Attached are plots of dust counts > .5 microns in particles per cubic foot. I have also included plots of the modes for dust monitors 10 and 16 in the LVEA (H0:PEM-LVEA_DST10_MODE, H0:PEM-LVEA_DST16_MODE) to show when they were probably swapped by Michael R. for dust monitors without internal pumps.
Keita and Bram.
We replaced the the RF LSC Diode, as we could not work out if it was behaving ok (edit: working badly was not the correct wording). We check the power cable (15-pin connector) and all seemed fine.
We pulled out S1000885 and inserted S1000881.
This was done prior the power measurements mentioned in entry 3471.
Keita and Bram
We measured the power inthe optical train on the ISCTEY (after the RF LSC Diode swap, see entry 3470).
Forward path: Laser -- FI1 --- 30 mW --- FI2 --- EOM --- 27 mW --- FI3 --- Mirrors + lenses --- 20 mW ---- retro mirror
Return path to RF LSC Diode: retro mirror --- FI3 --- 7 mW --- R=80% mirror --- 4 mW -- RF LSC Diode
Return path to WFS: FI3 -- 7 mW --- T=20% mirror --- 3 mW --- to both WFS.
The DC output gives us 45 mV (48 mV with lens), resulting in 3 mW (3.2 mW) of power being 'converted'. About 0.3 mW is being reflected and dumped.
We added a half waveplate just before the R=80% beam splitter, as all mirrors are coated for vertical polarised light (it becomes apperant that there are tom any waveplates on the table!!)
With this, we get 6.3 mW on the RF LSC Diode and 1.07 mW into the main WFS path (this will get split by a 50-50 beam splitter, so ~0.5 mW per WFS).
This in turn gives 69 mV (edit: removed the 0.) on the DC output of the LSC diode, e.g. 0.69 / (10 * 5 * 0.3) = 4.6 mW.
DAQ: staggered shutdown of both frame writers to remove memory from the ldas gateway machines.
Added slow temperature channels to the H2 frame.
booted h2boot machine to see if this would fix the FE EPICS slow down when h2boot is being backed up; result- it didnt
extended the EY RFM reflective memory loop from EY into the LVEA. The path is (starting with the 5595 RFM switch at EY):
single mode patch through to the VEA patch panel.
In MSR, patch between the EY to H2B patch panels (single mode)
Install of 5595 RFM switch in H2B in computer racks.
Patch cable from H2B's patch panel to new 5595 unit.
multimode fiber from new 5595 unit through hole-in-the-wall directly to the h2susb478 front end.
Installation of a 5595 RFM pcie card in h2susb478 (required replacement of 3 slot riser with 4 slot riser).
I attempted to make an IPC change to the h2susitmy model to test this, but other model/medm changes are happening which is confuscating things.
Performed patch of new cdsssh 2FA login machine.
Jim moved 48GB of memory from the H2 LDAS gateway machines to the h1 frame writers (h1fw0, h1fw0) to give them the same amount as the H2 frame writers. This has been on our to-do list for some time, but because it required the shutdown of both H1 and H2 DAQs it was delayed until it became a stability issue with the H1 frame writers.
After increasing the power into the ref cav yesterday and religning the FSS path today, we can lock the ref cav with 5.65V on the transmitted PD. Visibility is low, around 66%, so that will have to be worked on next.
I adjusted WP4 to change the DC voltage on the RFPD to 460mV. Common gain was set to 18dB giving a UGF of 180kHz. I don't believe this to be ideal so it will also have to be changed.
Managed to get three of the Horizontal Actuators attached today. Hopefully will be allowed to continue tomorrow. Just the NE Horizontal Actuator remains to be connected. Then we'll release all the actuators; they are locked in a mid-position during installation. Hopefully (Yes I do lot of hoping), the system won't move too far from aligned position.
Most pressing: ETMY screens modified in a way that left them with white boxes - broken! Dave is currently working on fixing it. Activities: Vincent - running a measurement on BSC8 - done at 13:50 kyle - moved a cart from ham3 to ham6 Dave - restart H2 DAC, restarted H1 DAC Forklift - work going on early afternoon at C&B Douglas - retrieved items from HAM4 clean room Keita and Bram to end station - worked on the table, and found that ETMY screen has white boxes Tour in the LVEA: 2:40-3:30 Betsy - work on MC2 chamber side Hugh - work on SEI
Today, the guys finished fully suspending the glass MC2 and took a preliminary look at it's height and pitch alignment. With the optical autolevel and a height guage (standard HXTS alignment procedure), the height measured to be at nominal (214mm to better than +/- 1mm).
The roll of the optic is out by 0.8mm over the distance from the left prism to the right.
The pitch was measured via looking at the pitch of the side scribe line on the optic (which is known to be crooked by ~0.1mm over it's length) so is estimated at ~4.5mRad. Independently, an optical lever was set up near the top edge of the optic (above the FC, so yes, high on the 27m ROC surface) and the pitch again measured to be 4.5mRad +/- 1mRad.
We're not sure what the IAS requirements are, so we'll need to find those before determining what errors to improve.
