40m QIL Cryo_Lab CTN SUS_Lab TCS_Lab OMC_Lab CRIME_Lab FEA ENG_Labs OptContFac Mariner WBEEShop
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  15936   Thu Mar 18 07:02:27 2021 KojiUpdateLSCREFL11 demod retrofitting

Attachment 1: Transfer Functions

The original circuit had a gain of ~20 and the phase delay of ~1deg at 10kHz, while the new CH-I and CH-Q have a phase delay of 3 deg and 2 deg, respectively.

Attachment 2: Output Noise Levels

The AD797 circuit had higher noise at low frequency and better noise levels at high frequency. Each TLE2027 circuit was tuned to eliminate the instability and shows a better noise level compared to the low-frequency spectrum of the AD797 version.

RXA: AD797 sad, all hail the op-amps ending with 27 !

Attachment 1: TFs.pdf
TFs.pdf
Attachment 2: PSD.pdf
PSD.pdf
  15980   Wed Mar 31 00:40:32 2021 KojiUpdateElectronicsElectronics Packaging for assembly work

I've worked on packing the components for the following chassis
- 5 16bit AI chassis
- 4 18bit AI chassis
- 7 16bit AA chassis
- 8 HAM-A coil driver chassis
They are "almost" ready for shipment. Almost means some small parts are missing. We can ship the boxes to the company while we wait for these small parts.

  • DB9 Female Ribbon Receptacle AFL09B-ND Qty100 (We have 10) -> Received 90 on Apr 1st
  • DB9 Male Ribbon Receptacle CMM09-G Qty100 (We have 10) -> Received 88 on Apr 1st
  • 4-40 Pan Flat Head Screw (round head, Phillips) 1/2" long Qty 50 -> Found 4-40 3/8" Qty50 @WB EE on Apr 1st (Digikey H782-ND)
  • Keystone Chassis Handle 9106 36-9106-ND Qty 50 -> Received 110 on Apr 1st
  • Keystone Chassis Ferrule 9121 NKL PL 36-9121-ND Qty 100 -> Received 55 on Apr 1st
  • Chassis Screws 4-40 3/16" Qty 1100 -> Received 1100 on Apr 1st
  • Chassis Ear Screws 6-32 1/2" 91099A220 Qty 150 -> Received 400 of 3/8" on Apr 1st
  • Chassis Handle Screws 6-32 1/4" 91099A205 Qty 100 -> included in the above
  • Powerboard mounting screw 4-40 Pan Flat Head Screw (round head, Phillips) 1/4" long Qty 125 -> Received 100 on Apr 1st

And some more additional items to fill the emptying stock.

  • 18AWG wires (we have orange/blue/black 1000ft, I'm sending ~1000ft black/green/white)
  • Already consumed 80% of 100ft 9pin ribbon cable (=only 20ft left in the stock)
Attachment 1: P_20210330_233508.jpg
P_20210330_233508.jpg
Attachment 2: P_20210330_233618.jpg
P_20210330_233618.jpg
  15981   Wed Mar 31 03:56:37 2021 KojiSummaryElectronicsA bunch of electronics received

We have received 9x 18bit DAC adapter boards (D1000654)

Attachment 1: P_20210331_013257.jpg
P_20210331_013257.jpg
Attachment 2: P_20210331_014020.jpg
P_20210331_014020.jpg
  15986   Thu Apr 1 18:16:28 2021 KojiUpdateElectronicsElectronics Packaging for assembly work

All small components are packed in the boxes. They are ready to ship.

 

  15989   Thu Apr 1 23:55:33 2021 KojiSummaryGeneralHEPA AC cord replacement

I think the PSL HEPA (both 2 units) are not running. The switches were on. And the variac was changed from 60% to 0%~100% a few times but no success.
I have no troubleshooting power anymore today. The main HEPA switch was turned off.

  16002   Tue Apr 6 21:17:04 2021 KojiSummaryGeneralPSL HEPA investigation

- Last week we found both of the PSL HEPA units were not running.

- I replaced the capacitor of the north unit, but it did not solve the issue. (Note: I reverted the cap back later)
- It was found that the fans ran if the variac was removed from the chain.
- But I'm not certain that we can run the fans in this configuration with no attendance considering fire hazard.

@3AM: UPON LEAVING the lab, I turned off the HEPA. The AC cable was not warm, so it's probably OK, but we should wait for the continuous operation until we replace the scorched AC cable.


The capacitor replacement was not successful. So, the voltages on the fan were checked more carefully. The fan has the three switch states (HIGH/OFF/LOW). If there is no load (SW: OFF), the variac out was as expected. When the load was LOW or HIGH, it looked as if the motor is shorted (i.e. no voltage difference between two wires).

