Restimation of the parameters

Camille and I went back to the lab to re-measure the beam profile follwoing the beam expanding lenses. I was observed after turning on the laser that the beam spot on  the turning mirror had displaced off to the mirror edge. We had to re-align the beam.

We have the following parameters from the fitting now, see attached.

w_0x: 1.44 mm +/- 0.0016 mm 
z_0x: 0.575 m +/- 0.046 m
w_0y: 1.50 mm +/- 0.0014 mm
z_0y: 0.004 m +/- 0.029 m

For the p - plane:

Beam waist occurs at 1.249 m +/- 0.002 m from the curved optic of f = 1.25 m 

For the s plane:

Beam waist occurs at 1.269 m +/- 0.001 m from the curved optic of f = 1.25 m 

And the angle of incidence on th ecurved optic was astimated to be 2.66 deg. This imparts a very negligible astigmatism in the reflected beam. But after collecting more data points of the beam profile we see that there is significant astigmatism in the input beam which translates to a decent amount of astigmatism in the reflected beam. 

w_0x: 1.429 mm +/- 0.006 mm
z_0x: 0.421 m +/- 0.131 m

w_0y: 1.526 mm +/- 0.023 mm
z_0y: 0.352 m +/- 0.597 m

Norna Robertson, Stephen Appert ||  29 Nov 2017, 2 pm to 4 pm  ||  227 Downs, CIT

We made some preparations for modal testing, but did not have enough time to make measurements. Below is an after-the-fact log, including some observations and photos of the current state of the OMC bench.

1. Previous testing results at T1700471 (technical note in progress as of 30 Nov 2017).
   1. One goal of the next round: add damping material to equate with damping material of T1600494.
   2. Second goal of the next round: use a more localized sweep to better resolve the body mode around 1080 Hz -1100 Hz
2. Transport Fixture was opened without issue, revealing the "Top" (suspending and cable routing) surface of the bench. Damping stacks were still in place from previous testing
3. We removed the bolts from the damper stacks, but found that all masses with metal-viton interfaces had adhered to viton washers, causing the stacks to stick together.
   1. By using an allen key as a lever to wedge apart bottom mass and the bracket where they were joined by a viton washer, we separated the masses from the bracket.
   2. An allen key was used as a lever to push apart the two masses, which were also joined by a viton washer
   3. Once exposed, viton washers were pried from metal surfaces.
4. After the damper stacks had been detached from the  No viton washer appeared to leave any residue or particulate - the separated parts all appeared as clean as they had been at the onset.

Also brought to the 40m on 10 April, in preparation for PZT subassembly bonding:

- new EP30-2 epoxy (purchased Jan 2019, expiring Jul 2019 - as documented on documents attached to glue, also documented at C1900052.

- EP30-2 tool kit (maintained by Calum, consisting of mixing nozzles, various spatulas, etc)

Already at the 40m for use within PZT subassembly bonding:

- "dirty" ABO A with temperature controller (for controlled ramping of curing bake)

- clean work areas on laminar flow benches

- Class B tools, packaging supplies, IPA "red wipes", etc.

Upon reviewing EP30-2 procedure T1300322 (current revision v6) and OMC assembly procedure E1300201 (current revision v1) it appears that we have gathered everything required.

[Stephen, Philip, Koji, Joe]

Breadboard D1200105 SN06 was selected as described in eLOG 338. This log describes unwrapping and preparation of the breadboard.

Relevant procedure section: E1300201 section 6.1.5

Breadboard was unwrapped. No issues observed during unwrapping.

• Attachment 1: packaging of SN06.

Visual inspection showed no issues observed in breadboard - no large scratches, no cracks, no chipping, polished area (1 cm margin) looks good.

• Attachment 2: engraving of SN06.

Initially the breadboard has a large amount of dust and fiber from the paper wrapping. Images were gathered using a green flashlight at grazing incidence (technique typical of optic inspection).

PROCEDURE IMPROVEMENT: Flashlight inspection and Top Gun use should be described (materials, steps) in E1300201.

• Attachment 3: particulate before Top Gun, large face.
• Attachment 4: particulate before Top Gun, small face.

Top gun was used (with medium flow rate) to remove large particulate. Breadboard was placed on Ameristat sheet during this operation.

• Attachment 5: particulate after Top Gun

Next, a clean surface within the cleanroom was protected with Vectra Alpha 10 wipes. The breadboard, with reduced particulate after Top Gun, was then placed inside the cleanroom on top of these wipes. Wiping with IPA Pre-wetted Vectra Alpha 10 wipes proceeded until the particulate levels were acceptable.

Joe and Koji then proceeded with placing the breadboard into the transport fixture.

[Stephen, Koji]

As mentioned in eLOG 331, either increased thermal cycling or apparent improvements in cured EP30-2 strength led to fracture of curved mirrors at unintended locations of bonding to the PEEK fixture parts.

The issue and intended resolution is summarized in the attached images (2 different visualizations of the same item).

Redline has been posted to D1600336-v3.

Drawing update will be processed shortly, and parts will be modified to D1600336-v4.

[LiyuanZ, StephenA]

Downs B119

Summary: Beginning on 20 May 2019, two CM PZT assemblies were soaked in Acetone in an effort to debond the EP30-2 bonds between tombstone-PZT and between PZT-optic. Debonding was straightforward after 8 days of soaking. 24 hours of additional acetone soaking will now be conducted in an attempt to remove remnant EP30-2 from bonding surfaces.

Procedure: The assemblies were allowed to soak in acetone for 8 days, with acetone level below the HR surface of the optic. No agitation of the solution, mechanical abrasion of the bond, or other disturbance was needed for the bond to soften.

GariLynn contributed the glassware and fume hood, and advised on the process (similar to debonding of CM and PZT from OMC SN002 after damaging event). The equipment list was (WIP, more detail / part numbers will be gathered today and tomorrow):

• crystallizing dish (no spout, like a deep petri dish)
• curved lid
• wax sheet (to seal)
• acetone
• fume hood

Results: Today, 28 May 2019, I went to the lab to check on the optics after 8 days of soaking. Liyuan had monitored the acetone level during the first 4 days, topping up once on 24 May. All bonds were fully submerged for 8 days.

There were 2 assemblies soaked in one crystallizing dish. Debonded assemblies - ref OMC eLOG 328 for specified orientations and components:

PZT Assy #9 - ref. OMC eLOG 334 - M17+PZT#12+C10

PZT Assy #7 - ref. OMC eLOG 332 - M1+PZT#13+C13

PZT Assy #7 was investigated first.

• C13 was removed with no force required.
• PZT#13 was removed with no force required.
• EP30-2 remained at the bond surfaces and tracing the diameters of each bond on each of the 3 bonding surfaces of the PZT and tombstone - these components were returned to the dish to soak.
• No EP30-2 remained on the surface of the curved mirror - C13 was removed and stored.

A video of removal of C10 and PZT#12 from PZT Assy #9 was collected (See Attachment 8), showing the ease with which the debonded components could be separated.

• C10 was removed with no force required.
• A slight force - applied by gripping the barrel of the PZT and pushing with the index finger on the surface of the tombstone - was required to separate PZT#12 from M17,
  • likely due to excess glue at the barrel of the PZT
• EP30-2 remained at the bond surfaces and tracing the diameters of each bond on each of the 3 bonding surfaces of the PZT and tombstone - these components were returned to the dish to soak.
• No EP30-2 remained on the surface of the curved mirror - C13 was removed and stored.

Photos and video have been be added to supplement this report (edit 2019/07/08).

Wedge and thickness measurements of PZTs 12 and 13 took place after debonding and cleaning - results are shown in the first image (handwritten post-it format).

These thickness measurements seem to have come back thinner than previous measurements. It is possible that I have removed some PZT material while mechanically removing glue. It is also possible that there is systematic error between the two sets of measurements. I did not run any calculations of wedge ange or orientation on these data.

