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ID Date Author Typedown Category Subject
  420   Thu Jul 21 14:55:48 2022 KojiGeneralGeneralOptics bonding for the backscatter measurement

The backscatter beam is supposed to appear in the backpropagation path. The transmission of the OMC has a couple of optics, it's not easy to access that beam.
To try to deflect the beam either horizontally or vertically, small optical pieces were made. (Attachment)

These are the combination of the optics

- Thorlabs PF05-03 Fused Silica Mirror Blank (dia12.7mm x t 6.0mm) + Thorlabs 1/2"sq BB Dielectric Mirror BBSQ05-E03

- Thorlabs PF05-03 Fused Silica Mirror Blank (dia12.7mm x t 6.0mm) + Thorlabs ME05-G01 Protected Al Mirror (dia12.7mm x t 3.2mm) + Thorlabs MRA10-K13 Right-Angle Prism Nd:YAG 10mm

Torr seal was used as the bonding epoxy. It uses a 1:2 volume mixture (not easy because of the viscosity) and is relatively fast to cure (in a couple of hours).
The test piece showed some softness after 3~4 hours so I left the parts cured overnight at room temp (i.e. 18degC)

Attachment 1: IMG_1098.JPG
IMG_1098.JPG
  421   Thu Jul 21 17:47:00 2022 KojiGeneralGeneralThe profile of the beam incident on the fiber input coupler

The profile of the beam incident on the fiber input

The fiber input was deflected by a 45deg mirror. The beam profile was measured with WincamD. The beam was too strong (~60mW) even at the smallest pump power (ADJ -50) of the NPRO. So the two ND20 filters were added to the lens right before the 45 deg mirror and the camera.

The measured profile had some deviation from the nice TEM00 particularly around the waist. This could be a problem of the too small beam on the ND filter and the CCD.
This is not an issue as we just want to know the approximate shape of the beam.

For the fiber coupling, if we have the beam waist radius of ~200um it is sufficient for decent coupling.

Attachment 1: fiber_beam_profile.pdf
fiber_beam_profile.pdf
  422   Fri Jul 22 00:31:17 2022 KojiGeneralGeneralOMC #002 backscatter measurement

Measure the power ratio between the forward-propagating and reverse-propagating beams.

  1. Place a small deflecting mirror at the transmission.
  2. Place a flat mirror at the deflected transmission. When the alignment of this mirror is adjusted to retroreflect this beam, the DC of the cavity reflection PD increases, and also the CCD shows spurious fringes.
  3. This condition allows us to locate the power meter at the reverse-propagating spot of the transmission (Attachment 1)
  4. Place a black glass beam dump for the main (bright) transmission (Attachment 2)
  5. Now the power meter is receiving the counter-propagating beam. Turn off the room light and place an anodized Al baffle as shown in Attachment 2. Move the baffle to block only the counter-propagating. Move the baffle out. => Record the power meter reading with/without the baffle in the counter-propagating path. The difference is the power of the reverse-propagating beam.
  6. Now measure the power of the reflected main transmission. This tells us the power ratio between the foward- and back-propagating beams.
  7. Remove the small deflecting mirror and measure the power of the main transmission.
  8. Now the back-propagating power can be estimated from 6 and 7. The same amount is going back to the IFO path.
  9. The reflectivity can be calculated from the 7 and the transmission

- To increase the incident laser power, NPRO Current ADJ was set to be 0 (increased from -50)

- 1st:  Without the baffle 0.373 +/- 0.001 uW / With the baffle 0.318 +/- 0.001 uW
- 2nd: Without the baffle 0.370 +/- 0.001 uW / With the baffle 0.318 +/- 0.001 uW
- 3rd: Without the baffle 0.370 +/- 0.001 uW / With the baffle 0.317 +/- 0.001 uW

==> 53.3 +/- 0.6 nW

- The main transmission was 84.0mW
==> Backpropagation ratio was 0.634+/-0.007 ppm

- Direct measurement of the OMC was  after BS 96.6mW
==> Backpropagation power from the cavity: 61.3 +/- 0.7 nW

- Cavity transmission for the matched beam is Tcav RinputBS = 0.963
==> Incident resonant TEM00 power 100.3mW

- Reflection 61.3+/-0.7 nW x RinputBS = 60.8+/-0.7 nW
-> The effective reflectivity for the mode-matched resonant TEM00 beam incident on the OMC (1st steering mirror) is 0.606+/-0.007 ppm

Attachment 1: OMC_backscatter.pdf
OMC_backscatter.pdf OMC_backscatter.pdf
  423   Fri Jul 22 17:41:01 2022 KojiGeneralGeneralSRS LCR meter SRS720 returned to Downs

SRS LCR meter SRS720 was returned to Downs as before.

 

Attachment 1: PXL_20220723_002330805.jpg
PXL_20220723_002330805.jpg
  424   Fri Jul 22 17:47:38 2022 KojiGeneralGeneralC&B request for the reinforcement blocks

OMC Reinforcement blocks

1. P/N D1600316; Version v4; Type 01; Qty 30; Source Chemistry Machine Shop
2. P/N D1600316; Version v4; Type 02; Qty 15; Source Chemistry Machine Shop
3. P/N D1600316; Version v4; Type 01; Qty 40; Source Resource MFG PO S422806
4. P/N D1600316; Version v4; Type 02; Qty 40; Source Resource MFG PO S422806

Stephen asked Srinath for the ICS entry.
Stephen made the C&B request https://cleanandbake.ligo.caltech.edu/clean_and_bake/request/1708/

Madeline was asked to take care of the C&B.

Also, the Torr Seal box was returned to Madeline.

Attachment 1: PXL_20220722_222013127.jpg
PXL_20220722_222013127.jpg
  425   Mon Jul 25 18:25:04 2022 KojiGeneralGeneralA/C Filter was replaced
New filter PN
Grainger
TK70457312T Mini-Pleat Air Filter, Style - Air Filters Box, Performance Rating MERV 14, Nominal Filter Size 12x24x2
 
Previous filter PN
Global Industrial Equipment
Extended Surface Pleated Cartridge Filter Serva-Cell Mp4 Slmp295 12X24X2 Gl WBB431699
-> No longer available
  426   Tue Jul 26 00:01:59 2022 KojiGeneralGeneralOMC #002 delamination check 2

More epoxy delamination check:

DCPD R (Attachment 1): Found half delaminated

DCPD T (Attachment 2): Found half delaminated

QPD1/QPD2 (Attachment 3): Looks fine

------

In total we need to fix bonding of three invar bases (including the one for the cable bracket)

Attachment 1: IMG_1106.JPG
IMG_1106.JPG
Attachment 2: IMG_1107.JPG
IMG_1107.JPG
Attachment 3: IMG_1110.JPG
IMG_1110.JPG
  427   Tue Jul 26 00:12:58 2022 KojiGeneralGeneralHigh QE PD: QE measurements

- Installed the High QE PDs to OMC #002

  • B1-22@Cage B1 was installed to the transmission DCPD
  • B1-23@Cage B1 was installed to the reflection DCPD

Upon the installation, the legs of the PDs were cut by 3mm. Also, the tab of the PD could not be embedded in the DCPD housing. Therefore, the tabs were cut.

