Displaying reports 75521-75540 of 82999.Go to page Start 3773 3774 3775 3776 3777 3778 3779 3780 3781 End
Reports until 18:26, Tuesday 10 September 2013
H1 SUS
arnaud.pele@LIGO.ORG - posted 18:26, Tuesday 10 September 2013 (7721)
TMSX BIO bit

One of the BIO bit representing the status of the analog dewhitening filter of the TMSX is either not displaying the right value, or the dewhitening filter is not switched to the requested state, cf bit 8 (RT LP) of picture attached. I will check tomorrow with Richard to see where the problem could come from.

Images attached to this report
H1 SUS
jeffrey.kissel@LIGO.ORG - posted 18:17, Tuesday 10 September 2013 (7720)
V/R 6.18 [Hz] Feature is NOT a function of the Drive
J. Kissel

Here're some spectra that are the same as what Vincent had posted, but focused on the LF and RT OSEMs, and calibrated into [um/rtHz]. I show four configurations (each config has the ISI/HPI in its best performance state):
(1) As we discovered the problem, with all SUS damping loops closed (shows giant feature)
(2) With only V loop turned off (still shows giant feature)
(3) With V and R loops turned off (does NOT show giant feature)
(4) With V and R loops turned off, and with a broad-band 1000 [ct] excitation sent out of the RT COILOUTF bank (does NOT show giant feature).

Note, I also measured 
(5) With only R loop turned off (still showed giant feature), 
(6) With V and R loops turned off, and with a broad-band 1000 [ct] excitation sent out of LF COILOUTF bank (still did NOT show giant feature), 
(6) With V and R loops turned off, and with a broad-band 100 [ct] excitation sent out of LF COILOUTF bank (still did NOT show giant feature), 
(6) With V and R loops turned off, and with a broad-band 10 [ct] excitation sent out of LF COILOUTF bank (still did NOT show giant feature), 
but they were redundant with the above information, and would have over-crowded an already crowded plot.

First page of the attachment shows configurations (1)-(4). Second page shows the ASD of the 1000 [ct] excitation, meant to look roughly like a damping loop signal. 

Given that we only see this feature with the damping loops that involve LF and RT ON, and we don't see it by turning the damping loops OFF and driving an artificial, non-OSEM-sensor, signal AND we know it's not a loop instability, I think we can narrow down the source to something in the analog sensing chain that is oscillating.

We should replace the M0LFRT, R0LFRT satamp tomorrow, and see if this feature goes away. I blame the satamp, because the satamps have plagued use wih a terrible history of oscilliations.

I bet $1.00 USD.

If anyone is betting against, please please please, shoot me more ideas on how to narrow down the source further.
Non-image files attached to this report
H1 SUS
jeffrey.kissel@LIGO.ORG - posted 17:59, Tuesday 10 September 2013 (7719)
V/R 6.18 [Hz] Feature is NOT a Loop Instability
J. Kissel, V. Lhuillier

With all SUS damping loops closed and with the ISI in full isolation, I've taken open loop gain transfer functions of the H1 SUS ITMY's Vertical and Roll Level 2.1 damping loops. As predicted by design, and by what was seen on H1 SUS ETMY there is plenty of phase margin, and no features around 6.18 [Hz].

NEXT: Determine whether it's the coils or the sensors, or some nasty interaction between them.
Non-image files attached to this report
X1 SEI
sebastien.biscans@LIGO.ORG - posted 17:28, Tuesday 10 September 2013 - last comment - 17:56, Wednesday 11 September 2013(7718)
Test Stand BSC-ISI Unit6 issue

Sebastien, Jim

We are currently testing the BSC-ISI unit #6 in the staging building. The 2 stages are unlock and balanced, everything seems to be well connected.

The power spectra show something wrong on GS13-V1 and GS13-V3 (see figure attached).

After further investigation, the issue seems to be 2 bad cables. They will be change tomorrow.

Images attached to this report
Comments related to this report
sebastien.biscans@LIGO.ORG - 15:07, Wednesday 11 September 2013 (7731)

***UPDATE***

We tried a bunch of different tests today.

