Keita, Sheila, Gabrielle

• We have a single shot beam from TMSY onto ISCT1, with 10uW of light, we have a beam from the ITM in the end station, and we have a second beam from ETMY on ISCT1. 
• Positive pitch is in the opposite direction on the ETMY alignment slider than on the TMSY alignment slider (I believe that TMS is the incorrect one).
• There seems to be a mix up with the baffle PD cabling.
• The ALS Y GigE camera has a softaware problem: the exposure cannot be changed from 2168317875, even though auto exposure is off.

Now, in chronological order:

result of TMSY to IMTY baffle PD search:

Based on D1200657-v4, (assuming the view shown is looking at it from the BS), this does not make sense with the arrangement of baffle PDs.  These votlages are low compared to what we see on the X arm, so we suspected that this was a second bounce or ghost beam, however, they do not move when the ITM or ETM are moved, so they are not reflections off of those optics.  If we think that if these are the real beam, the baffle PDs are mislabeled somewhere, so we used the TMS suspension alingment sliders to try to figure out which PD is which.  (Unfortuately, the TMS alignment slider also seems to be wrong.)

Based on our reinterpreation of the labels, we thought that the beam should be roughly centered on the optic when TMS is at -35 PIT, -31 Yaw.  However, we saw no sign of our beam at this location, nothing on ISCT1 and nothing returning to the ETM when we scan the ITM.  Keita trended the old values, and we saw the beam go by on SRM when he restored them.  Gabriele and I went to ICT1, and found a badly clipped beam by exciting the BS.  Later Keita and I returned and moved the TMSY alignment to get a somewhat better beam, with a TMS alignment of -87 PIT and -51.4 YAW and BS at 187 PIT and -258 YAW, we have 10 uW on ISCT1.  this was the same in the spring (alog 11296)  giving us some confidence that we really have the single shot beam on ISCT1.  (This is our first clue that the TMS alingment slider is wrong)

We went through the baffle PD game by moving ITMY and looking at the ETMY baffle PDs, using this TMS pointing which isn't necessarily centered on ITMY:

This seems to make sense, but the power is low again.  We think this beam should be roughly centered on the ETM with the ITM slider at 156.5 PIT -123 Yaw. 

Since exciting the ETM (around its saved alignment) and watching on the MC1 camera and at ISCT1 didn't show us any return beam, we redid the baffle PDs for the ETM pointing:

This beam also did not make sense with the baffle PD arrangement, or our interpretation of the actual PD arrangement based on the TMS alingment sliders.  This means that either ETMY or TMSY has a sign flip in the pitch alignment slider (our second clue): 

Once we understood this I decided that our ETMY interpretation of the cabling must be the correct one, since the TMS pointing that actually gets a beam through the optic is very different in pitch than the pointing we calculated based on the baffle PDs.  Using this information, our original TMSY centered pointing should have been -113 PIT, -35 Yaw.  Indeed, this pointing does result in a beam that doesn't look clipped on ISCT1.  I can also see two other beams on ISCT1 which come from the ETM, but haven't been able to easily align the arm cavity.  Although I see some fringing, the mutliple bounce beams seem to get clipped as I try to align them.  I think the next step is to start fresh with baffle PDs, now that we think we know which one is which.

Aidan. Greg.

Good news first:

Using the periscope, we got the green ALS beam aligned to the on-table irises that were pre-aligned to the HWS probe beam. This, nominally, mated the in-vacuum and in-air axes. To test this, we turned on the probe beam and recorded a frame with the HWS camera to see if there was a return beam. And ...

There was a return beam from ITMX. It looks clean (as clean as possible with the Hartmann plate on). The next steps are to remove the plate and

1. Tweak the position of the probe beam on the ITM using the shadow of the baffles as a guide.

2. Move the HWS along the optical axis until it is imaging the ITMX HR surface.

Bad news second:

The in-vacuum lens for the Y-arm Hartmann sensor is not correct (I'm 99% sure of this). It appears to be a concave lens when it should, in fact be a convex lens (PLCX-50.8-360.6-UV). There are two things that indicate this.

1. The green ALS leakge field is quite large (vs the X arm green beam which is quite small). The beams are designed to be small coming out of the viewports and should be, roughly, the same size.