Note that cleaning of debonded PZTs involved mechanically separating glue from the planar faces of PZTs. The second image shows the razer blade used to scrape the glue away.

There were thick rings of glue where there had been excess squeezed out of the bond region, and there was also a difficult-to-remove bond layer that was thinner. I observed the presence of the thin layer by its reflectivity. The thick glue came off in patches, while the thin glue came off with a bit of a powdery appearance. It was hard to be certain that all of the thin bond layer came off, but I made many passes on each of the faces of the 2 PZTs that had been in the bonded CM assemblies. I found it was easiest to remove the glue in the bonded

I was anticipating that the expected 75-90 micron bond layer would affect the micrometer thickness measurements if it was still present, but I did not notice any irregularities (and certainly not at the 10 micron level), indicating that the glue was removed successfully (at least to the ~1 micron level).

Here is a summary of the events of the last week, as they relate to EP30-2.

1) I lost the EP30-2 syringes that had been ordered for the OMC, along with the rest of the kit.

• Corrective action: Found in the 40m Bake Lab garbing area.
• Preventative action: log material moves and locations in the OMC elog
• Preventative action: log EP30-2 moves and locations in PCS via location update [LINK]
• Preventative action: keep EP30-2 kit on home shelf in Modal Lab unless kit is in use

2) The EP30-2 syringes ordered for the OMC Unit 4 build from January had already expired, without me noticing.

• Corrective action: Requested LHO ship recently-purchased EP30-2 overnight
• Preventative action: log expiration dates in OMC elog
• Preventative action: begin purchasing program supported by logistics, where 1 syringe is maintained on hand and replaced as it expires

3) LHO shipped expired epoxy on Thursday. Package not opened until Monday.

• Corrective action: Requested LHO ship current EP30-2 overnight, this time with much greater scrutiny (including confirming label indicates not expired)
• Preventative action: Packages should be opened, inspected, and received in ICS or Techmart on day of receipt whenever possible.

4) Current, unopened syringe of EP30-2 has been received from LHO. Expiration date is 22 Jan 2020. Syringe storage has been improved. Kit has been docked at its home in Downs 303 (Modal Lab) (see attached photo, taken before receipt of new epoxy).

Current Status: Epoxy is ready for PZT + CM subassembly bonding on Monday afternoon 23 September.

The following items are presently staged at the 40m Bake Lab (see photo indicating current location) (noting items broght by Koji as well):

1. Bonding fixtures, now modified with larger washers to constrain springs, and with modification from OMC elog 358.
2. Curved Mirrors and Tombstones as selected by Shruti in OMC elog 374.
3. PZTs as debonded from first iteration subassemblies (SN 12 and SN 13)
4. Epoxy-cure-testing toaster oven
5. Other items I can't think of but will populate later  =D

The following item is in its home in Downs 303 (Modal Lab)

1. EP30-2 epoxy (expiration 2020 Jan 22) with full kit (tracked in PCS via location update [LINK])

The 40m Bake Lab's Dirty ABO's OMEGA PID controller was borrowed for another oven in the Bake Lab, so I have had to play with the tuning and parameters to recover a suitable bake profile. This bake is pictured below (please excuse the default excel formatting).

I have increased the ramp time, temperature offset, and thermal mass within the oven; after retuning and applying the parameters indicated, the rate of heating/cooling never exceeds .5°C/min.

The ABO is controlled by a different temperature readout from the data logger used to collect data; the ABO readout is a small bead in contact with the shelf, while the data logger is a lug sandwiched between two stainless steel masses upon the shelf. I take the data logger profile to be more physically similar to the heating experienced by an optic in a gluing fixture, so I feel happy about the results of the above bake.

I plan to add the data source file to this post at my earliest convenience.

The 40m Bake Lab's Dirty ABO's OMEGA PID controller was borrowed for another oven in the Bake Lab (sound familiar? OMC elog 377), so I have had to play with the tuning and parameters to recover. This bake seemed to inadequately match the intended temperature profile for some reason (intended profile is shown by plotting prior qualifying bake for comparison).

The parameters utilized here are exactly matching the prior qualifying bake, except that the autotuning may have settled on different parameters.

Options to proceed, as I see them, are as follows:

1. reposition the oven's driving thermocouple closer to the load and attempt to qualify the oven again overnight
2. retune the controller and attempt to qualify the oven again overnight
3. proceed with current bake profile, except monitor the soak temperature via data logger thermocouple and intervene if temperature is too high by manually changing the setpoint.

Follow up on OMC elog 379

I was able to obtain the following (dark blue) bake profile, which I believe is adequate for our needs.

The primary change was a remounting of the thermocouple to sandwich it between two stainless steel masses. The thermocouple bead previously was 1) in air and 2) close to the oven skin.

OMC PZT Assy Production Cure Bake (ref. OMC elog 381) for PZT Assy #9 and #10 started 27 September 2019 and completed 28 September 2019. Captured in the below figure (purple trace). Raw data has been posted as an attachment as well.

We have monitored the temperature in two ways:

1) Datalogger thermocouple data (purple trace).
2) Checking in on temperature of datalogger thermocouple (lavender circles) and drive thermocouple (lavender diamonds), only during initial ramp up.

Comments on bake:

• No changes were made to the tuning or instrumentation of the oven between the successful qualifying bake obtained on 26 September (ref. OMC elog 380). However, the profile seems to have been more similar to prior qualifying bake attempts that were less successful (ref. OMC elog 379), particularly as the oven seems to have ramped to an overtemperature state. I am a bit mystified, and I would like to see the oven tuning characterized to a greater extent than I have had time and bandwith to complete within this effort.
• The maximum datalogger temperature was 104 °C, and the duration of the soak (94 °C or higher) was 68 minutes. This was in contrast to a programmed soak of 2.5 hours and a programmed setpoint of 84 °C.
• The drive thermocouple did appear to be under-reporting temperature relative to the datalogger thermocouple, but this was not confirmed during the soak period. Neither thermocouple was calibrated as part of this effort.

This post captures the curing timeline followed by OMC PZT Assys #9 and #10.

Source file posted in case any updates or edits need to be made.

The following is the current status of the epoxies used in assembly of the OMC (excerpt from C1900052)

Re-purchasing efforts are underway and/or complete

• DONE
  • Masterbond EP30-2 currently located in Downs 303, Modal Lab (see image)
    • ( WILL EXPIRE JANUARY 2020 )
    • ( tracked using THIS PCS LINK https://services.ligo-la.caltech.edu/Inventory/history.php?recid=1582&invtype=cit_noncap )
  • Electronic Materials Inc Optocast 3553-LV procured via PCard, will arrive today 22 October
    • plan to track using PCS is WIP
• WIP
  • Epoxy Pax EP-1730-1 quoted and requisitioned, PO is WIP

[Koji, Jordan, Stephen]

The beam dumps, bonded on Fri 06 Dec 2019, were placed in the newly tuned and configured small dirty ABO at the Bake Lab on Fri 13 Dec 2019.

Images are shared and references are linked below

Bonding log entry - https://nodus.ligo.caltech.edu:8081/OMC_Lab/386

Bake ticket - https://services.ligo-wa.caltech.edu/clean_and_bake/request/992/

OMC Beam Dump - https://dcc.ligo.org/LIGO-D1201285

OMC Unit 4 Build Machined Parts are currently located in Stephen's office. See image of large blue box from office, below.

Loaned item D1100855-V1-00-OMC08Q004 to Don Griffith for work in semi-clean HDS assy.

This includes mass mounting brackets, cable brackets, balance masses, etc. For full inventory, refer to ICS load Bake-9527 (mixed polymers) and Bake-9495 (mixed metals).

Inventory includes all items except cables. Plasma sprayed components with slight chipping were deemed acceptable for Unit 4 use. Cable components (including flex circuit) are ready to advance to fabrication, with a bit more planning and ID of appropriate wiring.

More explicit insights into the inventory for the Unit 4 build. Image of inventory included below.