I thought the motors may have been shorted. But if the load resistance was measured with the fluke meter, it showed some resistance

- North Unit: SW LOW 4.6Ohm / HIGH 6.0Ohm
- South Unit: SW LOW 6.0Ohm / HIGH 4.6Ohm (I believe the internal connection is incorrect here)

I believed the motors are alive! Then the fans were switched on with the variac removed... they ran. So I set the switch LOW for the north unit and HIGH for the south unit.

Then I inspected the variac:

  • The AC output has some liquid leaking (oil?) (Attachment 1)
  • The AC plug on the variac out has a scorch mark (Attachments 2/3)

So, this scorched AC plug/cable connected directly to the AC right now. I'm not 100% confident about the safety of this configuration.
Also I am not sure what was wrong with the system.

  • Has the variac failed first? Because of the heat? I believe that the HEPA was running @30% most of the time. Maybe the damage was already there at the failure in Nov 2020?
  • Or has the motor stopped at some point and this made the variac failed?
  • Was the cable bad and the heat made the variac failed (then the problem is still there).

So, while I'm in the lab today, I'll keep the HEPA running, but upon my taking off, I'll turn it off. We'll discuss what to do in the meeting tomorrow.

 

Attachment 1: 20210406211741_IMG_0554.jpeg
20210406211741_IMG_0554.jpeg
Attachment 2: 20210406211840_IMG_0555.jpeg
20210406211840_IMG_0555.jpeg
Attachment 3: 20210406211850_IMG_0556.jpeg
20210406211850_IMG_0556.jpeg
  16003   Wed Apr 7 02:50:49 2021 KojiUpdateSUSFlange Inspections

Basically I went around all the chambers and all the DB25 flanges to check the invac cable configurations. Also took more time to check the coil Rs and Ls.

Exceptions are the TTs. To avoid unexpected misalignment of the TTs, I didn't try to disconnect the TT cables from the flanges.

Upon the disconnection of the SOS cables, the following steps are taken to avoid large impact to the SOSs

  • The alignment biases were saved or recorded.
  • Gradually moved the biases to 0
  • Turned off the watchdogs (thus damping)

After the measurement, IMC was lock and aligned. The two arms were locked and aligned with ASS. And the PRM alignment (when "misalign" was disengaged) was checked with the REFL CCD.
So I believe the SOSs are functioning as before, but if you find anything, please let me know.
 

  16008   Thu Apr 8 20:58:17 2021 KojiUpdateCDSADC adapter boards assembly

5x 16bit ADC adapter boards (D0902006) assembled.

Attachment 1: P_20210408_205411_2_1.jpg
P_20210408_205411_2_1.jpg
  16038   Thu Apr 15 18:33:39 2021 KojiUpdateCDSMore 16bit ADC adapter boards

We received 10x 16bit ADC adapter boards from Todd. S2100687~S2100696

The number of soldered resistors seems to be less than that on the schematics. They are related to duotone, so check if it's OK upon use.

Attachment 1: P_20210415_183139_1.jpg
P_20210415_183139_1.jpg
  16039   Fri Apr 16 00:21:52 2021 KojiUpdateGeneralGlue Freezer completely frozen

I was looking at the laser head/amp and somehow decided to open the glue freezer. And it was stuck. I've managed to open it but the upper room was completely frozen.
Some of the batteries were embedded in a block of ice. I think we should throw them out.

Can the person who comes in the morning work on defrosting?

- Coordinate with Yehonathan and move the amps and the wooden crate so that you can move the freezer.

- Remove the contents to somewhere (it's OK to be room temp for a while)

- Unplug the freezer

- Leave the freezer outside with the door open. After a while, the ice will fall without care.

- At the end of the day, move it back to the lab. Continue defrosting the other day if the ice remains.

