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Reports until 13:42, Monday 07 April 2014
H1 ISC
keita.kawabe@LIGO.ORG - posted 13:42, Monday 07 April 2014 (11196)
EY green beam quality is much better than EX

Briefly measured the green return beam on ISCTEY. The first attachment shows the beam profile about 5" or so downstream of the BS that splits WFS and PDH. This is very good, though you might be able to tell that some broad thing is on top of mostly Gaussian main beam.

There are several ghost beams that potentially interfere with the main beam, the closest one being AR reflection from the 1" lens between two MadCityLabs PZT mirrors. The ghost beam is about 3uW in the WFS path while the main beam is 730uW, so this is not that bad, but I'll misalign the lens slightly so that the beam will not come on top of the main beam. The second attachment shows the beam profile of this ghost beam measured at the same position as the first one.

There was also a strong ghost beam coming from the BS to split WFS and PDH path. Total power coming to this BS is about 5.7mW, 5mW goes to PDH and 730 goes to main WFS beam while the ghost beam is about 17uW. This one is shifted in YAW and is easy to block. The third attachment shows this beam measured at the same position as previous two, but the scan head shifted in YAW by about 3mm.

Also there are many many internal reflections coming out of Faraday that  remain there even when the beam path to the chamber is blocked. The total power of these is 115uW. The brightest one is off in PIT but it was easy to block this by using an iris.

Images attached to this report
H1 ISC
stefan.ballmer@LIGO.ORG - posted 13:19, Monday 07 April 2014 (11200)
Control matrix for dither arm alignment
Calculated new output matrices for the IAL arm dither alignment:

Loops to be used:
OSC 1: ITM dither
OCS 3: PZT2 (angular dither at end station)
Loop better not used:
OSC 2: dither PZT1 (~position at the end station, but I don't know how accurately this is true.)

The output matrices are designed to only move the degree of freedom seen by the dither, i.e.
OSC 1:  only drives ITM
OSC 3: drives 1.065*ITM + 1*ETM (PIT) and -1.065*ITM + 1*ETM (YAW)
and for completeness
OSC 2: drives 2.065*ITM + 1.779*ETM (PIT) and 2.065*ITM - 1.779*ETM (YAW)

Calculation:
OSC 3:
- To rotate the beam axis around the end station, the ETM-to-ITM ratio has to be 1-to-gITM.
- The relative signs have to be the same as in the "soft" mode for the WFS output matrix.
OSC 2:
- To parallel-shift beam axis the ETM-to-ITM ratio has to be (1-gETM)-to-(1-gITM).
- Again, the relative signs have to be the same as in the "soft" mode for the WFS output matrix.

H1 PSL (PSL)
justin.bergman@LIGO.ORG - posted 13:08, Monday 07 April 2014 (11198)
PSL Status

I noticed the frontend watchdog was still in FAIL state from last restart---I went into the H1Diode room and reset watchdog.

 

 

Laser Status: 
SysStat is good
Output power is 27.9 W (should be around 30 W)
FRONTEND WATCH is Active
HPO WATCH is red

PMC:
It has been locked 3 days
Reflected power is 1.4 Watts and PowerSum = 11.7 Watts.
(Reflected Power should be <= 10% of PowerSum)

FSS:
It has been locked for 12 min (should be days/weeks)
Threshold on transmitted photo-detector PD = 0.82 V (should be 0.9V)

ISS:
The diffracted power is around 2.54 % (should be 5-15%)
Last saturation event was 13 minutes ago (should be days/weeks)
H1 CDS (VE)
david.barker@LIGO.ORG - posted 12:39, Monday 07 April 2014 (11197)
MEDM sitemap opening from icon bug fixed, added FMCS Fan sensors to SITEMAP

I forgot to define USERAPPS in the sitemap laucher script from icon, this should now be fixed.  You may have to log out and log back in to get the fix (in the mean time start the sitemap from terminal).

I added a link from the VE/FMC pink button to the H0VE_FAN_SENSORS.adl screen.