Machined Parts:

• New fabrication = Contents of Storage-11112 are consistent with upgrade ECR.
• Old leftovers = Storage-9482 and Storage-9483 .

Cable Components:

• Hughes Circuits made us Kapton flex circuits. These have not been processed in any way.
• Rich had supplied a spool of Gore 4-conductor in-vacuum wire (see below image). I returned the sppol for Rich but it is living in Downs and available for use.
• PEEK cable ties were damaged during bake, and will be replaced by SYS inventory.

Retrofit/Repair Capabilities:

• Aluminum reinforcement brackets D1600316
• Glass reinforcement brackets (Edmund Optics 45-072 and 45-071)

ref: E1900034 and other associated documents.

[Camille, Thejas, Stephen]

We set up the white light autocollimator in the Downs B119 cleanroom. (Nippon Kogaku, from Mike Smith).

After some initial effort to refine the fixturing and alignment, we located the S1 crosshair reflection and aligned to the autocollimator reticle using the pitch and yaw adjustments in the prism mount.

We subsequently used the rotation stage adjustment to locate the S2 crosshair reflection and measure the vertical and horizontal wedges.

Faint horizontal crosshair from the S2 reflection can be seen in the image below.

This is aligned with the reticle using rotation mount on which the prism mount is clamped.

Initial readiing of the rotation mount screw: 9.2 

Final reading: 2.2

Here we see that the crosshair from S2 reflected light is offset in the vertical axis by approx. 2 div. From hte image below this should

correspond to 2 arcmin vertical wedge angle.The horizontal wedge angle is yet to be caluclated.

Inspection

Updated ICS (Shipment-12578) and moved those parts to Storage-9482.

Inspection showed the following:

• Serial numbers matched the packing list
• SN S1301807: We observed some discoloration on the Gore wire close to one cable termination. [Attachment 1]
  • greenish tint
  • appeared to be superficial
  • slight removal observed when gently wiped with an IPA soaked AlphaWipe ("red wipe")
  • did not follow the helical of the teflon sheath
  • recommend additional inspection when Unit 4 build is resumed
• Cables were returned to the box labeled "OMC Cables" in the south cabinets in the OMC lab.

Observations for aLIGO OMC Unit 4 Build

An ICS Record Navigator search of onboard OMC cables reveals the following quantities appear to have been fabricated for aLIGO.

• D1300371 = Qty 3
• D1300372 = Qty 5
• D1300374 = Qty 3
• D1300375 = Qty 5

The leftover cables are all of the long variety (D1300372, D1300375), and the received quantities make sense. 3 aLIGO OMC assemblies used quantity 3 of each cable, leaving the remaining cables which had been stored at LHO:

• D1300372 = Qty 2
• D1300375 = Qty 2

The received cables from LHO may apparently be used interchangably, and the extra slack (~ 5", compared to the D1300371, D1300374 part numbers) should be managable.

Next Steps for aLIGO OMC Unit 4 Build

We will move forward in fabricating Unit 4 with the received cables from LHO, despite their extra length.

To complete the Unit 4 on board cable set (refer to OMC_Lab/203), we will need to crimp pins onto the PZT leads, and we need to find, clean, and bake quantity 1 4 pin mighty mouse connector.

• PZT leads terminate crimp pins inserted into Glenair Mighty Mouse 803-003-07M6-4PN-598A (per OMC_LAB/203, record navigator)
• Cable bracket interface to OMCS is Glenair Mighty Mouse 803-003-07M6-4PN-598A (per D1300376-v3).

I will ask Chub to see if there are any Class A spares of the PZT termination connector already on hand.

[Stephen, Camille, Thejas, with support from Marie, Dean, Luis]

We setup a shadow sensor! (Attachment 1)

• QPD (Thorlabs PDQ80A) and HeNe laser (< 4 mW @ 633 nm, Thorlabs HNLS008R, 12V / .7A) borrowed from Marie.
  • QPD supplied by 5V from DC power supply.
• Razor blade flag used to eliminate effect of pitch misalignment, atop a 62.5 gram mass.
• Lab jack used to provide height adjustment.
• Dial indicator (Mitutoyo Absolute +/- .001 mm, p/n S112TXB) mounted to height gauge, used to monitor stage height.

The calibration measurement proceeded as follows:

• Manually lowered the stage until the flag was not occluding any light on the QPD
• Raised the stage in 0.5 mm increments and recorded raw data (using the oscilloscope "Sampling" mode), until the flag occluded all of the light previously on the QPD.
• Identified the central 0.5 mm increment, and stepped through that range in .05 mm increments

Data collected in table at T2300050 Optical Component Testing Measurements, sheet "PiezoDCResponse"

In the linear range from stage position [3.450, 3.550] the least squares linear fit is:

QPD_Sum = m * Stage_Position + b

• QPD_Sum is the dependent variable of QPD signal voltage, derived from the Channel 1 (sum) average, unit V.
• m = -9.685 V / mm is the response of the QPD to change in stage position.
• Stage_Position is the independent variable of stage height, observed via dial indicator readout, unit mm.
• b = 35.6111 V is the best fit y-intercept - not a physical quantity.

So, does this setup allow us to measure the DC response of the PZT?

• Over the linear range, the "m" sensitivity parameter would correspond with a signal of .009685 V / micron
• We expect a stroke of 3 or 4 microns, yielding a signal of .03 to .04 V.
  • (Noliac NAC2124 nominal free stroke is 3.3 microns +/- 15% for a maximum operating voltage of 200 V)
• The typical standard deviation of each measurement is .009 to .011 V.
  • This would be a large error bar in comparison to the signal level.
• We will try again using a different photodiode.

Borrowed for PZT DC Response Shadow Sensor Setup (see Attachment 1):

• Thorlabs PDA100A Photodiode (and power supply)
• Thorlabs MDT694B Piezo Driver

Current Location: Downs 227

[Stephen, Camille, Thejas, with support from Luis]

Calibration reattempted with the PD borrowed from Koji, equivalent to the last PZT measurment (OMC_Lab/336). There were a couple of differences in contrast to the last measurement:

• We navigated to the central 1 mm of the range (the interval we found to be sensitive in the QPD calibration, dictated by the beam size) and we stepped through in .05 mm intervals.
• We had the oscilloscope on 10x Voltage probe mode. See setup in Attachment 1.

Data collected in table at T2300050 Optical Component Testing Measurements, sheet "PiezoDCResponse" (Day 2 section).

In the linear range from stage position [3.450, 3.550] the least squares linear fit is:

QPD_Sum = m * Stage_Position + b

• QPD_Sum is the dependent variable of QPD signal voltage, derived from the Channel 1 (sum) average, unit V.
• m = -136.45 V / mm is the response of the QPD to change in stage position.
• Stage_Position is the independent variable of stage height, observed via dial indicator readout, unit mm.
• b = 501.91 V is the best fit y-intercept - not a physical quantity.

So, does this setup allow us to measure the DC response of the PZT?

• Over the linear range, the "m" sensitivity parameter would correspond with a signal of .13645 V / micron
• We expect a stroke of 3 or 4 microns, yielding a signal of .40 V to .55 V.
  • (Noliac NAC2124 nominal free stroke is 3.3 microns +/- 15% for a maximum operating voltage of 200 V)
• The standard deviation was not consistent for each measurement; at this linear range, the standard deviation was between .10 V and .15 V.
  • This would be a large error bar in comparison to the signal level

So, is this DCPD setup better than the QPD?

• Comparing sensitivity against standard deviation, there is not much difference.
  • Standard deviation is the same for each measurement in the QPD case, while the PD has some variation (as the signal increases, the standard deviation also increases, but not with uniform scaling; at lower signal levels, the standard deviation is smaller for the PD than the QPD).
  • The ratio between Channel 1 Average and Standard Deviation is similar for the two setups, so neither setup reduces the error significantly.

We will probably just keep the PD in place, since there is not a great motivation to revert to the QPD, and the QPD could then be used for the OpLev independently. We will look at using the oscilloscope "Averaging" mode to reduce the noise in our measurement.

