A second round of testing on the all-metal 3IFO QUAD unit Q7 is attached.  After we saw a few cross coupling terms and struggled with coherence in the prior measurement set, we made a few adjustments to the QUAD mechanics.  However, readjusting the lacing cabling and retuning the sensor mounting tablecloth seemed to not help much.  There is still L and R bleeding into P on the reaction chain.  We were able to improve the coherence by building a fort around the test stand however.  The main chain looks to be in pretty good shape though.

The first attachement below is of Q7 with damping on and off.

(Keita, Alexa)

We moved IM2 in pitch to correct for the 60urad deviation that Kiwamu and Keita saw on Friday (alog 15081). Originally, IM2 P, Y = 17000, 5154 with M1_DAMP P, Y = 580, -51. This was adjusted to IM2 P, Y = 19200, 5154 with M1_DAMP_ P,Y = 637, -45. 

We then repeated an IM4 scan on PR2. The new good alignment values are:  IM4 P, Y = 6670.5, -2735.0

The scan procedure:

We moved IM4 in pitch until we saw the beam on the PR2 baffle. This allowed us to center the beam in yaw; we found that the good center position in yaw was -881.8 -- this was consistent for both top and bottom of the baffle. Then we found the pitch values for which the beam was just barely clipping the baffle:

 This average gave us the pitch position of 6670.5.

It turned out that yaw was bit more tricky. For whatever reason, the "barely clipping" procedure in yaw did not work; it gave us a center value of -3881. So instead we looked at the PR3 camera (with ITMs very misaligned), and determined when the beam disppeared in yaw:

This difference amounted to 18,100 counts. We then looked at the PR2 baffle lower left and lower right beam positions, and found that this yaw seperation for the PR2 baffle diameter made sense.

As noted in Keita's alog 15063, the diameter of the baffle is 65.4mm, and the beam must be aligned to 26mm from the right edge (or equivalently 6.7mm from the center). So we used

yaw  = center + radius in counts/ radius in mm * distance from center

yaw = -881.8 + (6.7 mm / 32.7 mm) * (-9050)  = -2735.0

The calibrations on PR3 angles are wrong.  In the attachecd screen shot you can see that someone moved the alignment slider -72 urad in yaw, the OSEMs sees a shift of -62 urad, and the optical lever records a shift of -26 urad

This morning the power on IM4 was about half of what it should be, even though all other readings of IMC ower were good. It turned out that the IM4 whitening gain was reduced by 6 db on Saturday night at about 9.15 LT (2014-11-16 05.15 UTC). We don't know why that happenened and if something else was also changed at the same time. For the moment being, I changed the gain back to the previous value.

[Sheila, Gabriele]

As suggested by Keita during the morning meeting, we checked the IM4 transmitted beam coming from the PRM reflection, on the in-air table. We dumped both beams on the table, and this improved a lot the situation. When the PRM is aligned, the noise on the ISS diodes doesn't increase much anymore. However, there is still a small worsening at 18 Hz, so maybe in the future we might want to better dump the beam at the level of the upper mirror into the enclosure.

SEI - plans to do some upgrading/standardiing on Tuesday (maintenence day). Otherwise, standing by to assist with commsissioners.

SUS - plans to work in W bay in the mornings for the entire week

PSL - working on issues with ISS second loop. Also, issues with an apparent 30% power fluctuation that may have something to do with an errant reflection??

3IFO - gearing up for SUS baffle build. Working in VPW to clean up for Contractors

CDS - X-end work - power up and checks

           Y-end work - cabling

Facilities - bring palette jack from MX to staging building. Working to maintain temperatures everywhere. Apolllo may be here this week. Their work will include sawing asphalt which will be conidered invasive.                        operators should be kept informed as to all activities of this nature.

Op Lev - re-alignment work of SR3 (work permit #4946). This will neccessitate transitioning to full LASER SAFE at some point.

Commissioning schedule to remain the same; 12:00 cutoff for noisy work in VEAs unless otherwise granted

grouting in the LVEA discussed as imminent in the not-so-distant future.

Laser Status: 
SysStat is good
Output power is 33.3 W (should be around 30 W)
FRONTEND WATCH is RED
HPO WATCH is RED

PMC:
It has been locked 3 day, 23hr 40minutes (should be days/weeks)
Reflected power= 2.5W and PowerSum =25.7W
(Reflected Power should be <= 10% of PowerSum)

FSS:
It has been locked for 0h and 4 min (should be days/weeks)
Threshold on transmitted photo-detector PD = 0.74V (should be 0.9V)

ISS:
The diffracted power is around 8% (should be 5-15%)
Last saturation event was 1d 16h and 38 minutes ago (should be days/weeks)

model restarts logged for Sun 16/Nov/2014
2014_11_16 08:27 h1fw1

unexpected restart

Sheila, Dan, Evan

Yesterday and today we have tried to get the interferometer into a state where we can lock ALS with a CARM offset, lock DRMI on 3f, and then reduce the offset while staying locked. The lesson learned this weekend is that it is taking too long to get DRMI and ALS locked so that offset reduction can begin.

