Jim and Dave

We returned the 18bit-DAC AI chassis to EX after reversing the internal ribbon cables. We verified it was working with DC offsets on PEM channels, and then connected the standard DB9 cable from chn6 (counting from zero) AI to chn28-31AA. We verified that the Duotone loop back the h1calex model was outputting on DAC ch6 is seen on the ADC ch28.

We went to EY and outputted a DC level on ch0 using the PEM model, we verified it was coming out of the AI on ch0 using a scope. No need to open up EY chassis.

We did note that the EX chassis has a vented lid, while EY has a solid lid.

SEI - nothing to report

SUS - 3IFO ongoing/hold Betsy out

BRS - good

P Cal - pulling cables at end Y; re-terminating cables at  End-X.

PSL - nothing to report

Commish - not much progress. Possibly a TCS issue hindering DRMI locking. More information in Sheila's A-Log (14492)

Facilities - HFD on site today to investigate an issue in the LSB building

I took the opportunity this morning to get the snap updated after doing the matrices yesterday 14380.  ISI back under Guardian control.

We just turned off the CO2 laser.  We had seen our contrast improve from 99.1% to 99.8% (after about 7 hours at 192 mW CO2 power), and finally after about 19 hours we measured the contrast at 99.6%.  Dan has also measured the OMC mode matching, which seems to have gotten worse for ITMX (measured around 17 hours).  In the few minutes since we turned it off, the contrast has improved again.

Today we have had considerable difficulty locking DRMI, beause of the mode hopping problems.  There are many examples of short locks where the mode hopping seems to have killed the lock, some times are (all UTC, october 16th) 23:50, 23:23:50, 22:48,  22:26:27, 22:10, 20:44:20, 20:41:30, 20:36:04 and 20:34.....

Our difficulty today may or may not have been related to the TCS, it may just have been that our alingment was bad.  We did have 2 longer locks, each about 20 minutes. 

We decided to try locking PRMI, to see if we could get a better handle on alignment.  I edited the PRMI guardian (in LSC configs) so now it is using the refl air PDs, and the gains are correct now that we are using the power scaling. (110 for MICH, 22 for PRCL) The distressing news is that now PRMI has a similar mode hopping behavoir to what we see in DRMI. 

The first attached screen shot shows the way that our as camera has looked when mich was on a dark fringe most of the day today.  The second one shows it about 7 minutes after we turned the laser off.

K. Venkateswara

The tilt subtraction is working correctly now. The attached pdf shows the output of the tilt-subtracted super-sensor (in red) along with the GND_STS_X (in blue). The wind at EX is a measly 4-5 mph and in the wrong direction so there isn't much RY tilt. The red barely dips below the blue where the two sensors are coherent. It will be more apparent when the wind picks up a bit :)

Note that there are some odd features in the output of the filter above 7 Hz, which appear to be due to the low-frequency high pass filters, which foton doesn't like for some reason. I had to increase the high-pass frequencies to reduce this effect.

Also, note that most of what the STS is measuring below ~50 mHz is probably tilt but the tilt-subtraction isn't working well below ~20 mHz because we lose phase due to the high-pass filters and the finite d correction has not been implemented yet.

We will test this with the sensor correction next week when we get a chance.

To protect the OMCR QPD  sled from pulse damage in case of the lock loss without working fast shutter (that is, once we're in full lock, see E1400405), OMC refl beam was misaligned from the sled in PIT.

5th pico mount for HAM6/ISCT5, which corresponds to one of the two pico mounts in front of the OMCR QPD sled, was moved in PIT by four magnum steps (+40000 counts).

Before: (X,Y)=(7900, -3402)

After: (X,Y)=(7900, 36598)

Before the move, the beam was more or less centered on the QPDs.

Note that the picomotor names for HAM6/ICST6 are messed up, and you cannot tell what is what from the MEDM screen nor H1:SYS-MOTION_C_PICO_C_CURRENT_NAME, according to Dan.

Pico 1 = AS A centering

Pico 2 = AS B centering

Pico 3 = AS C centering

Pico 4 = nothing

Pico 5 = Upstream(?) OMCR QPD sled pico

Pico 6 = Downstream(?) OMCR QPD sled pico

Took faraday analog scan of the Y-end at the request of others -> Data is useless (as expected) as the unbaked RGA (background) dominates the entire spectra.  
Note that the RGA is pumped only by the Y-end volume (i.e. the local pump cart is valved-out while the RGA is valved-in to the Y-end).  A valid RGA scan was not attempted here as the setup time isn't justified (at this time).

