Mark B.

Starting TFs on MC2 and PR2.

- tumbleweed baler started at 8:00 am along X-arm.  Baler was moved near the large access door for the LVEA, then to the front of the OSB by late afternoon.
- Unifirst change site mats.
- Ace port a potty drove in a drove out due to tumbleweeds.
- Apollo installated a couple of glass viewports on input tube.
- Removal of FC MC optics, see Betsy's entry below.
- Apollo is installing the East door on HAM03.

We ran a quick set of transfer functions on HAM3-ISI. We focused on the 500mHz to 5Hz frequency range. Results are a bit noisy due to a lack of averages, but they show good concordance with what we expected.

SEI-wise, doors can be closed on this chamber.

* Barring one more round of TFs.

Today, we finished locking nuts and tweeking OSEM centering on PR2 and MC2.  The MC2 closeup task-list took a side trip as we had poor cable connection of the L2 external cable both at the satellite box and at the feedthru on the chamber at the other end.  I called in the calvary who helped us hunt these joints.  Meanwhile, I attempted to remove the FC from PR2.  The AR sheet came off without a hitch.  The IAS-compatible HR sheet tore in many places leaving only the ring of the sheet in my hand when I was done.  The central portion of the sheet was too thin the pull so was torn in from numerous directions and would not lift off.  I reapplied FC (using the red "nail polish" bottle) over the torn sheet, added a PEEK tab and waited an hour before pulling again.  It came off.  There are still a few wisps near the edge of the sheet which did not come off, but I left it alone for now.  We won't use this optic until after the next vent so we'll revisit cleanup then.

Travis and Cheryl also spent some time adjusting mechanical pitch on MC1 to reduce the amount of electronic bias used.  CHeryl will re-check MC flashes in the morning.

[Volker / Kiwamu]

 This morning I went in the PSL room with an escort of Volker to replace a PD in one of the ALS paths. The PD (PDA100A) that had been in the ALS refcav transmission path [1]  was replaced with a Thorlabs SM1PD1A as designed. The output DC current from the new PD was about 0.36 mA when the laser light is on the PD. Note that I used a standard Fluke digital multi-meter for reading out the photo current. So no DC bias was applied on the diode.

[1] LHO alog #4721

JimW, HugoP

The 200lbs mass stack used to account for the missing PR3 apreared to be causing unwated resonances around 113Hz. We could hear the bottom mass tilting against the optical table when being hit. We untorqued the stack and put a folded alluminium strip under its problematic corner. Everything is torqued down. We cannot hear the mass rocking anymore.

2 potentially rubbing cables were found on the North and South sides. They were adjusted.

HAM2-ISI is locked so suspensions can be adjusted in pitch. It will be unlocked to pursue testing afterwards.

Volker Q.

I re-setup the OSA on the optical table and measured the modulation indices.  This was done to ensure that the recent cleaning of the modulator crystal did not have any adverse effects on the performance of the modulation.

The previous measurements are described here. This time I only measured the modulation depth on the center frequencies.

The sideband height was measured with a OSA on the PSL table. The frequency is the modulation frequency in MHz. All three modulator inputs were driven with 10Vpp (in 50ohm).

Carrier: 220mV

The values look reasonable close to the previous set of measurements

[Michael R., Volker Q.]

The reflections of the main beam of the the AR surfaces of the HAM window are accessible (under certain conditions, see here) and provide a reference for the beam coming from the PSL table.

We marked those beams, yesterday, Monday the 17th, on the PSL enclosure wall.  See picture below.

There were two weak and two very weak spots visible.

- Deepak, Cheryl

A camera was set up to look at the IM1 (SM1) transmitted beam, using the C3 door cover as a target.  MC1 was off in alignment, due to coming off earthquake stops, and required a pitch slider value of -4170, and yaw slider value of -2880 to get good IMC flashing.  MC2 and MC3 were initially unchanged, and MC3 was only tweaked at the end to optimize the modes coming from the IMC.  HAM3 was locked and HAM2 was floating during the alignment.

