Manual DTT transfer functions are now running on SR2 for the next few hours.

Measurements made yesterday indicated a problem on the SR2 (HSTS) M1 LF BOSEM channel (see LHO aLOG entry 12923), they also suggested it was an actuation issue and not sensing. This was confirmed this morning by applying offsets to each M1 channel in-turn and monitoring the sensor response (see SR2_M1_Offsets.png below).

Therefore, I've been further investigating this problem in the LVEA, first by using a break-out board at the Satellite Box (field cable H1:SUS_HAM4-10), to measure DC coil resistances as follows:-

T1 Pins = 10-23, R = 40.6 Ohm
T2 Pins = 7-20,  R = 40.1 Ohm
T3 Pins = 4-17,  R = 39.6 Ohm
LF Pins = 1-14,  R = Open Circuit

Thus verifying the issue was down-stream, i.e. either with the field cable or in-chamber.

I then repeated the same DC coil resistance measurements at the other end of the field cable i.e. the air side of the vacuum flange (HAM4-D6):-

T1 Pins = 10-23, R = 38.9 Ohm
T2 Pins = 7-20,  R = 38.4 Ohm
T3 Pins = 4-17,  R = 37.8 Ohm
LF Pins = 1-14,  R = 38.4 Ohm

Confirming that the issue resided with the in-air side of the flange with the field cable. I re-seated and tightened the connector at the flange and this rectified the problem.

Applying an offset to the M1 LF channel now exhibits the expected behavior (see SR2_M1_LF_Offset.png below).

A full set of TFs will now need to be taken to ensure there are no further issues with this suspension.

n.b. this issue is essentially identical to the loose cable connection at the air-side of the flange that was recently reported for H1 ITMX (see LHO aLOG entry 12544).

Attendees: Peter, Christina, Hugh, Stuart, Richard, John, Vern, Matt, Daniel, Mitchell, Gerardo, Aaron, Kate, Jeff B, Patrick, Travis, Betsy, , Jodi, Jeff K, Mitchell, Arnaud, etc …

Today's Tasks:

•	HAM 5 - Transfer Function Results are still showing problems on SR3. Investigation will continue today (Stuart/Arnaud)
•	HAM 3 – Cleaning will be done today by Jeff B. Alignment will be done tomorrow.  
•	First Contact application work on HAM 2 (Matt H/Kate/Jeremy)
•	Work will continue on Illuminator at End Y/ Picture will be taken (Aaron/Richard)
•	Cavity Baffle work (Betsy/Travis)
•	Mitchell will get Dog Clamps needed for Cavity Baffle.
•	BSC 2 Testing - Jim
•	Safety Talk : Be aware of animals on the road/ Don’t forget to read David Nolting document about “Complacency” (John W)

Calum, Rich, Matt

HAM4

The soft cover on the South door was not billowing at all. Despite the obviously low purge air and Matt working in HAM4, the initial particle counts were low. Before starting work, I wiped down everything I could reach with a pre-wetted wipe. Calum and I inspected the optic with a green flashlight (not to be confused with the Green Lantern, D1400060). For both faces of SR2, we estimated 25-100 particles per square inch depending on the region. BEFORE applying FC, we found a ~1 inch piece of leftover FC from the alignment layer on the HR side, and what appears to be a long strand of FC on an earthquake stop. There were numerous glove prints and leftover FC on both faces near the barrel. Because the HSTS legs are warped from welding, we had to use 2 washers on a side of the spray cone bracket to keep the cone on its intended track. Not surprisingly, the particle counts spiked while spraying FC. The "CAL Alarm" popped up on the count taken while spraying. I need to look up the settings for the handheld particle counters to check what that means. The FC appeared much thinner and had more bubbles than usual, but there were less cobwebs than we observed on Saturday. We moved on to HAM5 to let the FC dry.

Matt returned later to retract then remove the spray cone. The wipe on the end of the cone stuck against the optic when the cone was retracted. This has never happened before at either site, not even when a cone was left on overnight. I used the same procedure (E1300017) as always. Matt pulled very gently on the wipe, and it separated from the optic. I painted 3 layers of FC around the edges and added a PEEK tab. The painted crust was much darker in color than the sprayed FC.

HAM5

Like HAM4, there appeared to be very little purge air. Spraying SR2 with FC only a few minutes earlier likely caused the high initial particle count in HAM5. SR3's HR side had 10-30 particles per square inch and a big streak of FC from the alignment layer plus small bits of FC near the barrel. SR3 was sprayed on Saturday. A modified mix with slightly more thinner was used for the 1st layer in an attempt to reduce cobwebbing. It worked, but there was more backsplash (contained by the cone). The standard 1:1 mix ratio of FC and thinner was used for the 2nd and 3rd spray layers.

