I've added the RFM inputs from h2iscey to the h2susetmy and h2sustmsy models. These are the control inputs for ISC PIT and YAW.
I have not recompiled, installed, or restarted these models yet. I will do so first thing tomorrow morning.
Looked at cabling coming from Red QPD (chamber) to QPD Transimpedance Amplifier Chassis D1002481(rack). Used voltmeter to do a diode measurement across QPD1 (four segments) and QPD2 (four segments). Was expecting to see around 0.6V for the forward voltage drop across the diodes. Did not see any voltage drop on cable ISC-BSC6-1. Performed test on cable ISC-BSC6-2 (green QPD) and saw the expected 0.6V across the diodes. Next we swapped ISC-BSC6-1 and ISC-BSC6-2 at the chamber vacuum feedthru. Retested at rack side, and cable 1 tested good, cable 2 did not pass. We had also noticed cable 1 had a short from Pin 13 (GND) and Pin 16. Reverified at chamber side.
The crew returned to In-Chamber Cleaning at BSC3 today after being pulled to work on viewport and feedthrough installations at HAM1-2-3 yesterday. Wipe down and second vacuum were completed by the end of the day. Tomorrow we'll do close-out work, including FTIR samples and inspection.
The west door was removed from HAM3 and held on the forklift boom while the following activities took place: pre-work wipe of chamber floor (which showed the expected black oxide), septum blank install, and fit check/install of modified HAM spacers. (*Note: The septum blank and spacers were NOT torqued down.) The door was returned to the chamber and the bolts were torqued and tightened. HAM3 should be ready for pumpdown. The cleanroom will be moved to HAM1 tomorrow so that the ion pump can be installed.
The assembly validation testing report for HAM-ISI Unit #5 is posted under the DCC for validation.
Reports regading the previous units tested/validated (Phase I) at LHO are also available on the DCC:
HAM-ISI Unit #1
HAM-ISI Unit #2
HAM-ISI Unit #3
HAM-ISI Unit #4
While the crew had the HAM3 door off and were installing the Septum Window Cover, they also installed the HAM ISI Spacer (type for WHAMs 2 & 3) D1101180-v2 Type 00. They used the 5" long ISI-through-spacer-to-Support-Tube bolts to constrain the position while bolting down the Spacers to the Support Tubes (Separate 3" bolts.) The 5" bolts were then removed. Thanks to Mark, Scott, Slim and the Devil Dog.
PSL installation team Injection locking: We injection locked the oscillator. Total output power without corona aperture in place: 210 W Total output power with corona aperture mount in place: 204 W No measurement with corona aperture in place. We lert the system running over night with power watchdogs turned on. Other work in LAE: Alignment of optical components on optical table: ongoing Other: Work on purple cable pulling / electronics: ongoing
This one is a no-brainer.
The emails of the log posts (L-mail) would be much more convenient if they actually just included the contents of the log post directly in the message. One could just read the posts in their mail without having to click through. So nice.
Furthermore, the emails subject lines should just be the title of the log post. That way you could see if the post is relevant to you without even having to open the mail.
Links to the posts could of course still be provided in the message to provide direct access to the post for viewing images, etc.
I like the following format I get from the old SEI Notebooks: [Subject] New ETF Seismic lab elog entry [Similar to what L-mail does already] [Body] A new ELOG entry has been submitted: Author : Daniel Clark [could be replaced by ligo-org email] Type : Data and Analysis [would be replaced by "Section"] Category : Sensors & Actuators [would be replaced by "Task"] Subject : SPI Temperature Allowance - Aluminum Table Logbook URL : http://ligo.phys.lsu.edu:8080/ETFseismic/1918
But this provides barely more information than is currently in the emails. A subject that is always the same is basically useless. The subject should definitely be the title of the log post. And the body can include the information you suggest, but it should also include the full body of the post as well.
I have overhauled the h2iscey model to better conform to the ultimately desired ISC channel naming convention. The top level was broken into two sub-blocks, ASC_EY and ALS_EY. The ASC subblock has the two TR QPDs (A and B). The ALS block has the two ALS QPDs and the two ALS WFSs, as well as the control paths to the suspension actuators.
