Attached below are the initial results of the CIT FROSTI testing analysis.

cleaning cleanroom and particle count

• 1:45 pm: ran zero count test on particle counter
• 1:50 pm: started particle count
  • zone 3:
    • 0.3 u: 2660
    • 0.5 u: 332
    • 1.0 u: 41
• zone 4:
  • 0.3 u: 8106
  • 0.5 u: 2494
  • 1.0 u: 831
• 2:08 pm: began surface check and wipedown, including softwalls
• 2:22 pm: started vacuuming the floor
• 2:39 pm: finished vacuuming the floor
• 2:43 pm: started mopping the floor
• 2:53 pm: finished mopping the floor
• 2:54 pm: started cleaning the buckets
• 2:59 pm: started mopping with IPA wipes
• 3:06 pm: finished mopping with IPA wipes
• 3:10 pm: changed sticky floor mats
• 3:06 pm: started particle count
  • zone 3:
    • 0.3 u: 1496
    • 0.5 u: 83
    • 1.0 u: 0
• zone 4:
  • 0.3 u: 789
  • 0.5 u: 83
  • 1.0 u: 41

It should be noted that we can not have the zero length reducer and the gate valve on the same arm as they both have blind tapped holes. We need to decide if we want the gate valve or not as if we do, we will need to use the 3 inch long reducer.

Important Measurements:

From the back of the flange to the back of the RGA: 25.25 in

Height from bottom of the blank to the bottom of the chamber: 2.75 in

Some changes have been made to the FLIR readout code to help improve its functionality:

• More accurate temperature readings than before due to updates in the calculation procedure. A bug was causing one of the parameters to not update correctly; this is now fixed.
• Saved data now stored in HDF5 files rather than CSV.
• User can now enable automatic data storage by specifying a collection interval (in minutes). The choice of manually saving data is still present if desired.

Today the FROSTI RTD readout chassis underwent a redesign:

Instead of the original ratiometric method, which involved wiring the FROSTI RTDs in series, each element is individually powered by separate excitations. Each element additionally possesses its own reference resistor of 100 Ohm. Now, if an RTD experiences an electrical short, it should not affect the measurements of the others in sequence, as it had with the original design.

cleaning cleanroom and particle count

NOTE: particle counter was found dead, with the charging dock unplugged. For future reference, if you need to unplug the dock, please either plug it back in when you're done, or make a note in an elog so someone else can come down and charge it.

• 1:07 pm: ran zero count test on particle counter
• 1:26 pm: started particle count
  • zone 3:
    • 0.3 u:1787
    • 0.5 u:457
    • 1.0 u:41
• zone 4: We were only able to charge the particle counter a small amount before starting the cleaning, so it died again halfway through this measurement, and we didn't get results for zone 4. In interest of time, we just put it on the charger and started the cleaning.
• 1:49 pm: began surface check and wipedown, including softwalls
• 2:16 pm: started vacuuming the floor
• 2:24 pm: finished vacuuming the floor
• 2:26 pm: started mopping the floor
• 2:32 pm: finished mopping the floor
• 2:32 pm: started cleaning the buckets
• 2:35 pm: started mopping with IPA wipes
• 2:43 pm: finished mopping with IPA wipes
• 2:43 pm: changed sticky floor mats
• 2:45 pm: started particle count
  • zone 3:
    • 0.3 u: 1288
    • 0.5 u: 124
    • 1.0 u: 0
• zone 4:
  • 0.3 u: 415
  • 0.5 u: 290
  • 1.0 u: 0

Attached is a brief recap PDF file. A video file showing separate HOMs plots for the cavity scan with ETM08 surface map is also attached.

The codes are available at https://git.ligo.org/uc_riverside/hom-rh/-/tree/main/SIS

After meeting and discussing the current state of our work with Prof. Fulda a few weeks ago, we have decided that the best next step for the gtrace project is its integration into finesse work. Our first step towards this integration involved creating a sequential beam trace in contrast to the previous non sequential gtrace simulations. A sequential beam trace not only allows for faster runtimes of the simulation (<1 second) but also allows for more direct reading of certain beam parameters (beam size, gouy phase, and angle of incidence). The sequential model was created alongside a yaml output which provides values of parameters, now including the angle of incidence on a mirror.

Last Monday, Pooyan gave a report to the Cosmic Explorer optical design team on the current state of our project and the ultimate goal of our work. During the same meeting another group working in the optical design team presented their own work with gtrace and optical design, focusing more on optimization of parameters based on desired beam sizes at each mirror. It might be a good idea to begin attempting to bring our individual projects together to allow for collaboration and further developments.

Currently, only the crab1 layout has a sequential trace model. Pooyan is currently working on creating a finesse model for crab1 to serve as a proof of concept for how gtrace could be integrated with finesse by providing useful values such as angles of incidence.

