40m QIL Cryo_Lab CTN SUS_Lab CAML OMC_Lab CRIME_Lab FEA ENG_Labs OptContFac Mariner WBEEShop
  40m Log, Page 29 of 355  Not logged in ELOG logo
ID Date Author Type Categoryup Subject
  16432   Wed Oct 27 16:31:35 2021 AnchalSummaryBHDPart III of BHR upgrade - Removal of PR2 Small Suspension

I went inside the ITMX Chamber to read off specs from PR2 edge. This was required to confirm our calculations of LO power for BHR later. The numbers that I could read from the edge were kind of meaningless "0.5 088 or 2.0 088". To make it more worthwhile this opening of the chamber, we decided to remove the PR2 suspension unit so that the optic can be removed and installed on an SOS in the cleanroom. We covered the optic in clean aluminum foil inside the chamber, then placed in on another aluminum foil to cover completely. Then I traveled slowly to the C&B room, where I placed it on a flow bench.


Later on, we decided to use a dummy fixed mount mirror for PR2 initially with the same substrate thickness, so that we get enough LO power in transmission for alignment. In the very end, we'll swap that with the PR2 mounted on an SOS unit.

  16433   Wed Oct 27 16:38:02 2021 AnchalSummaryBHDPart II of BHR upgrade - Relocation of TT2 and MMT1/2 alignment

[Anchal, Paco]

We opened BSC and Injection Chamber doors. We removed two stacked counterweights from near the center of the BS table, from behind TT2 and placed them in the Xend flow bench. Then we unscrewed TT2 and relocated it to the new BHR layout position. This provided us with the target for the alignment of MMT1 and MMT2 mirrors.

While aligning MMT1 and MMT2, we realized that the BHR layout underestimated the clearance of the beam from MMT2 to TT2, from the TT1 suspension unit. The TT1 suspension stage was clipping our beam going to TT2. To rectify this, we decided to move the MMT2 mirror mount about a cm South and retry. We were able to align the beam to the TT2 optic, but it is a bit off-center. The reflection of TT2 now is going in the general direction of the ITMX chamber. We stopped our work here as fatigue was setting in. Following are some thoughts and future directions:

  • We realized that the output beam from the mode cleaner moves a lot (by more than a cm at MMT2) between different locks. Maybe that's just because of our presence. But we wonder how much clearance all beams must have from MC3 to TT2.
  • Currently, we think the Faraday Isolator might be less than 2 cm away from the beam between MMT1 and MMT2 and the TT1 suspension is less than 2 cm away from MMT2 and TT2.
  • Maybe we can fix these by simply changing the alignment on TT1 which was fixed for our purposes.
  • We definitely need to discuss the robustness of our path a bit more before we proceed to the next part of the upgrade.

Thu Oct 28 17:00:52 2021 After Photos: https://photos.app.goo.gl/wNL4dxPyEgYTKQFG9

  16434   Wed Oct 27 18:11:37 2021 KojiSummaryBHDPart II of BHR upgrade - Relocation of TT2 and MMT1/2 alignment

Closed the PSL shutter @18:11
During the vent, we want to keep the cavity unlocked if not necessary.

 

  16435   Wed Oct 27 18:16:45 2021 KojiSummaryBHDPart II of BHR upgrade - Relocation of TT2 and MMT1/2 alignment

- Moving the MMT2 south by a cm is fine. This will give you ~0.5cm at TT1 without changing the other alignment much.
- IMC mode is moving because of your presence + HEPA blow.
- 2cm at Faraday is plenty for the beam diameter of a few mm.

 

  16437   Thu Oct 28 16:32:32 2021 PacoSummaryBHDPart IV of BHR upgrade - Removal of BSC eastern optics

[Ian, Paco, Anchal]

We turned off the BSC oplev laser by turning the key counterclockwise. Ian then removed the following optics from the east end in the BSC:

  • OM4-PJ (wires were disconnected before removal)
  • GRX_SM1
  • OM3
  • BSOL1

We placed them in the center-front area of the XEND flow bench.

Photos: https://photos.app.goo.gl/rjZJD2zitDgxBfAdA

  16438   Thu Oct 28 17:01:54 2021 AnchalSummaryBHDPart III of BHR upgrade - Adding temp fixed flat mirror for PR2

[Anchal, Paco, Ian]

  • We added a Y1-2037-0 mirror (former IPPOS SM2 mirror) on a fixed mount in the position of where PR2 is supposed to be in new BHR layout.
  • After turning out all lights in the lab, we were able to see a transmitted beam on our beam finder card.
  • We aligned the mirror so that it relfects the beam off to PR3 clearly and the reflection from PR3 hits BS in the center.
  • We were able to see clear gaussian beams splitted from BS going towards ITMX and ITMY.

Photos: https://photos.app.goo.gl/cKdbtLGa9NtkwqQ68

  16439   Thu Oct 28 23:13:19 2021 YehonathanUpdateBHDSOS assembly

{Tega, Yehonathan, Koji}

Suspension of a Dummy Optic

We gathered the components needed for suspending a 2" optic housed in a 3" ring adapter:

1. SOS Tower

2. Winches+Winch adapter plate (Attachment 3)

2. HeNe Laser + Power supply

3. A steering mirror

4. QPD + ND2 Filter + Electronic amplifier

5. Oscilloscope

6. Dummy optic housed in a ring adapter (Attachment 2)

An OpLev was built using the HeNe laser, steering mirror, suspended optic, QPD (Attachment 1).

The beam height was set with a ruler. The QPD was placed in front of the laser and its height was adjusted until the Y signal vanished.

The beam was made parallel to the table. First, roughly by using an iris. Then, more accurately, by measuring the beam directed at the suspended optic with the QPD and zeroing the Y signal by adjusting the steering mirror.

We suspended the dummy optic using a music wire we found in the cleanroom cabinet.

All the wire clamps on the ring adapter, SOS, and winches were loosened.

About 0.5m of music wire was cut. Then, the wire was threaded through the wire clamp on the adapter side block, around the ring adapter, and through the wire clamp on the other side block, keeping the wire untwisted. The optic was put on the safety stop and the height was roughly adjusted using the lower EQ stops.