LHO VE
kyle.ryan@LIGO.ORG - posted 10:40, Monday 07 April 2014 (11195)
Increased voltage of IP9 pump #1 from 3000V to 5000V
Pump #1 was found to be 3000V and pump #2 5000V
H1 SEI
filiberto.clara@LIGO.ORG - posted 09:25, Monday 07 April 2014 (11193)
EY ISI GS-13 Corner 2
Last Friday, Jim W. reported an offset on corner 2 of GS-13. Found BSC ISI Anti-Alias Interface Chassis (S1103401) had one of its outputs railing. AA Board S1101875 had U3 AD8622 on channel 6 replaced. 
LHO VE
kyle.ryan@LIGO.ORG - posted 09:20, Monday 07 April 2014 (11194)
~0900 hrs. local -> Increased IP1 from 5000V to 7000V


			
			
H1 CDS (DAQ)
david.barker@LIGO.ORG - posted 08:44, Monday 07 April 2014 (11192)
CDS model and DAQ restart report, Friday, Saturday, Sunday 4th,5th,6th April 2014

Combined report for the weekend

model restarts logged for Fri 04/Apr/2014
2014_04_04 15:07 h1isiham5

model restarts logged for Sat 05/Apr/2014
2014_04_05 07:27 h1fw1
2014_04_05 23:53 h1fw1

model restarts logged for Sun 06/Apr/2014 None reported

h1isiham5 expected, h1fw1 unexpected.

H1 SEI
richard.mittleman@LIGO.ORG - posted 18:53, Sunday 06 April 2014 - last comment - 19:30, Sunday 06 April 2014(11189)
ISI Performance Plots

Last we we installed some lower frequency blend filters into the rX and rY filter banks for stage 1 and 2 of the ETMX and ITMX ISIs. This was motivated by seeing a lot of coherence between stage 1 and 2 rY motion to the optical lever pitch signal around the first suspension mode (COH >0.8 from 0.2-0.6Hz more or less).

 

 I've taken some performance plots for these controllers (all data was taken with level 3 controllers)

  Units are nm/rHz or nRad/rtHz

  I tested three states, 11 DOFs using TCrappy, Stage 1 rZ using Start, - Black and Orange dotted lines T240 and Gs13 signals

                                         9 DOFS using TCrappy, Stage 1 and 2 rY using TBetter (lower blend frequency see plot) Stage 1 rZ using Start Cyab line T240s

                                        10 DOFs using TCrappy, Stage 1 and 2 rY using TBetter Blue, Brown and Pinks curves, T240, Gs13 and L4Cs

  The interesting plots are rY which shows lots more isolation at the suspension mode, the GS13 sensor noise is ~3E-10 m/s/rHz @ 0.45Hz. Which says that we are way into the sensor noise (today was a windless sunday), so maybe we can relax the blend a bit and knock down the microseism a bit., I'm a little suspicious that i made a calculation error here

 

 

  The X plot shows some increase below 0,2Hz

 

  The rZ plot shows a fair amount of microseism which is being increase by the Tcrappy blends, we should try a more aggressive blend for stage 1 rZ

 

Also ITMY does not have a good set of level 3 controller installed

Images attached to this report
Comments related to this report
richard.mittleman@LIGO.ORG - 19:30, Sunday 06 April 2014 (11190)

I did screw up the noise floor, the GS13 spectrum hasn't  been taken out of the spetrum  yet,that adds a factor of 1/5 and makes the noise floor ~8E-11m/s/rtHz, the spectrum is at ~1E-11m/s/rthz at 0.5Hz

H1 ISC
keita.kawabe@LIGO.ORG - posted 18:36, Friday 04 April 2014 (11185)
Reduced diode current for ISCTEY Prometheus

On the test sheet of this unit (SN 2240A), the current was specified at 1.61A. Since the potentiometer for the current was maxed out and the current clamp LED was on, though the current was 1.63 I turned it down to 1.61. No current clamp LED any more.

H1 ISC
stefan.ballmer@LIGO.ORG - posted 17:40, Friday 04 April 2014 - last comment - 12:04, Saturday 05 April 2014(11182)
Today's WFS battle

 

Sheila, Chris, Stefan

In order to tackle the changing sensing matrix problem today we tried to use the soft-hard degree of freedoms. The theory
is that the beam overlap is much more sensitive to the hard DoF, thus this should be the one that is easily sensed independent
of the sensing-matrix-of-the-day. Then a gain hierarchy could be used to lock down everything.