2. The lens is close to the viewport and you can see objects through it. For instance, the SR2 triple, about 3 or 4 feet away) can be seen through the lens off-axis. It appears smaller when viewed through the lens. We I take a spare PLCX-50.8-360.6 (what should be in there) and look through it, objects that are 3 or 4 feet away look bigger.

So I'm pretty convinced the in-vacuum lens is concave when it should be convex. We'll continue investigating how occured (it looks like some typos in a design change have propagated through a few documents). The more important thing is what to do about it. We won't get it working this week, but it may be possible to correct this using additional in-air optics in, what Eric G has dubbed, a Hubble Space Telescope optical fix.

FYI: Livingston has the correct lenses installed in the vacuum system.

I rebooted h1digivideo2 to add the new green ITM cameras to the config.  This is the quickest way to ensure that the cameras will continue to work in the future after unintended/intended restarts.

Ran a first set of TFs for 3IFO-QUAD09. The undamped plots look OK (pitch is a bit off). The damped plots measurements do not match the model between .1 and 20Hz very well, for both the Main and Reaction chains. Will investigate the cause. Plots are attached.  

As Betsy noted in aLOG 14128 the second pitch mode shift is present as for the other 3IFO Quads tested to date. 

All files, plots, and scripts have been commited to SVN.     

Jeff and Andres finished the transfer functions of the 3IFO Q9 QUAD.  Attached is the TF plot compared to the other 2 3IFO QUADs.  Infact, this unit ALSO has the elusive 2nd pitch mode shifted up in frequency.  In summary, so far all 3 of the 3IFO all-metal QUAD builds have this "feature".

Continuing the HAM6 HEPI Trouble shoot.  Checked sensor readings against visual position and raange of motion.  2 vertical sensors readings where offset wrt their actual positoin enough to allow the sensor to touch its flag.  This had to be corrected so I did that.

This shifted the computed cartesian position.  I looked before and after the adjustments (Loops open all through out) and then adjusted the Target positions appropriately.

WHAM6 is back to Position control but without boost.

The V2 IPS continues to behave and I even jiggled the wires a bit this morning--Periodic maintenance: unplug & plug in cables repeatedly, fun!

Sudarshan, Gabriele

Since yesterday we were not able to move the beam on the ISS QPD or PDs using the picomotors, today we tried to use IM3 to change the beam position. In brief, we are able to see a change in the QPD signal when we move IM3, so it seems there is a beam on the QPD. We read a sum of about 830 count on the QPD, which corresponds to 0.5 V. The transimpedance should be 100kOhm, so the power on the QPS should be of the order of few microwatts, while we expect 1% of the total power going into the ISS box, which should be more like 0.1 mW.

We couldn't see any change in the mean value of the PD signals, however the RMS could be changed a lot, see the striptool trace. The initial position of IM3 was: PIT 55500, YAW 2600. The one corresponding to the largest RMS in the PDs was PIT 59500, YAW 1600.

The second plot shows a comparison of the PD spectrum (dewhitened) in the original position (red) and in the new position (blue). There is significantly more signal in the new position.

In summary

1. If we move the beam into the ISS box we can change the level of signals on the PDs
2. There still seems to be too low power, even on the QPD
3. We were not able to move the beam using the (old) picomotor, so this is likely not working

Aidan. Greg.

We removed the yellow viewport covers on HAM4 by the Hartmann sensor table (the acrylic covers are still in place). As expected, there was a leakage of the green ALS-X beam coming out of the HWSX and HWSY viewports (the HWSY green beam comes from the reflection of the ALS-X beam from the 50/50 surface of the beamsplitter, the HWSX green beam from the reflection of the ALS-X beam from the AR surface of the BS). The beams are incident on the apertures in the HWS table.

The beams are not centered on the apertures. However, due to the proximity of the HWS table to the H1-TCS-R1 rack (there's about 3"  and a lot of cables between them), and due to adequate clearance of the green beams (~2") from the edge of the apertures, I elected not to move the table any closer to the rack to center the beams more than they already are.

HWSX:

HWSY:

The I/O chassis of h1seib2 died Tuesday evening, requiring a power cycle of the I/O chassis and h1seib2 computer.