Attachment 1: P_20210416_000906.jpg
P_20210416_000906.jpg
Attachment 2: P_20210416_000850.jpg
P_20210416_000850.jpg
  16056   Wed Apr 21 00:08:15 2021 KojiUpdatePSLPSL Table (sort of) covered / HEPA "chimney"

Shutdown Procedure:
PSL Shutter closed / MC Autolocker disabled / PSL mechanical shutter closed / Laser injection current turned to zero / Laser turn off (red button) / Laser key turned off

The laser stat before the shutdown:
- LD Temp A: Set 22.07 (Untouched)
- LD Temp B: Set 21.03(Untouched)
- Laser Injection Current: Dial 9.53, Actual 2.100 -> Dial was moved to zero upon shutting down
- Laser Crystal Temp: Dial 3.34 (untouched)  Set 30.57 Actual 30.60 (Untouched)

PSL Table covering

- Because of the so many cables going up and down, sealing the PSL table with the metalized sheet was not easy. Therefore, the sheets have been just softly laid above the optics. (Attachment 1)
- The largest sheet which covers the east half of the table was taped to the table at the bottom, so that the air from the chimneys (see below) does not come up to the table

- The large dust could come from the opening of the enclosure during the filter replacement. So it was considered to be easier to seal the openings. (Attachment 2)
- Of course, the HEPAs are going to be tested after the maintenance work. It means that vent paths were needed so that the seals do not explode with the pressure (together with dust).
- Thus, the tubes of the sheets are attached to the seals to form "chimneys" for guiding the airflow beneath the table. (Attachment 2/3/4)
- This configuration was not meant to be sufficiently strong for a continuous run of the fans. Long running of the HEPAs may cause the failure of the seal tapes.
  Therefore the HEPA test should be done with a low flow rate and/or a short period of high flow.

- Once the work has been done, all the sheets should be carefully removed without scattering the fallouts onto the optics.

 

Attachment 1: 20210420235324_IMG_0560.jpeg
20210420235324_IMG_0560.jpeg
Attachment 2: 20210420235304_IMG_0559.jpeg
20210420235304_IMG_0559.jpeg
Attachment 3: 20210420235243_IMG_0558.jpeg
20210420235243_IMG_0558.jpeg
Attachment 4: 20210420235344_IMG_0562.jpeg
20210420235344_IMG_0562.jpeg
  16057   Wed Apr 21 01:14:03 2021 KojiUpdatePSLPSL Table (sort of) covered / HEPA "chimney"

I also located the (possible) HEPA filters in the lab. (Attachments 1~3)

Oh! This is NO-NO! We can't place anything in front of the mains breakers. (Attachment 2)
I relocated the objects (Attachment 3)

 

Attachment 1: P_20210421_005056.jpg
P_20210421_005056.jpg
Attachment 2: P_20210421_005114.jpg
P_20210421_005114.jpg
Attachment 3: P_20210421_005302.jpg
P_20210421_005302.jpg
  16065   Wed Apr 21 13:10:12 2021 KojiUpdateGeneralPSL HEPA Maintenance

It's probably too late to say but there are/were two boxes. (just for record)

 

  16069   Wed Apr 21 19:43:20 2021 KojiUpdatePSLNew HEPA speed control

The new HEPA speed controllers are attached at the middle of the HEPA unit (not at the edge of the unit)... (Attachment 1)
You still need a step./stool to touch the knob and need a ladder for a more precise setting.

We still don't know the optimal speed of the nominal IFO operation. For now, the HEPAs are running at the max speed (Attachment 2).
Once we know the optimal setting, we mark the knobs so that we can see them only with the step.

Attachment 1: P_20210421_193637.jpg
P_20210421_193637.jpg
Attachment 2: P_20210421_193627.jpg
P_20210421_193627.jpg
  16070   Thu Apr 22 01:42:38 2021 KojiSummaryElectronicsHV Supply Comparison

New HV power supply from Company 'M' has been delivered. So I decided to compare the noise levels of some HV supplies in the lab. There are three models from companies 'H', 'K', and 'M'.

The noise level was measured with SR785 via Gautam's HP filter with protection diodes.

'H' is a fully analog HV supply and the indicator is analog meters.
'K' is a model with a LCD digital display and numerical keypad.
'M' is a model with a knob and digital displays.

All the models showed that the noise levels increased with increased output voltage.

Among these three, H showed the lowest noise. (<~1uV/rtHz@10Hz and <50nV/rtHz@100Hz) (Attachment 1)

K is quite noisy all over the measured freq range and the level was <50uV/rtHz. Also the PSD has lots of 5Hz harmonics. (Attachment 2)

M has a modest noise level (<~30uV/rtHz@10Hz and <1uV/rtHz@100Hz)except for the noticeable line noise (ripple). (Attachment 3)

The comparison of the three models at 300V is Attachment 4. The other day Gautam and I checked the power spectrum of the HV coil driver with KEPCO and the output noise level of the coil driver was acceptable. So I expect that we will be able to use the HV supply from Company M. Next step is to check the HV driver noise with the model by M used as the supply.

