Date and Time: Around 2:20 PM on May 21, 2025

Location and Temperature:

• Back of the room, around the working station: 85.5 °F
• Front of the room, around the doorway: 82.3 °F

Particle count:
• 10 am: Started particle count
1. Zone 3 :
   • 0.3u: 1288
   • 0.5u: 332
   • 1.0u: 124
2. Zone 4 :
   • 0.3u: 498
   • 0.5u: 166
   • 1.0u: 83
• 10:40 am: Checked the surfaces inside the cleanroom.
• 10:50 am: Started vacuuming the cleanroom.
• 11:15 am: Started mopping the cleanroom.
• 11:35 am: Started wiping the cleanroom floor.
• 11:40 am: Finished cleaning the cleanroom.
• 11:41 am: Started the particle count.
• 12:17 am: Finished the particle count.
1. Zone 3 :
   • 0.3u: 3782
   • 0.5u: 706
   • 1.0u: 207
2. Zone 4 :
   • 0.3u: 374
   • 0.5u: 83
   • 1.0u: 83

Cleaning room and particle count

• 09:58 am: Started the particle count
1. Zone 3:
2. 0.3u : 1,995
3. 0.5u : 540
4. 1.0u : 0
5. Zone 4:
6. 0.3u : 124
7. 0.5u : 0
8. 1.0u : 0

• 10:25 am: Started checking the surfaces inside the cleanroom.
• 10:30 am: Started vacuuming the floor.
• 10:45 am: Finished vacuuming the floor.
• 10:46 am: Started mopping the floor.
• 10:58 am: Finished mopping the floor.
• 11:00 am: Started wiping floor with polypropylene wipes.
• 11:03 am: Started and finished cleaning the mop buckets.
• 11:15 am: Finished wiping floor with polypropylene wipes.
• 11:16 am: Changed sticky floor mats.
• 11:20 am: Started the particle count.

1. Zone 3:
2. 0.3u : 2,951
3. 0.5u : 872
4. 1.0u : 207
5. Zone 4:
6. 0.3u : 374
7. 0.5u : 83
8. 1.0u : 0

• Today i wiped, bagged and tagged two cables for the vacuum system. I used IPA wipes for cleaning this two split power cord. I attached a image below.

cleaning cleanroom and particle count

• 12:00 pm: started particle count
  • Zone 3
    • 0.3u: 3533
    • 0.5u: 540
    • 1.0u: 166
  • Zone 4
    • 0.3u: 290
    • 0.5u: 124
    • 1.0u: 41
• 12:31 pm: Started checking the surface inside the cleanroom and began surface wipedown
• 12:50 pm: started vacuuming the floor
• 1:05 pm: Finished vacuuming floor
• 1:09 pm: Started mopping the floor
• 1:21 pm: Finished mopping the floor
• 1:22 pm: Started cleaning the baskets
• 1:25 pm: Started mopping with IPA wipes
• 1:39 pm: Finished mopping with IPA wipes
• 1:41 pm: Changed sticky floor mats
• 1:45 pm: Started particle count
  • Zone 3
    • 0.3u: 2327
    • 0.5u: 581
    • 1.0u: 207
  • Zone 4
    • 0.3u: 1662
    • 0.5u: 374
    • 1.0u: 290

[Luke, Luis]

We couldn't access the bake log on the wiki. (see attached) So we looked in the documentation provided on the DCC to find at what temperature to bake the Viton O-rings. We found that we should bake Viton at 180°C for 24 hours. 

So we sonic-washed the O-rings, dried them, and then put them in the oven set to the following:

100°C in 15 minutes

100°C for 30 minutes

180°C in 30 minutes

180°C for 24 hours

30°C in 2 hours

Other things of note:

We refilled the water container as it was running out.

The nitrogen used to dry the clean and baked objects is now critically low.

The helium used in leak testing is also quite low (~400 psi).

Regarding the vacuum chamber:

I reattached the pressure gauges to the chamber and gave them about an hour to stabilize. They read out main 8.7e-9, RGA 2.6e-9. Please note these pressures should lower more as we only stopped baking on Saturday afternoon. 

