(Cheryl, Corey, Ed, Keita)

Items Removed 

The following assemblies/items were removed today & bagged/tagged:

ROM RH4:  

• 2" BS (90/10) only

ROM RH5:

• Siskiyou Mirror Mount
• Post

NOTE:  The 2" HR ("M-38-UNP-53") & Black Glass dump for this one was installed on ROM RH4

ROM RH6:

• 2" HR Mirror ("ATF PL M-17-P")
• Siskiyou Mirror Mount
• Black Glass Beam Dump assembly for mirror mount
• Post

ROM LH2:

• 2" HR Mirror
• Siskiyou Mirror Mount
• Black Glass Beam Dump assembly for mirror mount

NOTE:  A V-Black Glass Dump was installed on the post for LH2.

Misc:

• (2) Fork Clamps Removed

Tightening IM3 Assembly Screws

Here is a note Ed wanted me to take while Keita tightens:

1)  Tightened screws on top of IM3, and had this:

• Pit:  No Change
• Yaw +10 uradians

2) Tightened 1/4-20 bolts (on sides, OSEM plates, etc.), and had this:

• Pit:  No Change
• Yaw +70 uradians

Don't be alarmed when you hear a flow of air near GV7. Its compressed air solenoid valve is leaking. Replacement is on order.

   Betsy, Jeff B.,

   This afternoon we made a first pass at adjusting the M2 and M3 OSEMs to their mid-light positions. The adjustment went well. They are all within 200 counts of zero. A minor tweak was made to the T3 top OSEM. All these OSEMs will need final adjustments when the beam alignment is made.  

   Betsy tightened the flat head screws on the 25 pin connectors. The loose one may be the source of grounds.  

FRS ticket already exists as 5270.
Restarted.

Travis, Jason & Angus.	Oct 5th, 6th & 9th

The new ITMx has been welded and the violin modes of the fibres measured in air with the PUM clamped. The welding went quite smoothly apart from a couple of points. 
1)	The epoxy around the sapphire prism on one side of the PUM (+Y side) has charred due to heat from the welding of that fibre.
2)	The lengths of the horns on the PUM after fibre removal were not all exactly 6.0 mm above the ear, and this was not compensated for exactly with each fibre. The consequence is that the break-off values for one of the fibres (+X-Y) will be higher at the PUM and a bit lower at the ITM
The following fibres were used and the violin harmonics recorded

Posn	S/N		fund	2nd	3rd	4th	5th	(predicted in-vac)
+X+Y	S1400158 	502.45	994.8	1463.8	(1930)	[2390]	503.0
-X+Y	S1400137	503.96	997.85	1468.3	1931.6	(2391)	504.0
-X-Y    S1400164	504.71	1001.6	1472.4	1940.3	2408.3	504.6
+X-Y	S1400154	504.45	1002.6	1466.6	1936.4	2390.0	505.4

Accuracy is about +/- 0.05 for the fundamental, +/- 0.2 for the 2nd harmonic and the higher harmonics are generally +/- 0.5 or better, except for the ones in brackets which are worse. The round brackets are +/-1 and the square is +/-10 Hz (yes ten!).
It can be seen that the harmonics “cross” and that without this measurement it would be harder to determine which harmonic belongs to which fibre.
The pitch prediction from the fibre profiles was 0.1 mrad up (wrt PUM), the actual pitch is 0.3 mrad up. The roll and separation are as good as, or better than, the previous ITMx assembly. The yaw and pendulum frequencies were measured with +/- 0.005 Hz accuracy to 0.650 and 1.095 Hz respectively.
Attached are typical (linear) plots of the modes and a zip file of the original data files and excel files. Plus pics of the welds.
Fibre guards are on.

In anticipation of attaching AOSEMs to the OFI for HAM5, I laid out a string of the appropriate cables and AOSEMs next to the chamber on a staging table.  I've fastened to the table the clean-to-dirty ribbon-feedthru-simulator-cable to the table and Fil has run a grey temp out of vac cable from it to the sat amp located on the other side of the chamber.  So, the OFI guys can test fit and test the new AOSEMs and their brackets when ever they are ready.

The cables and AOSEMs are:

D1000234-88"  S/N 932

D1000225-230"  S/N S1104240

D0901065  S/N  525, 559, 511

The Noise eater has tripped and is currently NOT resettable. Jason and Peter are aware of this and are investigating it. An FRS ticket has been filed.

This morning I completed the weekly PSL FAMIS tasks.