[Stephen, Camille, Thejas]

A running log of our efforts from Monday 1 May. Data continues to be placed in T2300050 at sheet "PiezoDCResponse":

• Continuing with the DCPD and 3-axis piezo driver for our "final" setup
  • PD Thorlabs
  • Driver Thorlabs MDT694B
  • Function Generator in line
• "Averaging" mode of the oscilloscope only reported 3 significant figures, so there was no benefit from switching away from "Sampling" mode
• Acoustic buzzing test of PZT 36 and PZT 31 yielded consistent results
  • Audible buzzing tone with 1 kHz, 10 Vpp input
  • Reverse polarity also buzzes
• We attempted on/off testing, and also AC drive testing, for PZTs 31, 32, and 36
  • PZT 36 was used in the initial setup effort, and since there was inadequate insulation of the PZT from the setup, there was charge buildup and static discharge during that early effort. This PZT was chosen because it has the greatest wedge. We should be skeptical of it now that we have used it in these setup efforts.
  • PZT 31 was used next, also during setup but only after adequate insulation of the PZT had been implemented. It probably has been treated well! Except during today's efforts, one of the solder joints debonded. (Need to follow up with Dean to confirm that LIGO soldering practice follows recommendations of vendor - pads should be clean, solder should include Ag; see D1102070 and other sources)
  • PZT 32 was used afterwards, and was measured.
• We were not really satisfied with the "feel" of the measurement
  • The oscilloscope output didn't seem to change on time scales that we were expecting, when we manipulated the frequency of the drive
  • We attempted to directly measure the PZT extension using the dial indicator, but did not succeed
• We tried to make a list of items that we didn't understand fully, and came up with these:
  • We aren't really that familiar with the driver/amplifier and how it interacts with the input from the function generator:
    • Thorlabs documentation was reviewed - driver manual
      • https://www.thorlabs.com/drawings/d90d63f542e805de-80E05D38-00C3-80BB-4CF17F9FDBF42AB6/MDT693B-Manual.pdf
    • V_out = V_manual + 15 * V_external
      • We applied a 2 V peak-to-peak external voltage, so we were not driving through the full range of the output voltage
      • We may benefit from a low frequency, triangular wave drive so that we can better monitor the output voltage
  • Maybe the time constant of the capacitive charging is too long?
    • Thorlabs documentation was reviewed - Piezo Bandwidth section of Piezo Tutorial
      • https://www.thorlabs.com/newgrouppage9.cfm?objectgroup_id=5030
    • Slew rate (rate of capacitive charging, V/s) is more complicated for a sinusoidal wave than a triangular wave, but the maximum is characterized by the Maximum Driver Current / System Capacitance.
      • Max Driver Current I_max = .06 A, System Capacitance C_sys = C_PZT + C_driver = 5.1 E-7 F + 1 E-9 F
      • Slew rate = 1.18 E5 V/s, or a charging time of 1.28 E-3 s to reach 150 V (note that this is not a true value as the input waveform was sinusoidal)
    • More helpfully, the system bandwidth for a sinusoidal wave is f_max = I_max / (pi * V_pp * C_sys); a triangular wave with a minimum of 0 V is f_max = I_max / (V_pp * C_sys)
      • Our system, if driven sinusoidally from 0 to 150 V, would have a bandwidth of 249 Hz
      • Our system, if driven triangularly from 0 to 150 V, would have a bandwidth of 783 Hz
• We should try to get a low frequency triangular wave drive output from 0 to 150 V with a frequency of 100 Hz, and see if that generates any meaningful signal.

The measurement "results" for PZT 32 (note that these results seem to be dominated by a slow drift in the measurement, and this measurement was not reproducible):

• PD signal with PZT 32 on (150 V) : 3.242934 V, standard deviation 0.013894 V
• PD signal with PZT 32 off (0 V): 3.315395 V, standard deviation 0.014658 V
• sensitivity: -13.65102 V per mm PZT displacement
  • (from PD Calibration, removing factor of 10 from oscilloscope during that measurement)
• displacement of PZT = 5.308 microns
  • the standard deviation of the On measurement was 1.018 microns, and the standard deviation of the Off measurement was 1.074 microns.
• Conclusion: this measurement has a rather large error bar, and was not very repeatable / could not be directly observed by another means (see above comments in log) we were not really satisfied with the "feel" of the measurement
  • The oscilloscope output didn't seem to change on time scales associated with low frequency AC drive; Since high frequency AC drive does cause motion (witnessed by buzzing) maybe we need to find other ways to measure the motion that are more sensitive?

Efforts from Tuesday through Thursday Wednesday, 02 through 04 May, are described below.

The main outcomes were:

• We are able to see some response in the frequency domain (which confirms the response that we hear at acoustic drive frequencies) on a few PZTs Wednesday and Thursday.
• We then improved our drive input and monitoring, so we now see the full waveform delivered to the PZT.
• Now, we are able to reliably see some length response, though typically the reponse seems to be somewhat less than the expected 3.3 micron / 200 V from the spec sheet.
• We are also still subject to low SNR, though at least now the DC response is visible to the eye.
  • We also recalibrated the PD using the stage in the current setup.
• We met this morning to talk about data collection, and we realized it would be best to try to improve the setup.
  • Koji provided some good suggestions, some of which reflected feedback collected from Gabriele, Dean, and Luis.
  • Our setup was sensitive enough to observe the response (yay) but not sensitive enough to make a good measurement.

The next log will reflect the updated setup.

I hope to come back to edit this log to fill out more detail, but the detail reflects intermediate steps with the old setup.

[Thejas, Camille, Stephen]

In Downs 227 on 05 May 2023

We took the following actions:

• Reconfigure our data acquisition with a SR785 instead of the oscilloscope.
  • The scope had been limited to ~10 mV precision, and the SR785 has better than mV precision.
• Contract the beam using some lenses borrowed from Gabriele.
  • Increases sensitivity, following some feedback from Koji which Gabriele had also mentioned
  • We measured the spot size on our flag to be .44 mm (had been about 1 mm).
• Moved all electronics, especially AC function generator, off of optical table.
  • Feedback from Koji.

We recalibrated the photodiode using the razorblade flag. We continued to be plagued by slow variations but we had much better data quality (less fuzziness and fewer spikes in the time series). It seemed like the razorblade was not stiff enough and was sensitive to airflow.

We may readjust and recalibrate to see if our data is better, but in the meantime, below are images of the calibration and setup. Data is at T2300050 Optical Component Testing Measurements, sheet "PiezoDCResponse".

Revisiting the measurement requirements and applying the sensitivity of the new setup:

• The NAC2124 PZT nominally extends 3.3 microns with a 200 V drive, +/- 15%.
  • Our 150 V drive should extend the PZT by 2.5 microns nominally.
  • Our shadow sensor would ideally be able to observe with accuracy better by order of magnitude (.25 microns).
• Our stage-driven, dial-indicator-observed PD calibration reveals a sensitivity of -6.704 V PD output per mm of displacement.
  • This corresponds with 149 microns of displacement per V PD output.
  • Across these 11 stage calibration measurements, the error terms were:
    • Standard Deviation: max. 0.00182 V, min. 0.00008 V, avg. 0.00069 V (no, I'm not going to report the standard deviation of the standard deviations.)
    • Range, V (max. value - min. value): max. 0.00563V, min. {C} 0. 00042 V, avg. 0. 00232 V
• If we want to measure with accuracy of .25 microns, that corresponds with a PD output of .0017 V
  • Looks like some of our measurements had low enough error for this accuracy, but there were some measurements which did not.
  • Hopefully we can improve by reducing the impact of vibration and airflow.

12 May 2023, Downs 227

Stephen, Camille, Thejas

We completed a first batch of PZT DC response measurements, and we are working on the processing of quantitative results.

For now, presented below are some general observations and remarks, as well as qualitative results for the full set of 18 PZTs.

