current set points (in the bias screen) to see if they are the same as the target setpoints, if not set them to be the same. (this should only be a problem for the ETM)
ISI:
1)in watchdog screen set T240 limit to something large (only needed for ETM)
2) reset watch dogs if they are tripped
3) commands undamp (may not be necessary, especially if drives are small)
4) for ETM, make sure stage1 blends are all 750mHz
5) Isolate level 1
6) after that is done make sure that St 1 blend_x and blend_Y are T100mHz_N0.44 for the ETM. For the ITM make sure that Sebastians Notch_narrow (for the 0.5Hz noise) is engaged.
I think that is all!
7) Once the T240s have settled down (max of 5 min or so, but hopefully less if there is not a lot of tilt imposed), put the T240 Watchdog level back to its nominal operating point by pressing the 'reset' button on threshold level of the T240 in Watchdog screen. In any case, this should not be a problem, because the T240 blends will not work until the T240s have stopped saturating.
The Apollo working on parking beam beam dump cover installation on HAM2 from 09:07 to 09:15.
h1dc0 data concentrator restarted to clear .ini mismatch on h1isiham5.
Both frame writers are now writing longer frames. Testing is ongoing.
GPIB01-wifi IP: 10.22.10.20/20
GPIB01 IP: 10.22.10.30/20
...are at EX hooked up to the SR785
The python file to run the SR785 from the control room is under: /ligo/home/alexan.staley/Public/EX_SR785/TFSR786.py
Currently the SR785 is set up for the PDH servo board. In order to take other TFs the script is still valid, but one must manually change the cables.
There is an exictation running on ITMX L2 Y, I would like to start locking the green arm, so I would like to stop this.
Daniel and I saved your measurements on the ITM and ETM. You have data down to below 0.2 Hz, and you are loosing coherence on the ITM anyway, so when we get down to the end station we will turn off your excitation.
Kiwamu, Stefan We increased the input power to 10Watt. - We removed the lock from the rotational stage interlock. - We rotated the Laser Power rotation stage from 56.1 to 30deg, raising the power by a factor of 10. - The power levels IMC REFL and IMC WFSs were kept thge same by adjusting the lambda/2 rotation stage on IOT2L. We had and have 12mWatt on IMC REFL. - We reduced the analog electronic gain on MC TRANS by a factor of 10. - We verified that we now have 29.7mWatt on LSC-REFLAIR_A, and 30mWatt on on LSC-REFLAIR_B on ISCT1. - We confirmed that the IMC UGF is still 54kHz. - We updated the IMC Guardian to switch on all 3 stages, and increased the in-lock gain to 13dB. This left the phase margin at 26deg.
Next we fine-tuned the cross-over: - Lowered H1:SUS-MC2_M2_LOCK_L_GAIN from 0.2 to 0.1, - Increased H1:IMC-REFL_SERVO_FASTGAIN from -10dB to -6dB, and - lowered H1:IMC-REFL_SERVO_IN1GAIN by 4dB (from 13dB to 9dB in-lock, from -10dB to -14dB out-of-lock. This lowered the x-over by 4dB to 15Hz UGF. We did notice some "ring-up" tendency from the missed fringes during lock-acquisition at 10W.
Because the MC2 TRANS signal was not showing healthy signals probably due saturation in the analog chain, the guardian wasn't capturing a fringe with the trigger. So we changed the guardian script such that it looks at IMC-TRANS instead which is not saturating. The threshold is now set to be 500 counts. This seems working so far.
Here is another plot which is related to the crossover adjustment. There was a unwanted crossover bump at 20 Hz before the adjustment.
Blue curve: before the adjustment
Red curve: after the adjustment
Green curve: during the adjustment.
Another plot: OLTF of IMC after the power increment. As expected, the OLTF didn't change at all by the power increment.
Note that it might be too aggressive because of a shoulder at 200 kHz which is kind of close to the unity gain. If it turns out that this is not good, we can always disengage the boosts and decrease the UGF a little bit.