The alignment looked just fine. The weak reflections are directed to the black glass beam dumps.

- After the installation, the QEs were measured.

  • With Thorlabs S130C power meter, the QE was estimated to be ~95%. (Accuracy +/-7%)
  • With Thorlabs S401C power meter, the QE was estimated to be ~100%. (Accuracy +/-3%)

It is so confusing. So I decided to make the QE test setup.


Ophir RM9 with chopper (+/-5%): 8.97mW
Thorlabs S140C integrating sphere (+/-7%): 9.11mW
Thorlabs S130C PD power meter (+/-7%): 9.15mW
Thorlabs S401C thermal power meter (+/-3%): 8.90mW
So there looks ~3% discrepancy between S130C and S401C

Then tried to measure the QE of C1-03@Cage B3 with Ophir RM9
- Initial state: QE=0.95
- First FirstContact application: QE went up to 0.973
- Second FirstContact application: QE = 0.974, basically no change


To Do:
- Calibrate the trans-impedance amp with Keithley
- Apply FC to B1-22 and B1-23 to see if there is an improvement
- The power should be measured with S401C because the accuracy seems better (+/-3%).
- Take photos of the PD FC process

General To Do:

- Backscatter test 2nd trial

- Start applying the first contact to the optical surfaces
- Beam dump cleaning
- Apply FC cap to the PDs
- Delamination repair (light side)
- Delamination repair (dark side)
- Cable bracket replace (dark side)

 

Attachment 1: IMG_1118.JPG
IMG_1118.JPG
  428   Wed Jul 27 10:09:51 2022 KojiGeneralGeneral4+4 wire clamp in hand

Regarding: D1200971

- 4 CLASS A wire clamp obtained from the OMC spare
- 4 more DIRTY wire clamp obtained from WB experiments (they no longer use these)

Once the later ones are C&Bed, we have enough.

 

Attachment 1: PXL_20220727_072154009.jpg
PXL_20220727_072154009.jpg
  429   Wed Jul 27 10:34:09 2022 KojiGeneralGeneralHigh QE PD: QE measurements 2

- DLPCA-200 trans-impedance amplifier was calibrated.
  Keithley source meter 2450 was connected to the amp. Provide current and read the output voltage with the precision digital voltage meter (Agilent/Keysight).
  Gain: 999.7V/A@7mA, 999.6V/A@8mA

- From the power meter spec, Thorlabs S401C seemed the best (+/-3%). So the QEs of the 9 PDs were checked with this power meter again.

- All PDs exhibited the QE of 0.95~0.96. It's all relative as the power meter has a systematic error.
- Tried to clean B1-22 and B1-23 PDs. They didn't show significant improvement after the cleaning. To avoid the unnecessary risk of damaging the PDs, further cleaning was not performed. (Some photos were attached)

- What we can do is use this result as the relative measurements.
- For OMC#2, B1-22 is the DCPD(T) and B1-23 is the DCPD(R). C1-03 and C1-12 are the spares, according to this latest result.
- At LLO, we track down the source of the throughput reduction (-10%). The QEs of the PDs are going to be tested in the same setup at once to compare their PDs and our PDs.

PD Type SN Case DCV1 Pin [mW] dPin [mW] Power Meter DCV2 Avg(DCV) Std(DCV) DCVOFS (mV) Responsivity [A/W] dR QE dQE Date Note
IGHQEX3000 B1-22 B1 7.734 9.43 0.02 TL 401C 7.745 7.7395 0.006 -0.0260 0.821 0.002 0.957 0.002 July 26, 2022 clean1 / installed (T)
IGHQEX3000 B1-23 B2 7.679 9.26 0.02 TL 401C 7.709 7.6940 0.015 -0.0220 0.831 0.002 0.969 0.003 July 26, 2022 clean1 / installed (R)
IGHQEX3000 C1-03 B3 7.775 9.40 0.02 TL 401C 7.770 7.7725 0.003 -0.0450 0.827 0.002 0.964 0.002 July 26, 2022 clean3
                                 
IGHQEX3000 C1-08 C2 7.717 9.45 0.02 TL 401C 7.750 7.7335 0.017 -0.0430 0.819 0.002 0.954 0.003 July 26, 2022 initial
IGHQEX3000 C1-09 C3 7.737 9.50 0.05 TL 401C 7.776 7.7565 0.019 -0.0580 0.817 0.005 0.952 0.006 July 26, 2022 initial
IGHQEX3000 C1-10 C4 7.757 9.50 0.03 TL 401C 7.774 7.7655 0.009 -0.0650 0.818 0.003 0.953 0.003 July 26, 2022 initial
                                 
IGHQEX3000 C1-11 D1 7.826 9.66 0.01 TL 401C 7.828 7.8270 0.001 -0.0570 0.810 0.001 0.945 0.001 July 26, 2022 initial
IGHQEX3000 C1-12 D2 7.841 9.51 0.02 TL 401C 7.841 7.8410 0.000 -0.0410 0.825 0.002 0.961 0.002 July 26, 2022 initial
IGHQEX3000 C1-14 D3 7.769 9.55 0.01 TL 401C 7.789 7.7790 0.010 -0.0520 0.815 0.001 0.950 0.002 July 26, 2022 initial
Attachment 1: IMG_1119.JPG
IMG_1119.JPG
Attachment 2: IMG_1120.JPG
IMG_1120.JPG
  430   Wed Jul 27 10:34:30 2022 KojiGeneralGeneralOMC #002 Protective FirstContact Paint

The optical surfaces were coated with FirstContact to keep them clean / somewhat protected during the transportation.
The PD aperture was sealed with FirstContact "caps" (made by Kate in 2016?).

Attachment 1: IMG_1125.JPG
IMG_1125.JPG
  431   Wed Jul 27 23:52:18 2022 KojiGeneralGeneralOMC #002 Cable bracket replacement (1)

Parts check

- D1300052-V3 SN001 is going to be used (Attachment 1)

- This is the PEEK version of the cable bracket (Attachment 2). The side thread holes have no Helicoils inserted. This needs to be done!
 

Connector arrangement check / cable routing check

Attachment 3: Connector Arrangement from the Northside

Attachment 4: Connector Arrangement from the South side

Attachment 5: Cable routing (Northside down)

At this point, the delamination of the V shape beam dumps was visible. This is the subject of bonding reinforcement.

Attachment 1: IMG_1126.JPG
IMG_1126.JPG
Attachment 2: IMG_1135.JPG
IMG_1135.JPG
Attachment 3: IMG_1127.JPG
IMG_1127.JPG
Attachment 4: IMG_1129.JPG
IMG_1129.JPG
Attachment 5: IMG_1130.JPG
IMG_1130.JPG
  432   Thu Jul 28 00:28:15 2022 KojiGeneralGeneral OMC #002 Cable bracket replacement (2)

Connector unmounting

- (Attachment 1) The connector nut rings were removed using an angled needle nose plier. The connector shell has a tight dimension relative to the hole on the bracket. But of course, they could be extracted.

