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New entries since:Wed Dec 31 16:00:00 1969
ID Date Authordown Type Category Subject
  462   Wed Oct 23 11:48:06 2024 Luis MartinUpdateVACLeak Test Results

[Luke, Luis, Mary, Ma]

On 10/22/24 Luke, Ma, Mary and myself ran a leak test, the results are displayed below. The overall pressure of the vacuum was 2.0e-8 and the temperature readings were 26C for the RGA and 25C for the main volume.

Connection Leak rate (torr)
Tee - RGA 9.4e-12 (very low)
Tee - Cal leak 1.58e-11 (very low)
Tee - ZLR (2.75"-4.5") 7.32e-12 (very low)
ZLR (2.75"-4.5") - Reducing Cross 6.9e-11   (low)
Cross - Elbow 2.34e-11 (very low)
Elbow - Pressure sensor 1.96e-11 (very low)
Cross - Turbo pump (small) 1.91e-9   (lowish)
Cross - Gate valve 1.66e-10 (very low)
Gate valve - Port 7.41e-10   (low)
Port - ZLR (6.0"-8") 2.93e-10   (low)
ZLR (6.0"-8") - Turbo pump (large) 6.15e-11 (very low)
Port - Pressure sensor 2.0e-11 (very low)
Port - Up to air valve 1.42e-11 (very low)
Port - Blank 1.27e-11 (very low)
Port - Feed through port 4.59e-12 (very low)
Lid - Curtain side 3.09e-11 (very low)
Lid - Wall side 4.26e-11 (very low)

 

 

  463   Wed Oct 23 12:08:36 2024 Luis MartinUpdateVACRGA Scan

[Luke, Luis, Mary, Ma]

On 10/22/24 Luke, Ma, Mary and myself ran a RGA scan, the results are displayed below. The overall pressure of the vacuum was 2.0e-8 and the temperature readings were 26C for the RGA and 25C for the main volume.

As we can see, the vacuum is passing cleanliness standards again.

  467   Tue Nov 5 09:56:04 2024 Luis MartinUpdateClean & BakeMR Bake

[Luke, Luis]

On Friday, 11/1/24, the MR was unpackaged and cleaned under the flow bench. We noticed an ink stain on one of the corners of the material. After wiping it down with IPA and Vector Alpha wipes, the stain was removed. However, the material showed some wear.

After cleaning, we placed it in the bake station and applied a stainless steel baking protocol. On Tuesday, 11/4/24, the material was removed from the furnace and packaged in a static shielding bag. The MR was wrapped in Vector Alpha wipes.

  468   Tue Nov 5 11:08:40 2024 Luis MartinUpdateVACISO Test

[Luis, Luke, Ma Michael]

The isolation test was conducted on the vacuum system. Every pump was turned off under vacuum, and pressure measurements were taken every minute for 15 minutes. The results are displayed in the sheet linked at the end of this report. The pressure of the main volume dropped very slowly.

The pressure of the RGA Volume dropped in an exponential manner. The test had to be paused at 11 minutes due to concerns about the pressure exceeding the lowest permitted level for the RGA filament.

After the ISO test was performed, we attempted to tighten the bolts of the small turbo pump on the RGA Volume. However, we noticed that the pressure had increased by nearly an order of magnitude, going from 3.27 × 10-9 Torr to 1.45 × 10-8 Torr when both volumes were separated. We conducted a leak test for that particular flange and found a concerning leak of 2.15 × 10-8 Torr, which had previously been 1.9 × 10-9 Torr. We believe the copper seal was damaged during the ISO test.

View the results sheet

  485   Thu Dec 5 10:31:13 2024 Luis UpdateVACRGA Scan and RGA updates

[Luis,Shane]

An RGA scan was taken on Dec 4th. The results are attached at the end of the e-log. As we can see, the scan results are under the allowed limits. After the scan, Shane and I worked on the vacuum connections. The filament was turned off, and the RGA was disconnected from Spica.

After we finished the tests, we reconnected the RGA and attempted to turn the filament back on. However, the program was unable to connect to the instrument. We checked for any loose connections but did not find anything. The RGA connection needs to be troubleshot and fixed.

  476   Wed Nov 20 12:31:24 2024 LuisUpdateVACLeak test RGA Scan after vacuum repairs

[Luke, Luis]

After the gasket replacement performed on Monday (11/18/24) we let the vacuum pump down to UHV pressure for a couple days. Today (11/20/24) we measured the pressure to be 5.30*e^-9 with a temperature of 22C, and we performed a leak test and RGA Scan.

Here are the results:

Connection Leak rate (torr)
Reducing Cross - TP Left 4.5e-9 (lowish)
Reducing Cross - TP Right 6.0e-9 (lowish)

 

 

  487   Wed Dec 11 16:06:05 2024 LuisUpdateVACRGA Status

[Luis]

I rebooted Spica and I was able to connect the RGA again. After Connecting the RGA, I left the filament on.

