[Jeff,Torrey]

Assorted notes:

-I completed the assembly of the piezo mirror. This required having daniel machine a custom spacer for the assembly. With the spacer, the piezo alignment tool works. Note that this new piezo has a larger OD that is large enough to prohibit the use of the nylon tipped set screws for alignment. Because of this the spacer and piezo may not be concentrically aligned to the mirror.

-Installed a 2 meter 780 PM fiber at the OFC2/OFC3 sled fiber port hub. This allows a connection from the third AOM path to OFC3 775 input.

-We are going to start mode matching into cavity 3. The USB extension from the NUC computers does not recognize the scanning slit beam profiler. This is probably due to the USB extension being over 100 ft and needing external power. We are going to use the new lab laptop for now instead.

-The new laptop is unusable for the scanning slit software. For some reason it is constantly crashing and freezing.

-After switching to Torrey's laptop, we collected data for the beam size between the launcher and the third filter cavity. We noticed amplitude fluctuations on the beam, but they reduced when we raised the power on this path (by turning the amplifier current to 1A. This should correspond to ~1.5W total output on the distribution center).

-We spent some time profiling and finding a mode matching solution. The waist for this light needs to be .26 meters after the collimator for this configuration which is making it difficult to mode match. We are going to try moving the collimator back tomorrow and reprofiling.

-We turned the amplifier back down until tomorrow.

[Torrey, Daniel]

I designed and made a spacer to go between the top of the piezo assembly and the NAC 2125 piezo (2 mm thick) so that the mirror is within the piezo base and the piezo can be centered with the centering tool I previously made and the #4-40 nylon tipped set screws. The spacer is 0.75" OD, 0.469" ID, and 0.226" thick. I designed it to be 0.21" thick (see photo), but this came out a bit longer because I thought I would have to machine the surface to get it smooth. Instead, parting at 400 rpm gave a nice surface finish.

I measured the inside of the piezo to be ~0.468". It fit over the 0.46" diameter part of the centering tool, but not the 0.47" diameter part of the centering tool. 

I designed a plate to mount the TeraXion LXM-U Laser to the optics table with good thermal contact. I used a fly cutter at 1800 rpm to get a really nice top and bottom surface finish and a 3/4" end mill to get the sides. See attached files.

I unfortunately broke a tap in one of the mounting holes and couldn't remove it. Martin Mendez in the Chemistry Machine Shop said it would take 2-3 hours of shop time to burn through the tap with the plunge EDM, costing $120-$190. Since only 2-3 holes are needed to securely mount the laser, I cut out the hole with the broken tap with the band saw. 

For the other 3 #4-40 holes, I drilled them out to 0.0935" (using a #42 drill) instead of the standard 0.089" (a #43 drill) to help with the tapping. This is still plenty of thread engagement, and the tapping went much better.

Update to [12045]:

The 1550 IR viewer and the additional lens attachment have been returned to the cryo lab lista cabnet in the drawer labeled "IR Viewer".

I cleaned the 5/16"-24 thread cleaner that I previously machined and a 7/16" socket in acetone. I rinsed the paint off the 7/16" socket with the acetone spray bottle before putting it alone in a 100 mL beaker with acetone and sonicating for 3 minutes, replacing the solvent, and sonicating for another 7 minutes. I sonicated the thread chaser and socket in the same beaker with isopropanol for 10 minutes.

I used the thread chaser on a few holes on the LFC Input Vacuum Cube Top Flange, but the threads did not seem greatly improved. Either we just power through and hope the threads are actually fine with the silver coated screws, or we re-tap the threads. We have a 5/16"-24 tap, but I think we want some slightly nicer ones, including a bottom tap (which I don't think we have) to reach the bottom threads.

[Torrey, Jeff]

We performed a first contact cleaning procedure on the four optics planned for use in output filter cavity three. We struggled with the first contact solution creating strings, and two of the four optics had to be re-painted and will be peeled at a future date.

For each optic, the procedure was as follows:

1) Remove the optic from the package, and place it in a mount, HR side down. Create a label for this optic.

2) Paint the AR side of the optic with a first coat. Add a strip of plastic mesh to serve as a handle on removal, and paint another coat on top.