- The 4 screws mounting the bracket to the invar blocks were successfully removed. No extra damage to the bonding.

- (Attachment 2) The plan was to remove the cable pegs by unfastening the button head 1/4-20 screws from the bracket and then just replace the bracket with the new one. However, these screws were really tight. The two were successfully removed without cutting the PEEK cable ties. Two cable ties were necessary to be cut to detach the bracket+pegs from the fragile OMC. Then one screw was removed. However, the final one could not be unfastened. This is not a problem as we are not going to recycle the metal cable bracket... as long as we have spare parts for the new bracket.

- (Attachment 3) Right now, the new bracket is waiting for the helicoils to be inserted. So the OMC lid was closed with the cables piled up. Just be careful when the lid is open.

Attachment 1: IMG_1132.JPG
IMG_1132.JPG
Attachment 2: IMG_1133.JPG
IMG_1133.JPG
Attachment 3: IMG_1136.JPG
IMG_1136.JPG
  433   Thu Jul 28 00:46:47 2022 KojiGeneralGeneral Subject: OMC #002 Cable bracket replacement (3)

Checking the spare parts

- Conclusion for OMC#2: need PEEK cable ties
- for more OMCs: need more BHCS / PEEK cable ties / Helicoils

  • Helicoils: 1/4-20 0.375 helicoils / Qty 4 / Class A (Attachment 1)
    • looks like there are many more as the transport fixture bags (Attachment 2). Stephen noted that they are meant to be CLASS B
       
  • Cable pegs: D1300057 / Qty 24 + 3 recycled from OMC#2 / Class A (Attachment 3)
    • Requirement: 3+3+4 = 10 for the 4th OMC / 3x4 =12 for the cable bracket replacement -> we have enough
       
  • PEEK Cable Ties: Stephen reported they were deformed by baking heat... did not check how they are in the bags.
     
  • Button Head Cap Screws 1/4-20 length ? none found in the bags.
    • Qty 4 spare (forgot to take a picture) + 3 recycled. So we have sufficient for OMC#2
Attachment 1: IMG_1137.JPG
IMG_1137.JPG
Attachment 2: IMG_1148.JPG
IMG_1148.JPG
Attachment 3: IMG_1138.JPG
IMG_1138.JPG
  434   Wed Aug 10 18:42:27 2022 KojiGeneralGeneralOMC #002 Cable bracket replacement (4)

[Stephen Koji]

Now we got the C&Bed parts to continue to work on the cable bracket replacement.

1) Helicoil insertion

1/4-20 Helicoils were inserted into the 6 thread holes of D1300052. It went mostly okay. We witnessed that the Helicoil insertion tool delaminated the plating of the Helicoils upon insertion (Attachment 1). Stephen mentioned that this is not usual, but we didn't find anything further such as increased friction, more debris, etc. So we decided to go forward.

2) EP30-2 Kit

The EP30-2 kit was transferred from the 40m clean room to the OMC lab. The EP30-2 kit tracking was updated via C1900343

3) D1300052 reinstallation -> FAIL

Now resumed to the installation of D1300052 bracket. However, the hole size of the bracket is just a bit too small compared with the size of the mighty mouse connectors. It was already quite tight with the metal version. However, this PEEK version seems to have 0.1 mm further small diameter, and then the connectors do not penetrate the holes. The plan could be
1) Use a razor blade to shave the hole inner circle.
2) Use a cleaned drill bit to make the hole size 0.2mm bigger.

Attachment 1: PXL_20220809_235457354.jpg
PXL_20220809_235457354.jpg
Attachment 2: PXL_20220811_011910569.jpg
PXL_20220811_011910569.jpg
Attachment 3: PXL_20220811_013746139.jpg
PXL_20220811_013746139.jpg
  435   Thu Aug 11 15:24:57 2022 KojiGeneralGeneralOMC #002 Cable bracket replacement (5)

- The hole size extension is going forwared now.

- Madeline and Chub are cleaning (sonicating) a drill (29/64=0.4531")
- The parts in a bag were brought to the 40m C&B lab.

- The hole is going to be 11mil=0.28mm larger than the recommendation (0.442").
  It's not a D-hole. The connector has a rounded-rectangular flange that fits into the PEEK parts.
  So I don't think it's an issue.

- Chub has a proper spanner to fasten the nuts. We want to use it here and LLO.

 

  436   Mon Aug 15 21:31:56 2022 KojiGeneralGeneralOMC #002 Cable bracket replacement (6)

The cable bracket was successfully replaced.

  • Looking from the QPD side (North side in Attachment 1), the connectors for the DCPDs and PZT are sticking out, and the ones for QPDs are sticking to the other side. So only two rectangular holes (for QPDs) are facing north.
    • Top left is DCPDT
    • Top right is DCPDR
    • Bottom center is PZT
    • Bottom left is QPD (far/long)
    • Bottom right is QPD (near/short)
       
  • First, the cable pegs for the short sides are fastened with the original screws (Vented BHCS 1/4-20).
  • Then, the cables are started to be inserted from the bottom so that the nuts can be rotated with the spanner. The spanner helped a bit but the nut only has two positions to hook the spanner and the clearance is not sufficient to insert the spanner when one of the hook positions is facing the bottom. The enlarged hole (29/64") perfectly worked . The flange of the connector can be held with a rectangular hole, so a bit bigger hole than the connector size was not an issue. Finally, all the cables were attached to the bracket.
  • The bracket has not yet been fixed on the OMC breadboard yet. This was done with the four screws from the top. Along with the assembly document E1300201, the fastening torque was limited to 2 in-lb using a digital torque wrench.
  • Attachment 2 shows the view from the "North" side. Attachment 3 shows the view from the "South" side. The cables were not yet tied on the cable pegs on the long side of the bracket.
Attachment 1: IMG_1155.JPG
IMG_1155.JPG
Attachment 2: IMG_1149.JPG
IMG_1149.JPG
Attachment 3: IMG_1150.JPG
IMG_1150.JPG
  437   Mon Aug 15 22:06:18 2022 KojiGeneralGeneralOMC #002 new cable tie installed

[Stephen Koji]

New cable ties were installed on the cable pegs attached to the long sides of the cable bracket.