[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.

Another re-fit, but this time the quadratic coefficient (beta) is set to 1.003e-6:

       R_0 (ohm)   Alpha (1/C)

RTD 0   79.7386   0.001863

RTD 1   78.6248   0.002359

RTD 2   81.3254   0.002211

RTD 3   74.6127   0.003509

RTD 4   80.6652   0.001988

RTD 5   78.5450   0.002127

RTD 6   77.0144   0.002268

RTD 7   83.0204   0.002288

       R_0 (ohm)   Alpha (1/C)

RTD 0   79.3962   0.002031

RTD 1   78.2874   0.002530

RTD 2   80.9775   0.002381

RTD 3   74.2947   0.003684

RTD 4   80.3199   0.002157

RTD 5   78.2106   0.002297

RTD 6   76.6825   0.002438

RTD 7   82.6645   0.002458

Measurements taken can be found here. An uncertainty of 1 C was assumed for temperature.

We noticed that the RTD temperature readings given on the Cymac were off, and traced the issue to miscalibration in the relationship between the resistance and temperature of each RTD (Callendar-Van Dusen eqn). Below is the table of values inferred from independent measurements of temperature and resistance to rectify this problem. This data was then fitted to better determine the coefficients present in the temperature-resistance relation:

       R_0 (ohm)   Alpha    Beta

RTD 0   80.8674   0.001315   4.273e-6

RTD 1   79.5704   0.001887   3.7873e-6

RTD 2   81.7334   0.002014   2.1724e-6

RTD 3   74.3060   0.003677   3.6022e-8

RTD 4   81.1350   0.001761   2.3598e-6

RTD 5   77.9610   0.002423   -7.5192e-7

RTD 6   78.7980   0.001373   6.2909e-6

RTD 7   83.8616   0.001890   3.3529e-6

Cleaned and baked the Cal Tech FROSTI legs and showed Luke the procedure on how to clean parts.

Upon finishing the FROSTI assembly last week, we ran into some electrical issues. An electrical short was found between two of the d-sub pins (2 and 8). It appears that the pins were somehow coming into contact with the aluminum surrounding them. This was causing the power supply to trip. The issue was seemingly fixed by adjusting the positioning of the cabling leading out of the reflector. When handling the device in the future, please make sure to keep the wiring as undisturbed as possible. The setup is rather fragile, and moving the cabling around could potentially reintroduce a short like this.

FROSTI assembly was completed today. The RTD and power wires were terminated at the DB-25 connectors and the legs were put on. It is currently placed in front of the stand-in test mass (~5 cm away). The FLIR has also been moved back to it's nominal position. As of now, it appears there are some shorts within the power cabling. This will be a focus of tomorrow's work.

Heater 1= 72.8; 80.6

Heater 2= 69.5; 80.8

Heater 3= 70; 83.2

Heater 4= 70.6; 78.7

Heater 5= 69.9; 80.6

Heater 6= 71.1; 78.2

Heater 7= 68.5; 76.8

Heater 8= 70.1; 82.8

FROSTI assembly began today. After a final set of RGA scans were taken, the vacuum chamber was vented and the reflectors were removed. The chamber was then resealed and pumped down again. 

Today we completed the installation of the Macor hardware and heater elements between the two reflector halves. Tomorrow we will route, bundle, and terminate the power and sensor cables. 

The FLIR and test mass stand-in have been transferred into the cleanroom. A software test will be run as soon as we get an ethernet cable long enough to reach into the cleanroom where the camera is set up. Once this is finished, the FLIR will be moved aside for construction of the FROSTI! When completed, the camera will be placed back into position for in-air optical testing.

Summary

Following Wednesday's cleanroom cleaning [333], we proceeded to vent the vacuum chamber, remove the heater elements and their mount structure, and install the FROSTI reflectors. The reflectors are the final components to undergo RGA testing before the FROSTI prototype can be assembled. After installing the reflectors, we pumped the chamber back down and initiated a 48-hour 125 C bake.

Vacuum Vent

At ~1:00 pm, we shut off power to all eight of the FROSTI heater elements. Prior to shutoff, all were operating in vacuum at roughly 300 C. We then waited approximately 30 minutes for the elements' temperatures to fall below 50 C.

At this point, we isolated the RGA volume from the main volume by closing both gate valves, leaving the RGA volume to continue to be pumped through the bypass line. We then backfilled the main volume via the needle valve connected to one of the 2.75" ports. Once the pressures had equalized, we removed the chamber lid via our usual procedure (requiring only a small amount of flathead-screwdriver prying) and extracted the heater element assembly.