The wire pair was then threaded through the wire clamp on the suspension block and held near the winches. The wire was made to go through the groves at the side blocks. The wire was clamped to the side blocks. The wires were clamped on the winches. The wires were pulled by the winches until the magnet marking on the side blocks was centered on the OSEMs' holes on the side plates of the SOS (attachment 4).

Once the heights were set, the wire was clamped at the suspension block.

We balanced the dummy optic using a counterweight.

We placed the QPD at the laser reflection from the optic. We adjusted the screw set going through the counterweights to adjust the balance. The pitch imbalance was monitored by observing the Y signal on the oscilloscope.

Comments:

1. Turns out that for a 1/4" thick optic, the rear counterweight needs to be removed for achieving balance.

2. To fix the counterweight on the setscrew we will use some epoxy.

3. Seems like the left optical table in the cleanroom is slightly tilted. We need to fix it.

4. The bottom long EQ stop is not touching the adapter due to the balancing mass socket. We might want to put a nut on it.

5. Still need to glue 3 more side magnet+dumbell assemblies to rods and then glue them before gluing them to the side blocks which will take at least 2 more days until we can start suspending a real optic.

Attachment 1: OpLev_Setup.jpg
OpLev_Setup.jpg
Attachment 2: suspended_optic.png
suspended_optic.png
Attachment 3: 20211029_113011.jpg
20211029_113011.jpg
Attachment 4: 20211029_113052.jpg
20211029_113052.jpg
  16440   Fri Oct 29 14:39:37 2021 AnchalSummaryBHD1Y1 cleared. IY3 ready for C1SUS2 I/O and FE.

[Anchal, Paco]

We cleared 1Y1 rack today removing the following items. This stuff is sitting on the floor about 2 meters east of 1Y3 (see attachment 1):

  • A VME crate: We disconnected it's power cords from the side bus.
  • A NI PXIe-1071 crate with some SMA multiplexer units on it.

We also moved the power relay ethernet strip from the middle of the rack to the bottom of the rack clearing the space marked clear in Koji's schematics. See attachment 2.

There was nothing to clear in 1Y3. It is ready for installing c1sus2 I/O chassis and FE once the testing is complete.

We also removed some orphaned hanging SMA RG-405 cables between 1Y3 and 1Y1.

Attachment 1: RemovedStuff.jpeg
RemovedStuff.jpeg
Attachment 2: 1Y1.jpeg
1Y1.jpeg
Attachment 3: 1Y3.jpeg
1Y3.jpeg
  16443   Tue Nov 2 15:02:03 2021 YehonathanUpdateBHDSOS assembly

{Yehonathan, Tega}

We took the free-swinging spectra of the OpLev in the X and Y direction.

To make the motion of the optic quiet we turned off the airflow on the optical bench and moved the QPD close to the SOS so that the laser beam stays more or less within the QPD sensitive area.

In the process, we realized that the cleanroom HeNe went bad. It turned off after a few minutes after turning it on. The behavior repeated with another power supply. We replaced the HeNe and realigned it coarsely.

The data was taken using an oscilloscope while the optic was swinging freely. The PSD was calculated afterward (attachment 1).

Surprisingly, the pitch has a resonance frequency of ~ 2.5 Hz. And this is after we removed the back counterweight.

Additionally, we aligned the tilt of the optical table. Using a spirit bubble we adjusted the tilt by using a wrench on the table legs. As we suspected, the table was slightly tilted in the north-south direction.

Attachment 1: FreeSwingingSpectra.pdf
FreeSwingingSpectra.pdf
  16444   Tue Nov 2 16:42:00 2021 PacoSummaryBHD1Y1 rack work

[paco, ian]

After the new 1Y0 rack was placed near the 1Y1 rack by Chub and Anchal, today we worked on the 1Y1 rack. We removed some rails from spaces ~ 25 - 30. We then drilled a pair of ~ 10-32 thru-holes on some L-shaped bars to help support the c1sus2 machine weight. The hole spacing was set to 60 cm; this number is not a constant across all racks. Then, we mounted c1sus2. While doing this, Paco's knee clicked some of the video MUX box buttons (29 and 8 at least). We then opened the rack's side door to investigate the DC power strips on it before removing stuff. We did power off the DC33 supplies on there. No connections were made to allow us to keep building this rack.

When coming back to the control room, we noticed 3/4 video feed (analog) for the Test masses had gone down... why?


Next steps:

  • Remove sorensen (x5) power supplies from top of 1Y1 .. what are they actually powering???
  • Make more bars to support heavy IO exp and acromag chassis.
  • Make all connections (neat).

Update Tue Nov 2 18:52:39 2021

  • After turning Sorensens back up, the ETM/ITM video feed was restored. I will need to hunt the power lines carefully before removing these.
  16445   Tue Nov 2 18:54:41 2021 Anchal, PacoUpdateBHDOptical fibres laid for BHD upgrade

We successfully laid down all required optical fibre fiber cables from 1X4-1X7 region to 1Y1-1Y3 region today. This includes following cables:

  • Timing fibre fiber from Master Timing Synchornizer D050239 on 1X6 to C1SU2 I/O chassis on 1Y1.
  • Timing fibre fiber from Master Timing Synchornizer D050239 on 1X6 to C1BHD I/O chassis on 1Y3.
  • CX4 cable from Dolphin Card on 1X4 to C1SU2 FE on 1Y1 for IPC.
  • CX4 cable from Dolphin Card on 1X4 to C1BHD FE on 1Y3 for IPC.
  • DAQ Network extension fibre fiber optic cable from DAQ Network Switch on 1X7 to another switch we mounted on 1Y3 for local DAQ network distribution.
  16446   Tue Nov 2 22:50:30 2021 KojiUpdateBHDSOS assembly

2.5Hz is surprising. Can you move it down to sub 1Hz by adding a socket cap screw at the top instead of the set screw for the Teflon piece? How much mass do you need to add?

  16448   Thu Nov 4 15:03:43 2021 KojiSummaryBHD1Y1 rack work

I have visited the binder file for the 40m wiring file in the control room.
The 12V power supply on 1Y1 is for the CCD cameras. So we still want to keep the 12V 0.8A power and the side connections for these. It is not necessary to be Sorensen. Can we replace it with an AC-DC adapter with +12V/1A for example? BTW, the video matrix and quads are AC-powered.