 Old values for MC1:      P =   -840, Y =   -320
 New values for MC1:     P = -4170, Y = -2880

After talking to Mark Barton, it seems like it would be good to have the SUS team adjust the pitch of MC1 to reduce the drive we need.

I set the gains on Roll/Pitch/Yaw for MC1, MC2, and MC3.  The values were low and the optics were effectively not being damped in those degrees of freedom.

Final alignment attached.

WP#3607 Mark, Hugo and Dave

at 10:42 the models h1susmc1 and h1susmc3 were restarted on h1sush2a. The new models reactivated the IPC based watchdogs between these SUS and ISI on h1seih23.

•	Tumbleweeds completely blocking access to X and Y-arms as well as the main entrance to the OSB. Weather station at EY reported max wind velocity near 
        80 MPH early this morning.
•	Mid Columbia Forklift onsite to examine green forklift and turn various bolts with various wrenches and nod approvingly.
•	0900 - LVEA to laser hazard for Cheryl (mode cleaner) and Michael (PSL).
•	1020 - Hugo and Mark B connecting SUS and ISI watch dogs; restarting H1 SUS models.
•	1345 – Hanford Fire Dep onsite to inspect panels.
•	1330 - Bubba and crew prepping equipment in LVEA for septum removal at Ham 9.
•	1415 - LVEA returned to laser safe.
•	1530 – Kyle torquing bolts on conflat for HAM 3

The H2 daq system has been shut down.  This includes h2dc0, h2nds0, h2nds1, h2fw0, h2fw1, h2ldasgw0, h2ldasgw1, h2boot, and h2build.  This shutdown is permanent, all but h2boot and h2build will be reused to create a DAQ system for the X1 DAQ test stand.

No online data will be available from the h2 system using h2nds0 or h2nds1.

Old data will be available using NDS2.

Results of windstorm around OSB and arms. Pic 015 is the top 12-14" of the mast on Big Red forklift.

- Joe, Deepak, Volker, Cheryl

HAM2 IO install was completed last Friday.  The PRM surrogate was swapped to have the HR/HR optic, and to steer the beam to the parking position through the HAM2 top viewport.  MC3 OSEM protection baffle was installed using the template sent from LLO.  Minimization of the beam once the HWP after IM1 was installed reduced the beam to 7uW at PRM surrogate, which is a good thing since we're still sending the wrong polarization into the mode cleaner.

MC1 lower stage OSEMS were adjusted, so MC1's hanging position is unknown, so this morning I'll be working on it's alignment to get the mode cleaner flashing.

There is a black residue in cleaned chambers that comes off on latex gloves because they stretch further into the crevices that the wipes used to mop up the cleaning residue (here). We suggested in that alog that we test nitrile clean room gloves because they might not stretch into the crevices as much as the latex gloves. Jodi procured some nitrile gloves and when I was in HAM9, I compared the two types of clean room gloves. The photos show that much less residue came off on the nitrile (whiter) gloves than on latex gloves for the same pressure and length of rub against the HAM9 wall. I tested the 3 types of nitrile gloves (Hand PRO series 9100 and 7100 clean class nitrile,  and Valutek VTGNUTPFB95) that Jodi procured and they were all equally better than the latex gloves.

Robert S. Jodi F.

Summary: Fine particulate is visible in all nozzles of the H2 IMC tube, but not in the nozzles of the HAMs near it, suggesting that the particulate came with the beam tube. I measured dust counts during activity in the H2 IMC tube and they were low, about like cleaned chambers. I also looked for particulate that might have moved from the H1 IMC tube into HAM3 and did not find any clear examples. So I think the particulate is fairly stable and it is safe to pump the H1 IO chambers.