  488   Thu Dec 12 13:06:39 2024 LuisUpdateVACRGA Scan and vacuum system updates

[Luis, Luke]

RGA Volume: T = 21°C, P = 1.74e-9 Torr
Main Volume: T = 22°C, P = 5.60e-9 Torr

We performed an RGA scan of the system. As we can see, we met cleanliness standards. The S/N ratio was roughly calculated and it is about 100. I will update the code to make this calculation and to have it displayed on the plot in the next scan we perform.

After this, we closed the RGA to the main volume valve, degassed the filament, and after the pressure came down to what it was initially, we reopened the valve. After the degassing, we took another scan. The overlaid plots are attached below.

The noise floor seemed to be about the same. I will take another scan tomorrow to verify whether it was the same or if the system just needed a little more time to be completely clean.

  489   Sat Dec 14 07:58:25 2024 LuisUpdateVACVacuum sytem staus and Viton O-rings

[Luis]

RGA Volume: T = 23°C, P = 1.71e-9 Torr
Main Volume: T = 22°C, P = 5.71e-9 Torr

On 12/13 I took another RGA scan to verify the state of the vacuum system and to see whether the degassing of the filament had worked. The results of the scan shows that we did get an overall improvement of the noise levels, though we still have some peaks that are higher than the rest.

Also, while I was around, I transferred the Viton O-rings to a bag and labeled it properly. They are ready to be put into the clean room.

  490   Mon Dec 16 21:32:21 2024 LuisUpdateVACMR Testing

[Luis, Luke]

The MR material was placed in the vacuum chamber following standard procedures to ensure the vacuum remained as clean as possible. During this process, we only opened the main volume while keeping the gate valve between the two volumes closed to maintain the UHV in the RGA section.

An RGA scan was taken before this process, this will be used to compare the state of the vacuum with the sample inside to determine whether the MR material is vacuum compatible.

  491   Tue Dec 17 13:53:53 2024 LuisUpdateVACVacuum system status

[Luis]

The vacuum system is being baked. I disconnected the digital gages and the magnets, opened the Ar leak and started the bake by taking the temperature from 60C-90C-125C waiting about 15-20 minutes between each interval. The RGA electronics were left on since the temperature of the flange was 36.6C (bellow the 60C threshold)

  494   Sun Dec 22 20:43:35 2024 LuisUpdateVACMR Testing

[Luis, Luke]

RGA Volume: T = 23°C, P = 3.0e-9 Torr
Main Volume: T = 22°C, P = 9.90e-9 Torr

After letting the vacuum cool down for a couple days, we reattached the magnets and sensors, then we performed a RGA scan of the vacuum system, now containing the MR sample. The results are attached below. Something to notice is that we are technically not under UHV, though Luke and I believe the reading of the sensor is not completely accurate since it was still coming to a steady state, further test will be performed when the physics building is open again.

  496   Thu Jan 2 17:52:58 2025 LuisUpdateVACMR Testing Continuation

[Luis, Luke]

RGA Volume: T = 22°C, P = 2.10e-9 Torr
Main Volume: T = 21°C, P = 5.71e-9 Torr

Measurements of the current state of the vacuum systems were taken today, now that the system had reached UHV status, the results are attached bellow. The first plot overlays the data of the empty chamber taken on 12/16/24 before inserting the MR material, and the data of the system today, with the MR inside. The second plot displays the S/N Ratio of the system. The last plot displays the data of the system with the Ar leak open and closed. Notice that it is common for the Ar leak close data to fail due to the calculation of the gas flux per unit ion current, which is dependent on the Ar peak.

  510   Tue Feb 11 08:07:02 2025 LuisUpdateVACBake stopped

[Luis, Ma]

Feb/10/25 4:00pm

Bake was stopped.

  511   Fri Feb 14 11:57:50 2025 LuisUpdateVACVacuum Update

[Luis]

Feb/11/25 9:30am

Pressure gages were connected.

  512   Fri Feb 14 12:15:23 2025 LuisUpdateVACVacuum sytem staus

[Luis, Luke, Ma]

February 12, 2025 - 4:00 PM

We performed an RGA scan with the vacuum system containing the heater elements. The results are attached below.

Pressure (Torr) Temperature (°C)
RGA Volume 3.13 × 10⁻⁹ 23
Main Volume 6.15 × 10⁻⁹ 23

As we can see, we are not yet under cleanliness standards. The passing threshold is 4 × 10⁻¹⁰, and we are currently measuring nearly double this value. We will continue performing scans to monitor any changes in these readings.

  519   Thu Feb 20 17:07:36 2025 LuisUpdateVACRGA Scan

[Ma, Luis]

February 20, 2025 - 3:30 PM

Ma performed an RGA scan with the vacuum system containing the heater elements. The results are attached below.

Pressure (Torr) Temperature (°C)
RGA Volume 1.87× 10⁻⁹ 23
Main Volume 5.70 × 10⁻⁹ 23

As we can see, we are not yet under cleanliness standards. The passing threshold is 4 × 10⁻¹⁰, we are very close to it.