General observations

• The following improvements have helped us graduate to observing and measuring DC response:
  • Improving our drive electronics (better function generator, direct monitoring of function generator output and PZT drive amplifier input)
  • Improving our experimental design (focusing and collimating of input beam allowed greater sensitivity to same PZT motion)
  • Improving our signal chain (PD to SR785 Spectrum Analyzer allowed better resolution and reduced systematic noise)
• It seems that Qty 2 of the PZTs that we handled a lot during our test setup may have degraded due to some inattention or accidental mistakes.
• Qty 5 PZTs had solder preventing uniform contact with the end face, which seemed to effect our ability to observe well-resolved DC response.
  • Resoldering next for these articles!
  • We had not clearly specified that there was a restriction to the extent of the solder joint - something to add to the DCC entry for the PZT. We'd also like to recommend that specific soldering steps for the leads be documented here!
• The remaining articles were characterized using a 0.5 Hz triangle wave of range 0-150 Hz, sampled for 8 seconds on a SRS785 Spectrum Analyzer.

Qualitative DC Response Results

11 PZTs are Good (DC Response measured)
36 - labeled "?" due to a fair amount of initial handling
37 - good
38 - good
39 - somewhat high intrinsic noise
41 - good
42 - good
43 - good 
44 - good
46 - good
47 - good
48 - good

5 PZTs are WIP (Still need to measure DC Response)
31 - Solder extends past end face
32 - Lead Desoldered
35 - Solder extends past end face
40 - Solder extends (maybe) past end face
45 - Solder blob on ID of end face

2 PZTs are Bad (Inadequate DC response)
33 - 150 V applied in reverse due to lead polarity mistake; still buzzes, but now DC response is unreliable
34 - Low DC response, maybe because we were using it in tests?

Next Steps

We need to remeasure the 5 PZTs that had soldering issues. We'll call this Batch 2.

Soon we will finish analyzing the quantitative response, with an output of PZT Displacement per Drive Voltage.

Then we will decide whether we are happy to move forward without additional PZT spares to replace the faulty articles, or if we want to order additional units.

We also will continue characterizing the PZT Length-to-Angle Coupling and Reliability, per OMC Testing Procedure ref. T1500060-v2 PZT Testing Sections Section 2.3.2 and 2.3.4

A+ OMC Build efforts ongoing or completed this week:

•  PZT lead onboard strain relief (D2000172)
  • Brief discussion in A+ SUS call - PEEK material callout is to be updated in v2, Don is handling this.
  • v1 drawings posted and UK team out for production, with Angus already communicating PEEK grade requirement to vendor during procurement process.
  • DCN is WIP per Russell.
• Rework of Helicoil holes
  • D1201278 and D1300498 were already Class A, but we recognized that the hole callouts were not consistent with current LIGO notation, and we decided to make sure that these holes were in a good state.
  • Don and I chased the holes with taps (gloves on, but in a dirty area)
  • Don created a C&B Ticket request/1835
• PZT characterization (ref. T1500060-v2 - PZT Testing Section 2.3.2)
  • DC Response measurement - see OMC_Lab/542 for initial findings.
    • 11 units appear to be good, 2 units appear to be damaged, 5 units need to be recharacterized (after soldering rework).
    • Quantitative results WIP.
  • Lab move to Downs 320 - this work needs to be logged.
    • DC Response setup updated, beam focusing was changed.
    • Oplev setup for Length to Angle measurement constructed for the first time.
• Component matching for Curved Mirror Subassembly
  • Continued work on algorithm-based matching code
  • Discussion with Gari and Calum - we will move toward manual matching to expedite

We have the following plans for the week ahead:

• Complete PZT DC Response data analysis.
• Finish solder rework of PZT leads.
• Start PZT Length to Angle measurement.
• Manually match Curved Mirror Subassembly components, enough to bond first 4 assemblies.
  • (this will be pending full characterization of PZTs)
• Make sure clean and bake ticket gets processed for reworked parts mentioned above.

We have the following near future plans:

• Start PZT reliability testing (burn-in test) (ref. T1500060-v2 - PZT Testing Section 2.3.4),
  • Focused on units that will be used to bond first 4
• Bond first batch of Curved Mirror Subassemblies.
  • Make sure we have enough EP30-2 for subsequent batches (some used by HoQi effort)..
• Resume transport fixture build effort at 40m Bake Lab.
• Conduct walkthrough of OMC lab with build in mind.
• Follow updates of top level assy D2000172, and send finalized assy for 3D printing of mockup unit.

Koji, Rich

We took apart the unit removed from the 3rd IFO (Unit serial number aLIGO #3, XTAL 10252004) to see what makes it tick.  Koji has done a fine job of adding the plots of the impedance data to this log book.  Attached are some details of the physical construction showing the capacitor values used in shunt before the coils.

Attached please see my notes summarizing the models for the electrodes and inductors within the 3rd IFO EOM

Attached is a block diagram of the test setup used in the 40m lab to measure the modulation index of the IO modulator

[Koji, Philip]

Today we tested the functionality of the four remaining PZTs (11,12,13 and 22) .  Each PZT was placed within a collimated 500um beam.
Roughly half of the beam was blocked by the PZT. The PZT and a PD then acted as shadow sensor. Each PZT was tested with 0 and
150 V. The resulting power change then could be converted into a displacement of the PZT using the beam diameter.

The open light value for each of these tests was 3.25 V.

PZT 11:
0 V supply voltage     --> 1.717 V on PD
150 V supply voltage --> 1.709 V on PD
delta = 0.008 V

PZT 12:
0 V supply voltage     --> 1.716 V on PD
150 V supply voltage --> 1.709 V on PD
delta = 0.007 V

PZT 13:
0 V supply voltage     --> 1.702 V on PD
150 V supply voltage --> 1.694 V on PD
delta = 0.008 V

PZT 22:
0 V supply voltage     --> 1.770 V on PD
150 V supply voltage --> 1.762 V on PD
delta = 0.008 V

0.008 V --> 0.24% change in power on PD --> about  3.8 um displacement assuming no light which is blocked
by the PZT is hitting the PD.

We further started to drive all four PZTs over night with 100 V (half of their range) at 100 Hz.
We additionally display the impedance to ensure none of them degrades.

All four PZTs seem to be connected to Teflon coated wires. It needs to be checked if these
fulfill the vacuum compatibility requirements.

[Joe, Koji, Liyuan, Philip, Stephen]
Work done on 16.04.2019

Finishing assembly of transport box
Assembly worked fine except for the clamping structure to clamp the lid of the transport box to the bottom part.
It seemed that some of the plastic of these clamps became brittle during the baking. The plastic was removed and the
clamps where wiped clean. It appears that the clamps can't be locked as they should. Still the transport box should be fine
as the long screws will mainly clamp the two parts together.

Preparing the transport box to mount the breadboard
The lid of the the transport box was placed upside down and clamped to the table. All peak clamping structures where pulled back as far as possible.

Preparation and cleaning of the breadboard
We unpacked the breadboard and found lots of dust particles on it (most likely from the soft paper cover which was used). We used the ionized nitrogen gun
at 25 psi to get rid of the majority of particles and cross-checked with a bright green flash light before and after blowing. The second stage of cleaning was done
below the clean room tent and included the wiping of all surfaces. The breadboard was then placed into the prepared lid of the transport box and clamped with peak
screws.

Unpacking of the template
The previously cleaned template was unpacked while the last layer of coverage was removed below the cleanroom tent.