[Jon, Tyler, Aiden, Luke]

On Friday we completed assembly of the new stainless steel-topped benches in 1129. We then moved the clean and bake equipment from 1119 to its new larger space in 1129. This included the HEPA flow bench, ultrasonic washer, deionized water drum, nitrogen tanks, and forced-convection oven. The oven was re-anchored to the wall with earthquake restraints in its new location.

The power cords still need to be permanently routed, but the new clean and bake lab is otherwise ready for use.

Update: I have completed permanent routing of the electrical cables. I also ran the ultrasonic washer's drain line to the sink drain (the current hose does reach). The new clean and bake lab is now fully operational.

Following the problem with contamination particles observed in the the Leybold thermovac TTR 91, we have taken the following step to clean the gauge:

1. Wipe with IPA-wetted Vectra Alpha: Cover the tip of a ziptide with Vectra Alpha wipe corner that has been wetted with IPA, push the wipe around and remove visible particulates
2. Fill the gauge flange with IPA: (following Jon's recommendation to use Lesker's procedure for cleaning their Pirani gauge), flip the gauge up such that the CF flange points upward, fill the flange with IPA all the way up. Use the tip of a SSTL tweezer to agitate the IPA. Let it sits for 20 minutes, agitate every 5 minutes. After 20 minutes, pour the IPA out then spray with dry pure nitrogen
3. Passive drying : Let the gauge sit inside the flowbench for 3 hours (3:30 pm to 6:30 pm)to ensure all IPA has evaporated
4. Baking : Leave the gauge in oven at 50 degree C for 48 hours (maximum allowed temperature is 65 deg C, we use 50 deg C to ensure we are well below this limit). Baking started at 7pm, should finish on Sunday 7pm and ready for assembling to vacuum chamber on Monday morning

[Jon, Pooyan]

Moved Chimay from the server rack in Physics 1119 to a new rack in Physics 1129. It is connected to the switch in that rack and has the same ip address as before.

All services are up and running.

It appears that JupyterHub creates some processes whenever a user connects to an instance of it, but in some cases does not stop those processes after the user is not using that instance. This results in having lots of running idle processes, each using a small bit of the resources. Those processes are killed now as a result of rebooting. It might be a good idea to manually restart JupyterHub (or the whole machine) every few months to avoid this.

One ongoing work is to make all lab machines automatically backed-up on Scribe on a daily basis. The updates should be boatable and stored for some time (potentially a few weeks) on Scribe. Making whole disk images has already been tried for some of the machines with no problems. (e.g., Cymac and WorkStations)

The same thing can not be done with Chimay though, as it currently has one huge RAID-controlled volume that stores all the information (OS, home directories, and NDS-downloaded data). Creating daily full disk images of such a system is not practical. 

Here is the plan we came up with to overcome this issue:

1. Create one full disk image of Chimay and store it on Scribe (it was already done)
2. Move the nds-downloaded raw data temporarily to Scribe and remove it from Chimay
3. Make another full disk image of Chimay
4. Burn this image to a single disk and boot chimay with it

5. Restore the rest of Chimay disks and move the NDS data back

    

On the weekend (Sat and Sun 9/7-8) I tried to execute these steps. There wasn't enough free space left on Scribe to move all the NDS data to it, so I stored part of this data temporarily on WS4. Then I also checked storage-consuming directories and, in one case, removed some non-important stored files. As there was no free space left on Scribe to execute step no. 3, I initiated storing the image on WS3. Unfortunately, a couple of different trials of the image-creation process failed as there was not enough free space on WS3 to accommodate Chiamy image as well. I was not able to reduce the image size such that it can be stored on WS3. 

These are the options left for us to get this work done. 