Attachment 1: HV_Supply_PSD_H.pdf
HV_Supply_PSD_H.pdf
Attachment 2: HV_Supply_PSD_K.pdf
HV_Supply_PSD_K.pdf
Attachment 3: HV_Supply_PSD_M.pdf
HV_Supply_PSD_M.pdf
Attachment 4: HV_Supply_PSD.pdf
HV_Supply_PSD.pdf
  16083   Fri Apr 23 19:26:58 2021 KojiUpdatePSLHEPA speed lowered

I believe that there is an internal setting for the minimum flow, so the flow is not linear ("0%" is not zero), but we should mark this flow speed once you find this is sufficiently low for the locking too.

  16099   Thu Apr 29 17:43:16 2021 KojiUpdateCDSRFM

The other day I felt hot at the X end. I wondered if the Xend A/C was off, but the switch right next to the SP table was ON (green light).
I could not confirm if the A/C was actually blowing or not.

  16115   Mon May 3 23:28:56 2021 KojiSummaryGeneralWeird gas leakagr kind of noise in 40m control room

I also noticed some sound in the control room. (didn't open the MP3 yet)

I'm afraid that the hard disk in the control room iMac is dying.

 

  16131   Tue May 11 17:43:09 2021 KojiUpdateCDSI/O Chassis Assembly

Did you match the local PC time with the GPS time?

  16136   Wed May 12 16:53:59 2021 KojiUpdateSUSMass Properties of SOS Assembly with 3"->2" Optic sleeve, in SI units

No, this is the property of the suspension assembly. The mass says 10kg

Could you do the same for the testmass assembly (only the suspended part)? The units are good, but I expect that the values will be small. I want to keep at least three significant digits.

  16140   Fri May 14 03:29:50 2021 KojiUpdateElectronicsHV Driver noise test with the new HV power supply from Matsusada

I believe I did the identical test with the one in [40m ELOG 15786]. The + input of PA95 was shorted to the ground to exclude the noise from the bias input. The voltage noise at TP6 was measured with +/-300V supply by two HP6209 and two Matsusada R4G360.

With R4G360, the floor level was identical and 60Hz line peaks were less. It looks like R4G360 is cheap, easier and precise to handle, and sufficiently low noise.

Attachment 1: HV_Driver_PSD.pdf
HV_Driver_PSD.pdf
  16146   Wed May 19 18:29:41 2021 KojiUpdateSUSMass Properties of SOS Assembly with 3"->2" Optic sleeve, in SI units

Calculation for the SOS POS/PIT/YAW resonant frequencies

- Nominal height gap between the CoM and the wire clamping point is 0.9mm (cf T970135)

- To have the similar res freq for the optic with the 3" metal sleeve is 1.0~1.1mm.
As the previous elog does not specify this number for the current configuration, we need to asses this value and the make the adjustment of the CoM height.

Attachment 1: SOS_resonant_freq.pdf
SOS_resonant_freq.pdf SOS_resonant_freq.pdf
Attachment 2: SOS_resonant_freq.nb.zip
  16148   Thu May 20 16:56:21 2021 KojiUpdateElectronicsProduction version of the HV coil driver tested with KEPCO HV supplies

HP HV power supply ( HP6209 ) were returned to Downs

Attachment 1: P_20210520_154523_copy.jpg
P_20210520_154523_copy.jpg
  16149   Fri May 21 00:05:45 2021 KojiUpdateSUSNew electronics: Sat Amp / Coil Drivers

11 new Satellite Amps were picked up from Downs. 7 more are coming from there. I have one spare unit I made. 1 sat amp has already been used at MC1.

We had 8 HAM-A coil drivers delivered from the assembling company. We also have two coil drivers delivered from Downs (Anchal tested)

Attachment 1: F3CDEF8D-4B1E-42CF-8EFC-EA1278C128EB_1_105_c.jpeg
F3CDEF8D-4B1E-42CF-8EFC-EA1278C128EB_1_105_c.jpeg
  16150   Fri May 21 00:15:33 2021 KojiUpdateElectronicsDC Power Strip delivered / stored

DC Power Strip Assemblies delivered and stored behind the Y arm tube (Attachment 1)

  • 7x 18V Power Strip (Attachment 2)
  • 7x 24V Power Strip (Attachment 2)
  • 7x 18V/24V Sequencer / 14x Mounting Panel (Attachment 3)
  • DC Power Cables 3ft, 6ft, 10ft (Attachments 4/5)
  • DC Power Cables AWG12 Orange / Yellow (Attachments 6/7)

I also moved the spare 1U Chassis to the same place.

