One thing to note about this week's diagnostic breadboard scans, is that the reference cavity transmission has deteriorated
down to ~1 V.  Although the power reflected by the pre-modecleaner is about the same, at ~ 2.1 W.  For reasons unknown at the
moment, the frequency stabilisation servo had a tendency to lose lock and/or oscillate.  I reduced the common gain from 30 dB
to 27 dB for these measurements to see if that'd make things a little more robust - at least whilst the scans were being
conducted.  The input modecleaner was flashing during this period too, which would partly explain why the reference cavity
was blinking.

The relative power noise measurement looks the same as last week.  Nothing significant to report.

During the frequency noise measurement, the input modecleaner lost lock which caused the reference cavity to lose lock.
The pull on the laser frequency was such that even the pre-modecleaner in the diagnostic breadboard lost lock for a split
second.  Both error and control signals are higher than the reference measurement, most likely because of the problems mentioned.
Both are about a factor of 100 higher than normal.  There is a peak both spectrums at 10 Hz that was not present in prior measurements.
The problems seem to also coincide with a peak in the 1-3 Hz seismic noise region.

A repeat of the frequency noise measurement when things appeared "quieter" still had a peak at 10 Hz.  The measurement was disturbed by
a period of oscillation due to the input modecleaner losing lock and trying to re-acquire.

The beam pointing measurement looks nominal.  Nothing significant to report.

The mode scan looks nominal.  4.3% higher order mode power, higher order mode count 54.

The intensity stabilisation power noise measurement looks good.  Better than the reference measurement everywhere except above ~7 kHz.

Kiwamu, Dan, Alexa, Rana, Sheila

Today we spent most of the day working on PRMI sideband locked, we had trouble acquiring lock, Kiwamu thinks this is a problem with MICH.

• We measured the gain and phase of REFL 45 I and Q compared to REFL 9 I and ASAIR 45 Q (we would like to switch to using REFL 45 I +Q for PRCL and MICH)
  • REFL 9 I/REFL 45 I = 0.2
  • REFL 45 Q/ ASAIR 45Q = -0.108
  • we were able to transition PRCL to REFL 45, but didn't get a chance to try transitioning MICH.
• We noticed that the alignment of PRM that gives the best build up of PRX isn't a good alignment for PRMI.
• Using PRX, we tried changing our filters for PRM, we lowered our cross over to something like 4.5 Hz, we only have something like 30 degrees of phase there. At 3 Hz the model of the suspension says that there is a resonance.  We are now using distributed control on PRM, and not using the plant inversion filter.  (Screen shot of configuration attached.)  Kiwamu will attach open loop gain.  We are still using PR2, no changes to those filters.

Alastair & Greg

On Saturyday we finished with the alignment on the Y-arm table and made an off-table projection of the beam to check the size and shape.  Photo of the bench is attached.  The visible laser was aligned to the CP and the CO2 laser coaligned to the visible laser.  It should all be ready for testing on the CP now.

Some notes:

There are a few things still not in their final configuration.  Firstly we need to fab a housing for the FLIR camera to match the X-arm one.  Then the camera needs installed on the bench.  We also need to install the IR sensor on the viewport before the system is run long-term unattended.  The laser had a problem with its RF driver and we swapped in a spare but were missing power connectors (5pin 40A connec) so at the moment the laser is running on a Sorensen next to the table.  The connectors are ordered.  The mask is mounted in its flipper mirror but the flipper is not connected up yet.  The flipper also needs the up/down sensor.  And we still need to put in the second flipper with the annular heating mask.

Data from this table:  Will add this once I locate my notebook, but the following was measured:

Polarizers 2 & 3 extinction ratios measured: 

Power meter used to calibrate output power to CP as a function of rotation stage (1/2 wave plate) angle :

QPDs are installed and aligned.  Each quadrant calibrated for power and center position measured.  We'll need to decide if we want to calibrate for position or use the values from the X-table where the QPDs are mounted on translation stages.  Calibration data: 

Since it seems like a cumbersome job to walk the beam on PR2, I calculated the necessary combination of optics to walk the beam on PR2 without affecting the beam position and angle on BS and ITMs. I put this combination in INP2 of the WFS output matrix (as INP1 is being experimented for WFS).