1. We swapped GS13-V2 (good signal) with GS13-V3 (bad signal). Now the GS13-V3 presents a good behavior: the issue doesn't seem to come from the sensor.

2. We swapped, one by one, all the cables between corner 2 and corner 3 (in-air cables, extensions, sensor cables). Those changes didn't affect the results observed: the issue doesn't seem to come from the cables.

3. We plugged the corner 3 GS13s into another feedthrough (L4C feedthrough). No changes: the issue doesn't seem to come from the feedthrough.

4. We swapped the electronics of GS13-V2 and GS13-V3. The issue follows the swap: it doesn't seem to come from the electronics.

 

Thus no conclusion so far. Please let us know if you have any input. We'll think about it and continue the tests tomorrow.

 

sebastien.biscans@LIGO.ORG - 17:56, Wednesday 11 September 2013 (7735)

Find attached a more graphical way to look at all the tests we have done so far.

Non-image files attached to this comment
H1 ISC
alexan.staley@LIGO.ORG - posted 17:28, Tuesday 10 September 2013 - last comment - 21:13, Thursday 12 September 2013(7715)
ISCTEY information cont

In the optimal laser configuration (current = 1.503A, see alog7695), the power before ALS-FI2 was measured to be 39.7mW, while the power after the FI was measured to be 37.6mW. Thus, the throughput of the ALS-F12 was about 94.7%. The first jpg (532nmALSfI2FullCurrent.jpg) shows the beam profile after the ALS-FI2.

The first pdf (BeamProfile532nmRefALSFI2.pdf) is a graph displaying the mode measurement of the 532nm beam with ALS-F12 as a reference. Meanwhile, the second pdf (BeamProfile1064nmRefALSM1.pdf) is a graph displaying the mode measurement of the 1064nm beam with ALS-M1 as a reference. Using the 13.5% width (or 1/e^2 diameter) of both the horizontal and vertical profiles, the radii for the two profiles were determined at various distances from the respective reference points. In addition, the graph includes error bars of one standard deviation. A line of best fit was produced, and the difference between the line of best fit and the data points was plotted in the lower portion of both figures.

Images attached to this report
Non-image files attached to this report
Comments related to this report
alexan.staley@LIGO.ORG - 21:13, Thursday 12 September 2013 (7757)

Sorry, I meant ALS-FI3 in the table layout.

 

Also, as of today, we have moved the laser 1inch closer to the beam path (relative to when the beam profiles mentioned in the alog were taken).

LHO General
cheryl.vorvick@LIGO.ORG - posted 17:19, Tuesday 10 September 2013 (7716)
OPS"

 

Kyle - replace transducer at EX

TMSX measurements lst night

TMSX - Keita and Corey in AM - Betsy, Jeff, Andres in PM - gone now - TF running

BS - alignment in LVEA test stand - some alarms

IMC - Jamie working on Guardian, IMC has drifted out of alignment, WFS won't engage, left off waiting fix

H1 SUS
arnaud.pele@LIGO.ORG - posted 16:14, Tuesday 10 September 2013 (7705)
BS phase 3b M2 TF

After modifying the signs of the gains from the medm, I took a new set of transfer functions of phase 3b (under vacuum) M2 mass of the beamsplitter over the last week end (cf alog 7677 and 7693). During the measurement, the ISI was damped. The plots of the attached document are described below :

- H1 SUS BS M2-M2 undamped transfer functions phase 3b with corrected gain signs (Sept 06th 2013 19:00, in black) compared against H1 SUS BS M2-M2 undamped tf (Sept 06th 2013 15:00, in orange) against the model in blue.

The last measurements are showing a very good match with the model

Non-image files attached to this report
LHO VE
kyle.ryan@LIGO.ORG - posted 16:10, Tuesday 10 September 2013 (7714)
X-end instrument-air "Lead" compressor not running
Will fix tomorrow (after wasp hive relocated)
H1 SEI
vincent.lhuillier@LIGO.ORG - posted 16:03, Tuesday 10 September 2013 (7709)
6.18Hz hunt on ITMY - Source found + Fix in progress

Last Friday, I was mainly searching for the 6.18Hz in the HEPI and ISI actuators/sensors. There was no real conclusion from the study except that the 6.18Hz was not coming from HEPI and it was visible mainly in the vertical degrees of freedoms.