  • 5+7+9 = 21x 1U Chassis (Attachments 8/9)

 

Attachment 1: P_20210520_233112.jpeg
P_20210520_233112.jpeg
Attachment 2: P_20210520_233123.jpg
P_20210520_233123.jpg
Attachment 3: P_20210520_233207.jpg
P_20210520_233207.jpg
Attachment 4: P_20210520_231542.jpg
P_20210520_231542.jpg
Attachment 5: P_20210520_231815.jpg
P_20210520_231815.jpg
Attachment 6: P_20210520_195318.jpg
P_20210520_195318.jpg
Attachment 7: P_20210520_231644.jpg
P_20210520_231644.jpg
Attachment 8: P_20210520_233203.jpg
P_20210520_233203.jpg
Attachment 9: P_20210520_195204.jpg
P_20210520_195204.jpg
  16158   Mon May 24 20:55:00 2021 KojiSummaryBHDHow to align two OMCs on the BHD platform?

Differential misalignment of the OMCs

40m BHD will employ two OMCs on the BHD platform. We will have two SOSs for each of the LO and AS beams. The challenge here is that the input beam must optimally couple to the OMCs simultaneously. This is not easy as we won't have independent actuators for each OMC. e.g. The alignment of the LO beam can be optimally adjusted to the OMC1, but this, in general, does not mean the beam is optimally aligned to the OMC2.

Requirement

When a beam with the matched mode to an optical cavity has a misalignment, the power coupling C can be reduced from the unity as

C = 1 - \left(\frac{a}{\omega_0}\right)^2 - \left(\frac{\alpha}{\theta_0}\right)^2

where \omega_0 is the waist radius, \theta_0 is the divergence angle defined as \theta_0 \equiv \lambda/ \pi \omega, a and \alpha are the beam lateral translation and rotation at the waist position.

The waist size of the OMC is 500um. Therefore \omega_0 = 500um and \theta_0 = 0.68 mrad. If we require C to be better than 0.995 according to the design requirement document (T1900761). This corresponds to a (only) to be 35um and \alpha (only) to be 48urad. These numbers are quite tough to be realized without post-installation adjustment. Moreover, the OMCs themselves have individual differences in the beam axis. So no matter how we set the mechanical precision of the OMC installation, we will introduce a maximum of 1mm and ~5mrad uncertainty of the optical axis.

Adjustment

Suppose we adjust the incident beam to the OMC placed at the transmission side of the BHD BS. The reflected beam at the BS can be steered by picomotors. The distance from the BS to the OMC waist is 12.7" (322mm) according to the drawing.
So we can absorb the misalignment mode of (a, \alpha) = (0.322 \theta, \theta). This is a bit unfortunate. 0.322m is about 1/2 of the rayleigh range. Therefore, this actuation is still angle-dominated but a bit of translation is still coupled.

If we enable to use the third picomotor on the BHD BS mount, we can introduce the translation of the beam in the horiz direction. This is not too huge therefore we still want to prepare the method to align the OMC in the horiz direction.

The difficult problem is the vertical alignment. This requires the vertical displacement of the OMC. And we will not have the option to lower the OMC. Therefore if the OMC2 is too high, we have to raise the OMC1 so that the resulting beam is aligned to the OMC2. i.e. we need to maintain the method to raise both OMCs. (... or swap the OMCs). From the images of the OMC beam spots, we'll probably be able to analyze the intracavity axes of the OMCs. So we can always place the OMC with a higher optical axis at the transmission side of the BHD BS.

 

 

  16172   Wed Jun 2 01:03:19 2021 KojiUpdateBHDSOS assembly

Can you just cut the viton tips smaller? If you cut it to have some wedge (or say, taper), it can get stuck with the vent hole.

 

  16173   Wed Jun 2 01:08:57 2021 KojiUpdateSUSCoM to Clamping Point Measurement for 3" Adapter Ring

How about to use the non-Ag coated threaded shaft + the end SS masses with helicoils inserted? Does this save the masses to get stuck?

 

  16181   Thu Jun 3 22:08:00 2021 KojiUpdateCDSOpto-isolator for c1auxey

- Could you explain what is the blue thing in Attachment 1?

- To check the validity of the signal chain, can you make a diagram summarizing the path from the fast BO - BO I/F - Acromag - This opto-isolator - the coil driver relay? (Cut-and-paste of the existing schematics is fine)

 

  16184   Sun Jun 6 03:02:14 2021 KojiUpdateCDSOpto-isolator for c1auxey

This RTS also use the BO interface with an opto isolator. https://dcc.ligo.org/LIGO-D1002593

Could you also include the pull up/pull down situations?

