Ran purge air compressors for ~10 minutes @ ~0945 hrs. local

The h1seib1 front end computer was locked up since Aug. 10, 18:46 PDT.  Restarted computer this morning at 08:35 PDT.  IRIG-B timing was bad until 08:39.  No other computers were glitched restarting this dolphin-connected front-end.

model restarts logged for Sun 10/Aug/2014
2014_08_10 08:32 h1fw1

unexpected restart of h1fw1, other writer was running, no data loss.

• laser safe--->BS Oplev work in morn
• laser hazard at ~10am
• HAM6/ISCT6 alignment work
• LVEA pumping stalled:  HAM2 annulur still needs to be done (need to torque down HAM1 doors)
• ETMy:  back to low pressure.  May have a broken ESD channel (will investigate); will need Richard due to High Voltage
• EX:  doesn't look like it's pumping down normally
• Tiltmeter:  tightening up and sealing mini chamber today
• EY:  May require a 3rd Discharge test
• Bring in (1 of 3) empty storage container from high bay in the morning (Apollo)
• EY B&K hammering (Tim Mcdonald)
• H2 enclosure work:  PD Arrays (Peter King)
• Fire Dept here today
• Couple of quads moved to 3ifo storage in LVEA

(Borja)

This entry is a summary of the manual measurements results of the ETMY charge done before Rai's ionized gas injection discharge run1 and run2.

The measurement technique is the standard procedure of injecting a sinusoidal signal of 4Hz and 91.5Volt in amplitude to each quadrant of the ESD (with the exception of quadrant LL because it did not respond to the excitation, more about this on another entry). Then we monitor the deflection of the ETMY both in Pitch and Yaw by looking at the oplev which was carefully centre before any measurement was taken. The deflection was measured in diaggui as power spectrum plot of pitch and yaw, with a BW = 0.01Hz on the range between 1 – 5 Hz and averaged of 2 (for the before measurements) and 3 (for the after discharge measurements) times.

During the measurements the coherence between ‘excitation and Pitch’ and ‘excitation and Yaw’ was monitored to be sure that the excitation was observed. The phase (in degrees) of the transfer function between excitation and oplev pitch and yaw was measured to take into account the sign in the deflection.

Attached to this entry I provide a document with the results for each measurement. Also I provide the combined plots of the results in the standard way “Normalised deflection [µrad/V] vs V BIAS” where the deflection is normalised by dividing the deflection with the excitation amplitude (91.5Volt). The plot contains quite a lot of information (well explained by reading the plot legends) so a zoom version is also added around the Veff values (or deflection zero crossing).

Next I show a table with the summary, providing for each quadrant values of the pitch and yaw slope and Veff.

Looking at the Veff in the table above we notice that the first discharge run was effective by a factor between 2 and 4 depending on quadrant and type of deflection (pitch or yaw). However the second discharge did not have so big effects and in some cases showed an increased charge.

(R. Weiss)

Rai has suggested that the results may suggest that the gate valve, in the second ionized gas discharge run, may have not been opened into a clear aperture even though the measurements of the ion currents were larger. It would be advisable to learn the best injection method for which It all needs to be done a third time. Rai thinks that the results so far are useful enough to decide whether we want to build more of the ionizers. Another very important step in the final decision will be the effect that the green laser light will have in the charging of the ETMY.

G.Moreno, K. Ryan, B, Sorazu, J. Worden, R. Weiss
Preliminary results from the first discharging indicate the charge has been reduced to 1/4 of the originally
measured charge. As we were dissatisfied by the negative to positive ion ratio and the flow rates in the initial
attempt, we made a second injection on August 8 with 1/2 the flow rate and about 3 times the ion current
into the test mass chamber. The charge on the etmy has not been measured yet. The new flow conditions are closer
to those in the original experiment done at MIT which reduced the charge to 0 +-10% of its initial value.
Again, once all the data is together, a more informative posting of the results will be made.