The actual measured height of the top of the Bottom Mass is 215mm from the tabletop. The target height is 215mm +/- 1mm. I sent Betsy the incorrect height.
I installed an accelerometer to the table surface by epoxying the sensor to a metal cube, epoxying a layer of cling wrap to the bottom of the cube, then epoxying the whole thing to the table. The HEPA fan was turned on while the epoxy was curing, then turned off afterwards. A picture of the setup is included.
[covering morning part of shift for Cheryl]
This morning's primary activity is Reflective Memory work by Richard & Dave. (taking down the ITMy and also ETMy, as well as the DAQ), so this left the morning open for "loud" activities since there were no SEI or SUS measurements planned. This work should be complete before 2pm.
Other Activities:
I'll leave the cavity locked and the ISCTEY HEPA fan off. A thunderstorm brought strong wind between 5:20 and 5:30UTC (22:20 - 22:30 local), which made the lock rough. It is currently raining hard with occassional thunder, but the lock has cleaned up and the spectrum looks decent.
The DC output of the PDH detector on ISCTEY seems low, so I went to measure the power on the PD. The power meter says 2mW. The detector gives 17mV at the output, and it seems that the PD has 10 Ohm transimpedance with a gain of 5 and a responsivity of 0.3A/W at 532nm. 17mV / (5 * 10 mV/mA * 0.3 mA/mW) = 1.1mW, which is in the ballpark. The coupling efficiency is probably not good enough to achive 0.3A/W, so that might explain some of the discrepency... in any case, the real mystery is why we have only 2mW on the PD.
The SR785 reports coherence > 0.999 above 1Hz between the demod board Imon (output monitor) and the VCO monitor. That signal passes through the CM board and the VCO filters, so they are not adding any visible noise.
There is good coherence between the ISI stage 2 signals and the cavity length. I used the nominal calibration for the GS13s to nm (3 poles at zero, 2 zeros at 1Hz Q ~ 0.7, 1 nm / (2 pi f) above 1Hz), and it appears to match the VCO calibration for the cavity length quite well below the SUS resonances.
I also include a couple of driven measurements. The current motion of the optics is at the limit of our ability to keep the lock (due to alignment flucutuations and dominated by ITMY), so it is hard to drive hard enough to get a good measurement without breaking the lock, but I was able to get some coherence. I wonder if the drop-off below 200mHz in the driven measuements is due to some tilt-horizontal coupling in the drive, or possibly due to pickup in the GS13s. The suspension resonances seem to amplify the motion by a reasonable amount, given that we can't expect to achieve very low Qs with the damping all at the top stage.
Attached are plots of dust counts > .5 microns in particles per cubic foot.
I measured the power going into the AOM to be 32.6mW but only got 5.8mW into the EOM. After adjusting M24 to improve the pointing into the AOM we now get 18.4mW at the EOM. However, the rest of the FSS path is now misaligned and will have to be worked on. The ref cav still flashes so it's fortunately not too far off.
Andres R, Betsy B, and Jeff B took the transfer function for Phase 1b testing of the HSTS MC1 suspension. This data has been plotted and is ready for review.
To assist with reviewing the MC1 (HSTS) suspension, please find attached below a plot showing a comparison of all HSTS suspensions measured at LHO and LLO, to date (allhstss_2012-07-16_AllHsts_ALL_ZOOMED_TFs.pdf). Note that, these M1-M1 transfer functions were all obtained at Phase 1b of testing. Power spectra have been taken with damping loops both ON and OFF for each stage (2012-07-17_1300_X1SUSMC1_M*_ALL_Spectra.pdf). Power spectra plots, with both damping ON and OFF have been produced, which compare all LHO HSTS measurements for PR2, MC1 and MC2 (allhstss_2012-07-17_ALL_Spectra_Don.pdf and allhstss_2012-07-17_ALL_Spectra_Doff.pdf). Note that, the comparison power spectra provided for MC2 M3 AOSEMs, show an elevated noise floor at high frequencies above 100 Hz. A similar issues has also been observed for suspensions attached to the LLO triple test-stand, which was rectified by going chamber-side. In addition, power spectra for specific degrees of freedom (L, P and Y) can be more conveniently compared across multiple stages (M1, M2 and M3) of the same suspension in the final plots found below (allhstss_2012-07-17_X1SUSMC1_M1M2M3_Spectra_ALL_Don.pdf). All data, results, and scripts I have committed to the sus SVN as of this entry. This ensures all measurements have been taken required to complete Phase 1b testing.
For further reference, I have added power spectra plots comparing LHO MC1, with the LLO MC3 suspension. Results from all three phases for the MC3 suspension are shown as follows:- Blue trace = LLO MC3 Phase 1b (X2SUSMC3 2012−05−01_1600) Green trace = LLO MC3 Phase 2b (L1SUSMC3 2012−06−28_1600) Red trace = LLO MC3 Phase 3a (L1SUSMC3 2012−07−02_1400) Cyan trace = LHO MC1 Phase 1b (X1SUSMC1 2012−07−17_1300)