I also updated the QPD library part to include a limitter for the sum normalization path, and I updated the WFS library part to use the QPD part for it's DC path.
h2iscey was rebuilt, installed, and restarted, and the DAQ was restarted to incorporate the new channel names.
I made a new medm screen for the QPD library part (see below).
The filters for the individual segments are on the left, followed by the segment matrix, filter module links for the PIT, YAW and SUM, and indicators for the SUM level and an X/Y plot for the PIT/YAW.
I made a very simple medm screen for the OAT/h2iscey model. It has links for all the various elements currently in the h2iscey model except for the WFS RF components (we still need to make a screen for that). It needs a lot of work, but it's something to start with.
In particular, it provides links for the ISC-ALS_EY_QPD_{A,B} and ISC_ASC_EY_TR_{A,B} QPD screens.
B. Bland, J. Kissel
The results from the overnight TFs that Betsy started last night are attached. The lame news: the SUS is not yet ready for chamber close up. However, over the phone, Betsy informs me that more items on/around the suspended elements have changed and some other tweaking occurred today since the measurement and more will change tomorrow. Though this set of TFs is informative academically, we have to wait until we're "done" with mechanical stuff before a "final" close out measurement (which will hopefully show a clean bill of health).
From what we can [remember / piece back together / guess], the state of the chamber is:
- HEPI Floating, but OFF
- BSC-ISI Floating, but OFF
- QUAD
- Free, OFF
- One-off, wire loop, prisms, and glass optic main chain; Production ThinCP fully laced
- EQ stops brought into 0.75 mm gap
- One set of ECD magnets is removed (Betsy doesn't recall exactly which, but we think lower cluster below M0 F3)
Here's what I see, and what I think is going on:
Main Chain
Although the diagonal TFs (LtoL, TtoT, etc.) look OK, its obvious from the off-diagonal terms that there's a serious amount of cross coupling (see 2012-05-07_H2SUSITMY_M0_ALL_TFs.pdf). My guess is that this is because of the missing weight from the absent ECD magnet cluster. As mentioned in G1100865, pg 4, one of the possible VtoP / PtoV cross coupling mechanism is a static offset in pitch. The fact that PtoP looks "clean" (though a little bit low in overall magnitude), and both VtoV and RtoR show the 2nd pitch mode, my guess is that the missing ECD magnet cluster brought whichever corner of the mass up, creating both a static roll and pitch in the mass, causing the exact cross coupling described in G1100865.
We should get that ECD magnet back on there, do any other final tooling additions and removals, and measure again.
I use the "wire" model for this one-off, wire loop, prisms, and glass optic main chain, and it seems to predict it pretty well. In allquads_120507_H2SUSITMY_ALL_TFs.pdf I compare it against other metal mass wire SUS, and other than the cross-coupling mentioned about, and slightly less magnitude, it matches up pretty well.
Reaction Chain
Here, the VtoV transfer function shows something new, fun, and bad. Notice there's only two resonances? My gut reaction, is that the lower two modes have shifted up in frequency due to increased stiffness, and the lower two masses are stiffened to the point on moving as one; cabling's the only thing I can think of off-hand. Either that or something's interfering with the lower blades. Remember, the higher frequency the resonance, the more it involves lower stages. Also, because other modes, and other degrees of freedom show little to no reduction in Q, implies that whatever's stiffening up the vertical DOF, likely isn't at the top stage. Looks like the high-frequency Roll / Trans modes have changed shape too, likely due to the same vertical stiffness issues.
I'd check around the blades, and re-assess cabling on this one.
Unfortunately, phone conversations are less accurate than aLogs. In fact, the 4 (of 64 ECD magnets) were removed on the reaction chain, left top face cluster). They were restored to the suspension this morning. I re-checked the reaction chain cabling this morning and everything looked to be in order - no grounding to the structure or between the chains as sometimes happens. We have played with this cabling since the Garcia-Wed 5/2/12 measurements, although we were making the cabling "looser" in the clamps in order to avoid possible TFE flowing-to-shorting later. I don't know what to do with the cables now to alleviate stiffness because they "feel" like they are already seated with appropriate stiffness. I also can't quickly compare the Garcia 5/2/12 data to this set because they are plotted so differently and well, I'm on vacation so don't have the time to stare at it for an hour. I worry that fussing with them more may throw out the alignment of the reaction chain. We need to get better at checking alignment, running TFs for rubbing checks immediately, repeat alignment, repeat TFs. Could it be poorly diagonalized BOSEMs? I don't think we did much to check those this time around, and we have already seen one flag drastically mis-centered in a BOSEM...