Then, the SUS was suspected. Few tests were done:
- The damping loop and the coil drivers were unplugged. The 6.18Hz didn’t show up in the ISI spectra.
- The coil drivers were re-plugged. The 6.18Hz didn’t show up in the ISI spectra.
- Then, the damping loops were turned on independently. It appears that main chain damping loops using the left and right OSEMs create the vertical motion at 6.18Hz. Then, this motion is transmitted to the ISI and spectra show a 6.18Hz feature.

Two MO OSEM sensor spectra are presented in attachment. In both cases, the ISI is isolated.
- Without SUS Damping (first figure)
- With SUS Damping

J.K and A.P are taking open loop transfer functions.

During the hunt, I saw some excess noise on R0 OSEM RT

Images attached to this report
H1 CDS
david.barker@LIGO.ORG - posted 15:55, Tuesday 10 September 2013 (7710)
Tuesday Maintenance

Added h1iscex channels to the DAQ. 

Stopped h1fw1 writing frames and un-mounted disk system. Dan then replaced both controller cards on the MSR SATABOY RAID. Once the file system was available again, I re-mounted and restarted h1fw1. The data gap on this frame writer is from 11:33 to 13:43 local time. h1fw0 was writing frames the whole time.

Created a new MEDM screen to show GPS diagnostics for the Timing Master unit. It was attached to the SITEMAP via a new SYS related display button. On the next DAQ restart these channels will be added to the frames.

Restarted the h1fe-cds EPICS gateway to see if this sped up the reconnection of MEDM to the Guardian IOCs. It did help somewhat but the reconnection is still slow.

LHO General
bubba.gateley@LIGO.ORG - posted 15:38, Tuesday 10 September 2013 (7708)
Apollo crew
At End X, we relocated the garbing clean room back to the E-module, replaced the curtains and restocked.
Tyler assisted Thomas Vo and Lisa Austin with Ham 4 & 5 baffle assemblies.
H1 AOS
keita.kawabe@LIGO.ORG - posted 14:18, Tuesday 10 September 2013 - last comment - 09:07, Thursday 12 September 2013(7704)
TMSX ISC cable test: Done

We're done with in-vac cable test.

Tomorrow Corey needs to re-rout the cables on ISI back to the intended position (i.e. closer to the real feedthrough).

Comments related to this report
keita.kawabe@LIGO.ORG - 15:35, Tuesday 10 September 2013 (7706)

IR QPDs:

Connected a dirty DB25 cable with a breakout board via dummy feedthrough.

No short circuit, no ground loop.

Used the diode check mode of the DVM to see the continuity of the quadrants, and they are all conductive only from anode to cathode. DVM didn't beep but it showed 500 Ohm-ish number.

Connected a handheld QPD tester and a breakout board, used a strong flash light (Stinger), and the voltage across anode-cathode dropped by about a volt or so when there was a light for all quadrants for both QPD1 and QPD2. Note that the common cathode was biased at +5Volt by the QPD tester, so this was more like the change from 5V to 4V. The drop itself depends on the load impedance of the tester which I don't know and I'm too lazy to look it up. But the basic message is that everything is good.

keita.kawabe@LIGO.ORG - 15:58, Tuesday 10 September 2013 (7711)

Green QPDs:

Diode test mode of DVM didn't work, DVM told that nothing was connected to anything.

The cable section between the ISC table and the feedthrough was exonerated after using this section for the IR QPDs and confirming that IR QPDs looked good.

Swapped the cable back to original configuration, connected the handheld QPD tester, used a flash light, and all quadrants responded to the light correctly. Seems like everything is working.

Disconnected the tester, "measured" the resistance by using DVM though this is in DC and the number the DVM reports doesn't mean much.