The mysterious thick cables and cross-connects (green wires) on the side panel (labeled AP1/AP2/SP/IMCREFL) are for "EO shutters". It was meant for the protection of the PDs from bright beams.
I don't think they have been used. And we don't need them.

  16450   Fri Nov 5 12:21:16 2021 AnchalSummaryBHDPart VI of BHR upgrade - Removal of ITMYC optics

Today I opened the ITMY chamber and removed the following optics and placed them in Xend flow bench (See attachment 1-3 for updated photograph):

  • OM1
  • OM2
  • ITMYOL1
  • ITMYOL2
  • SRMOL1
  • SRMOL2
  • POYM1
  • 3 counterweights one of which was double the height of others.

I also unscrewed SRM and parked it near the Western end of the table where no optical paths would intersect it. Later we will move it in place once the alignment of the rest of the optics has been done.

While doing this work, I found two unnoted things on the table:

  • One mirror mounted on a mount but not on a post was just sitting next to ITMY. I have removed this and placed it on Xend flow bench.
  • One horizontal razor or plate on the South end of table, mounted on what I thought looked like a picomotor. The motor was soldered to wires without any connector in-line, so I could not remove this. This is on the spot of AS4 and will need to be removed later.

Photos: https://photos.app.goo.gl/S5siAYguBM4UnKuf8

Attachment 1: XendFlowBenchLeftEnd.jpg
XendFlowBenchLeftEnd.jpg
Attachment 2: XendFlowBenchMiddle.jpg
XendFlowBenchMiddle.jpg
Attachment 3: XendFlowBenchRightEnd.jpg
XendFlowBenchRightEnd.jpg
  16452   Fri Nov 5 20:35:10 2021 KojiUpdateBHDFeedthru / Optical Mounts

- New feedthrus [4xDB25 Qty 4 / 8xDB25 Qty 1] are placed on the wire shelf at the entrance -> Jordan, please clean them.

- There are plenty of 2" DLC mounts. There are also many 1.5" mounts but they are less useful.
  We need at least 3 1" moounts and 1 1" or 2" lens mount (and the lens). Let's purchase them on Thorlabs. I'll work on the order.

Attachment 1: P_20211105_200817.jpg
P_20211105_200817.jpg
  16453   Mon Nov 8 10:13:52 2021 PacoSummaryBHD1Y1 rack work; Sorensens removed

[Paco, Chub]

Removed all sorensen power supplies from this rack except for 12 VDC one; that one got pushed to the top of the rack and is still powering the cameras.

  16454   Mon Nov 8 13:13:00 2021 KojiSummaryBHD1Y1 rack work; Sorensens removed

Updated the rack layout. Now there is an issue.
We were supposed to have 1U space at the top, but it was occupied by the 12V.
We need to either lower the c1sus2 and IO chassis 1U or move the Sorensen at the bottom.

Attachment 1: 40m_BHD.png
40m_BHD.png
  16455   Mon Nov 8 15:29:05 2021 PacoSummaryBHD1Y1 rack work; New power for cameras

[Paco, Anchal]

In reference to Koji's concern (see previous elog), we have completely removed sorensen power supplies from 1Y1. We added a 12 Volts / 2 Amps AC-to-DC power supply for the cameras and verified it works. We stripped off all unused hardware from shutters and other power lines in the strips, and saved the relays and fuses.

We then mounted SR2, PR3, PR2 Sat Amps, 1Y1 Sat amp adapter, and C1SUS2 AA (2) and AI (3) boards. We made all connections we could make with the cables from the test stand, as well as power connections to an 18 VDC power strip.

  16456   Mon Nov 8 17:22:27 2021 YehonathanUpdateBHDSOS assembly

Big Gluing Day

Today I glued the magnet+dumbell assemblies on the optics adapters.

Unlike magnet gluing on a 3" optic where one can use a magnet gluing fixture, here I had to position the magnets manually. There is a complication though: the magnet is much heavier than the dumbell making it almost impossible gluing the dumbell side down onto the adapter since it is very unstable in this position. A workaround is to put the magnets on some paramagnetic sheet so that the magnets stick to it and then flip it over and glue it on the adapter dumbell sides down.

The problem here is that I need to position the magnets relatively accurately on the metal sheet. To make things slightly easier I printed some drawings of the positions of the magnet, laminated them, and cleaned them to have a decent starting point (attachment 1).

For each adapter:

1. I applied glue to the 4 circular grooves at the back of the adapter.

2. I picked 4 magnets (2 north, 2 south). Trying to match their strength.

3. Made a note of which magnets I picked for which adapter in the magnet+dumbell spreadsheet.

4. Clean the dumbells' surfaces when necessary.

5. Put the magnets on a laminated magnet-positions-drawing on a metal sheet that was precleaned in the right order.

6. Flip the metal sheet and position it on the adapter such that the dumbells go as precisely as possible into the circular grooves on the adapater.

7. Adjust the magnets' positions by pushing them slightly with a non-magnetic tip.

Attachment 2 shows the numbering on the adapters for future tracking.

I also glued some magnets and aluminum rods to side blocks. Next gluing session I will glue magnets to the aluminum rods. Probably some dumbells will not stick well to the adapters. These will have to be cleaned and reglued as well.

 

 

Attachment 1: Magnets_Positions.png
Magnets_Positions.png
Attachment 2: Adapters_Order.png
Adapters_Order.png
  16458   Mon Nov 8 18:42:38 2021 KojiSummaryBHDRack Layout / Power Strips
Rack # of units that
requires +18V
Power Source
1X3 (new rack) 15 1X3 U1/2
1X4 13 1X3 U1/2
1X5 8 or 9 (OL AA) 1X5 U40/41
1Y0 17 1Y0 U1/2
1Y1 15 1Y0 U1/2
1Y3 12 1Y3 U39/40
1X9 9 1X9 U38/39
1Y4 9

1Y4 U39/40

Notes:

  • There are 8 racks and there is only 7x 18V power strips. 1X5 could be the one without the power strip and to parasite with 1X3/4. Otherwise we need to modify some of the 24V power strips (no plan to use) into 18V by replacing the connectors.
  • We need total ~100 18V cables / We ordered 60x 3ft / 60x 3ft / 30x 10ft. Hopefully these are enough for our depand... I haven't checked the delivered number.
  • All the acromags are supposed to be powered with one voltage. I think they are supposed to run with +18V.
  • I didn't check the distribution of Sorensens through the lab. (i.e. how many we have / how many we need / ...)
Attachment 1: rack_plan.pdf
rack_plan.pdf
  16459   Tue Nov 9 11:11:37 2021 YehonathanUpdateBHDSOS assembly

The gluing was mostly successful. Only two magnets didn't stick (see attachment).