  16198   Fri Jun 11 20:19:50 2021 KojiSummaryBHDBHD OMC invacuum wiring

Stephen and I discussed the in-vacuum OMC wiring.

- One of the OMCs has already been completed. (Blue)
- The other OMC is still being built. It means that these cables need to be built. (Pink)
- However, the cables for the former OMC should also be replaced because the cable harness needs to be replaced from the metal one to the PEEK one.
- The replacement of the harness can be done by releasing the Glenair Mighty Mouse connectors from the harness. (This probably requires a special tool)
- The link to the harness photo is here: https://photos.app.goo.gl/3XsUKaDePbxbmWdY7

- We want to combine the signals for the two OMCs into three DB25s. (Green)
- These cables are custom and need to be designed.

- The three standard aLIGO-style cables are going to be used. (Yellow)

- The cable stand here should be the aLIGO style.

Attachment 1: 40mBHD_OMC_wiring.pdf
40mBHD_OMC_wiring.pdf
  16203   Tue Jun 15 21:48:55 2021 KojiUpdateCDSOpto-isolator for c1auxey

If my understanding is correct, the (photo receiving) NPN transistor of the optocoupler is energized through the acromag. The LED side should be driven by the coil driver circuit. It is properly done for the "enable mon" through 750Ohm and +V. However, "Run/Acquire" is a relay switch and there is no one to drive the line. I propose to add the pull-up network to the run/acquire outputs. This way all 8 outputs become identical and symmetric.

We should test the configuration if this works properly. This can be done with just a manual switch, R=750Ohm, and a +V supply  (+18V I guess).

Attachment 1: Acromag_RTS_BI_config.jpg
Acromag_RTS_BI_config.jpg
  16206   Wed Jun 16 19:34:18 2021 KojiUpdateGeneralHVAC

I made a flow sensor with a stick and tissue paper to check the airflow.

- The HVAC indicator was not lit, but it was just the blub problem. The replacement bulb is inside the gray box.

- I went to the south arm. There are two big vent ducts for the outlets and intakes. Both are not flowing the air.
  The current temp at 7pm was ~30degC. Max and min were 31degC and 18degC.

- Then I went to the vertex and the east arm. The outlets and intakes are flowing.

Attachment 1: HVAC_Power.jpeg
HVAC_Power.jpeg
Attachment 2: South_Arm.jpeg
South_Arm.jpeg
Attachment 3: South_End_Tenperature.jpeg
South_End_Tenperature.jpeg
Attachment 4: Vertex.jpeg
Vertex.jpeg
Attachment 5: East_Arm.jpeg
East_Arm.jpeg
  16211   Thu Jun 17 22:19:12 2021 KojiUpdateElectronics25 HAM-A coil driver units delivered

25 HAM-A coil driver units were fabricated by Todd and I've transported them to the 40m.
 2 units we already have received earlier.
The last (1) unit has been completed, but Luis wants to use it for some A+ testing. So 1 more unit is coming.

Attachment 1: P_20210617_195811.jpg
P_20210617_195811.jpg
  16212   Thu Jun 17 22:25:38 2021 KojiUpdateSUSNew electronics: Sat Amp / Coil Drivers

It is a belated report: We received 5 more sat amps on June 4th. (I said 7 more but it was 6 more) So we still have one more sat amp coming from Todd.

- 1 already delivered long ago
- 8 received from Todd -> DeLeone -> Chub. They are in the lab.
- 11 units on May 21st
- 5 units on Jun 4th
Total 1+8+11+5 = 25
1 more unit is coming

 

Quote:

11 new Satellite Amps were picked up from Downs. 7 more are coming from there. I have one spare unit I made. 1 sat amp has already been used at MC1.

We had 8 HAM-A coil drivers delivered from the assembling company. We also have two coil drivers delivered from Downs (Anchal tested)

 

Attachment 1: P_20210604_231028.jpeg
P_20210604_231028.jpeg
  16216   Fri Jun 18 23:53:08 2021 KojiUpdateBHDSOS assembly

Then, can we replace the four small EQ stops at the bottom (barrel surface) with two 1/4-20 EQ stops? This will require drilling the bottom EQ stop holders (two per SOS).

 

  16223   Thu Jun 24 16:40:37 2021 KojiUpdateSUSMC lock acquired back again

[Koji, Anchal]

The issue of the PD output was that the PD whitened outputs of the sat amp (D080276) are differential, while the successive circuit (D000210 PD whitening unit) has the single-ended inputs. This means that the neg outputs (D080276 U2) have always been shorted to GND with no output R. This forced AD8672 to work hard at the output current limit. Maybe there was a heat problem due to this current saturation as Anchal reported that the unit came back sane after some power-cycling or opening the lid. But the heat issue and the forced differential voltage to the input stage of the chip eventually cause it to fail, I believe.