Thus we started with calculation the theoretical hard-soft output matrix. Details can be found at
https://gwic.ligo.org/thesisprize/2011/dooley_thesis.pdf
For reference, the desin RoCs are ETM: 2245m, ITM: 1934m, giving (with L=3994.5m) g_ETM =-0.779, g_ITM =-1.065. 

We messed up the initial calculation and worked with
ITM =   .571  .495  * SOFT 
ETM    -.495  .571    HARD 
for yaw, and opposite off-diagonal sign for pitch.

while we should have used
ITM =   1.000 -0.867  * SOFT 
ETM     0.867  1.000   HARD 

We verified that the corresponding modes were mostly hard/soft by observing the power drop for a fixed offset in soft/hard.
The hard mode has the bigger power drop. 


Next we engaged DoF's one at a time, starting with the hard modes.

For yaw, DoF2 (hard mode) we inverted the last measured sensing matrix and converted it into the soft/hard basis. We got
SOFT =   5.14  11.7 *  WFS A 
HARD    -.272  1.04    WFS B
The hard loop easily closed that way. 

For the pitch DoF's we first tried the same scheme, but noticed that the hard mode ended up much stronger in what should have
been the soft signal. So instead we used the diagonal matrix WFS A -> hard, WFS B -> soft
SOFT =   0 1 *  WFS A 
HARD     1 0    WFS B
Again closing that loop was straight forward.

Next we closed the soft loops with low gain. That seemed straight forward. But then we started noticing that we saturated the PUM
with slow signals because the top-mass bleed-off was too slow. (We moved the bleed-off filters to the unused UIM filters to keep
the reliev script working.)

Before we could fix the saturation issue we noticed that the cavity transmitted spot on the camera did no longer line up
with the straight shot beam once all loops were on. So we manually realigned the cavity and tried to reengage the WFS, loop-by-loop.
Yaw hard worked fine, but to our surprise pitch hard didn't work at all - the error signal behaviour was completely different.

So our tentative conclusion is that our "sensing matrix of the day" doesn't seem provide a clean signal for the supposedly easy
hard pitch mode.


Comments related to this report
rainer.weiss@LIGO.ORG - 08:13, Saturday 05 April 2014 (11186)ISC
I have been following the struggle to get a stable sensing matrix for the WFS and urge you to make sure
the WFS head isn't driven into oscillation by the rf on the optical beam hitting the detector. This was a central
problem in the WFS heads in initial LIGO and led to the rewiring of input leads in the WFS head. The
symptom was that at some critical intensity into a vulnerable quadrant (not all quadrants in a given WFS head
did this), the amplifier attached to the offending quadrant would begin to oscillate at the drive frequency and
produce an output signal with a different RF phase, the transition from the correct phase to the phase when
oscillating was quite sudden as a function of the intensity. The rewiring and the removal of the gain adjust
chip in each channel stopped this. Do you suppose this is happening now? A good test is to illuminate the 
quadrant with RF modulated laser light and display the output of all four quadrants on an oscilloscope while
one varies the laser intensity and the amplitude modulation index. One of the traces will shift in phase relative 
to the others on the screen.  
christopher.wipf@LIGO.ORG - 12:04, Saturday 05 April 2014 (11188)

(Sheila, Stefan, Chris)

We again closed 3 WFS loops (the hard pitch loop, and both yaw loops), after decentering the beam on the WFS heads.  In this state, I compared Rich's new blend filters (Tbetter) and the standard (Tcrappy), finding a modest but repeatable improvement.

The reason we investigated the centering was that, with the beam spot well centered, the response of individual WFS quadrants to pitch drives on ETMX and ITMX was bogus. All quadrants responded with the same phase, as if it had been a length drive. We then suspected that an ugly beam profile on the WFS could make the DC light levels on the quadrants unreliable for centering. Moving the beam spot down on WFS_A, sure enough, there was a "happy place" where a usable error signal for the hard pitch DOF was recovered. We will check the beam quality on the WFS again to see if it can explain this.

The attached spectra show the ALS COMM noise with the ISI RY blends on Tcrappy (refs 10/11) and Tbetter (refs 8/9). Also, Rich advised us of a problem with the RZ blends, so those were left on Start for all measurements.