In each of the anode-cathode pair in a single QPD, in one direction it was pretty much 1 MOhm and in the other it was about 2 MOhm for both of the two QPDs.

Also, for some cathode pairs in a single QPD, it was about 500kOhm. Doesn't make sense, but I don't know how the DVM sets the voltage and the internal load either.

The green QPDs (Perkin Elmer C30845EH ) are silicon diodes with 8mm diameter while IR QPDs (OSI Q3000) are InGaAs with 3mm diameter. It might be that the photocurrent against ambient light, which is higher in the green ones, was enough to throw off anything done by DVM, or something else is going on that I don't know of.

Bottom line is, the QPD tester result looks good, and probably it's not a good idea to rely on DVM without using the QPD tester. If the handheld tester was the only thing I used (which was the case in EY) I would have said that everything is perfect. 

keita.kawabe@LIGO.ORG - 16:00, Tuesday 10 September 2013 (7712)

Beam diverter:

No short circuit, no ground loop. Reed SWs work. Coil measured to be about 12Ohm.

  "Right" reed SW "Left" reed SW
Beam diverter open open closed
Beam diverter closed closed open
keita.kawabe@LIGO.ORG - 16:04, Tuesday 10 September 2013 (7713)

Picomotors:

Connected the picomotor driver to the air side of the feedthrough via a flipper cable.

Used the picomotor test interface to manually control each picomotor.

Everything worked.

The only thing to remember is, "motor 1" of the controller is connected to the picomotor labeled "D",  2 to C, 3 to B and 4 to A. I'll wait until Sheila comes back next week to see how things were wired in Beckhoff world at EY.

corey.gray@LIGO.ORG - 09:07, Thursday 12 September 2013 (7739)

Ok, I just noticed Keita added all of these sub-entries.  But I just made a picture of the oddity with labeling of the Picomotor cable & Driver assignment.  Oh, and it's also useful to know where each picomotor is where on the Table.  Anyways, it's attached.

Images attached to this comment
H1 FMP
jodi.fauver@LIGO.ORG - posted 13:17, Tuesday 10 September 2013 (7703)
Y End Flooring
I spoke to the folks at Craftsman today. The trim pieces have been ordered and are due in next Tuesday, 17 September. Installation is scheduled for that day as well.
H1 SUS
arnaud.pele@LIGO.ORG - posted 12:33, Tuesday 10 September 2013 (7700)
ITMX TF

Transfer functions of the ITMX at the test-stand have been running overnight yesterday, after last alignement. The attached plots are showing :

(1) M0-M0 undamped transfer functions for the 6 dofs, compared against  "wire rehang" model

(2) R0-R0 undamped transfer functions for the 6 dofs, compared against "thincp" model

Main chain was showing source of rubbing (all dofs of first attachement, except yaw). It turned out that during those measurements, an EQ stop was touching the top of the M0 test mass (main chain). It has been pulled back this morning. Reaction chain looks similar to the model, except for pitch, which we assume

(3) Spectra of ITMX in euler basis for main and reaction chain :

-after alignement of main chain, reaction chain not aligned (blue curve Sept 04th )

-after alignement of main and reaction chain, EQ stop touching the test mass (green curve Sept 10th)

-after alignement of main and reaction chain, after pulling back the EQ stop (red curve Sept 10th)

Looking at the vertical dof of main chain for eg, page 9, we can see that the frequency of the first mode of vertical (0.55Hz) reappeared after the EQ has been moved. 

Data, script and result files will be commited on the svn after this entry.

Transfer functions for ITMX will be running again overnight

Non-image files attached to this report
H1 SEI
filiberto.clara@LIGO.ORG - posted 12:18, Tuesday 10 September 2013 (7702)
ITMY SUS ISI
ITMY Coil driver outputs were disconnected from field satellite units to help Vincent with 6.18Hz noise search at noon. See alog:
https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=7609
LHO VE
kyle.ryan@LIGO.ORG - posted 12:10, Tuesday 10 September 2013 (7701)
Replaced instrument-air transducer @ X-end


			
			
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