  522   Mon Feb 24 17:50:13 2025 LuisUpdateVACRGA Scan

[Ma, Luis]

February 24, 2025 - 1:00PM

Ma performed an RGA scan with the vacuum system containing the heater elements. The results are attached below.

Pressure (Torr) Temperature (°C)
RGA Volume 3.31 × 10⁻⁹ 25
Main Volume 5.75 × 10⁻⁹ 24
  376   Fri Jun 14 13:32:13 2024 LiuUpdateScripts/ProgramsCOMSOL simulation on rectangular heater elements design

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.

  377   Mon Jun 17 11:47:46 2024 LiuInfrastructureGeneralTemporary cooling units for the labs
Below are the temporary cooling units installed last week in labs 1119 and 1129. They are the temp. replacement for the building AC system, which will be shut down during the Physics roof replacement.
  380   Fri Jun 21 11:47:30 2024 LiuUpdateScripts/ProgramsCOMSOL simulation on alternative straightened heater elements design

In the previous post, we saw that for the heater element design with straight edges in replacement of the current eight-element ring-like design, it provides the similar Gaussian-like irradiance profiles, but with smaller power delivery efficiencies, as shown in the plot. This turned out to result in similar but less prominent thermal effects.

They only differ from the original baseline design by a source power rescaling, however, as shown in the plot, where we see the power-rescaled irradiance profiles for the straight edge designs are close to that for the ring design. The resulting temperature profiles and thermal distortions are shown in plot and plot. The thermal effects for the 16 straight-edge design with renormalized source power for instance are strikingly similar to that for the original ring design.

An alternative straightened heater element design has also been investigated with COMSOL FEA simulation. As shown in the attached, in this new design each heater element component is cut with multiple straight edges but remains connected, shown in the same colors (green and red). In the example, four straight edges are cut from each of the four heater components (4x4=16 edges in total). There is no spacing between the neighboring edges from the same element component, but the edges from different components are separated by 2mm, as can be seen in the attached. This new N-in-one straight edge design offers similar irradiance compared to that for the evenly-spaced N-sided regular polygon straight edge design with the same number of edges, as shown in the plot. It however has fewer heater components, four in this case, which makes it easier to implement in assembly and wiring, and less vulnerable to electrical and thermal shorts with their fewer heater element pins.

  387   Thu Jun 27 11:09:14 2024 LiuUpdateScripts/ProgramsStraight edge STEP files and ray loss analysis

Drawings and CAD models of the straight-edge designs are exported, and are visualized in SOLIDWORKS. Two are attached. One is a single edge of the evenly spaced polygon design with 16 edges, and the other is the 8x2 design, with two neighboring edges grouped together to replace the original single curved heater.

For the straight edge design in COMSOL, ray power detectors were placed at the heater's front surface. The irradiance is shown in figure. The amount of light rays deposited back to the heater is small when close to the center, where it is closer to the original ring. The ray power increases as we move further away from the center toward the edges. In addition, the total power integrated at the heater's front surfaces is about 21% of the original heater's emitted power. This could account for the power efficiency difference between the straight edge design and the ring design, as shown in plot for instance.

  393   Fri Jul 5 13:17:44 2024 LiuUpdateInterferometer SimulationsFour-quadrant FROSTI-like RH for astigmatic thermal actuation for CE optics
In the CE corner layout design and down selection study, interferometer layouts with large incidence angles on some of the curved optics are being considered, such as the folding mirrors in the "long crab". This however generates astigmatic beams upon reflection and results in mode mismatches in coupled cavities that need to be mitigated. Astigmatic thermal actuation for the optics involved is thus essential. One way we are considering is to implement a FROSTI-like barrel RH that delivers different irradiance for the four quadrants. This post summarizes primitive results on the astigmatic thermal actuation for the HR surface by powering the heater elements from one diagonal differently compared to the other.

For this study, we looked at a simple case with an aLIGO-like test mass geometry (R=0.17m, H=0.2m) plus a barrel RH with 0.02m width at 0.03m from the AR surface with FEniCSx. The irradiance profiles are constant inside the width along the longitudinal direction, and zero outside the width. For the baseline non-astigmatic actuation with constant irradiance azimuthally. We have obtained roughly equal quadratic actuations along the x and y directions, as shown in figure. The total delivered power on the entire barrel is normalized to 1 W. The actuation on the curvature per power Delta S/Delta P in this non-astigmatic case thus is 0.835 uD/W.

For the astigmatic case however, the irradiance for the regions from one diagonal is increased by a given amount, compared to the non-astigmatic case, whereas for the other diagonal regions is decreased by the same amount (thus the total power is unchanged at 1 W). The HR deformation when the power is changed by 50%, for instance, is shown in picture, where the deformation along the x direction is larger than the y direction. The deformation in each direction however remains quadratic, with different curvature per powers for the x and y components, as shown in plot. The actuation on the curvature per power for an increasing amount of astigmatism is shown in plot. In terms of Zernike polynomials, the maximum amount of Z22 (astigmatism) for 1 W of total power is 2um while the remaining curvature content (Z20) is 6nm. This is shown in plot.