Images attached to this comment
H1 SUS (SUS)
giles.hammond@LIGO.ORG - posted 17:23, Friday 04 April 2014 (11184)
ITMY modal frequencies
Today we finished off measuring the modal/violin frequencies of ITMY. Everything looks fine. These are briefly summarised below:

Modal
			frequency (Hz)			bin width (Hz)
pendulum		0.65				1.56E-02
transverse		0.656				1.56E-02
pitch			1.109				1.56E-02
yaw			1.094				1.56E-02
bounce (*)		6.87				1.25E-01
roll   (*)		9.7				1.25E-01
	
* Note: bounce and roll will be sqrt(2) higher when both PUM and ITM are free (9.7Hz/13.7Hz)

Violin modes						
			frequency (Hz)			bin width (Hz)
Back Left		501.5	          		2.50E-01
Back Right		501.3		        	2.50E-01
Front Left		504.2			        2.50E-01
Front Right		502.8			        2.50E-01

The average violin mode is 502.4Hz with a standard deviatioin of 1.3Hz (+1.7Hz, -1.1Hz)

Fibre guards have now been installed.

Giles, Travis, Jason, Gary, Betsy 
H1 CDS (CDS)
david.barker@LIGO.ORG - posted 17:15, Friday 04 April 2014 (11183)
medm launcher icon and guardian

I have been trying different things to fix the problem of starting of guardmedm from a sitemap which in turn was started from a panel icon. Following Keith's system I configured the icon to run a script to start MEDM instead of running it directly and it seem to have fixed the problem. If you are logged in as controls and need the new configuration you will have to log out and log back in again. 

I was not able to print the error of why a directly launched sitemap was unable to run guardmedm. I tried using fie paths in full or redirecting stderr to a file to no avail. If I ran within a terminal to get stderr printed it started working.

LHO VE
kyle.ryan@LIGO.ORG - posted 16:50, Friday 04 April 2014 (11181)
Sprayed new joints @ Y-end with helium
Sprayed "around" each new joint with an audible flow of helium for ~25 seconds duration -> Access to several joints was impeded by various obstructions and, in many cases, I could not apply the helium to the test slots etc. -> No flanges were bagged and this exercise should not be considered a definitive test but should have revealed any significant offenders.  

LD indicated baseline signal was "offscale" < 10-11 torr*L/sec for the 1st half of testing -> I guessed the time constant to be ~100 seconds for this V/S -> to validate the less than one time constant application duration I verified that the baseline helium indication was legitimate by spraying the O-ring at the inlet to the LD and observing the permeation.  The signal rose to a high of 8 x 10-9 torr*L/sec over the course of 60 minutes -> I let the signal decay to < 8 x 10-10 torr*L/sec before resuming and testing the remaining joints
H1 ISC
alexan.staley@LIGO.ORG - posted 16:22, Friday 04 April 2014 (11180)
EY PLL OLTF

End Y PLL Open Loop TF results:

Servo Board Settings:

 

The UGF is at 23kHz with a phase margin of 52 deg (consistent with HIFOX). Using the AG spectrum analyzer, I tried finding the PZT resonance. The data is a bit ratty, but there appears to be a resonance a little below 200kHz (see the picture -- the two pictures were collected with different BWs; the first at 300Hz and the second at 2Hz; this notch-looking feature seemed to be repeatable...).  Meanwhile, the board has a notch at around 280kHz, which also seems to appear in the pictures.

 

I have also uploaded and plotted the data I collected.

Images attached to this report
Non-image files attached to this report
H1 SEI
patrick.thomas@LIGO.ORG - posted 16:03, Friday 04 April 2014 - last comment - 10:39, Saturday 05 April 2014(11174)
Plots of SEI watchdog trips
Attached are plots of SEI watchdog trips.
Images attached to this report
Comments related to this report
jameson.rollins@LIGO.ORG - 10:39, Saturday 05 April 2014 (11187)

It would be useful if there was some context for each of these.  Do we know what was going on at the time of each trip?  It looks like there are four distinct events:

  • 09:15 ITMY ISI stage 1/2 drives
  • 14:52 BS ISI GS13
  • 15:10 BS HPI L4C, BS ISI T240
  • 15:21 ITMY HPI L4C

It would be useful to know what was going on around each of these times.

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