Mark Barton (and Travis Sadecki) I generated some variations on the production CP model with various components immobilized to see what the two-peak V-V transfer function implied. It turns out that immobilized UIM blades is a good candidate (see attached). Before I was able to tell him this, Travis poked around and found the hard way that indeed the UIM blades weren't free.
Working with Josh and Robert, I installed a new h2peml0 model to conform to the new PEM channel naming scheme. The new channels names for the LVEA are shown below [H2:PEM-CS_SEIS_LVEA_FLOOR_X_DQ] [H2:PEM-CS_SEIS_LVEA_FLOOR_Y_DQ] [H2:PEM-CS_SEIS_LVEA_FLOOR_Z_DQ] [H2:PEM-CS_TILT_LVEA_FLOOR_T_DQ] [H2:PEM-CS_TILT_LVEA_FLOOR_X_DQ] [H2:PEM-CS_TILT_LVEA_FLOOR_Y_DQ]
Jim, Cyrus, Dave we activated the new H1 DAQ system today, writing its first aLIGO H1 frames (can I hear corks popping?). The h1psl0 front end was started yesterday running the IOP only, today it is also running the PSL TEST models to support PSL cable testing. All H1 systems have been constructed in their true locations: DAQ and FE computer in the MSR; IOChassis in the H1 EE room. The new h1boot and h1build machines are fully operational. Three H1 networks have been created: H1 FE LAN; H1 Slow Controls LAN (for Beckhoff) and H1 AUX LAN for camera, video, etc. EPICS gateways were created for the first two LANs to provide connection to the control room. Two CDS workstations were converted from H2 to H1 controls machines, one is in the control room and one in the LVEA besides the PSL enclosure. A new PSL user account was created to be used on these machines. It is not possible to dynamically switch between IFOs from any one workstation due to NFS mounting issues. This problem will of course go away with H2 at the end of the OAT. H1 EPICS overview screens and site maps are being created. Care is being taken to differentiate between H1 and H2 systems to prevent accidental operation of the wrong system (we are speaking from experience).
I've noticed that Red QPD trans-impedance amplifier box has the tendency to switch off REALLY easily, and once it is switched off, I needed to wait for 30 seconds or something before I can switch it on again. It looked as if the board was near the capacity of the breaker circuit or something.
Also two of the four segments of the second red QPD had large offsets.
These were before swapping the amplifier box with the green one.
Once we've swapped the amplifier box, the problem persisted. The box connected to the red QPD was really easy to switch off, was reluctant to come back, and the same problematic channels had large offsets though the exact offset number changed.
When we disconnected the input cable connecting the QPD feedthrough on the chamber and the QPD box, the power switch felt normal and it was possible to switch on and off repeatedly without waiting for a long time.
Probably the QPD trans impedance amplifier is drawing too much current. We're suspicious of something like a cabling problem of the red QPDs that causes high frequency oscillation, and maybe this is happening for two channels.
This was apparently asked for several times but was never produced. Thing is, at some stage we thought that we needed a trans-impedance amplifier box without whitening, otherwise the green QPD would rail too much at least during the initial alignment process.
Since no such thing was manufactured, after consulting with Rich, we decided to modify one of the two boxes we have.
We took the red QPD box out, opened and disable the whitening by "removing" 200 Ohm R1 resistor (D1001974) from all 8 channels. The resistors are actually still on the board but rotated by 180 degrees so it is soldered on only one pad, and the other pad is on top of the empty area. When we want to put them back it would be easy.
After this we just swapped the red and green QPD box, i.e. the green QPD box is without whitening, red QPD is still with whitening.
a picture of the QPD box we modified (S1102811)
This report was validated today. However..
This unit was tested with non-production horizontal GS13s on. We just received a crate of production horizontal GS13s that were just tested and work.
We decided to install the production pods we just received on this Unit. All the tests involving GS13s will be redone. If no pod fails during/after installation, this unit will be our second unit after Unit#4 (HAM2) to be equiped with a full set of production pods, offering us another occasion to reduce the time needed for the chamber-side testing.