J. Kissel

I've gathered full sets of close out transfer functions for H1SUSPR3 (and HLTS) and H1SUSITMX (a wire-suspended QUAD). The results look good enough to proceed with pump down!

Yellow Flags:
H1SUSPR3 -- The Q of the 1st first vertical mode appears to be reduced from previous measurements of the free in-air suspension. I attach the .pdf of the raw DTT results for this DOF as well, to show that the coherence is still good for this resonance, implying a real loss mechanism. This is also noticeable on the R and T degrees of freedom as well, again only on the first resonance. But all resonant frequencies are in the same place, so the dynamics are as expected and well-behaved. In the end, we want these modes damped anyways, right? However if it is a real source of loss, then it's a source of noise. However, given that these are all the lowest frequency resonance, and it's the V/R DOFs it means that the loss is most likely on the top blade springs -- well away from the optic, so what ever excess noise is present will be filtered by the otherwise free SUS.

H1SUSITMX -- The only thing awry here is that the R0 V and R DOFs show much higher response (an overall DC scale factor) than expected. However, it was immediately obvious that this is a result of calibration filters not turned on. Taking a look, we immediately discovered this to be the case -- the "to_um" filters has been turned off for ONLY the R0 LF and RT OSEMs. They're now turned on, and we will be sure to capture a new safe.snap so this problem doesn't arise again.


All data and common scripts (with updated meas:ists) are committed to the SusSVN as of this entry.

• Lateral Error: +0.19 mm
  • Tolerance: ±2.0 mm
• Vertical Error: +1.88 mm
  • Tolerance: ±2.0 mm

Tested the cables at the Sat. Amp connector to Ground.  Verifying Pin 13
Was attached to Shield then Pin 13 to Ground.
H1:SUS_ETMX-1 PASSED
H1:SUS_ETMX-4 PASSED
H1:SUS_ETMX-7 PASSED
H1:SUS_ETMX-16 PASSED
H1:SUS_ETMX-19 PASSED
H1:SUS_TMON-1 Failed.  Showed short to ground somewhere between Sat Amp and OSEM.
H1:SUS_TMON-4 PASSED

Hugh Radkins and Richard M

Tested the ETM-X ESC cable.  Hugh was kind enough to work inside the chamber while I checked the connection from outside.  ON first inspection 3 out of the 5 pins were making contact.  Hugh removed the connector then reseated it rocking it back and forth as he inserted it.  This seemed to work.  He then tightened the connection alternating between screws until the unit was tight.  I retested all of the pins and we have connection through the system.

h1oaf0 was powered down to add a additional ADC and DAC to the IO Chassis. The computer remains down for now due to the EY systems being offline

At EY, h1susey, h1seiey and h1iscey are down to rearrange the cards in their IO Chassis to match the EX configuration.

Patrick, Kiwamu

This is a follow-up work of the PSL power control rotation stage (see #8606). The punch line is that:

• The rotation stage is now functional and controllable through Beckoff.
• It is ready for the installation.

This morning, we installed a +/- 24V power supply cable to enable the relay circuits for the interlock. This power cable connects the interface box, which is currently sitting on the PSL table next to the periscope (see #8606), and a LIGO-standard power strip underneath the PSL table. I confirmed that it lighted up an LED on the front panel of the interface box. Then I connected the two-pin motor power and DB15 cables at the Beckoff chasis which had been disconnected 10 days ago (see #8593) for a safety purpose. To plug them back in, I powered off the chasis for approximately a minute. Then, I powered it up again after I plugged them.

We tested the rotation stage to see if it is functional. At the beginning, because the interlock was at the disable position (the mechanical switch was in its down position), the rotation stage didn't move at all regardless of what kind of command I sent. This is good as this is how it is supposed to be. Then we switched the interlock to the enable position by toggling the switch. This then allowed the rotation stage to move. So it is working fine and ready to go.

Note that, at the moment, the rotational stage doesn't have a waveplate in it. Plus, the stage is sitting aside the main path, so it is not going to do anything for the main beam.

I have been working on using the lower stage sensors (L1 and L2 OSEMs together with optical levers) to get information about the longitudinal displacement of each test mass of a quadruple suspension. I have been experimenting with trying to match up yaw signals on the quad because this degree of freedom is relatively uncoupled, unlike pitch or longitudinal. The results are somewhat promising, except for an unexplained factor of ~10 difference between the OSEMs and optical lever data. More information can be found in this report on the DCC:

https://dcc.ligo.org/LIGO-T1300957

The matlab code that was used to generate plots in that document is

/ligo/svncommon/SusSVN/sus/trunk/QUAD/Common/MatlabTools/QuadModel_Production/Diagnostic_sensors/generate_damped_yaw_models.m

I will be taking doing maintenance on the LHO aLOG today at 12:15pm
Pacific.

Please have all entries posted to the logbook or saved to a draft before
12:15pm.

