All outdoor and indoor units are on site. Indoor units are all hung and refrigeration lines are being connected. Outdoor units will be set next week after the concrete pad is poured. Partition wall is up and sheet rock in place, taping and paint next week.
Evan and I found the ETMY and ETMX back to the distributed configuration and no longer in offloaded. Based on a dataviewer trend this got switched 12/09/2014 18:34 UTC. I have reverted them both back.
Kyle, Gerardo Moved engine hoist into VEA ~1340 - 1345 hrs. local -> Ran purge air compressors to confirm that 1 psi regulator was regulating at 1 psi
Bubba G. Andres R. & Jeff B. This morning, after placing a 4" wafer in the center of the container, we sealed the 3IFO Storage container #3 and moved it into its long term storage location. The C3 cover over the suspensions was arranged so as to allow free N2 circulation, (see photos below). Storage Container #2 was moved into the loading position and the cleanroom was moved back into place. The container is ready to accept the last group of suspension for storage. The six suspensions (the last of the SUS/TMS suspensions from the staging building) that were staged by the High-Bay door were also craned over the beam tube. These are the bulk of the suspension to be loaded into Storage Container #2.
Daniel, Patrick, Dave
we restarted h1iscex and h1iscey with Daniel's latest code. The DAQ was then restarted.
SheilaD, JimW, HugoP,
We updated the SEI Guardian on site. The update only impacts the BS chamber. It is a patch that allows switching the GS13s to low analog gain when in ST2 is DAMPED. The GS13 are switched back to high analog gain when ST2 is ROBUST_ISOLATED. This update was applied to prevent the ISI from tripping during 'kicks' of the BS, which are inherent to the commissioning tasks. Update details can be found in SEI aLog #662
JimW's WP can now be closed.
Hugo
I've made a simple change to the sus guardian. The impact will be that after the guardian changes the alignment of an optic, it sets the ramp time for the alignment slider back to a short time (2 seconds). This is a more convient ramp time when people are fine tuning alingments, this will just save us from always changing the ramp time by hand after we use the guardian.
The only changes to the code were to add one line ( line 301) at the end of the main of get_alinging_state
susobj.alignRampWrite(susconst.shortRampTime)
and to add a new parameter to susconst.py
shortRampTime = 2
Although this changes the ramp time setting before the first ramp has finished, the first ramp still finishes with the five second ramp time that was set when it started. If anyone wants to change the time for a particular optic that can be done in the same way that the ramp time for TMS was set to be 10 (look at the TMS guardian). I've committed the changes to SUS.py. which we are using an h1 version of, but not susconst since we are using a common file
K. Venkateswara
After the changes to the way BRS is used at ETMX, detailed in 15497, tilt-subtraction shows significant improvement. Attached files show ASD plots from 40k seconds of data from last night, when winds were barely a few mph at ETMX.
The first plot is in angle units. The blue line shows the ground seismometer output, the green shows the raw BRS output and the red curve shows the new tilt-subtracted super-sensor output. The roll-off at 5 mHz is due to the high-pass filter but most of the other difference is from the new tilt-subtraction. This is also clear in the coherence plot shown below - the coherence between the super-sensor and the T240 is less than the coherence between the T240 and BRS. The BRS ref is shown in cyan.
The tilt-subtracted super-sensor is tilt-free and reliable till ~30 mHz or so. Why is this important? For one thing, it can be used to do sensor-correction to Stage 1 of the BSC-ISI, while keeping tilt-reinjection at a minimum. This has the effect of reducing the microseism, which is a big problem at LLO and will be a problem here as well. This was shown recently in 15498.