  394   Fri Jul 5 14:12:32 2024 LiuUpdateInterferometer SimulationsCE BS Mechanical Resonances
The butterfly and drumhead mechanical modes for the aLIGO BS were calculated in COMSOL. The resonant frequencies for the two acoustic modes are 2.45 kHz and 3.61 kHz, matching the results in reference for instance.

For a quick projection for the resonant frequencies going from aLIGO to CE, the height and width of the BS are increased assuming the mass is increased from 14 kg to 70 kg, while keeping the aspect ratio fixed. The resonant frequencies for the two mechanical modes as a result becomes smaller, to 1.43 kHz and 2.11 kHz respectively, risking getting in the detection band.

Next step is to implement a mechanical ring with high stiffness outside the BS barrel to combat the decrement of the resonant frequencies of the relevant mechanical modes.

  395   Fri Jul 5 14:23:13 2024 LiuUpdateInterferometer SimulationsEngineering drawings for straight edge heater element designs for FROSTI
Step files and engineering drawings for the straight edge heater element designs have been created in COMSOL and SolidWorks. They are available in the group Git Repo. With those, we will initiate a discussion with the ceramics supplier for an estimate of the feasibility and benefits of the straight edge element over the curved element in terms of manufacturing cost and time.
  404   Mon Jul 15 09:36:44 2024 LiuUpdateInterferometer SimulationsETM Profile Optimization for FROSTI

This is to optimize the FROSTI heating profile for ETM, by minimizing the residual RMSE of the HR surface deformation after the beam size weighted curvature is removed by the current RH. The parameters of the profile being explored are the location, width, and total power for the Gaussian Annulus. As shown in the attached series of plots, the optimal location is 9.9 cm, with a width of 7.7 cm, and a total FROSTI power of 12.7 W (for 1 W of Gaussian beam absorption). The residual RMSE is 1.2 nm. About 0.5% of the FROSTI power is lost at the edges of the TM.

For comparison, without FROSTI, the residual RMSE after the beam size weighted curvature removed by the current RH is 44.5 nm. When the width of the Annulus is set to be 3 cm however, the residual RMS is 3.1 nm, with much smaller FROSTI power needed at 4.7 W, and less power loss at 0.02%.

