The main turbo pumping the vertex volume tripped at ~8:15 this morning. I currently do not know why and the turbo restarted with no issues.

Below is a duplicate of my SEI ELOG.  Talking with Calum this morning, seems we should have replacement for these in about a month.  Is it likely we'd be doing low noise experiments where this ground loop problem might appear?


SEI ELOG id 1970:
The BSC Trillium Cable D1100152 is unique in the BSC ISI In-vacuum cables in that it is one piece. All other cables, GS-13s L4-Cs and Actuators, are two piece and one of these two has one end where the peek connector has been metalized. Since the metal backshell has been shorted to the shield & pin1, the metalized connector is too now tied back into the rack ground. This is just fine for the two part cables as the metalized peek connector (with ears) are mounted to the Cable Bracket D1001347 isolating the ground connection.
The problem with the Trillium Cable is the cabling company got sloppy and put the metalized connector with ears on when it should not have. Now the metalized connector mates up to the Trillium and shorts the grounded shield & Pin1 to the Trillium pod, Stage1 etc etc. I understand this is not desirable.

Corey and I looked closely at one of these Trilliums to confirm and yes the backshell is shorted to pin1 and therefore likely to ground back at the rack. That connection continues to the metalized connector and to the front of the connector where it would contact the Trillium pod. We took the backshell back as far as comfortable and could not see where the Pin1/Shield/backshell connection was made so I'm not sure we can address it there.

Solution? Could we not just get another connector that wasn't metalized and exchange it? Needs to be classA'd, probably need a fancy gizmo to install it, and have to test the cable again.  [BenA has proposed cutting a groove around the metalized connector through the metalization to break the contact to the front of the connector--seems dirty, ugly, non-LIGO]
Maybe we'll actually get some cables that were made correctly soon and we can exchange it?

In-chamber cleaning recommenced in BSC-4 after lunch. First vacuum on the collar, upper, and mid-sections were completed as were the nozzles. Support tubes were unwrapped, vacuumed, and remaining fibers were removed.

Kyle 

 

Couple photos here showing the completed local welding at HAM8.  The welders finished Tuesday and have moved onto HAM10. They are not quite 1/2 done on the West end of HAM10.  The East end is in the Cleanroom over BSC4.

The first image shows the busy South side of HAM8 looking North.  The second photo is closeup to the NW pier plumbing looking South with the SW pier in the back ground.

It was discovered last night that an actuator link block had been left on one actuator. This part was likely responsible for the reduced twist on unit 3 after the last round of tinkering. We now have a rather large twist(not sure of the size just yet), but it is in the opposite direction from what we had previously. It appears that this rotation is very sensitive to Stage 0-1 flexure position. For the moment, we plan on readjusting the flexure position in one corner only, maybe we can tune the rotation one corner at a time. 

Kyle 
Removed leaking 4.5" CF ESC feedthrough -> Replaced with CF blank -> Pumping YBM

- LVEA Laser Hazard
- Sprague Pest Inspection
- Squeezers at HAM6
- Shipment from Peninsula Truck Line
- Leak Checks at BSC8

The crew went into BSC-4 and finished the hand brushing around the support tubes,the fins, and the ring. Then we shut down for the day due to laser hazard which makes it very difficult to vacuum or wipe down the chamber interior. 

Yesterday, we managed to fix the model. Renamed the DAC_x names so the first DAC name starts at '0' (DAC_0 and DAC_1), and also renamed the OSEM_OUT to COIL_OUT to be consistent with the quad models.

I am not sure if I fixed it the 'proper' way, but I changed coil output names in the TMTS_MASTER.mdl. I also used all capitals for the _IN and _OUT names. Then in the H2SUSTMSY.mdl I changed the names of the DAC_x blocks (as mentionedin the T080135-v4 (page 42), but left the card_num to 2 and 3 respectivily. I copied the models by changing the name to 'name'_24oct2011, but don't know if or how to upload them to svn or not.

We recompiled and installed the front-end, and all seemed to work. We check the output by setting an offset on one of the output filters (F3 in our case). There is a nice feature, that on the EPICS screen (SUS_CUST_TMTS_OVERVIEW.adl) the last value (just before the grey button to H2SUSTMSY_DAC_MONITOR_0.adl) is 100. But when looking on the H2SUSTMSY_DAC_MONITOR_0.adl (which is the output of the TMS model) the DAC0 OUT value is 99, and further looking on H2IOPSUSB6_DAC_MONITOR_0.adl (which is the IOP model which actually talks to the DAC) DAC2 OUT value is 101!? Go figure.