Some data from last night when winds were at an incredible ~5 mph! :)
Seismic: Evaluation of tilt correction on all platforms as available Suspensions: Dan H. working on OMC tip/tilt CDS: Cabling for illuminators Optical levers: Installation of weights on optical lever piers Facilities: Contractors will be pouring concrete tomorrow. Access to the Y arm will be restricted until Monday morning. 3IFO: Next to last BSC ISI is in its container, ready for exchange of containers
model restarts logged for Tue 09/Dec/2014
2014_12_09 10:45 h1susetmy
2014_12_09 10:46 h1iscey
2014_12_09 10:47 h1iscey
2014_12_09 10:48 h1susetmx
2014_12_09 10:49 h1iscex
2014_12_09 10:54 h1dc0
2014_12_09 10:56 h1broadcast0
2014_12_09 10:56 h1fw0
2014_12_09 10:56 h1fw1
2014_12_09 10:56 h1nds0
2014_12_09 10:56 h1nds1
2014_12_09 12:04 h1dc0
2014_12_09 12:04 h1fw0
2014_12_09 12:04 h1fw1
2014_12_09 12:04 h1nds0
2014_12_09 12:04 h1nds1
2014_12_09 12:07 h1broadcast0
Beckhoff:
C1PLC1 10:36 12/9 2014
C1PLC2 10:36 12/9 2014
C1PLC3 10:36 12/9 2014
X1PLC1 10:36 12/9 2014
X1PLC2 10:56 12/9 2014
X1PLC3 10:36 12/9 2014
Y1PLC1 10:36 12/9 2014
Y1PLC2 10:55 12/9 2014
Y1PLC3 10:36 12/9 2014
no unexpected restarts. Maintenance day. SUS and ISC model changes at end stations, with associated Beckhoff changes. Two supporting DAQ changes.
Conlog frequently changing channels list attached.
Dan, Kiwamu,
We locked the PRMI on the sidebands to assess the current recyclying gains. The result will be posted later.
We did the initial alignment sequence to get back to a good global interferomter alignment. One thing I have to note is that I had to touch PR3 in yaw by 2 urads in order to recover a high RF power in ALS COMM. It is now back to 3 dBm in the monitor. Also this gave a good spot position on the ALS X camera as it was clipping before I moved PR3. The clipping seems to be fixed now on the camera. I aligned TMSY, ETMY and ITMY using the green light with a hope that they still represent a good IR alignment. After going through all the alignment sequence, the ALS DIFF beatnote came back to a high RF power of about 0 dBm. So I think the global alignment came back to as good as before.
The PRMI was locked very easily by setting LSC_CONFIGS to PRMI_sb_OFFLOADED. Then we aligned the OMs and did OMC scans in order to evaluate the recyclying gains. The data is now under some analysis. After the OMC scan, we attempted to lock the PRMI on the carrier, by simply flipping the sign of the PRCL control sign. We tried different gain settings MICH which uses REFL45Q, but did not get good lock tonight. So, we still don't know the carrier recycling gain.
We locked the PRMI on carrier. The carrier recyclying gain was measured to be 35 at highest. However, since the alignment was not perfect, it probably would go up. To be continued.
After playing with the gain settings, we eventually became able to lock the PRMI on carrier. However the alignment was not stable to keep it locked with high build-up. I think this needs more study to understand what is going on. Anyway, so far, the highest buidl-up in POPAIR_A_LF we had tonight was about 3.5x104 uW. When the simple MICH without power-recycling was locked, POPAIR_A_LF was about 30 uW. Assuming that there is no mode-mismatch and Tp=0.03, we get a recycling gain of 3.5x104 / 30 * Tp = 35.
LSC settings:
Attached are the OMC scan results for a PRMI sideband lock, compared to a scan from a single-bounce beam. The first plot shows the results of three single-bounce scans and three PRMi scans (100 second ramps of PZT2); the second plot has averaged the traces. The PRMI data appears to be shifted upwards compared to the single-bounce data, by about 1V in the PZT2 output. We expect some drift and hysteresis in the PZT, but the single-bounce data was taken immediately after the PRMI lock, and a shift of this size is...surprising.
Using Kiwamu's expression from alog:14532, I calculate the PRC gain of the 45MHz sideband to be about 11.8 or 14, depending on which sideband peak you use. I think this is lower than we expect. The PRMI sideband lock was quite wobbly with a lot of angular motion, we might get a more robust measurement by locking the OMC to a particular mode and maximizing the transmission.
Here is a table of peak heights:
| Sideband Freq. | Single-bounce data | PRMI Data |
| -45 | 0.31 | 3.98 |
| -9 | 0.17 | 2.45 |
| 9 | 0.17 | 0.22 |
| 45 | 0.31 | 4.70 |
With a Schnupp asymmetry of 9.5cm the gain, for example for the upper 45MHz sideband, is (4.7/0.31) * (0.03*0.5*0.5) * (1/sin(2*pi*0.095*5*9100230/c)**2) = 13.9.