  413   Mon Jul 29 12:18:52 2024 LiuUpdateInterferometer SimulationsUpdate on FROSTI O5 ETM profile optimization
Update on FROSTI O5 ETM profile optimization is attached.
  414   Mon Jul 29 12:20:56 2024 LiuUpdateInterferometer SimulationsUpdate on wavefront actuation with astigmatically driven RH for CE
Update on wavefront actuation with astigmatically driven RH for CE is attached.
  415   Mon Jul 29 12:23:10 2024 LiuUpdateInterferometer SimulationsUpdate on mechanical resonances of CE BS with stiffener ring
Update on mechanical resonances of CE BS with stiffener ring is attached.
  455   Wed Oct 2 14:49:59 2024 LiuUpdate FROSTI ETM actuation
Proposed FROSTI ETM actuation on the HOM7 resonance. Animation
  460   Wed Oct 16 14:13:31 2024 LiuUpdate FROSTI with non uniform absorption scattering sources
Slides
  469   Wed Nov 6 13:48:55 2024 LiuUpdateInterferometer SimulationsQN modeling update
Slides
  545   Tue Apr 1 11:47:08 2025 LiuUpdate  
  91   Wed May 3 19:03:47 2023 Julian,Pamella and CaoPhysicsVACModify vacuum asssembly and install RGA
[Pamella, Julian, Cao]
    Today we started re-configuring the vacuum chamber components.
    Particle count
  • 10:45 am : Starting the particle count in the clean room.
  • 11:13 am : Finished the particle count in the clean room.
  • Zone 3 :
    • 0.3 u: 2535
    • 0.5 u: 1413
    • 1.0 u: 789
  • Zone 4 :
    • 0.3 u: 457
    • 0.5 u: 290
    • 1.0 u: 207
      Starting the reconfiguration.
    • 11:21 am: Started removing up-to-air valve
    • 11:30 am: Finished removing up-to-air valve.
    • 11:33 am: Started removing calibrated Ar Leak and the elbow.
    • 11:35 am: Finished removing calibrated Ar Leak and started assembling the up-to-air valve.
    • 11:47 am: Finished assembling up-to-air valve.
    • 11:48 am: Started removing magnetron gauge.
    • 11:55 am: Finished removing magnetron gauge.
    • 11:57 am: Started installing the elbow and calibrated Ar Leak and started removing the RGA probe
    • 12:13 pm: Finished installing the elbow and calibrated Ar Leak.
    • 12:20 pm: Break for lunch.
    • 01:25 pm: Come back from lunch break.
    • 01:30 pm: Started removing RGA line.
    • 01:39 pm: Finished removing RGA line.
    • 01:39 pm: Started removing gate valve [RGA line] and finished removing gate valve.
    • 02:00 pm: Started installing gate valve in the new position.
    • 02:08 pm: Fished installing gate valve [RGA line].
    • 02:09 pm: Checked the screws in the elbow to gate valve. [RGA line].
    • 02:28 pm: Finished checking the screws in the elbow to gate valve [RGA line].
    • 02:29 pm: Started installing RGA line.
    • 02:39 pm: Finished installing RGA line.
    • 02:50 pm: Started installing magnetron gauge.(In this part we assembled gauge with the used gasket)
    • 03:02 pm: Finished installing magnetron gauge.
    • 03:04 pm: Started installing RGA probe [RGA line].
    • 03:13 pm: Finished installing RGA probe [RGA line].
    • 03:15 pm: Connected the cables to the magnetron gauge.
    • 03:20 pm: Started the testing in the vacuum chamber.
    • 04:30 pm: Started installing the RGA 200 and connected the cables (power cable and DB9 cable).
    • 04:52 pm: Finished installing the RGA 200 and connected the cables (power cable and DB9 cable).
    • 04:53 pm: Started testing the RGA connections. Logrus is able to recognize and connect to RGA unit. We are leaving the turbo pump on for a few hours before checking back for pressure readouts.
    • 05:00 pm : Starting the particle count in the clean room.
      1. Zone 3 :
        • 0.3 u: 2244
        • 0.5 u: 997
        • 1.0 u: 207
      2. Zone 4 :
        • 0.3 u: 2993
        • 0.5 u: 1579
        • 1.0 u: 498
    • 05:30 pm : Finished the particle count in the clean room.
    • 05:34 pm: Test pressure readout from the gauges.
      1. Channel 1 : 1.06E-5 mbar
      2. Channel 2 :8.89E-6 mbar
      3. Channel 3 :5.0E-4 mbar
    • 05:59 pm: Test pressure readout from the gauges.
      1. Channel 1: 9.09E-6 mbar
      2. Channel 2: 7.75E-6 mbar
      3. Channel 3: 5.0E-4 mbar
  18   Fri Jan 27 18:44:31 2023 Julian UpdateGeneralVacuum Chanmber Cleaning
I used the IPA wipes to wipe down the inside of the chamber the best I could. I cleaned the main chamber but not any of the connecting joints. When I finished I did a once over with a fresh wipe and found no residue.
  15   Wed Jan 18 22:06:05 2023 JulianUpdateELOGCleanroom Update
I wiped down all the inner walls of the cleanroom using alcohol wipes, as per Cao's instruction.
  22   Mon Feb 6 20:02:32 2023 JulianUpdateGeneralCleanroom Update
I wiped down the main table (including frame, legs, and transparent shelf) and workbench using alcohol wipes. Once I cleaned all of the surfaces, I used the Hepa vacuum to pick up any fallen debris.
  27   Sat Feb 11 00:17:27 2023 JulianUpdateGeneralVacuum Chamber Cleaning
Today I finished wiping down the rest of the vacuum chamber, specifically focusing on the connecting ports and outside surface of the chamber. When I was finished, I test wiped every surface of the chamber and took pictures confirming the current state of cleanliness; Attachment 1 "Wipes for top and bottom of chamber's upper lip." Attachment 2 " Top and bottom of chamber's lower lip." Attachment 3 "Inside and Outside main chamber." Attachment 4 "Inside connecting ports."
  33   Thu Feb 23 21:12:33 2023 JulianUpdateGeneralVacuum Chamber Cleaning
Today I was able to come in and wipe down both sides of the vacuum chamber lid using the regular alcohol wipes and also wipes that were left to dry in the fume hood then saturated with acetone. I managed to get a good amount of the residue off both the inside and outside surfaces of the lid, then did a test wipe of both sides using acetone-soaked wipes; pictures of the wipes are attached below. Once I finished with the lid, I used another acetone wipe to test wipe the inside of the vacuum chamber. The inside is still giving off residue, but very minimally, a photo for this is attached as well.
  41   Thu Mar 2 20:53:56 2023 JulianUpdateGeneralCleanroom Update
Today Pamella and Julian began the final cleaning of the cleanroom, starting with the HEPA vacuuming and mopping then wiping down every surface of the laser table. We wiped the main tabletop as well as the legs, but we were unable to completely wipe down the upper frame of the table before we had to leave. For next steps, Julian will come in on Friday and finish cleaning the frame, then both of us will come in on Monday to finish the final cleaning.
  43   Sat Mar 4 00:34:46 2023 JulianUpdateGeneralCleanroom Update
Today I was able to finish cleaning the frame of the laser table, and for good measure I wiped down the tabletop and exterior of the vacuum chamber when I was finished. I was also able to go through and wipe down the bags containing the vacuum parts as well as the tabletop of the workbench.
  55   Thu Mar 23 18:40:08 2023 JulianUpdateGeneralCleanroom Update
Today Pamella and I came in to Hepa vacuum and mop the floor of the cleanroom for general maintenance.
  90   Tue May 2 17:03:14 2023 Jon, CaoPhysicsVACFirst pump-down test of vacuum chamber

[Jon, Cao]

1. Re-routing of cables

We re-routed the connections between the turbo pump and its fan to the controller. Instead of going through the side of the server rack, they are now routed along the the cable tray and came down from the top of the server rack.