 

Attachment 1: IMG_1929.JPG
IMG_1929.JPG
Attachment 2: IMG_1930.JPG
IMG_1930.JPG
  438   Mon Aug 15 22:43:35 2022 KojiGeneralGeneralOMC #002 Delamination repair Part1 (1)

[Stephen Koji]

Checked the delamination status:

  • The Invar bar on the cable bracket (DCPD side): Almost all delaminated (Attachment 1 left)
  • The invar bar on the cable bracket (QPD side): Rims still intact, center delaminated (Attachment 1 right)
  • The invar bar reinforced in 2016: One of the reinforcement bar half delaminated (Attachment 2)
Attachment 1: IMG_1926.JPG
IMG_1926.JPG
Attachment 2: PXL_20220816_011346581.jpg
PXL_20220816_011346581.jpg
  439   Mon Aug 15 22:49:03 2022 KojiGeneralGeneralOMC #002 Delamination repair Part1 (2)

EP30-2 preparation

  • Two Al foil cups + A sheet of Al foil (for test cure)
  • Set a tube on the glue gun
  • Attach an applicator tube
  • Push a couple of times, and dispense the glue for a single stroke on a waste Al cup
  • Pour the 6g of glue to the other cup.
  • Add 0.3g of silica beads powder to the cup
  • Steer. Pick a few drops to the test cure Al foil
  • Bake the test piece for 15min in 200F (95degC) ==> Very good

#1 The Invar bar on the cable bracket (DCPD side)

Added short (frosted) Al bars (Attachment 1) to the short sides of the invar bar. (Attachments 2/3). Some glue was sucked into the delamination gap by capillary action (=good) (Attachment 4)

#2 The Invar bar on the cable bracket (QPD side)

Added short (frosted) Al bars to the short sides of the invar bar. (Attachments 3/5). Maybe some glue was sucked into the delamination gap??? Not so clear. (Attachment 4)

#3 The Invar bar reinforced in 2016

Added a short (frosted) Al bars to a short side of the invar bar (Attachment 6). On both sides of the 2016 reinforcement, rectangular prisms are added (Attachment 6)
Some capillary action is visible beneath the invar bar (Attachment 7)


Leave it as it is for a day

 

Attachment 1: PXL_20220816_011256007.jpg
PXL_20220816_011256007.jpg
Attachment 2: PXL_20220816_020441901.MP.jpg
PXL_20220816_020441901.MP.jpg
Attachment 3: PXL_20220816_022033189.jpg
PXL_20220816_022033189.jpg
Attachment 4: PXL_20220816_022234784.jpg
PXL_20220816_022234784.jpg
Attachment 5: PXL_20220816_020415355.jpg
PXL_20220816_020415355.jpg
Attachment 6: PXL_20220816_022108122.jpg
PXL_20220816_022108122.jpg
Attachment 7: PXL_20220816_022244417.jpg
PXL_20220816_022244417.jpg
  440   Wed Aug 24 02:51:23 2022 KojiGeneralGeneralOMC #002 Delamination repair Part1 (3)

Inspection of the bonding on the suspension interface side. All look good.

Attachment 1: IMG_1156.JPG
IMG_1156.JPG
Attachment 2: IMG_1157.JPG
IMG_1157.JPG
Attachment 3: IMG_1158.JPG
IMG_1158.JPG
Attachment 4: IMG_1159.JPG
IMG_1159.JPG
Attachment 5: IMG_1160.JPG
IMG_1160.JPG
Attachment 6: IMG_1161.JPG
IMG_1161.JPG
Attachment 7: IMG_1162.JPG
IMG_1162.JPG
Attachment 8: IMG_1163.JPG
IMG_1163.JPG
  441   Wed Aug 24 02:53:46 2022 KojiGeneralGeneralOMC #002 Delamination repair Part2 (1)

Inspection of the delaminations in the optics side

Attachment 1: IMG_1168.JPG
IMG_1168.JPG
Attachment 2: IMG_1169.JPG
IMG_1169.JPG
Attachment 3: IMG_1170.JPG
IMG_1170.JPG
Attachment 4: IMG_1171.JPG
IMG_1171.JPG
Attachment 5: IMG_1175.JPG
IMG_1175.JPG
  442   Wed Aug 24 02:57:43 2022 KojiGeneralGeneralEP30-2 bonding setup

EP30-2 bonding setup

Attachment 1: IMG_1178.JPG
IMG_1178.JPG
Attachment 2: IMG_1179.JPG
IMG_1179.JPG
Attachment 3: IMG_1180.JPG
IMG_1180.JPG
  443   Wed Aug 24 03:20:59 2022 KojiGeneralGeneralOMC #002 Delamination repair Part2 (2)

Bonding

Attachment 1: IMG_1182.JPG
IMG_1182.JPG
Attachment 2: IMG_1183.JPG
IMG_1183.JPG
Attachment 3: IMG_1184.JPG
IMG_1184.JPG
Attachment 4: IMG_1185.JPG
IMG_1185.JPG
Attachment 5: IMG_1186.JPG
IMG_1186.JPG
Attachment 6: IMG_1187.JPG
IMG_1187.JPG
Attachment 7: IMG_1188.JPG
IMG_1188.JPG
Attachment 8: IMG_1189.JPG
IMG_1189.JPG
Attachment 9: IMG_1190.JPG
IMG_1190.JPG
Attachment 10: IMG_1191.JPG
IMG_1191.JPG
Attachment 11: IMG_1193.JPG
IMG_1193.JPG
  444   Wed Aug 24 03:26:43 2022 KojiGeneralGeneralOMC #002 Delamination repair Part2 (3)

Inspection

 

Attachment 1: IMG_1199.JPG
IMG_1199.JPG
Attachment 2: IMG_1200.JPG
IMG_1200.JPG
Attachment 3: IMG_1201.JPG
IMG_1201.JPG
Attachment 4: IMG_1202.JPG
IMG_1202.JPG
Attachment 5: IMG_1203.JPG
IMG_1203.JPG
Attachment 6: IMG_1204.JPG
IMG_1204.JPG
Attachment 7: IMG_1205.JPG
IMG_1205.JPG
Attachment 8: IMG_1206.JPG
IMG_1206.JPG
  445   Wed Aug 24 11:29:47 2022 KojiGeneralGeneralOMC #002 ready for shipment

[Stephen Koji]

The OMC #002 is ready for shipment.

Attachment 1: Work done on Sept 19, 2022

Other attachments: Putting the OMC in the pelican case.

Attachment 1: IMG_1207.JPG
IMG_1207.JPG
Attachment 2: PXL_20220825_004259850.jpg
PXL_20220825_004259850.jpg
Attachment 3: PXL_20220825_004307204.jpg
PXL_20220825_004307204.jpg
Attachment 4: PXL_20220825_005423342.jpg
PXL_20220825_005423342.jpg
Attachment 5: PXL_20220825_005549985.jpg
PXL_20220825_005549985.jpg
  446   Thu Aug 25 14:22:08 2022 KojiGeneralGeneralLLO OMC #001 Ballast Mass investigation

Inspected the past LLO add-on mass configuration.

There are unknown masses at the DCPD side. It looks like a small SS mass with an estimated mass of 5g. But the DCC number is unknown.

We are going to add 10g on each corner as well as the damping aterial. We should be able to figure out the fastener / mass configuration.

Attachment 1: DSCN0917.JPG
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Attachment 2: DSCN0922.JPG
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Attachment 3: P6108705.JPG
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Attachment 5: P6108706.JPG
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  447   Thu Aug 25 20:05:00 2022 KojiGeneralGeneralLLO OMC #001 Ballast Mass investigation

Here is the balance mass info for the LLO OMC#001 analyzed from the photographs

  • Added masses are: 50+10g, 50+20, 10+20+5, and 20+20+10 for the mass right above FM1/CM1/FM2 and CM2, respectively.
  • The length of the 1/4-20 screws seem L=3/4"~1"

If we attach the additional mass, longer 1/4-20 screws (1", 1" 1/8, 1" 1/4) are going to be used.