Attachment 1: 20211109_110408.jpg
20211109_110408.jpg
  16463   Tue Nov 9 19:02:47 2021 AnchalSummaryBHD1Y0 Populated and 1Y1,1Y0 powered

[Anchal, Paco]

Today we populated 4 Sat Amp boxes for LO1, Lo2, AS1, and AS4, 2 BO boxes for C1SU2, and 1 Sat Amp Adaptor box, at 1Y0 according the latest rack plan. We also added 2 Sorenson power supplies in 1Y0 at the top slots to power +/- 18V DC strips on both 1Y1 and 1Y0. All wiring has been done for these power connections.

  16465   Fri Nov 12 23:47:29 2021 YehonathanUpdateBHDSOS assembly

{Tega, Yehonathan}

First attempt at the suspension of a Lambda Optic mirror

We found the box with the 2" Lambda Optic mirrors in the cleanroom. We choose to suspend a mirror with a ROC = 5m, probably LO1.

The mirror was put inside an adapter that was prepared beforehand, put the mirror in place by tightening the Teflon rod, and then clamp it using the clamping pads.

We decided to cut two wires and clamp them to the side blocks of the adapter, while it sits on the EQ stops. The wires were threaded through the winches' clamps, through the wire clamp on the suspension block, and through the side blocks' wire clamps. We adjusted the wire position while pulling on it. The wire was made to sit inside the wire grooves on the side blocks. While tightening the clamp on the side block with the magnet, the LN key fell knocking off two magnets from the back of the adaptercrying.

Next time we think it might be a better idea to do all the adapter wire clamping on the table instead of on the SOS tower.

In the meanwhile, here are some pictures from today.

 

  16470   Tue Nov 16 17:42:46 2021 YehonathanUpdateBHDSOS assembly

{Tega, Yehonathan}

Another attempt at the suspension of a Lambda Optic mirror

The lambda mirror was removed from the adapter whose magnets were knocked off. We tried to mount the mirror on a different adapter but we knocked off magnets from two adapters crying. We succeeded in mounting the mirror at the third attempt (Adapter number 6). In the meanwhile, Tega threaded wires through side blocks separated from the adapter. He positioned the wires inside the grooves of the side block under a microscope (attachment 1). This procedure is much more accurate and pain-free than doing it on the suspended mirror.

We took the adapter and put it on the EQ stops. The wires were threaded through the wire clamp on the suspension block and clamped at the winches.

The adapter was rotated until the side magnet was roughly at the center of the side OSEM port. We then, as before, put coils in OSEM ports and try to adjust the height of the side magnet and the magnet groove on the other side block such that they are roughly at the center of the coil. We used the winches for fine adjustment.

I used the Canon camera to make sure the side blocks are leveled (attachment 2). I used the macro lens for that purpose. I set up a live stream from the Canon camera using these instructions only that I use OBS instead of CamTwist. I painted a semi-transparent green rectangle to annotate the position of the side magnet socket (attachment 3). I did this several times to confirm the repeatability of the results. Again using the winches for fine adjustments.

Once the height of the side magnets was confirmed to be leveled. I clamped the wires to the suspension block and cut them above it.

I tried to balance the optic but again I see that the suspensions are hysteretic. I check to see whether the wire is touching anything and indeed it touches the corner of the side blockcryingcryingcrying (attachments 4, 5).

 

 

 

Attachment 1: 20211115_170320_HDR.jpg
20211115_170320_HDR.jpg
Attachment 2: 20211116_163846.jpg
20211116_163846.jpg
Attachment 3: magnet_height_check(1).png
magnet_height_check(1).png
Attachment 4: side_blcok_touching_1.png
side_blcok_touching_1.png
Attachment 5: side_blcok_touching_2.png
side_blcok_touching_2.png
  16471   Tue Nov 16 18:28:53 2021 KojiUpdateBHDSOS assembly

Yehonathan told me that the wires are touching between the clamps! I went back to the CAD and confirmed it is really happening. Sad.

The distance of the wires at the upper clamp is 17.018mm.
The distance of the lower clamps is 74.168mm
The vertical drop of the wire is 251mm
--> The wire angle from the vertical line is 0.114 rad

The lower wire block has a step of 1.016mm with the vertical extension of the piece by 11.684mm
--> The angle clearance of the lower clamp is 0.087 rad

So the clearance was not enough.

If we cut the top center of the wire block more than 2.77mm, we can make the wires free.
For safety, we can cut 0.25" = 6.35mm. This will give 0.4mm clearance between the block and the wire at the closest point.

I did this modification on the 3D model and modified the 2D drawing too, so that we can find the machine shop to do it quickly.

Attachment 1: D2100546_Wire_Block.pdf
D2100546_Wire_Block.pdf
Attachment 2: D2100546_Wire_Block.png
D2100546_Wire_Block.png
  16475   Thu Nov 18 14:29:01 2021 KojiSummaryBHDBHD invac optics / opto-mechanics

I went through the optics list (in the BHD procurement google spreadsheet) and summarized how to build them.

The red ones are what we need to purchase. Because of the strange height of the LMR mounts, the post needs to have none half-integer inch heights.

They need to be designed as the usual SS posts are not designed to be vac compatible (not because of the material but the design like screw hole venting).