3) Wait for the first contact on the AR side to dry completely, then place it face down on a clean surface. We used a TEX wipe 1109. Based on the fact that later the first contact was stuck to the wipe, the 5 minutes or so that we waited was not long enough.

4) Repeat step 2 on the HR side.

5) Wait for the HR side to dry completely

6) Peel off the first contact, using the tweezers to lift the mesh handle to start. Be mindful of strings! They are likely to lurk around the edges of the optic as you pull away, and they will make you very sad if they land on the optic. We used the tweezers to remove strings if they were close to the edge of the optic, but when the optic had strings on the middle we re-painted that face.

7) Place clean optics into their mounts and label the mount.

I put the chuck into the drill press, and it seemed to be running fairly smoothly. I also rotated the platform to make it level and rotated the platform about the vertical support column so that the platform's hole was directly below the chuck.

[Alex, Daniel]

We began to assemble the Agilent Vacuum Pump for the SNSPD Dewer. We mostly followed the manual, but needed to find longer M3 screws (~10 mm long instead of 6 mm) to mount the bracket to the turbo pump (with the fan and the lock washers). We may have damaged the threading by insterting the included screws which were not long enough, so I re-tapped them.

Seperately, next time, it will be easier to assemble the scroll pump supports first with nothing else on the base plate.

After the scroll, turbo, and controller were assembled to the base plate, we wheeled the system into the clean room. We connected the included KF16 elbow to the Agilent turbo pump and KF16 to KF25 tubing from the turbo pump to the scroll pump. They included an o-ring with a mesh filter, so we attached it between the tubing and the scroll pump.

We started to attach electronics to the pumps and controller, but there isn't room on the controller for the cables. This seems like a design oversight on Agilent's end. We can mount the controller somewhere else near the pumps/dewer.

We need to design, purchase, and assemble the tubing and other vacuum components between the turbo pump and the main vacuum chamber. This is ongoing and Alex will add a cart to Techmart/OpenProject later today.

I cleaned a 5/16"-24 Thread Chaser to clean the threads for CF Flanges, specifically the threads for the top flange on the Laser Filter Cavity (LFC) Input Vacuum Cube. Because the thread chaser is made of carbon steel, I cleaned it in a 10 minute acetone bath/sonication and a 10 minute isopropanol bath/sonication. I first had to reclean the acetone container with DI water/simple Green and DI water because there was residual grease/gunk in the container from cleaning the locking pliers.

I used the thread chaser on one of the screw holes with the flanges still attached, and it seemed to allow the screw to go in deeper (I didn't do a rigorous measurment, partially because it's a bit ad hoc when to stop tightening the screw). The diameter of the threader chaser by the hex head is too large to fit through a 10" CF Flange (0.96" thick) and thread 0.75" deep into the vacuum cube. To get around this issue, I used the lathe to machine down the tip of the thread chaser to hypothetically fit into a 1.58" long, 0.312" diamter (< 5/16") cylinder so that it can be inserted all the way down the threaded holes. I can use the counterbored holes (0.25" deep) on the 10" flange from the holometer to get the remaining depth needed (1.83" measured). There is still ~0.3" left on top of the thread chaser to use so that a socket can be used. The narrowest part of the thread chaser is ~1/4" thick and ~1" long, so I don't think I meaningfully weaken it (famous last words). Nevertheless, one should be gentile with it.

Tomorrow, I plan on cleaning the 7/16" socket and re-cleaning the thread chaser to see if I can fully clean up the threads.

I've updated the layout diagram for OFCs 1, 2, and 3 for its current configuration in B111B. I've laid out all the optical elements on the table for a proof of concept. It will be cramped but it should fit. This configuration should allow continuous building and testing of OFC3 while allowing for chained cavities in the future. Couple of other notes:

-For this to be fully functional we need to buy a 775 50:50 BS and a thorlabs PDA10A2.

-Note the oxidation (I think?) in PXL_20250124_000346938MP.jpg. Unsure if we care, just pointing it out.

-Still need to calculate mode matching solutions for both 1550 inputs and the 775 inputs.