A fine particulate was noticed in the LLO IMC tube nozzles (here). Mike L. asked Jodi and I to go into H2 HAM9 and the new H2 IMC tube because there has been very little activity in there and we might be able to find if the particulate came from the IMC tube. The H2 input optics area has not been pumped down since the new tube was installed. Figure 1 contains photos comparing nozzles in the H2 IMC tube and HAM3. The top left photo is of particulate in the 4^th vertical nozzle from HAM9. I have drawn a face in the particulate with my finger. I found this particulate in every nozzle of the new MC tube that I examined. I inspected every nozzle of HAM9 and 8 and found none of this type (there were a few isolated  big pieces). Thus this particulate seems to have come in with the IMC tube.

To see how much particulate would be stirred up by activity, I did my scuffing walk test. The level in the MC tube averaged 140 0.5um particle counts per cubic foot, comparable to the cleaned chambers and much better than the ~1000 count levels from walking in the Y-Manifold (here).

Mike also asked me to go in and examine HAM3 to see if the vacuum cycling for leak checking had spread this fine particulate into the HAMs. The photo at the bottom of Figure 1 is a photo of a HAM3 nozzle, showing that there is very little dust compared to the H2 IMC Tube nozzle above it. Also, the few particles seem larger. I sampled the particulate at the HAM3-spool junction for elemental analysis to compare to the samples I took in the H2 IMC tube. I think it is safe to cycle the IO chambers because the particulate does not seem to have spread much – the burden of larger dust particles and especially silver metal particles near optics in HAM3 appears to be worse. 

Robert S., Jodi F.

The crystal chiller circuit has been increasing the motion of the PSL table by factors of 2 to 10 between 70 and 800 Hz (here). The vibration level varies in time and we have had some success by removing air from the manifold etc., but, until now, we have made no dramatic improvements.

In a recent alog (here) we showed that the quick-connect fittings in the high-flow crystal chiller circuit produced vibrations that were orders of magnitude larger than for barbed connector fittings, possibly because the nozzle in the quick-connects causes a small stream of water to spray chaotically and with high velocity inside the tube, and we suggested replacing the ones on the crystal box manifold.

Oliver Punken was here this week from UTB to work on PSL tasks, so we replaced quick-connects in 2 stages. In the first stage we replaced the connectors on the crystal box manifold, and straightened out the flow path (Figure 1). Figure 2 shows that the problem virtually went away after replacing these two connectors.  We also replaced the quick-connects and straightened out the flow in the manifold under the table (Figure 3) but made no further visible improvements (we were hoping to reduce the small residual at 100 and 150 Hz).

We may face future beam jitter problems from the chiller circuits, but the table vibration problem that we had identified is essentially solved. We recommend that LLO replace the two quick-connects on the manifold at the crystal box. They may also want to replace the two on the manifold under the table to keep both sites the same. 

Robert S., Michael R., Oliver P., Rick S.

Summary: No drop in magnetic coupling level over the 2 – 10 Hz measurement range was noted after removing eddy current damping magnets on M0 and L1. This was not unexpected because we had previously noted that there was also excess coupling at L2. The slit L2 parts are here and I suggest that we install these on ITMY and measure coupling again when possible.

We recently (here) found that large magnetic injections produced motions of ITMY that, when scaled linearly, suggested that ambient magnetic fields would produce motions that were orders of magnitude larger than our sensitivity goal at 10 Hz. Further tests (here) suggested that the coupling level was the same when SUS and ISI cables were disconnected and HEPI shut down, that the coupling was similar at ETMY, and that the coupling occurred at multiple suspension levels. We also found that coupling was within a couple of percent of linear for magnetic fields that were varied by a factor of 3 at both the ITM and the ETM.  Comparisons of BOSEM and OSEM injections to magnetic injections showed that coupling was excessive at L1 and L2 as well as M0, so the suggestion was made that in addition to removing the M0 ECDs, we also remove the blade spring ECDs and that we slit parts around the AOSEMS at L2, the penultimate level, in order to prevent eddy current circuits (here). For the test reported here, we removed the ECDs, but did not replace the L2 parts, so we expected coupling at L2 to be unchanged.