HPO Pump Diode Current Adjust (FAMIS 8443)

With the ISS OFF, I adjusted the operating currents of the HPO DBs, changes summarized in the below table.  A screenshot of the PSL Beckhoff main screen is attached for future reference.

I did not adjust the DB operating temperatures.  The HPO is now outputting 154.4 W and the ISS is back ON.  This completes FAMIS 8443.

PSL Power Watchdog Reset (FAMIS 3671)

I reset both PSL power watchdogs at 16:19 UTC (9:19 PDT).  This completes FAMIS 3671.

Yesterday we tied in ±18V to SUS-R3 and SUS-R4. We now have our standard 8 awg shielded cable running from the CER mezzanine down to the LVEA racks. The following electronics were moved to the new ±18V line: Op Lever whitening chassis, CPS Timing Fanout, and the SAT Amp units. Some of the "temporary" cabling used to previously power these electronics will be removed.

Both TCS LVEA racks are sharing their own dedicated power supplies for ±18V and ±24V. One thing to note is that the CPS Timing Fanout in TCS-R2 (next to BSC1) is being powered by TCS rack power.

The new SQZ-R1 rack is now powered by its own dedicated ±18V power supplies. We used the the existing ±24V from ISC-R3/R5 since the current draw is minimal.

The hex nut integral to the actuation lead screw on the 1.5" isolation valve separating VBOC's RGA from the oven chamber physically broke off! -> Venting the RGA was required to replace this valve.  As such, VBOC will be out-of-service for a week or more while the RGA volume bakes-out at high temperature etc...  

Kyle R., Arnab D., Rakesh K. 

Today we adjusted the "ATM" potentiometer on the new parani gauge (local electronics unit) but could only achieve a minimum value of 906 torr indication on CDS.  This is too high.  The actual pressure under these conditions is closer to 760 - 790 torr -> The measured voltage supplied to the gauge electronics is 24.5 VDC and the output signal from the sensor electronics, 5.6 VDC, which is consistent with the CDS-converted value of 906 torr.  Any voltage drops across signal wiring connections between the gauge and the CDS rack should result in a CDS value which would be biased to less than the actual value, not more than the actual value.  

We will continue troubleshooting at the next opportunity.  

Betsy, Hugh, TJ

Last week Betsy put the heater on the table and today Hugh checked it's vertical center with an auto-level. Some washers were added to get it as close to center as possible, which ended up around 0.4mm high. Betsy and I then had to wiggle the assembly into place, and rotate the entire gold ceramic holder to allow the screws on the outside to clear the OSEM brackets. The heater is currently sitting ~6mm away from the back of the SR3 optic and it is plugged into the feed through.

Picture attached.

With GregG in chamber and JimW helping outside, the installation of the ViewPort onto the -X most Septum Window was pretty straight forward.  A new o-ring was used and the window/flange clocking mark was put at 9o'clock (-X) and was torqued in three steps to 16 ft-lbs.  Attached photo shows these men in action.

The image attached shows the 5 way cross installed.  The Fiber feedthru (currently blanks) are visible below the cross.  The five ISI cables are rerouted to FTs on the cross but the in-air cables have not been reconnected.  I'll do that after Kyle gives it all a look and touch; fingers cross for leak checks down the road.  The facing 25p has no cables but it was readily available, that is why it isn't a blank.

I have compiled the results of in-air measurements during installation and in-vacuum measurements from the alogs; 14231 LLO (including corrections mentioned in alogs 21652 and 27901) and 17610 at LHO (including corrections mentioned on the comments).

In the case when a frequency split is shown on in-vacuum measurements we have taken the average of both frequencies. I have grouped these numbers per front and back fibres, then per test mass and then per detector, finally I obtained the difference as (in-vacuum – in-air) including the sign:

We notice that in most cases the frequency difference is always positive, so frequency increases when moving the suspension to in-vacuum.

The increase in frequency is always a few hundred mHz (mean of 0.3Hz and median of 0.4Hz), with a clear outlier on LLO_ITMY_FL (which as explained here seems to be involved with uncertainty in the identification).

There is not clear difference in frequency variation between front and back fibres (especially no sign difference) which would indicate pitch effect.

However, notice that as per the Technical document T1700399 the expected increase in frequency due to buoyancy is of 0.14Hz, and the variation in frequency due to pitch angles of 2mHz is of 0.33Hz (although that would be an opposite sign change between front and back fibres). Therefore while the observed changes cannot be explained through pitch and buoyancy alone, they are of the same order.