We also need to check how many clean forks we have.
-> The components were ordered except for the custom posts.
 

ssome partssss
Name Optic Mount Mount OH Post Post OH Fork / Base Base OH Total Height Notes
POP_SM5  Previous POYM1 / 2" Y1-2037-0 LMR2V Thorlabs 1.36 Custom Post 4.14 SS Fork 0 5.5  
POP_SM4 New CM254-750-E03 Thorlabs LMR1V Thorlabs 0.87 Newport 9953+PLS-T238 3.88 BA1V / BA2V 0.75 5.5  
BSOL1 New 2" VIS BB2-E02 LMR2V Thorlabs 1.36 Custom Post 4.14 SS Fork 0 5.5  
ITMYOL1 New 2" VIS BB2-E02 LMR2V Thorlabs 1.36 Custom Post 4.14 SS Fork 0 5.5  
ITMYOL2 New 2" VIS BB2-E02 LMR2V Thorlabs 1.36 Custom Post 4.14 SS Fork 0 5.5  
SRMOL1 New 2" VIS BB2-E02 LMR2V Thorlabs 1.36 Custom Post 4.14 SS Fork 0 5.5  
ASL LA1779-C Thorlabs or KPX217AR.33 Newport LMR2V Thorlabs 1.36 Custom Post 4.14 SS Fork 0 5.5  
GRY_SM1 Y2-2037-0 (in hand) DLC   DLC Post   DLC Fork   5.5  
BHDBS CVI (In hand) DLC 2 DLC Post   DLC Fork   5.5 (3" post for BHD)
LO3 Lambda (in hand) POLARIS-K1-2AH Thorlabs 1 Custom Post 4.5 SS Fork 0 5.5 (3" post for BHD)
LO4 Lambda (in hand) POLARIS-K1-2AH Thorlabs 1 Custom Post 4.5 SS Fork 0 5.5 (3" post for BHD)
AS3 Lambda (in hand) POLARIS-K1-2AH Thorlabs 1 Custom Post 4.5 SS Fork 0 5.5 (3" post for BHD)
OMC1R3 Y1-1025-45P (in hand) POLARIS-K1-2AH Thorlabs 1 Custom Post 4.5 SS Fork 0 5.5 (3" post for BHD)
OMC1R4 Y1-1025-45P (in hand) POLARIS-K1-2AH Thorlabs 1 Custom Post 4.5 SS Fork 0 5.5 (3" post for BHD)
OMC2R3 Y1-1025-45P (in hand) POLARIS-K1-2AH Thorlabs 1 Custom Post 4.5 SS Fork 0 5.5 (3" post for BHD)
OMC2R4 Y1-1025-45P (in hand) POLARIS-K1-2AH Thorlabs 1 Custom Post 4.5 SS Fork 0 5.5 (3" post for BHD)
                   
OMC1R1 Y1-1025-45P (in hand) LMR1V Thorlabs 0.87 Custom Post 4.63 SS Fork 0 5.5 (3.13" post for BHD)
OMC2R1 NB1-K14 Thorlabs LMR1V Thorlabs 0.87 Custom Post 4.63 SS Fork 0 5.5 (3.13" post for BHD)

 

  16483   Wed Nov 24 14:15:15 2021 YehonathanUpdateBHDSOS assembly

Late update. We got 2 modified side blocks from Jordan a few days ago. Yesterday, I glued a side magnet to one of the modified side blocks.

I took the opportunity to reglue some magnets that were knocked off from the adapters. I did this for 2 adapters only since w need 4 shallow adapters and we already had 2 complete ones.

Today, Jordan gave us the rest of the modified side blocks clean and baked. We are ready to suspend a mirror today.

  16484   Wed Nov 24 14:34:15 2021 YehonathanUpdateBHDSaving on SUSAUX slow channels

Koji found out that the stock for BIO Acromag modules is very low and that the lead time for ordering new ones is ~ 1-year X-o.

We figure we might need to minimize the number of modules but still keep the Acromag chassis functional.

 

Looking at the new C1AUXEY feed-throughs spreadsheet one can see that we actually normally need only 1 BIO (not 2) module since there are 16 suspensions related bios + 1 green shutter which is unrelated to SUSAUX so there is no room to cut back here.

 

There are 16 analog input channels, 5 for PDMONs and 5 VMONs, and 6 spares which require 2 ADCs. Removing the spares and 2 monitoring channels will be enough to get us to 1 ADC.

  16489   Wed Dec 1 12:57:08 2021 YehonathanUpdateBHDSOS assembly

{Yehonathan, Tega}

We glued some magnets onto modified side blocks. We followed pretty much the same procedure form last time. The music wires were clamped on the side blocks away from the optic adapter. The clamps were screwed down using the low profile screws the Jordan obtained from UC components to allow maximum clearance for the coils (Attachment 2).

The modified side blocks with wires already clamped in them were screwed onto the adapter. We put the adapter on the EQ stops and do rough adjustments, making sure the side magnet is roughly on the center of a coil we inserted to the side. The wires were threaded through the wire clamp on the suspension block and clamped on the winches. We realigned the Oplev beam such that it is parallel to the table using the quad photodiode.

We balanced the height of the adapter. This time we used a camera facing the adapter. The tilt of the camera was set by drawing a straight line (red line in attachment 1) such that the bottom clamps on the SOS are parallel to it.

Then, we adjusted the winches such that the screws on the side blocks are on the same green line on attachment 1.

Once the height was adjusted, we clamped the wire on the suspension block and cut it at the winches.

We balanced the optic. We had to take out the front counterweight to get the balance (attachment 3).

We checked whether the wire is touching anything. We confirmed that it doesn't. The wire goes nicely through the new hole on the side blocks (attachment 4, 5).

We measure the resonance frequency for both yaw (attachment 6) and pitch (attachment 7). They both seem to be sub-Hz. The pitch trace also shows that the oscillations are centered around 0 meaning the optic is balanced.

There's still the issue of what to do with the lower back EQ stop not touching the adapter.

Attachment 1: SOS_Roll_Balance.png
SOS_Roll_Balance.png
Attachment 2: IMG_20211201_120041570.jpg
IMG_20211201_120041570.jpg
Attachment 3: IMG_20211201_115551005.jpg
IMG_20211201_115551005.jpg
Attachment 4: IMG_20211201_115640728.jpg
IMG_20211201_115640728.jpg
Attachment 5: IMG_20211201_115454629.jpg
IMG_20211201_115454629.jpg
Attachment 6: IMG_20211201_115717907.jpg
IMG_20211201_115717907.jpg
Attachment 7: Pitch_oscillations.png
Pitch_oscillations.png
  16491   Mon Dec 6 18:23:04 2021 YehonathanUpdateBHDSOS assembly

I installed OSEMs on the LO1 SOS. To my surprise, the side magnet is not in the center of the side OSEM. It completely misses the LED as can be seen in the attachment.