2. Planning for vacuum assembly re-configuration

While preparing for our first pump-down, we notices that RGA pump line gate valve, at its fully closed position, is higher than the height of the chamber lid. The full range gauge attached to the RGA line, while not that high, can also cause obstruction during removal/ installation of the vacuum lid. The calibrated leak, eventhough is now running within the perimeter of the optical table, it stills introduce weak points that are susceptible to damage if personnel installing chamber lid may lean onto it. Thus we made a few suggested modification to the vacuum chamber assembly:
  • Move the entire RGA arm to the mirrored CF port, where the Up-to-Air valve is at
  • Move the Up-to-Air valve to the calibrated leak port
  • Move the calibrated Ar leak the main chamber full-range gauge port
  • Move the full-range gauge to the RGA line port

3. First test pump-down

  1. With all valves closed, we started scroll pump, pump line quickly got down to 6.08 mbar from atmospheric 1000 mbar (measured by Pirani gauge, channel 3 on controller )
  2. We open Lesker angled valve and let the RGA arm pumped down, Pirani gauge read 6.3 mbar while the full-range guage on RGA line reads 4.9 mbar ( channel 1 on controller )
  3. We open the pump line gate to expose the pump to the main volume, all gaugues readout immediate rise back up 1000 mbar. After 3 minutes, we started to see channel 3 slowly dropped down. A minute later channel 1 and 2 (main body) also dropped down. The slow pressure dropping speed and 6.3 mbar measured earlier got us suspected that there is some large leaks
  4. We proceed to tighten all the ports as the vacuum is pumped down. In particular, we found that large feedthrough port still required a lot of tightening up
  5. As we tighten up all the ports, after 40 minutes, the gauges are now
    • Channel 1 : RGA line full-range gauge: 2.55E-1 mbar
    • Channel 2 : Main chamber full-range gauge: 2.60E-1 mbar
    • Channel 3 : Pump line Pirani gauge: 2.94E-1 mbar
    Compare this to the scroll pump manual , Table 1, page 3, the ultimate pressure of the scroll pump is 2.5E-1 Torr (3.3E-1 mbar), we thus managed to achieve scroll pump ultimate pressure
  6. Turn on turbo pump : Change turbo pump controller from REMOTE to FRONT PANEL mode by pressing both "COUNTERS" and "MEASURE" buttons at the same time, select "MODE=FRONT"
  7. Shorting interlock pin: since we do not have an interlock signal for the controller, use the provided DB-9 connector that has pin 3 and 8 shorted and connect this to the P1 IN connection at the rear of the controller (see attachment 1 )
  8. Press "START" on the controller to start the turbo pump
  9. The pressure readout from the gauges quickly dropped down. After 3 minutes, the Pirani range is maxed out at 0.5E-3 mbar. After 20 minutes, we recorded the following values:
    • Channel 1 : RGA line full-range gauge: 1.50E-5 mbar
    • Channel 2 : Main chamber full-range gauge: 1.89E-5 mbar
    • Channel 3 : Pump line Pirani gauge: 5.0E-4 mbar
    This is Medium vacuum , we want to further reduce this by 2 orders of magnitude. However, we can run RGA test + helium leak test at this pressure
  10. Turn off turbo pump, wait for 10 minutes, turn off scroll pump, open Up-to-Air valve, all pressure gauges indicated pressure returned back to atmospheric pressure

3. To-do actions

  • Run RGA test to get information about contamination status of vacuum
  • Implement suggested changes in section 2
  • Check and modify suspected poor connection: Pirani gauge on pump line. A gap can be seen between connection. There's no good way to tighten it with the screw. Maybe use threaded pin + hex bolt?
  • Controller communications
  138   Thu Jun 29 18:27:26 2023 Jon, CaoInfrastructureVACVacuum bake attempt 3: success!
[Jon, Cao]

Summary : We resolved problems with heaters tripping power and were able to proceed with chamber baking

1. Circuit connection adjustment

After yesterday elog 137, today we resolved most of these issues. After Jon contacted Facilities, the LP3B 6 circuit was reset and the cleanroom filter & light panels resumed to work as normal.

Regarding the connection of the heaters. we made the following adjustments:

  • High-temperature controller powering lid + upper volume heater: connect to LP3B 8 circuit (clean room sides, 2 outlets)
  • High-temperature controller powering bottom + lower volume heater : connect to LP3B 4 circuit (workstation side, 2 outlets)

2. Replacement of vacuum nipple insulation

We had also received new insulation pieces from Worbo today to replace the existing insulation with the new ones (see images). These cover the 2 4" tubes (for 6" flanges ) and the 4 1.5" tubes (for 2.75" flanges). The new insulations fit perfectly on these tubes. I also placed all insulation taken off from the last elog back onto the chamber ( these are insulations for the pumps and RGA lines).