Reflector Assembly

We then removed the FROSTI reflectors from their protective packaging (for the very first time) on the cleanroom tabletop. We tested the fit of the Macor and stainless steel hardware in the reflectors' tapped holes. The Macor standoffs and bolts appear to fit perfectly. However, the 1/4-20 tapped holes for joining the two reflector halves are too shallow by ~1/4". As a temporary fix, we used some on-hand stainless steel washers (which had already been cleaned and baked) to securely fasten the two halves together. In the final assembly we will replace these with slightly shorter 1/4-20 vented bolts.

Pumpdown and Bake

The two fastened reflector halves were placed inside the chamber, sitting on top of the two mounting legs (see attached photos). We then reinstalled the lid. In order to rough the main volume, we isolated the RGA volume from the pumpline (by closing the bypass line valve), shut down the pumps, and then backfilled the pumpline via the manual vent valve on the turbo pump.

Once the pressures had equalized, we opened the 6" gate valve separating the pumpline from the main volume and powered on the roughing pump. Once the main volume pressure fell below 0.5 Torr, we powered on the turbo pump as well. The main volume pressure reached 5e-6 Torr within ~30 minutes, consistent with previous experience, and was continuing to slowly fall.

Lastly, we initiated a 125 C bake-out of the entire system following our usual procedure. We plan to run this bake for 48 hours (i.e., through the end of the day Friday).

cleaning cleanroom and particle count

• 11:50 am: ran zero count test on particle counter
• 11:55 am: started particle count
  • zone 3:
    • 0.3 u: 1787
    • 0.5 u: 581
    • 1.0 u: 166
• zone 4:
  • 0.3 u: 623
  • 0.5 u: 290
  • 1.0 u: 124
• 12:17 pm: began surface check and wipedown, including softwalls
• 12:25 pm: started vacuuming the floor
• 12:36 pm: finished vacuuming the floor
• 12:44 pm: started mopping the floor
• 12:57 pm: finished mopping the floor
• 12:58 pm: started cleaning the buckets
• 12:59 pm: started mopping with IPA wipes
• 1:05 pm: finished mopping with IPA wipes
• 1:06 pm: changed sticky floor mats
• 1:08 pm: started particle count
  • zone 3:
    • 0.3 u: 1621
    • 0.5 u: 581
    • 1.0 u: 332
• zone 4:
  • 0.3 u: 1080
  • 0.5 u: 457
  • 1.0 u: 249

The replacement door for the HEPA garment cabinet arrived last week, and was installed on Thursday. However, it looks like there's a small gap between the door and where the hinge is attached to the cabinet frame. No screws were provided with the replacement door. If we want to perform any adjustments, we have to be very careful; the screws break very easily.

On Thursday we installed the power conditioning/distribution equipment and networking equipment in the new 1129 rack. The hardware is identical to the setup in the 1119 rack and includes:

• Tripp Lite SU5KRT3UTF - 208V, 5kVA on-line UPS with 120V transformer
• CyberPower PDU20M2F12R - metered power distribution unit, (14) NEMA 5-20R
• Ubiquiti USW-Pro-48 - 48 port 10Gbps network switch

The UPS is connected to a 208V NEMA 6-30R outlet in the overhead cable tray, which is on the building's "standby" (backup power) circuit. An 8-ft L6-30 extension cord has been ordered to permanently run the power cable through the cable tray.

The network switch will be connected to a Cat6 cable that was recently run by ITS from the 1119 rack, allowing the lab's LAN to be extended into 1129. This Ethernet link remains to be tested.

I ended the bake of the UHV system (that began on Monday) at 6:23 pm today by switching OFF both PID controllers. The heaters elements were run at max power (24 V DC / 200 mA per element) during this bake, and I left them powered at the same level.

At the time, the instrument readings were as follows:

• Left high-limit controller: 138 C
• Right high-limit controller: 128 C
• Left PID controller: 100 C
• Right PID controller: 100 C
• Main volume pressure: 8.17e-7 Torr
• RGA volume pressure: 4.63e-7 Torr

I reproduced Cao's CE beamsplitter code (see below for example plots). I received the current info on the beamsplitter parameters for A+ and A# from GariLynn also. The next steps are to perform a similar power loss analysis on the anticipated A# beamsplitter.

Below is the proposed schematic for FROSTI optical testing, chosen so enough space is allotted for prototype assembly.

Steps to be taken include:

1. Reconstruct FLIR staging apparatus
2. Move test mass stand-in to cleanroom
3. Mark FLIR camera position on cleanroom optical table at correct distance
4. Run ethernet cable into cleanroom
5. Move FLIR aside to allow for more assembly space
6. Upon assembly completion, reposition FLIR onto optical table again

Tentative plan is to begin setup early next week.