Attachment 1: balance_mass_config_LLO.pdf
balance_mass_config_LLO.pdf
  448   Fri Aug 26 22:29:02 2022 KojiGeneralGeneralTool Shipping Prep

Shipping preparation for the LLO trip

Started July 15, 2022 and finished Aug 30. So it took ~1.5 months (with a couple weeks of break)


Class B special tools

  • Screw Drivers 1
    • https://www.steritool.com/
    • https://www.steritool.com/precision-screwdrivers-mini.aspx
  • Screw Drivers 2
    • What I have seems S555Z-7
    • https://www.starrett.com/
    • https://www.starrett.com/dms/flipbooks/Cat-33/index.html?page=354
  • Allen Wrenches
    • Bondhus: These are not made of SS, but of so called protanium steel. I have a chrome finish one (BriteGuard) and K14 gold finish one (goldguard).
    • https://intl.bondhus.com/pages/goldguard-ball-end
    • https://intl.bondhus.com/pages/briteguard-ball-end
  • Scissors
    • VWR - Stainless Steel
    • Unknown PN /  probably this?
    • https://us.vwr.com/store/product/4527635/vwr-dissecting-scissors-sharp-blunt-tip
  • Forceps
    • VWR - Stainless Steel
    • https://us.vwr.com/store/product/4531765/vwr-hemostatic-forceps
  • Wire cutters
    • Looks like they are orthodontic wire cutters. One has the marking "Orthomechanic Stainless Steel" but the company does not sell cutters anymore. The other has a marking "333" but the company is unknown. Similar products can be found on Amazon
  • Long nose pliers - straight stainless steel
    • https://www.aventools.com/
    • https://www.aventools.com/long-nose-pliers-stainless-steel-6-2
  • Bent nose pliers - stainless steel
    • unknown 
  • Tweezers
    • Excelta 
    • The short one is 20A-S-SE. The longer one is 24-SA-PI, maybe?
    • https://www.excelta.com/
    • https://www.excelta.com/straight-laboratory-instruments-forceps
    • https://www.excelta.com/style-24-24-6-sa
  • Mighty-Mouse spanner
  • 2x driver bits for the digital torque wrench

First Contact Kit

  • FC bottole / PEEK mesh

Bonding kit (excl EP30-2 bond)

  • reinforcement bars (4 types)
  • bonding liner powder
  • tools: spatula / bond applying rod

Power meters (excl Power meter controller)

  • Thorlabs Thermal
  • Thorlabs Photodiode
  • Thorlabs Integrating Sphere

Electronics

  • preamp + power cable
  • PD testing kit (PD connector / DB9 break out / grabber-BNC)
  • Nitrile gloves

Cable bracket replacement kit

  • PEEK cable bracket (Helicoiled)
  • Cable pegs (x4 salvaged / spare)
  • fastners
  • kapton sheet
  • cable ties

Optics / Optomechanics

  • Optical fiber / spare fiber
  • OMC transport feet
  • OMC backscatter inspection prisms

Misc tools

  • digital torque wrench

=== Action done on Aug 30 ===

Fiber MM setup / Fiber coupler mount
Glass Beamdumps (for optical testing)
Flipper mirror
Thorlabs fiber coupler tool
General bent nose plier for fiber
Thorlabs collimator tiny allen
Spare High QE PDs

Spare OMC bags / Zip bags

Balance Mass 10g Qty 8 (Different Type D11*** 1.25" dia), 20g Qty 10 / Mass damper D1700301 -04 / Mass damper screws SHCS 1/4-20 x 1.25 Qty 25 / 1" screws and 1 1/8" screws

Shipping request: https://services1.ligo-la.caltech.edu/FRS/show_bug.cgi?id=25002


=== Low supply! ===

  • Masks
  • 7.0 gloves supply low
  • 7.5 glove completely gone
  • Wet vectra cloth
  • Dry vectra cloth
Attachment 1: PXL_20220831_025623318.jpg
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Attachment 3: PXL_20220831_030234581.jpg
PXL_20220831_030234581.jpg
  449   Tue Sep 20 08:54:33 2022 KojiGeneralGeneralPD cage arrangement

Upon the LLO work, the current PD arrangement in the cages are:
CAGE B
B1 OMC1 PDT (A1-23)
B2 OMC1 PDR (A1-25)
B3 original (C1-03)
B4 OMC2 PDT (B1-22)

CAGE C
C1 OMC2 PDR (B1-23)
C2 original (C1-08)
C3 original (C1-09)
C4 original (C1-10)

  450   Mon Sep 26 14:27:49 2022 KojiGeneralGeneralLLO OMC ICS work

OMC #001

OMC #002

  3   Wed Jun 20 00:10:53 2012 KojiFacilityGeneralHole on the wall was patched

P6191706.jpg

  14   Wed Aug 1 19:35:00 2012 KojiFacilityGeneralFloor cleaned / Workbench being built / Table top defect

- The floor of the room was cleaned and waxed!

- Sticky mats are placed! Now we require shoe covers!

P8011949.JPG

- Work benches are being built. One unit is done.

P8011948.JPG

- The other is half done because the table top has chippings.

P8011947.JPG

  15   Sat Aug 11 00:59:14 2012 KojiFacilityGeneralLaser Safety Barrier

It seemed that a laser safety barrier was installed today!?

P8131960.JPG

 

  19   Wed Aug 22 20:16:43 2012 KojiFacilityGeneralWorkbenches have been installed / Clean room stools

Last Friday, new workbenches were installed. Vladimir got a new table and a cleanroom stool.

P8171968.jpg

The other two workbenches were also nicely set.

P8171969.jpg

  46   Wed Dec 26 14:33:33 2012 KojiFacilityGeneralLase Interlock wired

Two switches are connected in series.

Attachment 1: PC263073.jpg
PC263073.jpg
Attachment 2: PC263074.jpg
PC263074.jpg
Attachment 3: PC263075.jpg
PC263075.jpg
  57   Tue Jan 22 11:10:25 2013 KojiFacilityGeneralEyeware storage and hooks for the face shields are installed

A carpenter has come to install the eyeware storage and hooks for the face shields.

Attachment 1: P1223116.JPG
P1223116.JPG
  75   Sat Mar 23 02:32:23 2013 KojiFacilityGeneralN2 cylinder delivered

Preparation for ionized N2 blow

- 99.9998% N2 cylinder delivered (ALPHAGAZ 2 grade by AIR LIQUIDE) ALPHAGAZ 2 [PDF]

- Filter and Arcing module already in the lab

- A brass regulator to be installed (Done - March 24)

- 50 ft air line already in the lab / needs to be wiped/rinsed (Done - March 24)

- Air line and filter installed (Done - March 24)

Attachment 1: P3233349.jpg
P3233349.jpg
  288   Fri Sep 8 15:14:05 2017 KojiFacilityGeneralPreparation for the plumbing work

[Steve, Aaron, Koji]

We've finished the preparation for the forthcoming plumbing work on (nominally) Sept 16th Saturday.
We've covered most of the west side of the OMC lab with plastic sheets and wraps.