model restarts logged for Sat 09/Aug/2014
2014_08_09 01:52 h1fw0
2014_08_09 04:02 h1fw0
2014_08_09 04:07 h1fw0
2014_08_09 04:12 h1fw0
2014_08_09 04:16 h1fw0
2014_08_09 04:20 h1fw0
2014_08_09 04:24 h1fw0
2014_08_09 05:16 h1fw0
2014_08_09 05:22 h1fw0
2014_08_09 05:31 h1fw0
2014_08_09 05:41 h1fw0
2014_08_09 05:53 h1fw0
2014_08_09 05:56 h1fw0
2014_08_09 06:07 h1fw0
2014_08_09 06:10 h1fw0
2014_08_09 06:16 h1fw0
2014_08_09 06:20 h1fw0
2014_08_09 06:30 h1fw0
2014_08_09 06:52 h1fw0
2014_08_09 07:04 h1fw0
2014_08_09 07:09 h1fw0
2014_08_09 07:17 h1fw0
2014_08_09 07:20 h1fw0
2014_08_09 07:25 h1fw0
2014_08_09 07:33 h1fw0
2014_08_09 07:37 h1fw0
2014_08_09 07:42 h1fw0
2014_08_09 07:50 h1fw0
2014_08_09 07:53 h1fw0
2014_08_09 08:01 h1fw0
2014_08_09 08:06 h1fw0
2014_08_09 08:12 h1fw0
2014_08_09 08:16 h1fw0
2014_08_09 08:23 h1fw0
2014_08_09 08:28 h1fw0
2014_08_09 08:31 h1fw0
2014_08_09 08:36 h1fw0
2014_08_09 08:40 h1fw0
2014_08_09 08:48 h1fw0
2014_08_09 11:48 h1iopsush2b
2014_08_09 11:48 h1susim
2014_08_09 11:54 h1iopsush2b
2014_08_09 12:11 h1iopsush2b
2014_08_09 12:11 h1susim
2014_08_09 14:03 h1fw0
2014_08_09 14:11 h1fw0
2014_08_09 14:28 h1fw0
2014_08_09 14:42 h1fw0
2014_08_09 14:59 h1fw0

Unexpected restarts of h1fw0 due to disk problems. Restart of crashed h1sush2b. Restarts of h1fw0 following disk repair.

We'll stay at this power level until we confirm the amount of loss in IMC.

Alexa, Kiwamu

We performed another ring down measurement using the REFL port. The data still did not make sense.

We probably should switch the approach to something else e.g. a cavity pole measurement (see alog 5429).

The setup:

Since we had the PRM reflection on ISCT1, we used this light instead of the one in IOT2L (see alog 13280). First of all, wiggling PRM and looking at the REFL analog camera, we confirmed that there was no clipping in the REFL path. In fact, the beam already looked quite centered on the REFL camera from the beginning because of our alignment effort (see Alexa's previous alog 13317). We intentionally misaligned PR2 to avoid any interference from the main interferometer.

We moved a PDA55, which had been on ISCT1 for triggering the REFL shutter, to a point right in front of the 3-f broadband PD. In the process of aligning the beam, we touched a steering mirror that was in front of the broadband PD. We then made sure that the gain setting is at its minimum of 0 dB. Since at this point the light was too bright for the PDA55, we placed a ND1 filter to cut down the laser power. This resulted in a DC voltage of about 440 mV when the IMC is in lock -- therefore the dark offset of the PD was negligible this time.

The results:

We repeated the same measurement as the previous one, but with the PRM reflection. We flipped the polarity of the fast path in the IMC common mode board to rapidly unlock it. Every measurement, we obtained a 1/e time of roughly 20 usec. This was coarsely measured with the cursor in a digital oscilloscope. Obviously, the results don't make sense. The attached is a photo of the oscilloscope display.

In Y-end from 1735-1745 hrs. local, X-end 1755-1800, LVEA 1805-1810

Alexa, Kiwamu, Borja, Stefan

With the IMC locking reliably, and the input beam hitting the BS, we
- Found the good alignment for PRM and got the REFL beam centered on ISCT1.
- tweaked the PR2 alignment to get fringes in PRX (ITMY misaligned)
- locked PRX on the carrier and tweaked down the REFL power with PR2 and PRM.
- installed a camera looking down to HAM5 from HAM4. We could clearly find the beam on the Faraday cage.
- Using SR2 we steered the beam through the Faraday, and verified that it arrives in HAM6.

Attached is an alignment snapshot.

Remarks:
- while the input beam through IM3,IM4 and PR2 might still be going a bit up and down, after PR3 it should be pretty good (we didn't change the PR3, BS, ITMX and SR3 aligment (compared to alog 12816 )
- we didn't try to tweak the SRM yet.

Greg, Dan, Dave

h1fw0 is back up and running. 

The problem was with disk9 in the raid raid-dcs-h1a. Its status led was flashing yellow instead of steady green. But it appears to have only partially failed, and the raid continued to try to use it. The result was an unstable file system which cannot keep up with the frame writing.

Step 1 was to run the Oracle 'guds' command to provide diagnostics.

The second step was to stop reading this file system and only have h1fw0 write it, still unstable.

The third step was to power cycle the solaris box h1ldasgw0, remount to h1fw0 and restart frame writer, still unstable.