3. Baking

We started ramping up chamber temperature at 1:41 pm over the course of two hours:
  • Starting set point: 40 deg C
  • Step increase: 10 deg C up to 80 deg C, 5 deg C from 80 deg to 120 deg C
  • At each step, the temperature readouts show approx. 2.1 deg C overshooting, wait to settle back to approx 1.5 deg C overshoot before increase the set point again
We noticed some smoke emanating from flexible bypass line insulation but none from other locations that were previously smoking . We think this is because the high winding density around the bypass line for such a small volume. Adjustment for next bake: Change the location of PID controller RTD to the bypass line . For now, we remove the insulation around bypass to prevent insulation overheating and encourage convection cooling (see image)

The temperature of the chamber reached as stable 120 deg C without any power issues at 3:45 pm. I waited another 15 minutes to verify its stability and the official baking duration started at 4:00 pm Jun 29 2023. Since we are baking at 120 deg C instead of the standard 150 deg C for Aluminium, the duration for the bake will be over three days until Monday morning, upon which we will slowly ramp down the the temperature.

  265   Mon Nov 13 11:23:54 2023 Jon UpdateCDSCyMAC testing

[Jon, Shane, Luis]

My repair of the internal ribbon connecting the ADC to the adapter board resolved the timing signal problem. After this repair, we were able to start the front-end IOP model and checked out the RTS diagnostic screens (pictured below). All indicator lights were green except for the DK flag (indicating the DAC outputs are not enabled) and the DAQ flag (indicating that the system is recording data to disk). Those were both as expected, because the DAQD data acquisition service was not set up yet and the DAC outputs are not enabled until at least one user model (which outputs signals to the DAC) is started. I created and installed a simple user model (C1MSC) and confirmed that the DK flag clears once this model starts.

I later attempted to set up the DAQD service, which is needed to save data, but am yet to successfully debug it. I have received some guidance from one of LIGO's CDS experts and will try it at my next opportunity for lab work.

  2   Thu Jun 2 16:14:58 2022 JonHowToGeneralCustom conda environment on JupyterHub

Cross-linking instructions: How to run a Jupyter notebook in your custom Conda environment

  3   Thu Jun 2 21:55:02 2022 JonUpdateCamerasFLIR Camera Setup

The new FLIR A70 infrared camera has arrived. Tyler and I unpacked it in the lab yesterday. In less than an hour, we succeeded in powering it on and connecting it to the lab network. We have assigned it the static IP address 192.168.1.6.

Online Configuration Portal

The FLIR camera can be configured, as well as stream live data, through a web browser interface. It can be accessed from any workstation on the lab network by navigating in the browser to http://192.168.1.6. The login credentials are stored here (log in with your LIGO.ORG credentials).

Next Steps

The next step is to install FLIR's Python API for controlling and reading out the camera on chimay. The API comes with demo codes which we can use to test the basic connectivity and which will serve as a reference for developing our own Python interface over the summer.

  4   Fri Jun 3 13:03:33 2022 JonUpdateCamerasFLIR Camera Setup

Summary

I have installed the requisite software on chimay for interfacing the FLIR A70 camera in Python. There are two packages required from FLIR:

  • Spinnaker SDK, which provides the low-level camera drivers and a C/C++ API.
  • PySpin, a wrapper of the Spinnaker library which provides the Python API.

These installations did not work out-of-the-box for Debian 11 (only Ubuntu is officially supported). I had to make several modifications which are documented below for future reference.

This setup has not yet been tested with the camera connected to chimay.

Documentation and Demo Codes

The PySpin package comes with a number of Python demo codes and a complete API reference. These can be found on chimay at the following locations.

  • Example codes: /opt/spinnaker/python/Examples/Python3/
  • Python API reference manual: /opt/spinnaker/python/docs/PySpinDoc.pdf

Installing Spinnaker SDK

Below were the steps required to install Spinnaker on chimay (Debian 11).

  1. Download the Spinnaker binaries (AMD64 architecture) and copy the tarball to, e.g., /home/controls on chimay.

  2. Unpack the tarball contents and enter the new directory:
    $ tar -xf spinnaker-2.6.0.160-Ubuntu20.04-amd64-pkg.tar.gz
    $ cd spinnaker-2.6.0.160-amd64


  3. Next, install the dependencies (on chimay, these were all already installed):
    $ sudo apt-get install libavcodec58 libavformat58 \
    libswscale5 libswresample3 libavutil56 libusb-1.0-0 \
    libpcre2-16-0 libdouble-conversion3 libxcb-xinput0 \
    libxcb-xinerama0
     
  4. There is one additional dependency, qt5-default, which is obsolete in Debian and no longer available via the package manager (that is, its functionality was absorbed into other Qt packages). I was able to find a workaround based on these instructions.