1. Distribute the NDS files between different machines to make enough free space on Scribe for the image and then follow the previous plan
2. Shrink the Chimay drive size, create the image and then follow the previous plan
3. Temporarily transfer some services to Megatrone (Network gateway, Wiki, elog) and recreate chimay and its services from scratch

For future reference, the calibrated Argon source has a leak rate of 7.55E-8 atm cc/s, or equivalently 5.74E-8 torr L/s. This can be used to calibrate RGA scans to units of physical leakage (outgassing) rate.

Jon, Cao, Peter

This morning Facilities delivered and installed two new cabinets with sliding glass doors.

The smaller of the two (36" W x 13" D x 84" H) has been installed in the Clean & Bake area adjacent the flow bench. The larger one (48" x 16" D x 84" H) has been installed in the back of the room next to the electronics bench. Both cabinets have been securely anchored to the wall in two places each for earthquake safety.

We also installed the sliding glass doors and leveled them. However, we have not installed any of the shelves yet because the cabinets are quite dirty from the installation. Everything needs to be wiped down with IPA wipes, and it will be easier to do that before the shelves are in place.

[Jon, Tyler, Aiden, Shane, Pooyan, Michael, Cynthia, Luke]

On Wednesday, we completed long list of work towards making the new lab (1129) fully operational and enabling the next phase of FROSTI testing. 

Cabinet Installation

Three new VWR cabinets with sliding glass doors were installed in 1129. Each unit measures 48" (W) x 22" (D) x 84" (H) and sits along the back wall (see attachment 1). The 350-lb. cabinets were laid in place by Facilities on Monday and permanentized on Wednesday. Work included:

• Earthquake anchoring to the masonry wall
• Sliding glass doors leveled
• Shelving installed
• Wiping down of interior and exterior surfaces with IPA wipes

Server Rack Installation

A new Tripp Lite 42U open-frame rack was laid in place in 1129 and anchored to the floor (see attachment 1). This rack will house all of our general-purpose and simulation computers, which will be relocated from the 1119 rack at a later time.

Lab Clean-Up

Following installation of the new cabinets and rack, we proceeded to organize and clean both labs. Work included:

• Moved parts and equipment into permanent storage in 1129 cabinets
• Wiped down surfaces in 1119 and 1129 with polypropylene IPA wipes
• HEPA-vacuumed floors of 1119 and 1129
• Mopped floor in 1119 with Liquinox solution
• Installed new sticky mats in 1119 and 1129
• Regular cleanroom cleaning and particle counts (see 302)
• Positioned new stainless steel gowning bench outside the cleanroom (see attachment 2)

At this point, the only piece of lab equipment still to be delivered is a HEPA garment cabinet for reusing our (semi-disposable) bunny suits. It is schedule to arrive in mid-February and will sit outside the cleanroom in 1119, in the former location of the HEPA flow bench.

I have been looking at the feasibility of an alternative heater element design for FROSTI that replaces the original ring-like heater elements with n rectangular elements with straight edges. They form an n-sided regular polygon that could well approximate the original annular ring if n is large enough. This eliminates curved surfaces requirement for the heater elements, which was the source of the many month production delay for the prototype parts.

This design was implemented in COMSOL, shown in the attached. From the face on view, each element has a trapezoid shape with straight edges. The edges between neighboring elements are parallel, with a space of 2 mm in between them.

The ray tracing and thermal analysis obtained from COMSOL are shown in the attached pdf.

In particular, the 2D irradiance profiles were obtained from the ray tracing (so far from the front heating surfaces only). The 1D radial profiles were integrated and shown in the attached. The power delivery efficiency for the original ring-like heater element design is integrated to be roughly 65%, for comparison. The plot also shows the radial irradiance profiles for three different straight-edge designs, which correspond to 16 edges, 18 edges, and 24 edges. We see that with the straight-edge designs, the irradiance profiles stay in a good Gaussian shape. In addition, with a larger number of edges, the power efficiency increases, but is always less than the case for the optimized ring-like design.

The thermal distortions for the TM were also obtained from COMSOL, using the irradiance profiles at the TM HR. As shown in the attached, with the straight-edge design, the effects on the thermal lens OPD and the HR surface deformation are similar to the ring design, but with less severe edge roll-off for instance.