Cheryl reported that IMC wouldn't lock and WFS was breaking the lock.

When I came into the control room the DC alignment of MC seemed OK. Disabled ASC output and manually enabled the PZT offset.

MC2 M3 watchdogs were found tripped, and assuming that this stage is necessary for locking I reset the watchdog.

After this IMC would lock but it lasted for 3 seconds that's incidentally the same as the ramp time for M2 and M3 lock filter. The lock was repeatedly broken by an oscillation at a few Hz that develops right after M2 and M3 lock filters were turned on.

I disabled the L-L element of the drive align matrix of M2 and M1, and the lock would last until the M3 coils rail.

Apparently something changed between this morning and afternoon, and now I had to make the M2 and M1 gain ridiculously small, otherwise a few Hz oscillation just kills the lock.

For the moment I changed the setting in Stefan's lock script such that H1:SUS-MC2_M2_LOCK_L_GAIN is 0.008 (VS the nominal 0.2) and M1_LOCK_L_GAIN is 0.3 (VS the nominal 1). I didn't fix anything, whatever the problem is it's still there, and the lock lasts for only a few minutes at most until M3 coils rail.

I haven't done anything to WFS, I don't know if it was doing something bad, but the DC alignment right now is OK.

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.

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.

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.

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.

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.

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

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

Will fix tomorrow (after wasp hive relocated)

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

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.

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.

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).

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.

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

Phase 3b spectra have been measured on the beamsplitter after Jeff Kissel implemented the new filters.

The attached pdf are showing a comparison between spectra taken in March 26th phase 3a (in blue), and May 17th phase 3b (in green) with the suspension damped (first pdf) and undamped (second one). The ISI was damped.

Data, measurement lists and figures have been commited on the svn