Anchal came up with the brilliant idea to bypass this issue. The sat amp box has the PD mon channels which are single-ended. We simply shifted the output cables to the mon connectors. The MC1 sus was nicely damped and the IMC was locked as usual. Anchal will keep checking if the circuit will keep working for a few days.

Attachment 1: P_20210624_163641_1.jpg
P_20210624_163641_1.jpg
  16240   Tue Jul 6 17:40:32 2021 KojiSummaryGeneralLab cleaning

We held the lab cleaning for the first time since the campus reopening (Attachment 1).
Now we can use some of the desks for the people to live! Thanks for the cooperation.

We relocated a lot of items into the lab.

  • The entrance area was cleaned up. We believe that there is no 40m lab stuff left.
    • BHD BS optics was moved to the south optics cabinet. (Attachment 2)
    • DSUB feedthrough flanges were moved to the vacuum area (Attachment 3)
  • Some instruments were moved into the lab.
    • The Zurich instrument box
    • KEPCO HV supplies
    • Matsusada HV supplies
  • We moved the large pile of SUPERMICROs in the lab. They are around MC2 while the PPE boxes there were moved behind the tube around MC2 area. (Attachment 4)
  • We have moved PPE boxes behind the beam tube on XARM behind the SUPERMICRO computer boxes. (Attachment 7)
  • ISC/WFS left over components were moved to the pile of the BHD electronics.
    • Front panels (Attachment 5)
    • Components in the boxes (Attachment 6)

We still want to make some more cleaning:

- Electronics workbenches
- Stray setup (cart/wagon in the lab)
- Some leftover on the desks
- Instruments scattered all over the lab
- Ewaste removal

Attachment 1: P_20210706_163456.jpg
P_20210706_163456.jpg
Attachment 2: P_20210706_161725.jpg
P_20210706_161725.jpg
Attachment 3: P_20210706_145210.jpg
P_20210706_145210.jpg
Attachment 4: P_20210706_161255.jpg
P_20210706_161255.jpg
Attachment 5: P_20210706_145815.jpg
P_20210706_145815.jpg
Attachment 6: P_20210706_145805.jpg
P_20210706_145805.jpg
Attachment 7: PXL_20210707_005717772.jpg
PXL_20210707_005717772.jpg
  16246   Wed Jul 14 19:21:44 2021 KojiUpdateGeneralBrrr

Jordan reported on Jun 18, 2021:
"HVAC tech came today, and replaced the thermostat and a coolant tube in the AC unit. It is working now and he left the thermostat set to 68F, which was what the old one was set to."

  16250   Sat Jul 17 00:52:33 2021 KojiUpdateGeneralCanon camera / small silver tripod / macro zoom lens / LED ring light borrowed -> QIL

Canon camera / small silver tripod / macro zoom lens / LED ring light borrowed -> QIL

Attachment 1: P_20210716_213850.jpg
P_20210716_213850.jpg
  16252   Wed Jul 21 14:50:23 2021 KojiUpdateSUSNew electronics

Received:

Jun 29, 2021 BIO I/F 6 units
Jul 19, 2021 PZT Drivers x2 / QPD Transimedance amp x2

 

Attachment 1: P_20210629_183950.jpeg
P_20210629_183950.jpeg
Attachment 2: P_20210719_135938.jpeg
P_20210719_135938.jpeg
  16255   Sun Jul 25 18:21:10 2021 KojiUpdateGeneralCanon camera / small silver tripod / macro zoom lens / LED ring light returned / Electronics borrowed

Camera and accesories returned

One HAM-A coildriver and one sat amp borrowed -> QIL

https://nodus.ligo.caltech.edu:8081/QIL/2616

 

  16260   Tue Jul 27 20:12:53 2021 KojiUpdateBHDSOS assembly

1 or 2. The stained ones are just fine. If you find the vented 1/4-20 screws in the clean room, you can use them.

For the 28 screws, yeah find some spares in the clean room (faster), otherwise just order.

  16278   Thu Aug 12 14:59:25 2021 KojiUpdateGeneralPSL shutter was closed this morning

What I was afraid of was the vacuum interlock. And indeed there was a pressure surge this morning. Is this real? Why didn't we receive the alert?

Attachment 1: Screen_Shot_2021-08-12_at_14.58.59.png
Screen_Shot_2021-08-12_at_14.58.59.png
  16279   Thu Aug 12 20:52:04 2021 KojiUpdateGeneralPSL shutter was closed this morning

I did a bit more investigation on this.