The fourth and most drastic step, was to walk to the LDAS server room and physically remove the offending disk #9 from the raid (hot removal). This forced the raid to stop trying to use disk9 and to start using the hot-swap spare.

At the time of writing h1fw0 has been running for 20 mins, which is longer that it has since 4am this morning.

Came on site to resolve this issue. Console for h1sush2b shows many errors and is frozen. First recovery attempt is a power cycle of the front end computer.

First removed h1sush2b from the Dolphin IPC network using h1susb123 as a remote disabler, this worked.

Power cycled the computer, let the models start themselves. As I suspected, h1sush2b was actively corrupting the DAQ data streams to the concentractor. As soon as h1sush2b was powered down all front ends DAQ data became good again.

IOP model started with large IRIG timing error, daq status 0x4000. Stopped h1susim and restarted h1iopsush2b, still get IRIG-B errors. Checked IRIG-B is OK, suspect problem is at the IO Chassis end.

Step 2 was a full power down of both computer and IO Chassis. Stopped all models, and removed h1sush2b from Dolphin using itself to do this. Powered down h1sush2b. In CER, turned front panel switch to OFF, this did nothing. Disconnected the 24V-DC power cable at the power strip, noting that this was the only thing plugged into this strip (the two other IO Chassis use a different strip) maybe a hint. Powered IO Chassis backup, switch to ON, waited for timing slave to sync. In MSR power up h1sush2b, both models start with no errors.

So not sure why h1sush2b died, but suspect a glitch in CER at 00:08 this morning.

Two unrelated problems with the DAQ ongoing:

1. disk9 of the DCS raid system for h1fw0 failed at 10pm Friday night. h1fw0 lost its file system at 1:50am this morning and has not been running since then.

2. h1susim front end has failed and has caused a DAQ error for the following frontends: h1susb123, h1sush2a, h1sush34, h1sush56, h1susauxh2, h1susauxh34, h1susauxh56, h1sieb1, h1sieb2, h1seib3, h1seih16, h1seih23, h1seih45, h1psl.

both end stations have good DAQ data.

I've emailed LDAS regarding the disk failure in the LDAS server room.

For problem 2, I'm going to try restarting the DAQ data stream from those frontends.

model restarts logged for Fri 08/Aug/2014
2014_08_08 00:32 h1fw1
2014_08_08 04:32 h1fw1

unexpected restarts of h1fw1

(Stefan, Kiwamu, Koji, Alexa)

We repeated the ringdown measurement with the low gain setting (0dB compared to the nominal 30dB) and the ND0.6 filter removed (we still need to eventually revert to the nominal configuration). This time we found that the ringdown time was approximately 25µs, which is still larger than what we expected. We want to repeat this measurement with REFL from ISCT1, however, we could not find the beam for a while and then got distracted with other things...This is still to be done.

We adjusted the gains, phase rotation, I-Matrix and IMC WFS matrix. We can now engage the WFS; this increased the trans PD to ~1200 and was stable. I have attached a screenshot of the current configuration.

We increased the PSL power to 1.9W.

The beam is too high on MC3 by 1.5mm and horizotanlly off by 2.138mm in the direction away from IOT2L. This result is almost the same as the previous measurement in alog 8943, so we are fine with this off-centering.

(Richard, Cyrus, Alexa. Kiwamu)

GigE camera 08 of PR2 was first rebooted and then had to be adjusted because the image was clipped. 

(Borja)

Several issues has not allowed me to drive the ETMY ESD until late afternoon today. At this point I was able for the first time to test, with real data, the automation code for the ESD charge measurements develped at Livingston. I did have previously adapted it for Hanford's slightly different configuration but this was the first time I was able to test its results. Unfortunately the automation on the injection, data request and analysis is not robust, not allowing for the whole process to finish several times. Also the code does not take into consideration conversion factors on the V BIAS from Voltage to counts and viceversa. I assume this is taken care in Livingston outside of the code but certainly that solution does not make it universal.

Looking at the procedure with Rai I realized that we have to be careful on the level of the driving signal amplitude to be below the minimum V BIAS used in the analysis otherwise linear approximation assumptions in the methodology are no longer valid.

Rai is leaving on Saturday and we need to apply his discharging technique before then (optimally tomorrow). Before this takes place we need to have some ESD charge measurement data so that we can compare with data taken after the discharge and see the effects observed. This time constrains has made me decide to do the measurements manually tonight. I may be able to run the automation code afterwards and compare it tomorrow with the manual measurements but this may not be possible. See manual measurements in the attached document.