It will NOT be safe to work on an entry after that point until I have
sent an all clear notification (which will include a comment on this aLOG entry).

If everything goes smoothly the aLOG will go through a few phases:

* total outage (a few minutes)
* read only while the system is being verified
* back to normal use

The work will not extend the functionality of the aLOG.  It is a
operating system upgrade and a relocation which will be a step towards
making the LHO computer users room an overflow for the control room.

The file server cdsfs0 became unresponsive this morning.  Power cycled the computer, the file server restarted and is functional again.  Cause is unknown at this time.

This alog should be filed on last Thursday's date. 

Last Thur, Calum and I cleaned the ITMx suspension and BSC chamber surfaces (IPA and wipes).  We pulled the First Contact on the CP-AR, ITMx-HR, and the little 1" witness plate attached to the structure.  (We had reinforced the FC the day before, via painting over the ITMx-HR windows and spray-cone-ing the CP window.)  We then checked a few DOF TFs on the ITMx and exited.  The West door was promptly put on.

On keita's (and daniel and stefan's) suggestion, I went back into the PSL to check on the ref cav power budget.  

First I measured the AOM diffraction efficiency, measuring with the filter:

Before the AOM there are 34.5mW, after single pass there is 19.6mW, after the second pass there is 14.05mW,  40% double pass efficency.  This has degraded since christina's meassurement of 72% in Link  I measured the RF power to the AOM by first disconecting the input to D1201423 (VCO AOM driver in PSL racks), then connecting the cable to the AOM (after the blue SLP-100) to an RF analzyer, then reconnecting the input to D1201423.  there is 30dBm of 79Mhz.  According to Christina's alog it should be 1.2W, I'm not sure if the 0.2W matters.  Since the cable was attached to the AOM verry tightly and the translation stage moves, I could have disturbed the AOM alingment in the process.  

Measuring without the filter, there were 11.9mW incident on the ref cav (after the circulator), and 6.9mW in transmission.  I measured 11.3mW after the circulator when the REFL PD DC ( measured using the lemo cable connected to the TNC DC output) had 66.4mV above the dark offset of 0.8mV.  When the cavity is locked, there are 14mV above the offset on this PD, meaning we have 2.4mW of power in reflection.  This means we are loosing 18% of our power somewhere.  We are probably loosing a few percent in the circulator, but that is at most 5%.  

[Jeff K Arnaud P]

Quick summary of TFs taken today on HAUX (IM1 IM2 IM3 IM4), TIp Tilts (RM1 RM2) and TMSX, following 8709. Quads and HSTS are (almost) done and will be processed tomorrow.

HAUX (1st pdf)

IMs are consistent from one to an other, but are slightly different from the model. Looks good though, probably just a model issue.

HTTS (2nd pdf)

-RM1 has its resonances matching the model. RM2 has an extra resonnance in Yaw.
-RM1 and RM2 do not roll off the same way, and it might be due to the eddy current dampers, poorly tuned.
-Calibration between both sites is still suspect, because of confusion in the electronics chain. Transconductance of HAM-A driver used in the script : 9.6 [mA/V], and 20 / 2^16 [Vpp / ct] for the 16 bit DAC
 

It may be good enough for now, but we should keep an eye on those next time the chamber will be opened.

TMSX (3rd pdf)

TMSX looks fine, and in good agreement with the model and the measurement before the centering of the osems and balancing of the table (cf alog 8705).

Data and scripts will be commited under the svn tomorrow.

Thanks to the HEPI model update (see alog#8703), the alignment offsets will now be installed into the cartesian basis.

Thus, on HPI-HAM3 and HEPI-HAM2, I recalculated the alignment offsets used to lock the IMC a couple of months ago into the good coordinates.

Here's the procedure to do so:

- turn off the IPSINF inputs.

- put the IPS readouts value that you want to go to in your IPSINF_offsets (same sign)

- turn on the IPSINF offsets

- copy the BLND_IPS<DOF>_IN1 value in Target (DC_BIAS screen)

- After you turned on the position loops, if you copy paste the Target value into Current Setpoint, HEPI should go to the wanted position.

New snapshots with the new Target  values have been saved. They'll be found in the svn at:

/opt/rtcds/userapps/release/hpi/h1/burtfiles/

Gerardo M, Mike V, Mark and Randy from Apollo and Mitchell R

Today the ETM-Y Cryo baffle was completed and installed into the tube. The baffle was balanced and ready just before lunch allowing for a post-lunch install. The installation of this baffle was one of the smoothest of the 3 I have been apart of. Great job to all those involved your hard work payed off. The lower copper plate which are part of the Eddy current damper system has yet to be added. These parts had minor modifications done to them and will begin the bake cycle tomorrow. Most tools and hardware has been cleaned up. Final cleanup will take place tomorrow. The teflon pads have been removed from the install fixture allowing it and the balance fixture to be removed from the end station at any time. 

Symetrization filters and damping loops have been installed on BSC-ISI ITMX (without any issue).