Some tips:

  • The plastic sheets Eric gave us were a bit too thin and pron to got torn. Thicker sheets are preferable.
  • The blue tape that Eric gave us was very useful.
  • The stretch wrap film, which I bought long time ago, was so useful. Office Depot "Office Depot(R) Brand Stretch Wrap Film, 20 x 1000 Roll, Clear" PN: 445013
  • We also used patches of Kitchen Trash Bags to cover some small opening of the large sheets. Office Depot "Glad(R) Tall Kitchen Trash Bags, 13 Gallon, White, Box Of 28" PN 269268
Attachment 1: DSC_0405.jpg
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Attachment 7: DSC_0411.jpg
DSC_0411.jpg
  391   Mon Aug 10 15:34:04 2020 KojiFacilityLoan / LendingGlue bake oven

Black and Decker Glue Baking Oven came back to the OMC lab on Aug 10, 2020, Georgia had lent the unit for the SAMS assembly/testing.

  412   Thu Jun 23 21:03:33 2022 KojiFacilityGeneralMoving the small optical table to CAML (TCS Lab)

I've cleared the small optical table and wondered how to move it out of the room. Fortunately, the north side of the big table had wide enough clearance and let the 36" wide table go through. This was easy without moving other heavy stuff.

From here to the door, a bit of work is required. A possibility is to roll the laser blocking wall to the south side of the big table. This will require moving the shelving in the entrance area but it's not a lot of work compared to disassembling a part of the wall.

If this does not work somehow, we will consider removing the last panel of the wall and it will definitely allow the table to get out from the door.

Attachment 1: PXL_20220624_035628602.jpg
PXL_20220624_035628602.jpg
  25   Tue Oct 9 05:03:15 2012 KojiElectronicsGeneralOMC Test Electronics Setup

electronics_setup.png

Attachment 2: electronics_setup.pdf
electronics_setup.pdf
  36   Thu Nov 8 19:47:55 2012 KojiElectronicsConfigurationSolder for PZTs

Rich saids:

I have ordered a small roll of solder for the OMC piezos. 
The alloy is: Sn96.5 Ag3.0 Cu0.5

  72   Fri Mar 15 02:15:45 2013 KojiElectronicsCharacterizationDiode testing

Diode testing

o Purpose of the measurement

- Test Si QPDs (C30845EH) for ISC QPDs Qty 30 (i.e. 120 elements)

- Test InGaAs PDs (C30665GH) for OMC Qty 10 (i.e. 10 elements)

o Measurement Kit

- Inherited from Frank.

- Has relays in it.

- D0 and D1 switches the measurement instrument connected to an element

- D2 and D3 switches the element of the QPDs

- Digital switch summary

d0 d1 0 0 - ln preamp
d0 d1 1 0 - dark c
d0 d1 0 1 - omc preamp
d0 d1 1 1 - impedance

d2 d3 0 0 - A x x x
d2 d3 1 0 - C x o x
d2 d3 0 1 - B o x o
d2 d3 1 1 - D o o o

- The universal board in the box is currently configured for C30845.
  Pin1 - Elem A. Pin3 - B, Pin7 - C, Pin9 - D, Pin 12 - Case&Bias

o Labview interface

- Controls NI-USB-6009 USB DAQ interface and Agilent 82357B USB-GPIB interface

o Dark current measurement

- Borrowed Peter's source meter KEITHLEY 2635A

- For C30845GH the maxmum reverse bias is set to -20V. This drops the voltage of the each element to the bias voltage.

o Spectrum measurement

- The elements are connected to FEMTO LN current amp DLPCA-200.

- Bias voltage is set to +10V. This lifts up the outside of the amplifier input to +10V.

 

o Impedance measurement

- Agilent 4395A at PSL lab with impedance measurement kit

- For C30845GH the maxmum reverse bias is set to -15V. This drops the voltage of the each element to the bias voltage.

- Calibration: open - unplug the diode from the socket, short - use a piece of resister lead, 50Ohm - a thin metal resister 51Ohm

- Freq range: 30-50MHz where the response of the cables in the setup is mostly flat.

- Labview VI is configured to read the equivalent circuit parameters in the configuration "D" (series LCR).

- Labview fails to read the series resistance. This was solved by first read the equiv circuit param and then read it with Sim F-CHRST.
  F-CHRST does nothing on the parameters so the second request successfully acquires the first ones.

 

Attachment 1: QPD_GR_TEST_130316.pdf
QPD_GR_TEST_130316.pdf QPD_GR_TEST_130316.pdf QPD_GR_TEST_130316.pdf QPD_GR_TEST_130316.pdf QPD_GR_TEST_130316.pdf QPD_GR_TEST_130316.pdf QPD_GR_TEST_130316.pdf QPD_GR_TEST_130316.pdf
  73   Sun Mar 17 21:59:47 2013 KojiElectronicsCharacterizationDiode testing ~ DCPD

- For the dark noise measurement, the lid of the die-cast case should also contact to the box for better shielding. This made the 60Hz lines almost completely removed, although unknown 1kHz harmonics remains.

- The precise impedance of the setup can not be obtained from the measurement box; the cable in between is too long. The diode impedance should be measured with the impedance measurement kit.

- With the impedance measurement kit, the bias voltage of +5V should be used, in stead of -5V.

- diode characteristics measured at 10-100MHz

- Typical impedance characteristics of the diodes

Excelitas (Perkin-Elmer) C30665GH Rs=9Ohm, Cd=220pF, L=0~1nH (Vr=5V)

Excelitas (Perkin-Elmer) C30642G Rs=12Ohm, Cd=100pF, L=~5nH (Vr=5V) longer thin wire in a can?