Just for a book-keeping purpose:
Two weeks later from this entry, we have measured the recycling of the carrier with the ASC loops fully engaged. We measured it to be 45 (see alog 15793).
Kiwamu, Dave O, Paul, Elli
We used the digital cameras looking at the test masses to compare scattering from ITMx and ITMy and from ETMx and ETMy. From our measurements, it appears that ETMy scatters more light than ETMx. The two ITMS scatter comparable ammounts of light.
We took photos of each of the test masses with the IR locked in each arm and the green beam misaligned. Examples of the kind of scattering we saw are attached in scatteringPRofileExamples.jpg.
We then estimated the total light scattered onto each camera.
-The camera aperature was opened to maximum for each camera. The exposure time was chosen to be the same for both ITMs and both ETMS, and the exposure was chosen so very few (<5) pixels were saturated. When we did this, we noticed two particularly bright smears on ETMy. We had to reduce the ETM exposure level right down before these two spots stopped saturating the camera.
-We also took background images of each optic with no IR or green beam in the arms at the same exposure level. We also subtracted the noise floor from the images. The images with background and noise removed are attached in backgroundAndNoiseRemoved.jpg.
-Finally the pixel value for each image was summed over the entire image to give a value proportional to the ammount of light scattered onto the camera. These pixel sums are: (the matlab code for calculating these is attached.)
| Pixel Sum | |
| ETMx | 0 |
| ETMy | 36 |
| Pixel Sum | |
| ITMx | 43 |
| ITMy | 25 |
At a super low exposure time of 200microseconds, we detected no light scattered off of ETMx, but we can still see an appreciable ammount of light comming off of ETMY.
The ITMs were imaged at 10000microseconds exposure time, and the amount of scatter we see is much more comparable than for the ETMs.
Alexa, Evan
We want to perform some ringdown measurements of the arms (particularly the Y arm) in order to corroborate our other loss measurements. We intend to use the technique described by Isogai et al., which has already been carried out at LLO (see, e.g., LLO#13748, LLO#11727).
In preparation, we've done the following work:
Tomorrow we'll try to take some data and analyze it.
In case someone wants to use Chris's script in the future it can be found here: /ligo/home/alexan.staley/Public/RingDown/RoboRingdown.py
It appears that Conlog had stopped running at around 15:16. The following error was logged: Dec 9 15:16:54 h1conlog2 conlog: ../conlog.cpp: 301: process_cac_messages: MySQL Exception: Error: Out of range value for column 'value' at row 1: Error code: 1264: SQLState: 22003: Exiting. Dec 9 15:16:55 h1conlog2 conlog: ../conlog.cpp: 331: process_cas: Exception: boost: mutex lock failed in pthread_mutex_lock: Invalid argument Exiting. I've restarted it for now.
These instruments have just been sitting on thefloor with no insulation so Krishna Jim and I got them under Trillium igloos. We had trouble with the internal Cable routine and may revisit to improve that.
The seismometers may be a little better - I've attached a pdf showing the X, Y, Z channels on the HAM2, HAM5 and ITMY seismometers and the coherence between them.
ITMY in particular looks significantly different and shows much less coherence than it probably should. It also refuses to zero out very well when the 'zero' button is hit on the control unit for the seismometer.
An overnight measurement may be a bit more illuminating.
J. Warner, H. Radkins, K. Venkateswara
The data from last night looks about the same. Plots are attached. The ITMY_Z and HAM2_Y channels look odd at low frequencies. The rest look reasonable.
Jim, Hugh and I checked the U,V,W outputs from the seismometers and confirmed that they were within the +/- 2 V spec described in the STS-2 manual.
Evan, Krishna, Alexa, Dan, Kiwamu,
At some point in this evening, we noticed that the IMC kept dropping its lock for some unknown reason. It turned out that the HAM2 ISI sensor correction was amplifying seismic at 0.3-ish Hz which resulted in a large drive in MC2 to keep it locked. So we turned the sensor correction off for now. This fixed the issue.
