[Jeff, Daniel]

From one of the Holometer bend cubes (with only 3 lifting points), we took off the 8" diameter bellows and 10" to 8" Zero Length Reducer CF Flange (while still attached to each other) and wrapped the open end in UHV foil. The cube was fairly dirty on the inside and outside, so we lightly cleaned the outside. We did not clean the inside, but there are particulates that need to be removed.

We then added a 10" blank CF Flange. We felt a lot of resistance from one of the holes, so we used a 1.25" long screw instead of a 1.75" long screw to avoid the bad part of the thread in the cube. As I was tightening the flange to the cube (at around 20 Nm), I stripped the silver-coated screw. See the screw in the foreground of the attached photo. I was able to tighten the other screws (at around 45 Nm) so that the flange is flush along the cube face and the gasket isn't visible. It isn't noticiely worse where the screw is missing.

After I removed the stripped screw, I was not able to add another screw into the cube. However, I was able to "touch up" the thread with a 5/16-24 tapered tap (making sure to only apply a light amount of torque so that the existing thread is only improved) and insert a 1.75" screw. I felt the same resistance as I did with the initial screw insertion, so I want to use a 1.5" long screw. This will hopefully avoid the two bad parts of the thread in the cube that I believe exist: the shallow part, which might be my fault, and the deep part, which existed. We can get this screw from Duniway or McMaster. 

We need to tip over the Holometer Bend Cubes to install the custom tapped CF Flanges onto their (eventual) bases. However, one of the bend cubes has a screw broken off into its 1/4-20 lifting point, so we can only use 3 of its lifting points. Unfortunately, the unusable lifting point is at the corner of two bellows, so when we use 2 lifting points to tip over the cube, a bellows would get in the way. We will have to remove one of these bellows anyway, but now we will have to do it sooner. I propose using a blank 10" CF Flange and making this Holometer Bend Cube the Power Recycling Cube so that we won't ever have to move it if everything goes well.

[Jeff, Daniel]

In preparation for installing the custom tapped CF Flange Bases onto the Holometer Bend Cubes, Jeff and I took off the end cube top, moved them away from the cube, and removed the ribbon cables from the Bend Cube insides. In order to do this, we needed a flat head screwdriver to remove a plastic cap and a 3/32" hex ball key to unscrew the ribbon cable terminator from the flange. We then needed to screw the cap back into the ribbon cable terminator so that it can be easily gripped and removed. We then replaced the end cube top CF Flanges and screwed them in finger tight so the top don't come loose when we turn the cubes onto their side. We stored the ribbon cables and some of its screws in foil and a labeled pouch in the white south cabinet in B111B.

I cleaned a flathead screwdriver for UHV. It is made of multiple metals, so we should get some better ones for UHV.

Ioana and I met this morning to go through every stage and component that is needed to operate the SNSPD in the ICE fridge such that we may begin assembling carts for procurement for GQuEST.

Additionally, we will look for off-the-shelf fiber feedthroughs but if not Ioana can assist me in making our own. 

The 3 axis stage has also been moved from ICE in Downs to Bridge for testing when we do our first cooldowns on the Dewar. We will look for a replacement for the brass component inside it that expands under cryo.

Here is our current list of needed materials and the chain for the signal paths for the SNSPD:

         cryostat parts needed doc

I connected the 3 Moku Pros currently in the large electronics rack to a wall ethernet port via a switch placed on a shelf in the back of the rack.

They are accesible on the desktop on the other side of the room (also connected to the network via ethernet) but cannot be seen by the iPads.

[Ian, Sander, Daniel]

I designed some guardrails that go 3" above the M6 tapped holes of the shelf above the optics tables in B111B. I used 1/8" thick, 1/2" wide aluminum bar. There were 3 piece types (all holes centered along the 1/2" width):

Vertical bar: 4" long; 0.24" (C drill) diameter hole 0.5" from bottom; 0.27" (H drill) diameter hole 3.5" from bottom

Long horizontal bar: 36" long; 0.27" diameter holes at 0.78", 1.5", and 3 more holes with a regular 250 mm spacing beyond 1.5" to match the shelf hole pattern.

Short horizontal connection bar: 19" long; 0.27" diameter holes 0.375" from side and 2 more holes with 9.125" spacing

This short horizontal connection bar is designed to be replaced by a patch panel if desired.

Ian helped me drill some holes and Sander helped me install the connection bars.

We were not able to install 1 long and 1 short horizontal bar because the seeder breadboard overhangs the shelf by ~1". 

See attached photos.

[Sander, Jeff]

First we installed the H1A:PCIe Gen 2x1 Host Adapter into the front-end machine named Babbage.

lspci | grep "PCI bridge"

the above command shows devices connected via the host adapter.