9:16 Aaron and Filiberto to EX for PCal cabling

9:19 Hugh to electronics bay to rezero ground seismometer

9:46 Alsco onsite for Bubba

10:05 Jeff and Andres to LVEA for SUS storage box hunt

10:30 Jeff and Andres to EX and EY on continued storage box hunt

11:20 Kyle to LVEA retreiving vac parts

12:43 Fil and Aaron to EX

13:21 Krishna to EX

14:00 Jeff and Andres to MX  for storage box

15:02 Kyle done @ EY

Notes for tomorrow's operator:

IP-01 Pump B is flashing red 'Not OK'.  Kyle will investigate when available.  Ignore for now.

HAM 6 DACKILL WD was tripped when my shift started this morning.  I reset it.  It tripped again at ~3:50pm.  Reset again.

While the spectrum looks pretty good, the DC level which typically appears DC coupled, the offset from zero is >4000 counts.  It would appear from trends that this has been the case for months but since we don't use these sensors for anything we've decided to ignore this.  And if the spectrum is good, maybe the sensor is still usable

Attached is spectra from ~3am this morning and the IPS weirdness is evident, the issue with the H1 L4C is not as obvious.  Historically looking at past data (back to Dec 2013,) the L4C variance is noted but the IPS looks worse now.

Replaced non functioning whitening chassis S1101631 with S1101602 on 10/15

At the request of Jameson, I had done the output HAMs on Monday and this morning I completed all the others.  None of the platforms were disturbed so this was completely non-invasive.  In general though, the restarted node switched to EXEC with a request of NONE.  Returning the mode to MANAGED and the request to whatever put things back with no fuss.  The Chamber manager typically lost communication with the subordinate but I always restarted it last and all finished in good shape.  I say "In general...and ...typically..." because the behaviour was not universally consistent.

Kiwmau, Alexa, Sheila

Tonight we were having difficultly keeping DRMI locked stably, so we decided to spend some time looking into it rather than continuing to try locking the arms +DRMI.

First we had a look at our ASC loops.  We copied the filters from the OMC QPD centering servos for the AS WFS centering servo, this keeps the beam centerd on the WFS much better.  We also had to use the picomotor to steer it a few times because we ran out of range wth OM2.  Sometimes our 4 DRMI ASC loop (AS A 45 Q to BS, REFL A 9I to PRM) worked, well, sometimes they did not.  We loked again for a signal to use for SRM, (they are using refl B 45 Q at livingston according to 13513)  So, far, all of the 45 signals have a large offset.  We haven't looked at 36, or AS B since we don't have AS B centered. 

We decided to try some TCS CO2 laser on ITMX to see if this would alleviate our mode hopping problem.  We tunred the CO2 laser on at 1 Watt.  We had DRMI locked with our 4 ASC loops working, however the buildup in DRMI degraded.  We then measured the contrast by locking mich on the dark fringe then the bright fringe.  32 minutes after we turned the laser on, the contrast was 97.8%, (worse than what Kiwamu measured 13824) it continued to get worse for the next ten minutes.  We then turned off the laser, and watched the contrast improve (kiwamu has the screenshot). 

We then looked at G1401119, to gues that we need about 370/572 of the laser power that livingston uses, ( 14673), so we set the power to 180 mW, according to H1:TCS-ITMX_CO2_LSRPWR_MTR_OUTPUT, which is a requested power of 0.12 and an angle of 45 degrees on the rotation stage.  (we set this at 8:09 UTC on october 16)

Here are some lockloss times for DRMI 2:51:29 UTC 2:57:07 (arms were locked with ALS)

DIFF 2:34:40 2and 2:37:20 UTC all of these times are october 16

Whitening chassis S1101631 was removed from the ISC-R1 rack this morning. Unit was found to have missing positive rail. Unit was replaced with new unit (Need to get serial number).

For the records, and in order for us to define new threshold values, I am posting here the pressure fluctuations for all the BSC-ISI pods (L4C, GS13 and T240), for all units on both sites (I will link this to the LLO log).

The first table attached shows the variations of pressure and the average leak rates for LHO. The L4C varies more than the GS13. The T240 pressure readout is pretty much the same than six months ago.

In this sample of data, we observe larger fluctuations at LLO than LHO, in all pods. The variations are however very similar within all the pods of a given chamber. So it is likely temperature related.

The last table compares the average variations and apparent leak rate for both sites.

The ISC Whitening chassis S1101631 mentioned in Kiwamu's log entry (14430) was removed from the X-End LVEA electrnoics rack. The -15VDC failed. I also removed a small snake from the computer cart all snuggled up to the warm monitor and keyboard.

I'm leaving the interferometer with LSC feedback disabled, the the green lasers trying to lock to the arms.  We are currently having both high winds and high microseism, so anyone who is interested in looking at the motion of our optics or performance of ISIs when the ground motion is high could use this time, starting at 23:39 UTC October 11.

I've left the intent bit as undisturbed, could the first person to come in and commision or work in the LVEA toggle it to commisioning?