- I checked P1~P4, PTP2/3, N2, TP2, TP3. But found only P1a and P2 were affected.

- Looking at the min/mean/max of P1a and P2 (Attachment 1), the signal had a large fluctuation. It is impossible to have P1a from 0.004 to 0 instantaneously.

- Looking at the raw data of P1a and P2 (Attachment 2), the value was not steadily large. Instead it looks like fluctuating noise.

So my conclusion is that because of an unknown reason, an unknown noise coupled only into P1a and P2 and tripped the PSL shutter. I still don't know the status of the mail alert.

Attachment 1: Screen_Shot_2021-08-12_at_20.51.19.png
Screen_Shot_2021-08-12_at_20.51.19.png
Attachment 2: Screen_Shot_2021-08-12_at_20.51.34.png
Screen_Shot_2021-08-12_at_20.51.34.png
  16281   Tue Aug 17 04:30:35 2021 KojiUpdateSUSNew electronics

Received:

Aug 17, 2021 2x ISC Whitening

Delivered 2x Sat Amp board to Todd

 

Attachment 1: P_20210816_234136.jpg
P_20210816_234136.jpg
Attachment 2: P_20210816_235106.jpg
P_20210816_235106.jpg
Attachment 3: P_20210816_234220.jpg
P_20210816_234220.jpg
  16284   Thu Aug 19 14:14:49 2021 KojiUpdateCDSTime synchornization not running

131.215.239.14 looks like Caltech's NTP server (ntp-02.caltech.edu)
https://webmagellan.com/explore/caltech.edu/28415b58-837f-4b46-a134-54f4b81bee53

I can't say it is correct or not as I did not make the survey at your level. I think you need a few tests of reconfiguring and restarting the NTP clients to see if time synchronization starts. Because the local time is not regulated right now anyway, this operation is safe I think.

 

  16288   Mon Aug 23 11:51:26 2021 KojiUpdateGeneralCampus Wide Power Glitch Reported: Monday, 8/23/21 at 9:30am

Campus Wide Power Glitch Reported: Monday, 8/23/21 at 9:30am (more like 9:34am according to nodus log)

nodus: rebooted. ELOG/apache/svn is running. (looks like Anchal worked on it)

chiara: survived the glitch thanks to UPS

fb1: not responding -> @1pm open to login / seemed rebooted only at 9:34am (network path recovered???)

megatron: not responding

optimus: no route to host

c1aux: ping ok, ssh not responding -> needed to use telnet (vme / vxworks)
c1auxex: ssh ok
c1auxey: ping ok, ssh not respoding -> needed to use telnet (vme / vxworks)
c1psl: ping NG, power cycled the switch on 1X2 -> ssh OK now
c1iscaux: ping NG -> rebooted the machine -> ssh recovered

c1iscaux2: does not exist any more
c1susaux: ping NG -> responds after 1X2 switch reboot

c1pem1: telnet ok (vme / vxworks)
c1iool0: does not exist any more

c1vac1: ethernet service restarted locally -> responding
ottavia: doesnot exist?
c1teststand: ping ok, ssh not respoding

3:20PM we started restarting the RTS

  16290   Mon Aug 23 19:00:05 2021 KojiUpdateGeneralCampus Wide Power Glitch Reported: Monday, 8/23/21 at 9:30am

Restarting the RTS was unsuccessful because of the timing discrepancy error between the RT machines and the FB. This time no matter how we try to set the time, the IOPs do not run with "DC status" green. (We kept having 0x4000)

We then decided to work on the recovery without the data recorded. After some burtrestores, the IMC was locked and the spot appeared on the AS port. However, IPC seemed down and no WFS could run.

  16294   Tue Aug 24 18:44:03 2021 KojiUpdateCDSFB is writing the frames with a year old date

Dan Kozak pointed out that the new frame files of the 40m has not been written in 2021 GPS time but 2020 GPS time.

Current GPS time is 1313890914 (or something like that), but the new files are written as C-R-1282268576-16.gwf

I don't know how this can happen but this may explain why we can't have the agreement between the FB gps time and the RTS gps time.

(dataviewer seems dependent on the FB GPS time and it indicates 2020 date. DTT/diaggui does not.)


This is the way to check the gpstime on fb1. It's apparently a year off.

controls@fb1:~ 0$ cat /proc/gps
1282269402.89

Attachment 1: Screen_Shot_2021-08-24_at_18.46.24.png
Screen_Shot_2021-08-24_at_18.46.24.png
ELOG V3.1.3-