I tagged this as AOS, but not sure if that does the trick.

Last Friday we (Matt and I) connected the BOSEMs to the CDS system. We mounted the 'test stand' interface plate to the Bosch frame and connected the field cables on one side and the female-female cables from the BOSEM quad-fanout cable to the interface plate (by borrowing two female-female cables from Betsy). The original ~200in cables are being tested.

We rearranged the BOSEMs around to reflect their position on the EPICS screen (F1, F2, F3 and LF), although the RT and SD BOESMs didn't give us any signal. This may be due to the fact that thy are on the second quad-fanout calbe and not connected to the right 9-pin micro-D-sub connector. We used SUS_CUST_TMTS_M1_OSEM_ALIGN.adl (no H2?) to align the BOSEMs w.r.t the flags, this was a bit cumbersome because we didn't have the fancy socket drives:)

We populated the various matixes on SUS_CUST_TMTS_OVERVIEW.adl. We noticed that the monster matrix SUS_CUST_TMTS_M1_DRIVERALIGN.adl has all the elements 'ON' by default, which we may want to set to 'OFF' by deafult. We tried to implement some crued damping filters, but it turned out that the coil outputs didn't go into the DAC (as seen on the EPICS screens, either H2SUSTMSY_DAC_MONITOR_0.adl or H2IOPSUSB6_DAC_MONITOR_0.adl).

We informed Dave, but on the Friday afternoon we left it as is.

- Squeezers at HAM6. After venting, L1 OMC Installation
- PSL will start running overnight
- SEI delivery - Swagelok
- SEI Welders at HAM8, moving to HAM10
- Feedthrus being tested at EY
- Work in H2 electronics building
- Second cleaning at HAM6, cleaning at EY
- Laser Hazard from 1pm.

The B&K hammer impulse response tests were performed last Thursday on the FMY attached to the BSC-ISI with the BSC-ISI "floating" (blade springs allowed to move freely). Tap test locations were the same as those selected previously with the BSC-ISI locked.  There were 5 locations on the lower half of the FMY and 5 locations on the upper half of the structure.  The taps tests were conducted with the M1 Stage damping loops both ON and OFF.  However, during the tap tests on the upper half of the structure with the damping loops ON, the software reported trouble recognising the hammer hardware.  After several reboots, the FrontEnd could still not detect the hammer. It was noticed that the BNC cable connecting the hammer to the FrontEnd had it's shielding stripped with some loose wiring at the hammer end.  This was noticed while performing tap tests on the Upper half of the structure with Damping loops ON. Thus, the M1 Damping loops ON tests are only of the locations on the LOWER half of the structure.  The tap tests with the M1 damping loops OFF were completed for all 10 locations on the upper and lower halves.  


The first pdf has plots of the B&K hammer response on the Lower half of the FMY structure in 5 locations. The Damping loops on the M1 stage were OFF. Second pdf is of the Upper half locations with M1 Damping Loops OFF. Third plot is of the same locations with M1 Damping ON, the fourth of the same Upper half locations.

Comparison Plots:
The fifth, sixth, and seventh plots compare the 5 locations of the LOWER half of the structure separated by degree of freedom.  The degrees of freedom are the X,Y,and Z local coordinates of the accelerometer.

The Advanced LIGO high power laser is now fully set up (but uncharacterized and unstabilized) and will therefore stay turned on over night today.

After Kyle found the leaking ESD style feed-thru on BSC8 (aLOGs 1595,1596,1604) we pulled another out of C&B and it was checked on the leak detector.  KKyle found that to be good.  Since we are flanging BSC6 at this time, it seemed reasonable to check for leaks pre-install.  This feed-thru did not pass and has a 2e-7 Torr-L/sec leak.  So that is two of three feed-thrus that have gone through Clean & Bake that have failed.  We grabbed the one RMcCarthy had in EE and leak checked it as well.  While this unit had not been through clean and bake it too failed at 3e-7Torr-L/sec.  These leaks we've found to be associated with the ceramic portion of the seal rather than the welding.
SO leaking on 3 of 4 units so far--we'll check more certainly soon.
The leaks would not reveal themselves until we put the He source right down in the ceramic zone.  It was not sucked it at the surface near the welds.  Also it only showed up at 1 of the 5 conductors--they are all separate, see image.

The crew finished brushing in BSC-4 today. One drill was used for all the brushing in this chamber (#21) and one drill with a flat brush was used for the fins and the ring (#29).