The MC2 suspension have been misaligned by the guardian since 8:00 pm last night probably for the green light activity. I restored it at 9 am this morning.

We  opened to both arms yesterday. The attached shows the result of exposing the chambers to the 80K pumps and the arms.

model restarts logged for Tue 23/Sep/2014
2014_09_23 02:28 h1fw1
2014_09_23 11:49 h1ascimc
2014_09_23 12:46 h1ascimc
2014_09_23 12:59 h1ascimc
2014_09_23 16:06 h1broadcast0
2014_09_23 16:06 h1dc0
2014_09_23 16:06 h1fw1
2014_09_23 16:06 h1nds0
2014_09_23 16:06 h1nds1
2014_09_23 16:07 h1fw0

unexpected restart of h1fw1. ASC-IMC model work with associated DAQ restart.

all the models on h1seib2 (Seismic Beam Splitter) stopped running around 7pm Tuesday night PDT. Looks like the IO Chassis is having problems.

Alexa, Keita, Gabrielle, Dan, Sheila

The bottom line: X arm is locked on green, we are having trouble finding the beam on ITMY and it might be helpfull to have a camera on ITMY tomorow. 

Both PLLs are now working.  Both beatnotes needed to be realinged.  I reduced the power on the end Y BBPD, and realinged the laser green power monitor diode which was totally off. 

We spent some time searching for the green beam on the ITMY baffle PDs, but didn't find the real beam, I think. 

There is a beam which doesn't seem to have enough power, which can be found on PD1 at 2.2PIT, 7.3 YAW (20dB gain setting we get 3.6 Volts)  PD4 at -97.8 PIT 74 YAW (3.6 Volts, 20dB setting) When aligned to the center of these points, there is no beam arriving on ISCT1, and we could not find any return beam on the ETM baffle PDs even after a long search.  The ETM baffle PDs are working, since they clearly see the IR when PRMI flashes.  I have left  slow excitations on TMSY pitch and YAW hopping that at some point we will see light on the ITMY baffle PDs. 

Other things today:

Keita and I briefly tried to move the bem spot on PR2, using the output matrix he described here :  alog 13939

To do this we coped the gains from the opticalign filter banks into cal filters for pitch and yaw of iM4, PRM, PR2, and PR3.  However, when I briefly tried moving the spot around I misaligned the cavity. 

Gabrielle and I also tried locking DRMI using the configuration Kiwamu described from last night.  We were able to see any lock longer than a few seconds. 

PRMI however seems to be locking consistenly within a minute. 

J. Kissel, J. Warner, K. Izumi.

Jim and I were working on ETMX; wiamu rolled over asking us what's up with HAM2 ISI. It had single-saturation tripped on actuators. We've got no idea. Our best guess is Kyle jumping around opening up the ARMs, but it's a terrible guess and probably not right. Sensor correction on HAM2 has been turned off since this morning.

#fortherecord

QUAD 06 (Q6) Phase 1B transfer function plots are attached.   We had a hard time obtaining good coherence in the Transverse TF, so it is a bit hashy.  Will try again.  

Most notably is that, like Q8, the second pitch mode frequency is unexpectedly pushed upward on the main chain.  Recall, we never found the mechanism to fix it on Q8.  Interestingly, both the Q8 and Q6 assemblies are of the same batch of wires and are fresh builds, but by 2 different assembly teams, and on 2 different solid stack/test stand units.  Q8 is an ETM type of QUAD while Q6 is an ITM QUAD, but both main chains have the same pendulum parameters - both are detailed in the 'wireloop' model.

The Q6 data is plotted as QUADTST.

Alexa, Gabrielle, Kiwamu, Sheila

This morning we moved PRMI to the 3F sensors, we used a gain of 3 in the input matrix to move PRCL from REFL 9 I to REFL 27 I, and a gain of 15 to move MICH from REFL 45 Q to REFL 135 Q.  This was locked from about 22:26:55 UTC (september 22) to 22:33:20. 

We then tried to move on to DRMI but have struggled most of the day to get it locked.  We locked it a few times this morning, (21:00 UTC) but haven't been able to recently. 

Also, as is typical recently, the anthropogenic noise is higer durring the evenings than durring the day, there must be an evening shift of hanford work.  Screen shot of the last week is attached. This pattern started in mid august and has been true since then.