Excelitas (Perkin-Elmer) C30641GH Rs=8Ohm, Cd=26pF, L=12nH (Vr=5V) leg inductance? (leg ~30mm)

- PD serial

C30665GH, Ls ~ 1nH

  1 - 0782 from PK, Rs=8.3Ohm, Cd=219.9pF
  2 - 1139 from PK, Rs=9.9Ohm, Cd=214.3pF
  3 - 0793 from PK, Rs=8.5Ohm, Cd=212.8pF
  4 - 0732 from PK, Rs=7.4Ohm, Cd=214.1pF
  5 - 0791 from PK, Rs=8.4Ohm, Cd=209.9pF
  6 - 0792 from PK, Rs=8.0Ohm, Cd=219.0pF
  7 - 0787 from PK, Rs=9.0Ohm, Cd=197.1pF
  8 - 0790 from PK, Rs=8.4Ohm, Cd=213.1pF
  9 - 0781 from PK, Rs=8.2Ohm, Cd=216.9pF
10 - 0784 from PK, Rs=8.2Ohm, Cd=220.0pF
11 - 1213 from the 40m, Rs=10.0Ohm, Cd=212.9pF
12 - 1208 from the 40m, Rs=9.9Ohm, Cd=216.8pF
13 - 1209 from the 40m, Rs=10.0Ohm, Cd=217.5pF

C30642G, Ls ~ 12nH

20 - 2484 from the 40m EG&G, Rs=12.0Ohm, Cd=99.1pF
21 - 2487 from the 40m EG&G, Rs=14.2Ohm, Cd=109.1pF
22 - 2475 from the 40m EG&G glass crack, Rs=13.5Ohm, Cd=91.6pF
23 - 6367 from the 40m ?, Rs=9.99Ohm, Cd=134.7pF
24 - 1559 from the 40m Perkin-Elmer GH, Rs=8.37Ohm, Cd=94.5pF
25 - 1564 from the 40m Perkin-Elmer GH, Rs=7.73Ohm, Cd=94.5pF
26 - 1565 from the 40m Perkin-Elmer GH, Rs=8.22Ohm, Cd=95.6pF
27 - 1566 from the 40m Perkin-Elmer GH, Rs=8.25Ohm, Cd=94.9pF
28 - 1568 from the 40m Perkin-Elmer GH, Rs=7.83Ohm, Cd=94.9pF
29 - 1575 from the 40m Perkin-Elmer GH, Rs=8.32Ohm, Cd=100.5pF

C30641GH, Perkin Elmer, Ls ~ 12nH

30 - 8983 from the 40m Perkin-Elmer, Rs=8.19Ohm, Cd=25.8pF
31 - 8984 from the 40m Perkin-Elmer, Rs=8.39Ohm, Cd=25.7pF
32 - 8985 from the 40m Perkin-Elmer, Rs=8.60Ohm, Cd=25.2pF
33 - 8996 from the 40m Perkin-Elmer, Rs=8.02Ohm, Cd=25.7pF
34 - 8997 from the 40m Perkin-Elmer, Rs=8.35Ohm, Cd=25.8pF
35 - 8998 from the 40m Perkin-Elmer, Rs=7.89Ohm, Cd=25.5pF
36 - 9000 from the 40m Perkin-Elmer, Rs=8.17Ohm, Cd=25.7pF

 

Note:
  1mm Au wire with dia. 10um -> 1nH, 0.3 Ohm
20mm BeCu wire with dia. 460um -> 18nH, 0.01 Ohm

Attachment 1: OMCPD_TEST_130317.pdf
OMCPD_TEST_130317.pdf OMCPD_TEST_130317.pdf OMCPD_TEST_130317.pdf OMCPD_TEST_130317.pdf OMCPD_TEST_130317.pdf OMCPD_TEST_130317.pdf OMCPD_TEST_130317.pdf OMCPD_TEST_130317.pdf
  78   Sat Mar 23 16:36:15 2013 KojiElectronicsCharacterizationDiode QE measurement

Quantum efficiencies of the C30665GH diodes were measured. 

- The diode was biased by the FEMTO preamplifier.

- Diode Pin 1 Signal, Pin 2 +5V, Pin 3 open

- Preamp gain 10^3 V/A

- Beam power was measured by the thorlabs power meter.

 

PD #1
Incident: 12.82 +/- 0.02 mW
Vout: 9.161 +/- 0.0005 V
PD Reflection (Prompt): 0.404 mW
PD Reflection (Total): 1.168 mW

PD #2
Incident: 12.73 +/- 0.02 mW
Vout: 9.457 +/- 0.0005 V
PD Reflection (Prompt): 0.364 mW
PD Reflection (Total): 0.937 mW

PD #3
Incident: 12.67 +/- 0.02 mW
Vout: 9.1139 +/- 0.01 V
PD Reflection (Prompt): 0.383 mW
PD Reflection (Total): 1.272 mW

PD #4
Incident: 12.71 +/- 0.02 mW
Vout: 9.3065 +/- 0.0005 V
PD Reflection (Prompt): 0.393 mW
PD Reflection (Total): 1.033 mW

PD #5
Incident: 12.69 +/- 0.02 mW
Vout: 9.1071 +/- 0.005 V
PD Reflection (Prompt): 0.401 mW
PD Reflection (Total): 1.183 mW

PD #6
Incident: 12.65 +/- 0.02 mW
Vout: 9.0310 +/- 0.01 V
PD Reflection (Prompt): 0.395 mW
PD Reflection (Total): 1.306 mW

PD #7
Incident: 12.67 +/- 0.02 mW
Vout: 9.0590 +/- 0.0005 V
PD Reflection (Prompt): 0.411 mW
PD Reflection (Total): 1.376 mW

PD #8
Incident: 12.63 +/- 0.01 mW
Vout: 9.0790 +/- 0.0005 V
PD Reflection (Prompt): 0.420 mW
PD Reflection (Total): 1.295 mW

PD #9
Incident: 12.67 +/- 0.02 mW
Vout: 9.2075 +/- 0.0005 V
PD Reflection (Prompt): 0.384 mW
PD Reflection (Total): 1.091 mW

PD #10
Incident: 12.70 +/- 0.01 mW
Vout: 9.0880 +/- 0.001 V
PD Reflection (Prompt): 0.414 mW
PD Reflection (Total): 1.304 mW

PD #11
Incident: 12.64 +/- 0.01 mW
Vout: 9.2861 +/- 0.0005 V
PD Reflection (Prompt): 0.416 mW
PD Reflection (Total): 1.152 mW

PD #12
Incident: 12.68 +/- 0.02 mW
Vout: 9.3650 +/- 0.001 V
PD Reflection (Prompt): 0.419 mW
PD Reflection (Total): 1.057 mW

PD #13
Incident: 12.89 +/- 0.01 mW
Vout: 9.3861 +/- 0.001 V
PD Reflection (Prompt): 0.410 mW
PD Reflection (Total): 1.047 mW

 

PD serial number
 1 - 0782
 2 - 1139
 3 - 0793
 4 - 0732
 5 - 0791
 6 - 0792
 7 - 0787
 8 - 0790
 9 - 0781
10 - 0784
11 - 1213
12 - 1208
13 - 1209

 

{
  {1, 12.82, 9.161, 0.404, 1.168},
  {2, 12.73 , 9.457, 0.364 , 0.937} ,
  {3, 12.67 , 9.1139, 0.383 , 1.272 },
  {4, 12.71 , 9.3065, 0.393 , 1.033 },
  {5, 12.69, 9.1071, 0.401 , 1.183 },
  {6, 12.65, 9.0310, 0.395 , 1.306} ,
  {7, 12.67, 9.0590, 0.411 , 1.376} ,
  {8, 12.63 , 9.0790, 0.420 , 1.295} ,
  {9, 12.67 , 9.2075, 0.384 , 1.091} ,
  {10, 12.70, 9.0880, 0.414 , 1.304 },
  {11, 12.64 , 9.2861, 0.416 , 1.152} ,
  {12, 12.68 , 9.3650, 0.419 , 1.057} ,
  {13, 12.89 , 9.3861, 0.410 , 1.047}
};

Attachment 1: P3213308.JPG
P3213308.JPG
Attachment 2: P3213310.JPG
P3213310.JPG
  131   Thu May 30 14:38:42 2013 KojiElectronicsGeneralCable fitting

Yesterday Jeff and Chub worked on the cabling of the OMC. It turned out that the gender of the cable connectors
going from the cavity side to the connector bracket on top of the OMC were opposite from what is needed. 
This way, the connectors can't fixed on the cable harness, thus they are free during the shipping.