Looking at the CAD model, it turns out the position of the OSEM on the left side plate is different from the position of the OSEM on the right side plate in the SOS tower.

We need to take the optic down, swap the right and left side blocks, and resuspend it.

There is not enough 🤦🏻‍♂️in the world

Attachment 1: signal-2021-12-06-165751_001.jpeg
signal-2021-12-06-165751_001.jpeg
  16497   Thu Dec 9 21:57:35 2021 YehonathanUpdateBHDSOS assembly

{Yehonathan, Tega}

We took the optic out of the SOS tower and removed the side blocks. We mounted new side blocks with wires already clamped in them in the reverse order.

The Adapter was placed back into the SOS and the wires were threaded through the wire clamp and suspended on the winches. The roll of the optic was balanced using a camera (attachment 1).

The pitch was balanced. this time I used 2 counterweights instead of 1 in order to not have to take so much of the weight out.

The mechanical resonances were measured by taking a 100 sec time series of QPD readout and doing PSD estimation (attachment 2). The mirror motion was damped as much as possible before taking the measurement.

3 peaks below 1.5Hz can be seen with frequencies of 755mHz (Yaw), 942mHz, 1040mHz (Pitch + Pos). The pitch/pos peaks are a bit close to each other, I bet if we go back to 1 counterweight the situation will be better.

While inserting the side OSEM I realized I didn't check the overall height of the adapter. The magnet was too high. I will fix it tomorrow and repeat the roll balancing.

 

Attachment 1: balancingsos2.png
balancingsos2.png
Attachment 2: FreeSwingingSpectra.pdf
FreeSwingingSpectra.pdf
  16499   Fri Dec 10 15:59:23 2021 PacoUpdateBHDFinished Coil driver (even serial number) units tests

[Paco, Anchal]

We have completed modifications and testing of the HAM Coil driver D1100687 units with serial numbers listed below. The DCC tree reflects these changes and tests (Run/Acq modes transfer functions).

SERIAL # TEST result
S2100608 PASS
S2100610 PASS
S2100612 PASS
S2100614 PASS
S2100616 PASS
S2100618 PASS
S2100620 PASS
S2100622 PASS
S2100624 PASS
S2100626 PASS
S2100628 PASS
S2100630 PASS
S2100632 PASS
S2101648** FAIL (Ch1, Ch3 run mode)
S2101650** FAIL (Ch3 run mode)
S2101652** PASS
S2101654** PASS

** A fix had to be done on the DC power supply for these. The units' regulated power boards were not connected to the raw DC power, so the cabling had to be modified accordingly (see Attachment #1)

Attachment 1: dc_fail.jpg
dc_fail.jpg
  16505   Tue Dec 14 14:02:33 2021 YehonathanUpdateBHDSOS assembly

{Yehonathan, Paco}

I fixed the overall height of the adapter (attachment 1). I put an OSEM next to the side magnet. I positioned a camera in front of the SOS and connected it to my laptop for live streaming. I painted a line indicating the height of the OSEM plates and a line in between with the mean height. I discarded the wire clamp on the suspension block I released the wires from the winches and pulled on them until the magnet was roughly in the right position. I clamped the wires back on the winches and adjusted them until the magnet was on the middle line. I also verified that the roll of the adapter is aligned as before by making sure that the horizontal features on the adapter are parallel to the horizontal features on the SOS tower.

The wires were clamped to the suspension block using a new wire clamp.

I Found that locking the counterweight setscrew changes the alignment. Today we verified this effect. We released the setscrew and pre-compensated by adjusting the counterweight such that when the setscrew was locked the mirror was aligned.

We measured mechanical resonances (attachment 2). This time the yaw motion was very quiet so we got a smaller peak for the yaw. The peaks are the same as before. Y readout has peaks around the pitch and pos resonances that don't appear in the X readout. I'm not sure what they are. Maybe coming from the QPD electronics.

We locked the adapter using the EQ stops. We made sure the alignment stays close to ideal.

We installed OSEMs on the SOS. We chose suboptimal OSEMs because LO1 will only be used for steering. I made a spreadsheet copying the OSEM catalog into it. There we mark which OSEM goes where.

I cleaned the optic using the ion gun with a pressure of 30 PSI.

The next steps are:

1. Engrave the SOS tower.

2. Cut the wire at the winches and remove the winch adapter plate.

3. Wrap the SOS with foil.

4. Install the SOS in the vacuum chamber.

 

 

Attachment 1: magnetcentring.png
magnetcentring.png
Attachment 2: FreeSwingingSpectra.pdf
FreeSwingingSpectra.pdf
  16506   Tue Dec 14 19:29:42 2021 PacoUpdateBHD1Y0 rack work for LO1

[Paco]

Two coil drivers have been installed on 1Y0 (slots 6, 7, for LO1 SOS). All connections have been made from the DAC, AI board, DAC adapter, Coil driver, Sat Amp box. Then no SOS load installed, all return connections have been made from Sat Amp box, ADC adapter, AA board, and to ADC. We will continue this work tomorrow, and try to test everything before closing the loop for LO1 suspension.

  16509   Wed Dec 15 16:11:38 2021 AnchalSummaryBHDPart VIII of BHR upgrade - Placed LO1

[Anchal, Yehonathan, Paco]


Today we opened ITMX chamber and removed the following optics and placed them in the Xend flow bench (see attachment 1):

  • POPM1
  • POPM2

Yehonathan brought his first SOS baby next to ITMX chamber. The suspension was carried by hands throughout. He gave me the suspension over the IMC beam tube from where I placed it on the table. I checked through the OSEMs and the face magnets were still on. I could not verify the side magnet but nothing seemed out of place.

I then moved LO1 near its planned place. I had to bolt it at 1 inch North and 0.5 inch West of its planned position because the side OSEM on ITMX is long and protrudes out of the base footprint. Even if it was small, the current layout would make the OSEM pins of the side OSEMs of ITMX and LO1 very near each other. So we can not place LO1 closer to ITMX from current position. This means the layout needs to be redesigned a bit for the modified position of LO1. I believe it will significantly shift and turn the beam from LO1 to LO2, so we might need to change the beam upstream from TT2 onwards. More discussion is required.