On the ALS side:

1. Yesterday the ALS DIFF guardian was a little too agressive in turning on the DARM loop, so Sheila and I have added some timers so that the full gain and the boots are engaged more softly.
2. We quickly remeasured the OLTF of ALS DIFF yesterday, and it looks almost identical to what was measured in LHO#15025 (i.e., a UGF of 8 Hz with 60° of phase).
3. Locking ALS seems to be straightforward, but a bit slow. The biggest time sinks here seem to be (1) initial alignment of the arms, and (2) finding the IR resonances. For (1), Alexa, Kiwamu, and I have been working on some modified LLO scripts that use baffle PDs to align the TMSs. We want to expand these so that the ITMs are also aligned using baffle PDs. For (2), we need a better strategy for finding the resonances. Although the ALS DIFF and ALS COMM guardians have "find IR" states, they weren't successful this weekend.

On the DRMI side:

1. Although DRMI was well-behaved yesterday, today we saw a reappearance of modehopping in the SRC. We tried realigning the corner optics several times (and the Y arm once), but this issue kept appearing and throwing DRMI out of lock. After unlocking and then relocking DRMI, it went away, for no reason apparent to us.
2. When DRMI was stable on 1f, we were able to transition to 3f with no issue. However, the mode-hopping issue continued to reappear intermittently.
3. We tried turning on the ASC with DRMI on 1f. It initially improved the POP18 buildup, but then overshot, so we had to turn it off.
4. The POP18 buildup in both PRMI and DRMI varies between 190 and 270 cts. This has been true for at least a week, despite multiple realignments. Previously, we've been getting buildups in excess of 300 cts.

ALS+DRMI, other:

1. Yesterday we were able to get ALS locked with a CARM offset. We tried getting DRMI to lock, but it refused. According to Sheila, this may mean we need to turn down the DRMI loop gains during locking to compensate for the increased optical gain from the arms.
2. Today (like Friday), work was completely stopped by a long earthquake. It started nearly 3 hours ago (ca. 2014-11-16 22:30:00) and continues to prevent us from locking.

Patrick, Dave

We have been scouring the houly conlog reports of EPICS PVs which change more than 500 times an hour for a reoccurrence of the rapid (many times a second) setting of the LSC ramped mux matrix which was observed last weekend. Unfortunately we have not seen anything yet, we will continue our vigilance.

FYI: here is the report from the last hour. (Remember that a 16Hz front end slow channel, if constanly changing, will give 16*3600 = 57,600 changes per hour.)

Process variables in conlog that have changed more than 500 time(s) in the last 3600 second(s):

H1:SUS-ETMY_L1_LOCK_L_RSET        57541        
H1:SUS-ETMX_L1_LOCK_L_RSET        57541        
H1:ALS-Y_CAM_ITM_SUM               2361        
H1:ALS-Y_CAM_ITM_YAW_POS           2361        
H1:ALS-Y_CAM_ITM_PIT_POS           2361        

model restarts logged for Sat 15/Nov/2014
2014_11_15 21:27 h1fw1

unexpected restart.

Keita, Kiwamu,

This is a follow up of the previous investigation for the input pointing issue (alog 15028). We are concluding that the IM2 is the one which messed up the input pointing the other day before the temperate issue hit us.

According to a back-of-envelop calculation, this well explains why we had to move IM4 by 88 urad in pitch to get back to good alignment (alog 15063). Also, from the OSEM spectra, there is no obvious indication of the mirror sticking to the cage or something. Therefore we don't think this is an issue.

Here are summary:

• IM2 suddenly moved when HAM2 ISI was restored at around 22:00:00 on Nov 11 (alog 15032)
• The move was mainly in pitch by 60 urad. Yaw moved by only 5 urad and longitudinal was almost nothing.
• After the move, it stayed at the new angle and never came back to where it was.
• So it looks as if the IM2 mirror slipped in pitch.
• The other IMs showed a similar behavior at the same time, but they are smaller than IM2 did.
• We checked the ASC and some other dignal paths, but there had been no signals other than the alignment biases. So we think it happened mechanically.

The attached is trend of various relevant signals:

Here is the spectra of the OSEMS before and after the slip. The bold curves are the ones taken on Nov 10 and the thin curves are the ones from today. All the spectra from today are consistenly lower at low frequencies supposedly due to different seismic level. Also we are having a small bump at around 2 Hz today for some unknown reason. In any case, we don't see an obivous indication of the mirror touching the cage or OSEMs. Therefore we are concluding that IM2 is still healthy. 

K. Venkateswara, J. Warner

The BRS damper (see 14388)  has been malfunctioning since yesterday afternoon. It's controller is an open loop system that assumes it is in the centered position when it is first started. Occasionally it can get restarted accidentally when the insulation box is bumped (probably due to a short somewhere, but I'm not sure where). It looks like this happened yesterday around noon.

This requires a manual re-centering of the turn-table for the feedback system to work as designed. I've attached the directions to do this. Jim will do this later today or tomorrow.