Template adjustment on the breadboard
All peak screws of the clamping structure of the template where removed. The template was placed onto the breadboard only seperated by peak spacers.
All peak screws have been inserted for horizontal clapming. A calipper was used to measure the distance of each edge of the template to the edge of the
breadboard. For documentation the labeled side of the bradboard (facing away from the persons on the pictures) of the upside down breadboard is defined to 
be the south side, continuing clockwise with west, north and east. First rough alignment was done by shifting the template on the breadboard and then the 
peak screws where used for fine tuning. The caliper values measured where:
North   C 8.32mm     E 8.52 mm     W 8.41 mm
East     C 8.08 mm
South   C 8.32 mm
West    C 8.02 mm
(E indicating east side position, W indicating west side position and C indicating center position)

ach[Joe, Phillip, Koji, Stephen]

Work from 17.04.2019

First contact cleaning of OMC optics
We cleaned the OMC optic with first contact. After a first cleaning run all mirrors except for two looked
fine. One had some first contact residuals on the left at center height and another had some particle sitting
near the center area. As the ionized nitrogen gun didn't help we applied another round of first contact which resolved
the two issues. Unfortutanely the second run of cleaning again left some residuals of first contact at the edges.
We were able to peal these off with tweezers.

Placement of Optics at the breadboard
We cleaned the contact surfaces for the bonds using optic wipes and pure isopropanol. The placement wen't well for 3 of the 5 optics (low number of newtonian rings).
One was recleaned and placed on the breadboard again which seemed fine. For the 5th no newtonian rings could be seen (either verry ood or bad) we planed on trying it in the current set-up. Mirrors used can be seen in attachment 3.

 

This is a test bake conducted in Air Bake Oven A (ABO-A) held in the 40m Clean and Bake facility. The overall objective is to sucessfully cure the Curved Mirror Subassemblies with the appropriate temperature profile. In this test run, we wanted to ensure that the temperature profile dictated via the Platinum software is stable and repeatable.

Specific curing instructions can be found in LIGO-E1300201-v1, section 6.2.4 (https://dcc.ligo.org/E1300201-v1). This test air bake load contained several stainless steel masses and a stainless steel tray that will be utilized in the production curing run. Note that the thermacouple has been placed between two stainless steel masses.

Temperature profile results from 4/14/23 test cure can be seen in attachments below.

RoC: 2.65m ! Interesting. I'll wait for the follow-up analysis/measurements. The RoC may be dependent on the area (diameter) for the fitting. You might want to run the fitting of your own. If so, let me know. I have some Matlab code that is compatible with the CSV file exported from MetroPro data.

If the mirror has the RoC, it works as a lens. And you should be able to see the effect in the beam profile.

Just what you need to do is to compare the beam profile without the mirror (or with a flat mirror) and then with the curved mirror.

I hope you can find useful lenses from the lens kit in the cabinet. If you need more lenses and mounts, talk to our students in WB and the 40m.

Thanks Koji, the lenses available in the cabinet in the lab actually sufficed. 

LIGO Document G1200683-v1:
aLIGO OMC fabrication and testing plan

aLIGO OMC wiki

Facility

• Work
  • Replacing wooden work benches
    • W60" x H28-34" x D30" http://www.globalindustrial.com/p/work-benches/systems/adjustable-height/60x30-esd-square-edge-power-apron-production-bench-blue
    • W72" x H28-34" x D30" http://www.globalindustrial.com/p/work-benches/systems/adjustable-height/72x30-esd-square-edge-power-apron-production-bench-blue
    • Lower shelf W60" http://www.globalindustrial.com/p/work-benches/systems/adjustable-height/60-w-lower-shelf-bench-15-d-blue 
    • Lower shelf W72" http://www.globalindustrial.com/p/work-benches/systems/adjustable-height/72-w-lower-shelf-bench-15-d-blue
  • Replacing a cabinet at the south wall by a lockable cabinet
    • W36" x H72" x D20"
  • Cleaning of the floor
  • Plug a big hole on the wall (Done)
  • Plug slits on the roof of the HEPA booth - "There should be the blanking panels there."
     
  • Install laser Safety curtain (Peter is working on this)
     
  • Place a sticky mat
  • Prepare clean supplies (Shoes/Coverall/Hats/Gloves) => go to VWR stock room
  • Prepare Al foils (All foils inc, should get a certificate everytime to ensure UHV compatibility)
  • Plastic boxes for storage http://www.drillspot.com/products/422140/Rubbermaid_2282-00-CLR_18GAL_Clear_Snap_Case
    (Steve is helping Koji to get them)
     
• Design
  • Optical layout
     
• Test
  • Confirm particle level
     
• Note: Optical Table W96" x D48" x H27"

Mechanics

• Work 
  •  
• Design
  • How do we hold the PDs, QPDs, and black glass - we put 2 PDs and 2 QPDs on the PD mounting blacket.
  •  
•  
• Test
   
• Things to be tested
  • New suspension scheme (cup & cone design)
  • Balancing the plates
  • Dummy metal payload?
• => Suspending test with a suspension cage for a Faraday isolator@CIT
  • Supporting block for the suspension cage (to mimic the OMC suspension)
• Things to be designed
  • Wire end (cone)
  • Diode holding structures
    PD/QPD/PZT holding structure
• PZT alignment
• Prototyping with metal parts?
• UV glue? (heat) / gluing test
• Balance / ballast
   
• Solid works

Optics

• Mirrors to be delivered ~Aug
• Design down select
  • Between "Single output & BS" vs "Two outputs & no BS"
• Mode design
• Finalization of scattering paths / PD angles etc
   
• Things to be decided / confirmed:
  • How to handle optics / assemblies (Talk to the prev people)
  • First contact? (Margot: applicable to a short Rc of ~2.5m)
  • Gluing templates to be designed (how to handle it?)
• Things to be tested:
  • R&T of each mirror
  • Cavity ref/trans/finesse
  • PD QE / incident angle
     
• What PD do we use?
   
• CCD beam analyzer (Zach: It is fixed.)
   
• PD angle measurement
• Obtain EG&G 3mm PDs

Electronics

• Electronics / CDS electronics / software
   
• Things to be tested
  • QPD/PD pre-selections (QE/noise)
  • Functionality test of QPD/PD/PZT

Shipping, storage etc

• Shipping cage drawing
  https://dcc.ligo.org/cgi-bin/private/DocDB/ShowDocument?docid=70209

Jun/July
    - Lab renovtion
    - Mechanics design
    - Glue training
Aug
    - Mirror delivery
    - Basic optics test
Sept
    - Cavity test
    - Suspending test
NOV~DEC
    - Shipping to LLO

Open questions
    Two optical designs
    Procedure
    Modeling
    Clamp design / stencil design
    gluing-installation procedure

Facility/Supplies

• Work in progress
  
  • Floor cleaning
  • Plug slits on the roof of the HEPA booth - blanking panels have been ordered (Peter)
  • Install laser safety barrier (Peter is working on this)
  • Place a sticky mat
     
• Work to be done
  • Replacing a file cabinet next to the south wall by a lockable cabinet
  • Replacing a lab desk at the west side of the room. (Vladimir's)
  • Replacing Vladimir's rack with nicer one.
  • Laser sign
  • Safety glass holder
  • Prepare clean supplies (Shoes/Coverall/Hats/Gloves) => go to VWR stock room
    
    • glove 8.5,9,9.5
       
  • Label maker (P-Touch) & Tape
     　
• Design
  • Optical layout - Laser SOP
  • Additional HEPA stage
     
• Test
  • Confirm particle level
     
• Note: Optical Table W96" x D48" x H27"

Beaurocracy

• Laser SOP
• HV use?
• UV?

Mechanics

• Ongoing Work 
  • Cone-shaped wire clamp design (at the OMC end) - Jeff
     
• Design
  • Wire preparation fixture - Jeff
  • How do we hold the PDs, QPDs, and black glass - we put 2 PDs and 2 QPDs on the PD mounting blacket. - Jeff
  • Integrated solidwork model - Sam
    • Q: How the wires are clamped at the top side?
    • Q: How much the length of the wire should be?
    • Q: Locations of the wire mounts on the plate
  • Cabling investigation:
    • Where do the cables from the feed-thrus anchored? - Sam
    • List of the current internal cables and their lengths - Sam
    • List of the required internal cables and their lengths
    • Can we route the intermediate stage of the suspension? Do we need new cables?
  • Dummy intermediate stage structure
     
  • Metal templates
    • First, decide an optical design
    • takes at least a month
       
  • Weights how heavy / how many
     
• Test
  • Cone-shaped wire clamp test - Jeff/Koji 
  • Balancing the plates
    • The Faraday isolator cage isn't clean
  • Dummy metal payload test at the sites???
     