We next installed the advantech ADC, DAC, and digitizer card (also a DAC) into the 4U expansion chassis. We can then see new devices on running lspci, but the digitizer card is still invisible, and we believe this is due to a missing driver.

Boot sequence:

power supply to expansion chassis

power on backplane board

power on front-end machine

I've set up 3 ant traps at the base of the optics tables in B111B. This post is mainly a reminder to replace/remove them in 3 months. The extra traps chub gave me are located above the red tool chest in B111D.

I checked the dimensions, the custom SM05 threads, and the fits with the other parts for the custom 3D MOT holder from Hubs. We have previous issues with bad surface quality and bad SM05 threads. As far as I can tell, everything is up to spec (for the one part I checked). Everything fits together and the SM05 threads are good. I marked in the box which part I checked. The surface quality isn't amazing and could out gas a bit more than we would like, but I don't think we can get around it.

[Jeff, Daniel]
 

We cleaned the two recently machined 10" CF Flanges with the custom tapped pattern. We did a bath of 30:1 simple green + DI water and the sonicated it directly in the sonicator in DI and then isopropanol. We noticed a bit of a "scum" on the flanges. We aren't sure of the cause. We then put the flanges in the vacuum oven to bake out at 200°C for 48 hours.

I printed and posted these two signs to make using the drill press easier. The first is a chart that converts from diameter to drill size name. It also has what drill should be used to make tapped holes. The second sheet provides the recommended drill speed as a function of drill diameter for drilling into aluminum. I got this from the Caltech MCE Machine Shop.

After getting the 10" CF Flange from the CCE Machine Shop, I added the 2 grooves needed to vent the hole that had the broken tap. The hole that had the broken tap did not need to be rethreaded. I used a spindle speed of 3000 rpm and a feed rate of 2" per minute. I went approximately 0.015" deep like the other grooves, but it's hard to say exactly the depth with the mill I used.

[Torrey, Daniel]

I designed a part to hold this flexible metal conduit around the laser amplifier input and output fibers. It works by using a set screw to clamp on the conduit. It is made of 2 parts so that it can easily be interchanged around the fiber. It mounts on the #10-32 screws on the 19" rack. 

After making these parts with the water jet and mill, I cleaned them.

Torrey and I then put the amplifier output through the tube using gravity. We protected the amplifier output using kapton tape.

Attached are SolidWorks Part Files, STEP files, WaterJet files, Drawings, and photos.

I attached an aluminum wire screen to the back of the AOM Amplifier 2U Chassis to (hopefully) prevent RF radiation from going around the lab but allowing for airflow to cool the amplifiers. I needed to cut the chicken wire to allow for the #4-40 screws to go thorugh. I also needed some 0.281" outer diameter washers to hold the chicken wire since the screw head diameter went through the (cut) chicken wire. The wavelength of 200 MHz light is 1.5 m, so this chicken wire should be sufficiently dense to contain most of the RF output. See attached photo.

The 16 port patch panel has been installed in the rack and on the optics table. We have made 16, 24ft cables to go between these two patch panels. These cables are completed and installed. During testing we found one shorted cable and replaced it while strung up. 3 cables have a small piece of orange tape on them as a warning that the pin that makes the connected may be recessed too far in the cable. All 16 have been tested and are functioning however. Currently they are simply labelled according to numbers on the patch panel. We may update this labeling system. At minimum we will add these numbers to the cabel themselves in case they are unplugged for whatever reason.

I tapped the remaining 36 holes in the 10" CF Flange with a new tap. I raised the tapping depth by 0.0463" in case it was a chip in the bottom of the hole that broke the tap. I then added the groove pattern with the 1/8" end mill. The grooving would have hit the broken tap and possibly damaged the end mill, so I did not groove into it.

I will go to the chemistry machine shop tomorrow to see if I can use their sinker EDM to remove the tap. I will then retap or remake the hole, add the grooving pattern, then clean the two 10" CF Flanges.

We have two EVAL-ADH4702-1CPZ evaluation boards which are nominally configured as 21V/V gain noninverting amplifiers.

First I provided power with a Newport +-15V supply, connecting +, -, and GND on the power supply to VCC, VEE, and GND respectively, on the eval board.

This resulted in a gain of 12.3dB up to about 100kHz

Next, I used the on board power supply by connecting the DC jack to the +15V and GND of the power supply. I then connected the power supply half of the eval board to the opamp circuit by jumping VCC_TRANSFORMER
to VCC, VEE_ TRANSFORMER to VEE, and GND_TRANSFORMER to AGND, as described in the manual of the eval board in the section "Initial Power-Up." These jumper wires are white, turquiose, and yellow.

I performed a transfer function and a pulse delay measurement.