We considered several ideas to mitigate this issue and decided to swap the gender of the Mighty Mouse connectors.

In order to check this operation may cause the shortage of the cable length, we made the fitting of the cables.
They seem all long enough for Chub to replace the Mighty Mouse connectors with the proper gender. 

We also checked the polarity of the PZT wires. We marked the positive side of the PZT by a knot at the wire end.

  156   Thu Aug 22 15:40:15 2013 KojiElectronicsConfigurationPZT endurance test

[Koji, Jeff]

Background

In response to the failure of one of the PZTs on L1OMC (LLO:8366), we have been taking place an endurance test of
the four PZT sub-assemblies in prior to their being glued on the glass breadboard.

According to the technical note by Noliac, the common mode of PZT failure is degradation of the impedance
due to cyclic actuation (like 10^7 times) with over voltage. Therefore our procedure of the test to actuate the PZTs
at least 10^7 times with half voltage of the nominal operating voltage (i.e. nominal 200V) and check the degradation
of the impedance.

Driving signal

For the driving of the PZT, a thorlabs HV amp is used. A source signal of 3.5Vpp with an offset of 1.7V is produced
by DS345 function generator. This signal turns to a sinusoidal signal between 0 and 100V in conjunction with the gain
of 15 at the HV amp.

The maximum driving frequency is determined by the current supply limit of the HV amp (60mA). The capacitance
of each PZT is 0.47uF. If we decide to cycle the signal for 4 PZTs in parallel, the maximum frequency achievable
without inducing voltage drop is 100Hz. This yields the test period of 28hours in order to achive 10^7 cycles.

P8214340.jpg

Initial impedance diagnosis

To check the initial state of the PZTs, a DC voltage of 100V was applied via 1kOhm output resistance.
(Note that this output resistance is used only for the impedance test.)
For each PZTs, both side of the resister showed 99.1V for all measurement by a digital multimeter.
Assuming the minimum resolution (0.1V) of the multimeter, the resistance of each PZT was more than 1MOhm before
the cycling test.

Failure detection

In order to detect any impedance drop of the PZTs, the driving signal is monitored on the oscilloscope via a 1:10 probe.
If there is any significant impedance drop, the driver can't provide the driving current correctly. This can be found
by the deviation of the driving voltage from the reference trace on the oscilloscope (below).

P8214337.jpg

Temperature rise

Because of the loss angle of the PZT capacitance, heating of the PZTs is expected. In order to check the temperature rise,
an IR Viewer (FLIR) was used. We did not take care of careful calibration for the PZT emissibity as what we want was a
rough estimation of the temperature.

Before the driving (LEFT) and at the equilibrium (RIGHT)
IR_0457.jpg
IR_0461.jpg

The temperature change of the PZT was tracked for an hour (below). Fitting of the points indicated that the temperature rise is 2.3degC and the
time constant of 446 sec. This level of temperature rise is totally OK. (Note that the fitting function was T = 27.55 - 2.31 Exp[-t/446.])

 

Results

DAY1:

Start driving
20:27 25.2 degC, status OK
20:33 26.7 degC, status OK
20:41 26.9 degC, status OK
20:48 27.6 degC, status OK
20:54 27.4 degC, status OK
21:10 27.4 degC, status OK
21:37 status OK
Stop driving

70 minutes of driving (i.e. 4.2x10^5 cycles) => no sign of degradation

DAY2:

Start driving
14:15, 24.5 degC, status OK
14:17, 26.0 degC, status OK
14:24, 27.0 degC, status OK
14:40, 26.8 degC, status OK
14:50, 26.8 degC, status OK
15:30, 26.8 degC, status OK
15:55 status OK
17:40 status OK
21:00 status OK (2.43Mcycles + 0.42Mcycles = 2.85Mcycles)
1d+12:00 status OK (7.83Mcycles + 0.42Mcycles = 8.25Mcycles)
1d+15:00 status OK (8.91Mcycles + 0.42Mcycles = 9.33Mcycles)
1d+18:40 status OK (10.23Mcycles + 0.42Mcycles = 10.65Mcycles)
Stop Driving

After 10.65Mcycles no sign of degradationwas found.

  157   Fri Aug 23 19:24:32 2013 KojiElectronicsConfigurationPZT endurance test (II)

The PZT tests were finished with the conclusion that the PZT won't be damaged with our expected usage.


This is another test of the PZTs to make sure small (~10V) reverse voltage does not break the PZTs.

Background

At the site, we decided to use one of the PZT, which is still alive, for the HV and LV actuation.
The HV actuation is limited to 0 to 100V while the LV actuation is 10Vdc with 1Vpp fast dithering.
This means that a reverse voltage upto 10.5V will be applied to the PZT at the worst case.

From the technical note this level of reverse voltage does not induce polarization of the PZT.
The test is to ensure the PZT is not damaged or degraded by this small reverse voltage.

Method

HV drive: Thorlabs HV amp (G=15) driven with DS345 function generator (3.5Vpp+1.7Vdc, 0.1Hz)
=> 0-100V @0.1Hz
=> The hot side of the potential is connected to the positive side of the PZT

LV drive: Phillips function generator (1Vpp+9.5Vdc@1kHz)
The driving frequency is limited by the current output of the function generator.
=> The hot side of the potential is connected to the negative side of the PZT

These drives shares the common ground.

Tests

Testing with spare PZTs 

Started @19:23 (Aug 23)
Stopped @20:15+2d (Aug 25, duration 48h52m)
17600cycles for the 0.1Hz drive.
176Mcycles for the 1kHz drive.

Checked the impedances of PZT1 and PZT2.

Apply 100Vdc via a 1kOhm resister, 0V detected across the 1kOhm resister
This is equivalent to the resistance of 1MOhm.

 

Testing with the PZT subassemblies

Started shaking of the four PZT assemblies @20:20 (Aug 25)
No impedance change observed @11:10+1d
No impedance change observed @15:30+1d
Stopped shaking of the four PZT assemblies @XXXX (Aug 26)

 

Wiring for the test

PZT_shaking.png

 

 

  203   Thu Jul 10 01:39:38 2014 KojiElectronicsGeneralPZT wire

Rich came to the OMC lab. Pins for the mighty mouse connector were crimped on the 4 PZT wires.
We found the male 4pin mighty mouse connector in the C&B area.

The cable inventory was checked with ICS/DCC combo. It turned out that most of the on-board cables
are at LHO. We decided to send the OMC there and then the cables are installed at the site.

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