• Procedures to be decided
  • PZT alignment
  • Prototyping with metal parts?
  • UV glue? (heat) / gluing test
  • Balance

Optics

• Ongoing Work 
  
  • Mirrors to be delivered ~Aug
     
  • Design down select - Between "Single output & BS" vs "Two outputs & no BS"
  • Down selecting procedure:
    
    1. Assume ELIGO beam component
    2. Assume amount of 9MHz / 45MHz sidebands at the OMC input
    3. Calculate transmitted power
    4. Require HOM to be smaller than the TEM00 offset 
        
  • UV cured epoxy (Quate obtained)
    
    • Electronic Materials Inc.'s Optocast 3553LV-UTF-HM
      (A Low Viscosity, Ultra Thin Film epoxy with Heat Mechanism. The assembly/cure procedure includes both a UV binding step and a 120 degree cure for 24 hours.)
    • Ref1: Dennis Coyne, LIGO-E960050-v11,
      https://dcc.ligo.org/cgi-bin/private/DocDB/ShowDocument?docid=3879
    • Ref2: Tobin Fricke, LIGO Document P1000010-v1, Homodyne detection for laser-interferometric gravitational wave detectors
      https://dcc.ligo.org/cgi-bin/private/DocDB/ShowDocument?docid=8443
    • Ref3: OMC Construction Wiki https://awiki.ligo-wa.caltech.edu/aLIGO/OMC_Construction
    • The glue should be stored at T<0degC ==> Freezer in a lab
       
• Design
  
  • Mode design for HAM6 layout
  • Finalization of scattering paths
     
• Tests
  • Measurement of PD angles
  • R&T of each mirror
  • Curvature of the curved mirrors
  • Cavity ref/trans/finesse
  • PD Q.E. & Reflectivity measurement vs incident angle
     
• Things to be decided / confirmed
  • How to handle optics / assemblies (Talk to the prev people)
  • First contact? (Margot: applicable to a short Rc of ~2.5m)
  • Gluing templates to be designed (how to handle it?)
     
• PDs
  • Primary choice for DC PD: Exelitas C30665GH 3mm
    0.76A/W => Q.E. 0.88
    http://www.excelitas.com/downloads/dts_pe_pd_14_ingaasandsipindiodes.pdf
     
  • Primary choice for DC QPD: OSI FCI-InGaAs-Q3000
     
• Misc
  • CCD beam analyzer (Zach: It is fixed.)
  • Are two PZTs used?
    • YES, for redundancy, range, upconversion tests.
       
• Things to buy
  • Obtain EG&G 3mm PDs
  • Black Glass / Black Glass holder
  • Acetone.
  • N2 cylinder: 4N - UHP or 5N - Research Grade.
  • Paper lens tissue
  • Lint free cloth
  • The ionized gun used in the clean room at Downs: made by Terra Universal.com
    http://www.terrauniversal.com/static-control/ionizing-blow-off-guns.php
  • Flow path: N2 cylinder - Filter - Gun
  • Freezer

• Need to buy a fiber for mode cleaning?
  
• Mode content of the ELIGO dark beam?
• Jitter noise?
• How to determine the design?
• Why Fused Silica? (How much is the temp fluctuation in the chamber?)
• How to align the cavity mirrors, input mirrors, QPDs, PDs, beam dumps.
   

Electronics

• Thorough scrutinization of cabling / wiring / electronics
• Electronics / CDS electronics / software
• Things to be tested
  • QPD/PD pre-selections (QE/noise)
  • Functionality test of QPD/PD/PZT

Shipping, storage etc

• Shipping cage drawing
  https://dcc.ligo.org/cgi-bin/private/DocDB/ShowDocument?docid=70209

Jun/July
    - Lab renovtion
    - Mechanics design
    - Glue training
Aug
    - Mirror delivery
    - Basic optics test
Sept
    - Cavity test
    - Suspending test
NOV~DEC
    - Shipping to LLO

Open questions
    Two optical designs
    Procedure
    Modeling
    Clamp design / stencil design
    gluing-installation procedure

July:Facility/Supplies

• Completed Work: Facility/Supplies
  • Plug a big hole on the wall
  • Purchasing work benches
    
    • W60" x H28-34" x D30" http://www.globalindustrial.com/p/work-benches/systems/adjustable-height/60x30-esd-square-edge-power-apron-production-bench-blue
    • Lower shelf W60" http://www.globalindustrial.com/p/work-benches/systems/adjustable-height/60-w-lower-shelf-bench-15-d-blue
  • Wooden work benches removed(arranging the work with Louisa)
     
  • Al foils (All foils inc, should get a certificate everytime to ensure UHV compatibility)
  • Laser / UV safety glass/face mask (Ordered with Gina, UV face shield ordered through Techmart)
    • 35-200 Laser Glasses (PN 100-35-200) Qty.2 Price 189.00 ea
      http://www.lasersafetyindustries.com/35_200_Laser_Safety_Glasses_p/35-200.htm
    • Black Sport-wrap Laser Glasses 950-3600 nm (PN 100-38-200) Qty.1 Price 169.00 ea
      http://www.lasersafetyindustries.com/Black_Sport_wrap_Glasses_Diode_Nd_YAG_Er_YAG_p/100-38-200.htm
    • VWR has FACE SHIELD UVC-803 and this is ANSI-Z87.1 1986 compliant and the O.D. is more than 5.
      https://us.vwr.com/store/catalog/product.jsp?catalog_number=33007-151
  • Sticky mat
    
    • VWR MAT ADHESIVE 30L 18X36 BLU, 21924-110
  • Shoe cover
    • VWR SHOECVR NSKID AP XL 150PR, 414004-650
    • VWR SHOECVR NSKID AP 2XL 150PR, 414004-651
  • Lab coat
    
    • VWR Lab coat L 82007-618 / XL 82007-620
  • Hat
    
    • VWR Hat 10843-053
  • Mask
    
    • VWR Face Masks 10869-020
  • Gloves
    
    • VWR GLOVE ACCTCH NR-LTX SZ7.5 PK25 79999-306 x4
    • VWR GLOVE ACCTCH NR-LTX SZ8 PK25 79999-308 x4
  • Plastic boxes for storage
    http://www.drillspot.com/products/422140/Rubbermaid_2282-00-CLR_18GAL_Clear_Snap_Case
    (We have 12 for now. More stored at the 40m)
     
• Completed Work: Optics
  • UV Lamp arrived (shipped from LLO)
    
  • Fiber light guide for UV lamp (Quote obtained / Ordered via techmart) 

Nic Smith sent me a bunch of elog lists where the results of the mode scan can be found.