On Sunday, we removed the cone and painted the crust on SR3. The dried FC spray looked uneven and runny.

BSC2

The beamsplitter was absolutely filthy, and had over 50-100+ particles per square inch. There were tiny circles all over the HR side that looked like rings left by evaporation. There were noticeably more fibers on the AR side. Both faces had glove prints and lefover FC near the barrel. I didn't get any good pictures unfortunately.

I sprayed both faces on Friday, and painted the crusts on Sunday. Like SR3, the FC on the BS was extremely runny.

I'll add photos soon.

model restarts logged for Tue 22/Jul/2014
2014_07_22 11:24 h1susetmy
2014_07_22 11:31 h1susetmy
2014_07_22 11:35 h1susetmy
2014_07_22 11:43 h1susetmy
2014_07_22 15:06 h1pemcs
2014_07_22 15:08 h1broadcast0
2014_07_22 15:08 h1dc0
2014_07_22 15:08 h1fw0
2014_07_22 15:08 h1fw1
2014_07_22 15:08 h1nds0
2014_07_22 15:08 h1nds1
2014_07_22 15:08 h1pemex

no unexpected restarts. HWWD testing, PEM channel name changes, supporting DAQ restart.

[Arnaud P, Stuart A]

Following doors being re-hung on the HAM5 chamber earlier today (see LHO aLOG entry 12915), Phase 3a DTT TF measurements have been taken this afternoon for SR3 (HLTS) suspension as follows:-  

- SR3 M1-M1 undamped results (2014_07_22_1200_H1SUSSR3_M1_ALL_TFs.pdf)

HAM5 ISI Status: ISI unlocked, no damping or isolation loops running.

SR3 alignment: No offset was applied during this measurement.

SR3 undamped measurements from above have been compared with previous measurements for H1 SR3 at Phase 3a of testing (allhltss_2014-07-22_Phase3a_H1SR3_UnDamp_ALL_ZOOMED_TFs.pdf). The plot key is as follows:-

Blue Trace = Model (hltsopt_metal)
Orange Trace = H1 SR3 M1 (2014−07−15_1089513028), (in-chamber, doors open)
Black Trace = H1 SR3 M1 (2014−07−21_1090036316), (in-chamber, doors hung)
Magenta Trace = H1 SR3 M1 (2014_07_22_1200), (in-chamber, doors hung)

It can be seen that despite having gone in-chamber to improve the M3 alignment and attempt to mitigate any sources of rubbing (which we thought we had) the peculiar damping of the first vertical mode persists. Furthermore, comparing before (Black trace) and after (Magenta trace) there appears to be no improvement.

Somewhat frustratingly, before closing up the chamber, higher resolution measurements of the vertical DOF TF had indicated that the potential rubbing issue had been alleviated (see SR3_V2V_Doors_Open_vs_Closed.png).

We had considered the possibility of hanging the door may have changed the air flow due to purge air, so we carried out a measurement both with purge air on and off (SR3_V2V_PurgeAir_Off_vs_On.png), but again this failed to improve the Q of the first vertical peak.

Finally, a measurement was made with damping loops on for comparison (see SR3_V2V_Damping_On_vs_Off.png), which seems stable.

Also, last night Arnaud repeated the vertical TF while applying +/- biases to various degrees of freedom to try and check in which way SR3 could have been hung up, but to no avail.

Attached below is a log of particle counts taken during the HAM5 work covering the duration 1035 to 1126 (local).

All data, scripts and plots have been committed to the sus svn as of this entry.

(Dan, with pointers from Jeff and Arnaud)

Yesterday and Friday I measured spectra and transfer functions for the tip-tilts in HAM6.   The transfer functions were taken with the tip-tilts in the undamped state, the spectra were taken with the damping both on and off.  The transfer functions all agree with the model.

These TTs are not in their final positions and they only have temporary dog clamps (two each, I think, instead of the nominal four, and they're not torqued to any precision), so these measurements will have to be repeated once the optics in HAM6 are aligned and clamped.

As for the OMC, Arnaud captured TFs a month ago; things looked good.

J. Kissel, R. Schofield

I discovered a lonely, forgotten, disconnected GS13 hiding under BSC9 (H1 ETMX) chamber today. I attach pictures. 