Unfortunately, what I thought was clicking photos was just changing modes between video and image mode, so I have no photos from today but only a video that I recorded in the end.


Photos: https://photos.app.goo.gl/23kpCknP3vz7YVrS

 

Attachment 1: signal-2021-12-15-161437.jpeg
signal-2021-12-15-161437.jpeg
  16510   Wed Dec 15 17:44:18 2021 KojiSummaryBHDPart VIII of BHR upgrade - Placed LO1

If ITMX already has another side magnet, we can migrate the side OSEM of ITMX to the other side. This way, the interference of the OSEMs can be avoided.

  16511   Wed Dec 15 22:09:53 2021 YehonathanUpdateBHDSOS assembly

{Paco, Yehonathan, Anchal}

I cut the wires from the winches and removed the winch adapter plate. I engrave  'LO1' on the SOS tower. Me and Paco wrapped the SOS with foil and transported it to Anchal who put it inside the ITMX chamber.

The transportation seems to be successful. Nothing broke. However, we found that even with the short side OSEM the LO1, as it is now, cannot sit in its designed position since ITMX's side OSEM stands in its way.

If there are magnets on both ITMX sides we can move its side OSEM to the other side. Another option is to resuspend LO1 with a side magnet on its left side.

 

  16512   Thu Dec 16 12:21:16 2021 AnchalUpdateBHDCoil driver test failed for S2100619-v1

Today I found one of the coil driver boards, S2100619 failed the test on CH2. There appears to be an extra phase lag after 10 kHz and some resonant-like feature at 7 kHz. This of course is very high-frequency stuff and maybe we don't care about these deviations. But it could mean something is off with the channel and could potentially lead to failure in the relevant frequency band in the future. I'll need help to debug this. Please see the attachment for details of test failure.

Attachment 1: D1100687_S2100619-v1_TF_CH2_Not_Matching.pdf
D1100687_S2100619-v1_TF_CH2_Not_Matching.pdf D1100687_S2100619-v1_TF_CH2_Not_Matching.pdf
  16514   Thu Dec 16 15:32:59 2021 AnchalUpdateBHDFinished Coil driver (odd serial number) units tests

We have completed modifications and testing of the HAM Coil driver D1100687 units with serial numbers listed below. The DCC tree reflects these changes and tests (Run/Acq modes transfer functions).

SERIAL # TEST result
S2100609 PASS
S2100611 PASS
S2100613 PASS
S2100615 PASS
S2100617 PASS
S2100619 FAIL (CH2 phase)
S2100621 PASS
S2100623 PASS
S2100625 PASS
S2100627 PASS
S2100629 PASS
S2100631 PASS
S2100633 Waiting for more components
S2101649** PASS
S2101651** PASS
S2101653** PASS
S2101655** PASS

** A fix had to be done on the DC power supply for these. The units' regulated power boards were not connected to the raw DC power, so the cabling had to be modified accordingly.

Further, Paco fixed the two even serial number units (S2101648, S211650) that failed the test. The issues were minor soldering mistakes that were easily resolved.

  16516   Thu Dec 16 17:41:12 2021 KojiUpdateBHDCoil driver test failed for S2100619-v1

Good catch. It turned out that the both + and - side of the output stages for CH2 were oscillating at ~600kHz. If I use a capacitance sticks to touch arbitrarily around the components, it stops their oscillation and they stay calm.
It means that the phase margin becomes small while the circuit starts up.

I decided to increase the capacitances C6 and C20 (WIMA 150pF) to 330pF (WIMA FPK2 100V) and the oscillation was tamed. 220pF didn't stop them. After visually checked the signal behavior with an oscilloscope, the unit was passed to Anchal for the TF test.

The modification was also recorded in the DCC S2100619

Attachment 1: PXL_20211217_001735762.jpg
PXL_20211217_001735762.jpg
Attachment 2: PXL_20211217_001719345.jpg
PXL_20211217_001719345.jpg
Attachment 3: PXL_20211217_005344828.jpg
PXL_20211217_005344828.jpg
Attachment 4: PXL_20211217_010131027.PORTRAIT.jpg
PXL_20211217_010131027.PORTRAIT.jpg
Attachment 5: PXL_20211217_011423823.jpg
PXL_20211217_011423823.jpg
Attachment 6: HAMA_Driver_V4.pdf
HAMA_Driver_V4.pdf
  16517   Thu Dec 16 17:57:17 2021 AnchalUpdateBHDFinished Coil driver (odd serial number) units tests

S2100619 was fixed by Koji and it passed the test after that.

Quote:
SERIAL #  
S2100619 FAIL (CH2 phase)

 

  16518   Thu Dec 16 18:16:36 2021 YehonathanUpdateBHDSOS assembly

Today I glued magnets onto the new 3/4" mirror adapters. I also took the opportunity to make some more side magnets assemblies.

Yesterday I mounted PR3/SR2 3/4" thick mirror onto one of the new adapter. There seem to be no issues for now.

I started the process of suspending AS1 (E2000226-A). The Lambda Optic mirror with the closest specs has Rc = 2 m. I attached side blocks with clamped wires onto adapter number 7 - side block with a magnet on the right.

I then took one of the Lambda Optic mirrors and tried mounting it in the adapter. It was quite difficult to get it right. Unfortunately, I chipped the edge of the substrate (attachment 1) 🤦🏻‍♂️. I put the mirror back in the box and decided to use the spare mirror. I successfully mounted it into the adapter but when I put the clamping screws one of them fell on the mirror 🤦🏻‍♂️🤦🏻‍♂️. There is no visible damage though. I took some pictures (attachment 2-4).

I and Anchal then started suspending the mirror but then we found that one of the wires is dented in the middle 🤦🏻‍♂️🤦🏻‍♂️🤦🏻‍♂️. I'm burned out for today.

Late update: one nice thing that I found yesterday is that the glue is viscous enough to hold the dumbells without a metal sheet from above holding the magnets. This greatly simplifies the gluing process.

 

Attachment 1: chippedmirror.png
chippedmirror.png
Attachment 2: IMG_6311.JPG
IMG_6311.JPG
Attachment 3: IMG_6310.JPG
IMG_6310.JPG
Attachment 4: IMG_6309.JPG
IMG_6309.JPG
  16520   Fri Dec 17 17:50:17 2021 YehonathanUpdateBHDSOS assembly

I threaded a new wire through a different side block with a magnet and clamped it under a microscope. It was hard, but eventually, I was able to do it by holding the wire on both sides of the side block with weights.