Even though the MC2 coil DACs were not saturating, somehow the motion was big enough to unlock the IMC. It is still unclear why it could unlock. Anyway, after turning off the sensor correction, the amont of drive in MC2 suspension reduced by a factor of 5 or so and IMC became able to stay locked. With the sensor correction on, the MC length was moving approximately +/- 5 um according to IMC_X displacement monitors. We don't know what changed in the HAM2 ISI sensor correction as it has been running fine for a while recently. Only thing we immidiately noticed was that the seismic freq-limited RMSs were pretty high in 0.1-0.3 Hz and 0.03-0.1 Hz bands in this evening. The attached is a time series of the IMC_X signals when we did a simple test of turning on and off the sensor correction in the HAM2 ISI. Since we were a bit rough for turning on and off the correction, it gave a transient when switcing it, but one can still see that when the correction was running, the IMC_X signal increased by roughly a factor of 5.
According to Valera, we should have sensor correction on for both HAM2 and HAM3, or for neither.
If both of them have sensor correction on, the MC benefits from the reduced seismic noise. If both of them have sensor correction off, the MC benefits from some amount of common-mode rejection in the ground motion between HAM2 and HAM3. If only one or the other has sensor correction on, then the MC is fully exposed to the ground motion, since one platform moves with the ground and the other is isolated.
For PRC/SRC the sensor correction has to be ON on all HAMs (as BSCs are already inertial due to low blend) to avoid the full ground motion impression on these cavities.
SudarshanK, TravisS, EvanH, AlexaS, RickS Using the Pcal beam localization cameras at both end stations, we took images of the ETM surfaces under three conditions: IR and Green resonating; IR only resonating, and Green only resonating. Attached below are two composite images composed of four separate images taken with the same camera settings: Upper Left: Xarm Green Lower Left: Xarm IR Upper Right: Yarm Green Lower Right: Yarm IR The images in the first composite were taken with the following camera settings: F8, ISO 200, 30 second exposure, WB-cloudy. For the second composite image the aperture was F29 (~13 times less light) The Yend camera was re-focused for the IR-only images, but the Xend camera was not re-focused.
Thomas Abbott at LLO applied the Pcal beam localization analysis the the LHO ETMY image to calculate the position of the center of the optic in the image from last Friday. The image below contains lines that indicate the center of the optic using the Pcal image analysis.
Attached is a picture of the original FirstContact (FC) sheet, circa ~Jan 2014, showing the "IAS window" which is a thinner film of FC in the central 3" of the larger sheet. To me, the shape of the FC window looks similar to the 3" ring showing up in green on the recent optic photo above. SYS is working with us to get our cleaning game plan together in order to remove the ring. As well, they are investigating other possible scenarios of where the ring came from if not the window. Note, there was a full FC sheet re-cleaning in March that apparently did not remove all of the ring that was left behind apon the removal of the first sheet. To be continued...
I've attached an overlay of (a) the SolidWorks CAD view of ETMy along the PCal camera path and (b) the PCal camera image of H1 ETMy (scaled and rotated). Since SolidWorks does not diffract the image viewed through the ETM optic, I indicate the shift in the ETM Telescope Baffle aperture as well. Three of the 4 bright areas are along the ETM Telescope Input aperture/baffle edge (a coincidence?). (The upper one is red.) One of the 4 bright spots does not correspond to any feature in the CAD image and is likely a spot of residual First Contact. As subsequently shown by the zoomed in PCal image using the Green Lantern flashlight (green LED) after venting (see entry #15635), it is simply a coincidence that the two prominent bright areas appeared to be along the ETM Telescope baffle aperture edge.
Travis/Betsy
This morning, we staged to put the ETMy QUAD monolithic structure back together. We vacuumed as much of the structures as we could. I re-first-contact-cleaned the ERM-front surface since it had been exposed to the elements since the last vent and showed much particulate dispite blowing it with N2. The FC cleaning worked and the surface looked improved. We then removed the ETMy test mass HR First contact (which has been on since it left CIT) and attached the 2 lower structures. Using the Genie, w transfered the completed lower structure to the silver pallet jack + 5-axis lift table. We then maneuvered the LS into place and attached it to the upper structure already on the ISI table. We removed all of the lifting EQ from the QUAD and stowed everything in the unused welding cleanroom. All went well. We did not suspend the QUAD - we'll start that on Monday.
In the above alog I state that we removed the ETMy-HR First Contact sheet in order to mate the chains togther. This MUST be a typo as we always remove the TM-AR FirstContact (not the HR) when we mate the chains together.