-The .svg that created this image is at "\Nextcloud\GQuEST\Layout_Mockups\readout_FCs_1_2_and_3.svg"

-It is unclear how the output of OFC3 will get to the eventual OFC4. 

[Jeff, Daniel]

We attached a 10" to 6" reducer flange to the front face (where the laser enters) to the Laser Filter Cavity (LFC) Input cubed and tightened the screws to 34 Nm. We attached a 6" to 2x2.75" reducer flange to this reducer flange, and I tightened the screws to 34 Nm using the new 2" torque adaper extension tool. This new tool doesn't affect the torque amount if it's perpendicular to the handle.

I then attached a 2.75" blank flange to the unused port on the 6" to 2x2.75" reducer flange and tightened the screws to 14 Nm.

I put a command hook in B106 to hold various keys on key rings. I put my key to B150 and a key to the fire cabinet in B102B.

[Alex, Daniel]

I designed some custom plates that mount to the Agilent Base Plate and allow POC001 Caster Wheels to be attached. We had 4 of these caster wheels around from the SNSPD Dewer Cart. The purpose is to move the vacuum pump system along with the dewer.

I attached the wheels to the plate with the 4 M6 screws included with the wheels. I attached the plate to the Agilent Base Plate using a 3/8-24 hex bolt (and a lock washer) from the "inside" of the Agilent Base Plate. I also used a #10-32 set screw to help align the custom plate into the Agilent Base Plate since there is a rotational degree of freedom. 

See attached part file, STEP file, drawing for tapping, and photos.

[Ian,Torrey]

We found why the second chassis wasn't working. In order to diagnose we first confirmed these new RF amplifiers were working by snipping the leads and powering it via a variable power source. A deflected beam was seen after AOM3. We tried a bunch of short testing and finally concluded that the the 5 pin power connector was rotated 90 degrees with respect to the original power cable (in that picture, original means the correctly functioning chassis, new means the newer one that was built that was not functioning correctly). This orientation doesn't have a preferred direction, but they do need to be the same. I believe we could fix this by quickly swapping the wires here and keeping this 90 rotation, but we decided to resolder this box to make it the same as the old one. This is better for the long term.

We plugged everything back in and now see a deflected beam on AOM3. The left side of the box is significantly under supplying the AOM (i.e. there is a deflected beam, but way less than the other side). We will diagnose this tomorrow. 

[Alex, Daniel]

We have moved the agilent vacuum pumps (3x) to B111A. The systems have been organized into stacks along the wall as seperate pump systems.

It was then decided that because the Dewar cart is inherently on wheels and capable of being mobile; wheels should be added to the pump system.

Thus, Daniel and I are now retrofitting the old casters from the original thorlabs cart to fit the base plate for the vacuum pump to enable it to move with the dewar when the time comes.

This should be ready sometime next week for pump down with the Dewar assembly.

A smoke smell has been reported earlier in the morning (althoguh I haven't smelled anything, potentially because I went downstairs at 11 AM), so I took some particle counts.

The 0.3 um counts outside the clean rooms are ~3x higher than Tuesday, January 14. The larger particle counts are also elevated.

[Jeff, Daniel]

We placed a 10" blank flange on the Input Laser Filter Cavity (LFC) Vacuum Cube North End and tightened the screws to 34 Nm. We moved 10" flange with electronics D-Subs to the Demonstrator Interferometer Vacuum Cube (transmitted arm) so that we can lock the interferometer with a piezo. I tightened the screws to 13.6 Nm with one pass but decided to go home and not work alone. These flanges and faces on the cubes were a bit dirty, so we did some cleaning with the wipes meant to clean inside vacuum chambers. We moved the 10" to 4.5" zero length reducer flange to the top of the Input LFC Vacuum Cube, but the screws did not want to go in more than ~0.35" before almost all of them had a lot of resistance. The holes seem tapped and deep enough; I measured 1.8" from the top of the flange to the bottom of the hole. I think we need to re-tap or clean up these threads. Ian recommended getting a thread chaser kit. I think this one would be a good option. We placed foil on the newly exposed face on the Input LFC Vacuum Cube. I want to seal up the flanges before potentially making chips on top of the vacuum chamber.