You should be able to, say, give INP2 WFS filter an offset to manually walk the beam, and/or you should be able to route one of the POP sled QPD signal to it to servo the beam position on PR2.

Changed default print driver for matlab to psc2 to enable color printing on the control room printer.  Was originally ps2.

I'm attempting two jobs on opsws3.  Please take it easy on this work station but I won't say don't use it.

Please reenable any watchdog trips on the HEPI, ISI, and SUS.

My tf on Sat at ITMX went poorly, so I will be taking a new tf ITMX, starting at midnight tonight. Re-taking tf's on ETMX, because I have the opportunity, and I haven't taken good data there since the last time we opened.

LVEA is Laser Hazard

09:49 Hugh – Recycling HAM5 HEPI
10:04 Aaron – Installing illuminater chassis at HAM2 and HAM5
10:18 Betsy & Travis – Working in west bay on 3IFO Quads
10:40 Dave – Cabling at the HAM6 bay
13:12 Karen – At Mid-Y
14:20 Besty & Travis – Working in LVEA west bay on 3IFO Quads
14:37 Peter – Going to Diode room to reset PSL watchdog

Jason, Rana, John

Credit for this one goes to John Worden.  He noticed the sawtooth pattern seen by the ITMy optical lever was very similar to that produced by the instrument air system re-pressurizing itself.  Sure enough, we go out and the copper instrument air line is touching the north end of the ITMy transmitter pier, so we moved it.  As can be seen on the attached graph, after the move the sawtooth pattern was gone.  I'll keep an eye on this over the next couple days to make sure this is actually fixed.

PSL Status: 
SysStat: Green 
Output power: 33.7w  
Frontend Watch: Red
HPO Watch: Red  

PMC:
Locked: 3 days, 14 hours, 33 minutes
Reflected power:    2.0w
Power Transmitted: 22.9w 
Total Power:       24.8w 

FSS:
Locked: 0 days, 1 hours, 40 minutes
Trans PD: 0.586v

ISS:
Diffracted power: 11.206%
Last saturation event: 3 days, 14 hours, 24 minutes  

Frequency of DAC lock out events (requiring IOP model restart to fix). Two more events since my last summary alog Link

9/11 2014 h1seih45

9/10 2014 h1seih23

8/11 2014 h1susb123

8/9 2014 h1seih23

4/21 2014 h1sush2a

3/18 2014 h1sush2a

2/27 2014 h1seih23

12/16 2013 h1seih23

11/7 2013 h1sush2a

11/7 2013 h2sush34

8/8 2013 h1seih23

Like HAM4, no problem taking HEPI down with Guardian, loading the new filters and bringing the loops back on with Guardian all while the ISI remains isolating.  Checked DTT and it looks better but I really need the full TF-hopefully tonight.

SEI – Working on TFs on HAM2 and HEPI commissioning

OpLev – Working on ITMY sawtooth laser glitch. 
	       Swapping BeamSplitter laser due to glitch

TCS – Laser alignment of TCS-X table

Test Mass Charging experiment is making measurements in the LVEA west bay cleanroom

The HAM2 TF data after the 1st couple of sections got corrupted so this needs to be run again.  Still, we can see that again the sharpe peaks between 10 & 40 hz, believed to be HEPI structures, are lowered in frequency and Q.  Also, the H3 CPS response does not develop into the deep zero around 6-7hz.  The lower UGF of 2hz on the HEPI position controller is believed to be the reason.  The attached plot compares the HEPI locked to closed HEPI Position loops ISI TFs.

Heard the chiller alarm this morning.  Found the water level to be a little below minimum.  Added about 400 milliliters.