Things that Robert and I can surmize:
- It's serial number is 574, and has a "property of the USGS, greater than $5k" sticker on the side with the number G12077 and a bar code.
- It may have been used for S5/S6 feed-forward studies (Will check with Mike, Keita, Richard)
- Ski may have purchased it, given the bar-code on the side (Will check with John)
- It's a 2005-ish era model, based on the color of its can and unfinished look of the feet.
- It's currently configured as a horizontal
- It claims of a broken locking mechanism, but after a few turns the mass seemed locked enough for transport
- It's functionality is unknown.

Finder's keepers ...

J. Kissel, for R. Schofield and R. McCarthy

While in the EE Lab today, I discovered an STS peaking out of the corner under some boxes. Asking around, Robert / Filiberto confirm that this STS is the H1 Vault STS that has been retrieved for the recommended repair at the beginning of the year. Robert recalls removing it from the vault on 2014-Jun-18. It will be sent out to Quanterra for repair, in due time.

The STS's serial number is 89921. 

The breakout box / satellite box that goes with the STS has been left out in the vault. 

Note: this is a PEM STS2, NOT an SEI STS2. It should be returned to the vault once repaired.

J. Kissel, H. Radkins

To investigate the H1 EX GND T240's input matrix confusion, I drove down to the end-station to check the alignment of the T240. I've found the "N" label pointing in the North direction, which for LHO is the +X direction. Seems logical. 

However, looking further into the T240's user's manual, on pg 23, section 5.2, table 5-1 (for revision 6; in revision 4 has this table on pg 14, section 4.4, table 4-1) it states 

Axis    Orientation        Positive Voltage
 X       east-west         represents motion to the east
 Y       north-south       represents motion to the north
 Z       vertical          represents upward case motion

Hence, the "N" label should be aligned parallel to the Y axis, and it is not. 

We've misplaced all of our alignment rods (STS2s and T240s alike), so Hugh's ordering some stock to make several "swizzle sticks" which have ends that fit in both instruments (see SEI aLOG 523 for dimensions of the alignment holes). Once we have an alignment rod, I'll rotate the T240 and correct the input matrix.

The attached pictures show proof of the mis-alignment:
Page 1: From a distance, looking EAST (-Y direction), with the WEST wall at my back, and BSC4 to the left; the T240 sits in its black igloo at the focal point of the picture.
Page 2: A little closer now, igloo removed, looking in the same direction (EAST, -Y).
Page 3: Even closer, but now I've rotated to look DOWN, SOUTH (-Z,-X) direction, with the +X direction and BSC4 at my back.
Page 4: And ... scene. Looking in the SOUTH / -X direction I see the "N" staring me in the face. Eureka!

[Arnaud P, Stuart A]

Purge air was turned off at the valves near HAM4 and HAM6 in the LVEA at 5:20pm (local) while we take measurements on the SR3 (HLTS) suspension.

added 368 channels, removed 367 channels
The number of unmonitored channels dropped from 354 to 13. The list of unmonitored channels is attached.

Following doors being hung on the HAM4 chamber earlier today Phase 3a DTT TF measurements have been taken this afternoon for SR2 (HSTS) suspension as follows:-  

- SR2 M1-M1 undamped results (2014-07-22_1200_H1SUSSR2_M1_ALL_TFs.pdf)

HAM4 ISI Status: ISI unlocked, no damping or isolation loops running.

SR2 alignment: No offset was applied during this measurement.

SR2 undamped measurements from above have been compared with other H1 HSTS suspensions at the same Phase of testing (allhstss_2014-07-22_Phase3a_H1SR2_UnDamp_ALL_ZOOMED_TFs.pdf). The plot key is as follows:-

Blue Trace = Model (hstsopt_metal)
Orange Trace = H1 SRM M1 (2014_07_21_1400), Phase 3a (in-chamber, doors hung) 
Magenta Trace = H1 SR2 M1 (2014−05−07_1083546862), Phase 3a (in-chamber, no doors)
Cyan Trace = H1 SR2 M1 (2014−07−22_1200), Phase 3a (in-chamber, doors hung)

Summary:

It can be seen that back on May 7th SR2 M1-M1 TFs looked good (magenta trace). However, subsequently, SR2 appears to have developed an issue with the M1 LF BOSEM channel (cyan trace). This was not evident in recent TFs taken during close-out activities since there is a window of opportunity to take P and V DOFs. We next need to further investigate the actuation chain (applying offsets, measuring coil resistances etc.) to determine if the fault resides in-chamber or with the electronics.   

All data, scripts and plots have been committed to the sus svn as of this entry.

Manual DTT transfer functions are now running on SR2 and SR3 for the next few hours.