    1. Install all the dependencies of qt5-default:
      $ sudo apt-get install qtbase5-dev qtchooser qt5-qmake qtbase5-dev-tools
       
    2. Manually remove the qt5-default dependency from the Spinnaker package.

      Unpack the spinview-qt_2.6.0.160_amd64.deb package:
      $ mkdir tmp
      $ cd tmp
      $ ar -x ../spinview-qt_2.6.0.160_amd64.deb
      $ tar xf control.tar.xz

      Open the file control in a text editor and delete the qt5-default dependency from the Depends list.

      Then repackage the contents:
      $ tar cfJ control.tar.xz control
      $ ar rcs ../spinview-qt_2.6.0.160_amd64.deb debian-binary control.tar.xz data.tar.xz
      $ cd ..
      $ rm -rf tmp

      This overwrites the original package with a version no longer containing the qt5-default dependency.


  5. Now proceed with running the install script:
    $ sudo sh install_spinnaker.sh

This will install the Spinnaker library at /opt/spinnaker. Spinnaker also provides a standalone GUI application, SpinView, which can be executed from the terminal (from any directory) via the command spinview.

Installing PySpin

The main challenge with installing PySpin was that it is currently only supported for Python <=3.8. The system installation on Debian 11 is Python 3.9 and 3.8 is not available within the package manager. Following these instructions, I manually installed a second version of Python (3.8) on chimay, in a way that should not interfere with the system installation.

The Python 3.8 executable is in the system path and can be run only via the command python3.8. It is not symlinked to python or to python3. Those remain linked to the preexisting Python 3.9.

After installing Python 3.8, I proceeded with the installation as follows:

  1. Download the PySpin package (x86_64 architecture) and copy the tarball to, e.g., /home/controls on chimay.

  2. Unpack the tarball contents and into a new directory:
    $ mkdir python
    $ mv spinnaker_python-2.6.0.160-Ubuntu20.04-cp38-cp38-linux_x86_64.tar.gz python
    $ tar xf spinnaker_python-2.6.0.160-Ubuntu20.04-cp38-cp38-linux_x86_64.tar.gz

  3. Move the new directory into the Spinnaker installation directory:
    $ sudo mv python /opt/spinnaker
    $ cd /opt/spinnaker/python
     
  4. Install the dependencies:
    $ sudo python3.8 -m pip install --upgrade numpy matplotlib

  5. Finally, install PySpin itself:
    $ sudo python3.8 -m pip install spinnaker_python-2.6.0.160-cp38-cp38-linux_x86_64.whl

If this succeeded, you should now be able to enter import the package PySpin as

$ python3.8
>>> import PySpin

without error.

  5   Mon Jun 6 17:11:48 2022 JonUpdateCamerasFLIR Camera Setup

Today I tested the Spinnaker/PySpin software installations (detailed in ELOG #4) with the FLIR camera connected to chimay. It works!

Example codes

I was able to run several of the PySpin example codes. In particular, there is one which connects to the camera and streams live data to a pop-up Matplotlib window that looks very useful. It is called AcquireAndDisplay.py.

When running these, it is important to keep in mind that PySpin requires Python 3.8, which is not the default system version on chimay. So to run AcquireAndDisplay.py, for example, you must explicitly call the correct version of Python:

$ python3.8 AcquireAndDisplay.py

The standard python and python3 aliases are still linked to the system version (3.9), so calling these will result in a PySpin import error.

Git repository

I have set up a git repo for our FLIR camera control code. I have populated it with an Examples directory which contains the PySpin Reference Manual as well as all the example codes (see the README). There is a local copy of this repo on chimay at /home/controls/FLIR.

Other FLIR streaming software

In addition to the PySpin demos, there are several fully developed applications provided by FLIR. While we do not plan to use these long term, they may be very useful for debugging and cross-validation of our Python interface during development:

  • Browser interface: From any web browser on the local lab network, navigate to http://192.168.1.6 and log in (credentials here). This interface supports live data streaming as well as full control of the camera settings.

  • SpinView: A standalone application provided as part of the Spinnaker SDK. It supports streaming live camera data as well as saving images and videos. It can be launched from the terminal on chimay via the command: $ spinview

  • Research Studio: This is FLIR's proprietary software, for which we have a one-year license. It can be launched from the terminal on chimay via the command: $ FLIRResearchStudio

Permanent cabling

Since everything appears to be working, I ran a permanent Cat 6 cable from the lab switch to the camera's power+I/O adapter. The adapter is plugged into a UPS-protected power strip overhanging the optical table, as pictured below. To prevent the adapter from unplugging itself under its own weight, I attached a zip tie around the adapter to hold it securely in place.

  7   Mon Jul 11 14:29:45 2022 JonOmnistructureGeneralHEPA filter installed
Today I unpacked and installed the new HEPA filter for the lab. It is an Omni CleanAir OCA1210 capable of 1200 CFM. This flow rate is sufficient to turn over the air in the room once every 4 minutes, or 14 times per hour. Hopefully this will cut down on our particulate accumulation issues.
ELOG V3.1.3-7933898