The dented wire was discarded and the side block that was mounted on the AS1 adapter was put aside. I mounted the side block with the new wire on the AS1 adapter.

 

Anchal and I hanged the AS1 adapter and clamped the wires on the winches of an SOS tower. I balanced the roll and adjusted the height of the magnet with respect to a side OSEM using a camera (attachments 1 & 2).

I shoot the Hene laser on the optic and look at the reflection. I align the laser beam to be as close as possible to the center of the mirror. The OpLev needs to be realigned.

To my surprise, the ghost beam shoots up above the reflected beam! See attachment 3. I check to see that the arrow which marks the thinnest side of the mirror is horizontal (attachment 4). WTF?!

Also, now I realize that the marking on the Lambda optics are pencil markings 😵😵😵.

Attachment 1: AS1rollbalance.png
AS1rollbalance.png
Attachment 2: AS1Magnet_height.png
AS1Magnet_height.png
Attachment 3: ghostbeam.png
ghostbeam.png
Attachment 4: lambdaopticarrow.jpg
lambdaopticarrow.jpg
  16521   Fri Dec 17 19:16:45 2021 KojiUpdateBHDSOS assembly

We @40m do the convention of the arrow at the thinnest side & pointing the HR side, but nobody says Lambda does the same.

We can just remount the mirror without breaking the wires and adjust the pitching if you do it carefully.

Does this mean that the LO1 also likely to have the wedge pointing up? Or did you rotate the mirror to have the wedge reflection to be as horizontal as possible?

  16523   Fri Dec 17 22:16:07 2021 YehonathanUpdateBHDSOS assembly

I specifically checked the specification before mounting the mirror. It says clearly "Arrow at the thinnest location pointing towards Side 1". I guess they just ignored it.

As for LO1, I mounted it without noticing the location of the arrow. Later, I checked and the ghost beam was horizontal so I left it as it is. Yeah, I guess I will remount the mirror. Also, what do we do with the pencil markings? It's not vacuum-compatible.

Quote:

We @40m do the convention of the arrow at the thinnest side & pointing the HR side, but nobody says Lambda does the same.

We can just remount the mirror without breaking the wires and adjust the pitching if you do it carefully.

Does this mean that the LO1 also likely to have the wedge pointing up? Or did you rotate the mirror to have the wedge reflection to be as horizontal as possible?

 

  16524   Sat Dec 18 00:56:14 2021 KojiUpdateBHDSOS assembly

Sad... We just need to check the wedge direction everytime, unfortunately.

Pencil: can you try to gently wipe it off with solvent & a swab? (IPA / Acetone)
If it does not come off in the end, it's all right to leave. Do we want to scribe the arrow mark? You need a diamond pen.

  16526   Mon Dec 20 13:52:01 2021 KojiUpdateBHDSOS assembly

LO1: No need to remove the pencil mark for the damping test. Until we see serious contamination on the LO1 optic, we don't need to take the optic off from the mount and clean it. If there is a chance of rehanging (because of a broken wire/etc), we do wipe the pencil mark.

Other optics: wipe the pencil mark as much as possible.

  16527   Mon Dec 20 14:10:56 2021 AnchalUpdateBHDAll coil drivers ready to be used, modified and tested

Koji found some 68nF caps from Downs and I finished modifying the last remaining coil driver box and tested it.

SERIAL # TEST result
S2100633 PASS

With this, all coil drivers have been modified and tested and are ready to be used. This DCC tree has links to all the coil driver pages which have documentation of modifications and test data.

  16528   Mon Dec 20 17:26:13 2021 YehonathanUpdateBHDSOS assembly

{Yehonathan, Anchal}

I released the AS1 wires from the winches, removed the adapter from the SOS tower, and removed the Lambda optic from the adapter. Attachment 1 shows the pencil markings on the optic before cleaning. I cleaned the pencil marking from the side of the optic with acetone using swabs until there were no pencil residues on the swab (attachment 2 shows the swab I used next to an unused swab). I was not able to remove the markings completely though (attachment 3).

I remounted the optic with the arrow rotated by 90 degrees counterclockwise.

We hang the adapter on the winches and adjust the height of the magnet and the adapter roll using the winches. We monitor the height of the adapter using a live stream from the Cannon camera. The camera's tilt was adjusted using straight features on the SOS tower. When we ran out of winch travel we adjust the height using the lower EQ stops and pull tight the wires. Attachment 4 shows the alignment of the side magnet with respect to the SOS tower and a side OSEM.

We checked the ghost beam trajectory and it looks much better (attachment 5)

We started realigning the OpLev. We realize that the height of the beam should be 5+14/32" = 5.437 by measuring the height of the screw holding the side OSEM from the table. The real height from the schematics is 5.425 We make the beam parallel with the table first using an iris and then the QPD.

Today, I balanced the counterweight. First using an iris, then by placing a QPD close to the SOS measuring the reflection from AS1. I locked the counterweight's set screw and the QPD Y readout looks good. Attachment 6 shows the QPD y readout near the beat node between pitch and pos. The node comes very close to zero which indicates that the pitch is balanced.

I measured the free-swinging motion using the QPD x and y axes. Attachment 7 shows the spectra of that motion. The major peaks are at 755mHz, 953mHz, and 1.05Hz.

 

Attachment 1: IMG_6312.JPG
IMG_6312.JPG
Attachment 2: IMG_6315.JPG
IMG_6315.JPG
Attachment 3: IMG_6314.JPG
IMG_6314.JPG
Attachment 4: AS1adapterbalancing.png
AS1adapterbalancing.png
Attachment 5: as1ghostbeam2.png
as1ghostbeam2.png
Attachment 6: beat.png
beat.png
Attachment 7: FreeSwingingSpectra.pdf
FreeSwingingSpectra.pdf
  16531   Tue Dec 21 18:04:46 2021 YehonathanUpdateBHDSOS assembly

I locked the EQ stops while retaining the XY alignment on the QPD and installed 5 green OSEMs. AS1 is ready for transfer into the vacuum chamber.

ELOG V3.1.3-