Figure 1 shows that coupling, as measured by the optical lever reflecting off of the ITMY test mass, has not significantly changed. For an ambient magnetic field background of 10 pT, the graph predicts about 1e-16 radians/sqrt(Hz) of motion. The point at 63 Hz measured in Aug. has been left off of the graph because there was no clear indication of the 63 Hz peak in the one 12 hour injection I had time for this month.  For the previous measurement at 63 Hz, cables were installed and damping was on. Thus one possibility is that the point at 63 Hz may have indicated coupling to the cables, but not directly to magnets on the quad. For all measurements here, except for one of the 3.5 Hz measurements, the SUS cables were disconnected and ISI and HEPI were off.

As a next step, I suggest that we install the slit L2 parts (Betsy says they can be installed in situ), and re-test magnetic coupling when possible.

Optical lever calibrations

We used two independent methods to re-calibrate the optical lever. First, the original DC method, calibrating beam spot motion by moving the quad diode on its translation stage and converting displacement to angle using the geometry. We also used an AC method to cross check the calibration; we injected 5000 counts at 1 Hz into M0 pitch or yaw, measured the beam spot displacement at the photodiode using a scale, and then calibrated the photodiode output using a 500 count injection (to be in the linear region of the photodiode) and assuming the amplitude of beam spot motion was 1/10 of the motion measured for the large injection (we confirmed actuation linearity with a 2500 count injection). The independent calibrations differed by 4% in yaw and 15% in pitch. We used the average of the two calibrations for the gain; Pit: 23.38, Yaw: 24.74. The August gain values are still on the MEDM screen because I did not want to change gains in the middle of collecting data, so the calibration was corrected off-line.

Peak disappeared when beam was blocked

We had previously tested for coupling of our injected field directly to optical lever electronics by blasting the electronics with large magnetic fields (here). This time I checked by blocking the optical lever beam while injecting a 5.5 Hz magnetic field. A flashlight was used to bring the signal level from the diode segments up to their nominal signal levels either in total RMS or at 5 Hz. The 5.5 Hz peak in the optical lever signal disappeared in both cases.

Set up

The setup was similar to what was used before. The attached photos show the coils. We ran 12 amps through these coils for most injections, producing magnetic fields at the test mass of several tens of micro Tesla. We have measured injected fields inside a BSC for a similar coil configuration and found the ratio of gradients to fields for the injection to be about the same as for ambient 60 Hz fields (here). The magnetometer, used in determining radians per Tesla of injection, was placed 10 cm under the center of BSC1. 10X attenuators were used and the amplifying filter box was bypassed in order to get the large magnetometer signal on scale. The magnetometer was calibrated in situ using a small calibration coil.

Robert S., Thomas V.

(Corey, Keita)

My mode-matching lessons from master Jedi Kawabe continue with the building of the EX Green QPD Sled.  This Sled is one of two on EACH Transmission Monitor Suspension (TMS); the other is an IR QPD Sled (to be assembled next).  We actually built this Sled twice.  After completing it the first time, Keita noticed, "this sled looks like EY.  It's supposed to be a mirror image!"  It was all a learning experience.  So, we ended up re-building the sled (it went much quicker since we, in essence, already had an assembly dry run).

Once the Sled was completed, we draped wipes over all optical components, wrapped the entire assembly in foil, double-bagged it, and placed the entire thing in a large plastic bin for storage under our Optics Table in the Optics Lab (the HAM1WFS Sled is also stored here). 

Keita has plots and data from our mode matching measurements and will post a more thorough document about our EX Green Sled work to the DCC.

Note:  The "J-Clip" Black Glass Beam Dumps on our Steering Mirrors are tough to install.  There's a screw on the mount which interferes with the J-Clip and makes installing/removing these parts tough.