From Nic:

There have been many mode scan analyses done at LLO:
http://ilog.ligo-la.caltech.edu/ilog/pub/ilog.cgi?group=detector&date_to_view=06/07/2008&anchor_to_scroll_to=2008:06:07:20:55:41-jrsmith
http://ilog.ligo-la.caltech.edu/ilog/pub/ilog.cgi?group=detector&date_to_view=06/16/2008&anchor_to_scroll_to=2008:06:16:17:47:11-waldman
http://ilog.ligo-la.caltech.edu/ilog/pub/ilog.cgi?group=detector&date_to_view=08/06/2009&anchor_to_scroll_to=2009:08:06:12:23:16-kissel
http://ilog.ligo-la.caltech.edu/ilog/pub/ilog.cgi?group=detector&date_to_view=09/25/2009&anchor_to_scroll_to=2009:09:25:20:57:47-kate

We didn't do as much of this at LHO. At some point we were trying to figure out how the arm cavity mode was different from the carrier mode:
http://ilog.ligo-wa.caltech.edu/ilog/pub/ilog.cgi?group=detector&date_to_view=04/17/2009&anchor_to_scroll_to=2009:04:17:23:15:05-kawabe
http://ilog.ligo-wa.caltech.edu/ilog/pub/ilog.cgi?group=detector&date_to_view=03/27/2009&anchor_to_scroll_to=2009:03:27:21:38:14-kawabe
http://ilog.ligo-wa.caltech.edu/ilog/pub/ilog.cgi?group=detector&date_to_view=02/18/2009&anchor_to_scroll_to=2009:02:18:20:15:00-kawabe

Here's a long mode scan that was done, and the data is attached to the elog, but none of the amplitudes are analyzed.
http://ilog.ligo-wa.caltech.edu/ilog/pub/ilog.cgi?group=detector&date_to_view=07/08/2009&anchor_to_scroll_to=2009:07:08:17:02:19-nicolas

I consulted with Margot about the cleaning of the optics

• Optics are considered as a clean object. Large dusts can be removed by ionized N2 flow etc.
• Barrel of optics can be wiped with Acetone.
• Optical surfaces are best to be cleaned by First Contact.
• A peek mesh should be embedded in the first contact so that the First Contact sheet can be easily removed.
• When peeling a F.C. sheet from a mirror surface, ionized N2 should be brown for discharging.
• If there are residuals visible on the mirror surface, it should be removed by Acetone. Don't use alchols.
• Use paper lens tissue for wiping as the lint free wipe can be eaten by Acetone.
• In fact, All of the procedure is described in a certain document.
• For a small amount, Margot can provide us a bottle of F.C. and some PEEK meshes.

Details of the Ionized N2 system

• This N2 should have higher purity than 4N (UHP - Ultra High Purity). This means we should use 4N - UHP or 5N - Research Grade.
• The ionized gun used in the clean room at Downs: made by Terra Universal.com
• Flow path: N2 cylinder - Filter - Gun

Nicolas Smith,
LIGO Document T0900383-v1
3mm Photodiode Characterization for Enhanced LIGO
https://dcc.ligo.org/cgi-bin/private/DocDB/ShowDocument?docid=4498

Tobin Fricke,
LIGO Document P1000010-v1
Homodyne detection for laser-interferometric gravitational wave detectors
https://dcc.ligo.org/cgi-bin/private/DocDB/ShowDocument?docid=8443

Nicolas Smith,
LIGO Document P1200052-v1
Techniques for Improving the Readout Sensitivity of Gravitational Wave Antennae
https://dcc.ligo.org/cgi-bin/private/DocDB/ShowDocument?docid=90498

• Completed Work: Facility/Supplies
  • Plug a big hole on the wall [ELOG]
  • Purchasing work benches
    
    • W60" x H28-34" x D30" http://www.globalindustrial.com/p/work-benches/systems/adjustable-height/60x30-esd-square-edge-power-apron-production-bench-blue
    • Lower shelf W60" http://www.globalindustrial.com/p/work-benches/systems/adjustable-height/60-w-lower-shelf-bench-15-d-blue
  • Wooden work benches removed(arranging the work with Louisa)
     
  • Al foils (All foils inc, should get a certificate everytime to ensure UHV compatibility)
  • Laser / UV safety glass/face mask (Ordered with Gina, UV face shield ordered through Techmart)
    • 35-200 Laser Glasses (PN 100-35-200) Qty.2 Price 189.00 ea
      http://www.lasersafetyindustries.com/35_200_Laser_Safety_Glasses_p/35-200.htm
    • Black Sport-wrap Laser Glasses 950-3600 nm (PN 100-38-200) Qty.1 Price 169.00 ea
      http://www.lasersafetyindustries.com/Black_Sport_wrap_Glasses_Diode_Nd_YAG_Er_YAG_p/100-38-200.htm
    • VWR has FACE SHIELD UVC-803 and this is ANSI-Z87.1 1986 compliant and the O.D. is more than 5.
      https://us.vwr.com/store/catalog/product.jsp?catalog_number=33007-151
  • Sticky mat
    
    • VWR MAT ADHESIVE 30L 18X36 BLU, 21924-110
  • Shoe cover
    • VWR SHOECVR NSKID AP XL 150PR, 414004-650
    • VWR SHOECVR NSKID AP 2XL 150PR, 414004-651
  • Lab coat
    
    • VWR Lab coat L 82007-618 / XL 82007-620
  • Hat
    
    • VWR Hat 10843-053
  • Mask
    
    • VWR Face Masks 10869-020
  • Gloves
    
    • VWR GLOVE ACCTCH NR-LTX SZ7.5 PK25 79999-306 x4
    • VWR GLOVE ACCTCH NR-LTX SZ8 PK25 79999-308 x4
  • Plastic boxes for storage
    http://www.drillspot.com/products/422140/Rubbermaid_2282-00-CLR_18GAL_Clear_Snap_Case
    (We have 12 for now. More stored at the 40m)
     
• Completed Work: Optics
  • UV Lamp arrived (shipped from LLO)
    
  • Fiber light guide for UV lamp (Quote obtained / Ordered via techmart)
  • Optical test planning by Zach [ELOG]
  • How to handle First Contact by Margot [ELOG]
  • Useful links / OMC scanning [ELOG]

Completed work of the previous months: [Jul] [Aug] [Sep] [Oct] [Nov] [Dec]

Facility/Supplies

• Work done
  • Floor cleaning [ELOG]
  • Placing sticky mats [ELOG]
  • Label Maker purchased
  • Ordered a lab desk at the west side of the room
    http://www.globalindustrial.com/p/work-benches/systems/adjustable-height/72-l-x-36-w-production-bench-esd-square-edge-blue-2
  • Ordered clean / ESD  stools (~25" height)
    http://www.globalindustrial.com/p/office/stools/vinyl/esd-safe-vinyl-clean-room-stool-with-nylon-base-with-drag-chain-blue
  • Asked Gina for the electronics rack
    www.racksolutions.com/server-racks-cabinets-enclosures.html
    36U Height / 20" depth + Caster kit
  • 5 shelves ordered from AlliedElectronics (Quest technology ES0319-0115, 19"x15" non-vented shelf)
    http://www.racksolutions.com/rack-shelves
  • Plug slits on the roof of the HEPA booth (Peter)
  • Laser safety barrier (Peter) [ELOG]
  • Workbenches and clean room stools [ELOG]
     
• Things ordered
  
  • Office Depot
    • [delivered] Office Depot(R) Brand Stretch Wrap Film, 20 x 1000 Roll, Clear / 445013
    • [delivered] Eveready(R) Gold AA Alkaline Batteries, Pack Of 24 / 158448
    • [delivered] Rubbermaid(R) Roller Sponge Mop / 921841
    • [delivered] Rubbermaid(R) Roller Sponge Mop Replacement / 921858
    • [delivered] Rubbermaid(R) Sanitizing Caddy, 10 Quarts, Yellow / 674125
    • [delivered] Glad(R) Tall Kitchen Trash Bags, 13 Gallon, White, Box Of 28 / 269268
  • Global Industrial Equipment
    
    • [delivered] Extended Surface Pleated Cartridge Filter Serva-Cell Mp4 Slmp295 12X24X2 Gl    WBB431699
  • Global Industrial Equipment
    
    • [delivered] Nexel Poly-Z-Brite Wire Shelving 30"W x 21"D x 63"H Nexel Poly-Z-Brite™ Wire Shelving Starter Unit WB189209
    • [delivered] Stem Casters Set of (4) 5" Polyurethane Wheel, 2 With Brakes 1200 lb. Capacity WB500592    
  • Rack Solutions
    • [delivered] Open Frame Server Racks
      1 x 20" Depth Kit (Ideal for Audio/Video or Networking Racks) P/N: 111-1779
      1 x 36U, Rack-111 Post Kit P/N: 111-1728
      1 x Caster Kit for Open Frame RACK-111 P/N: 111-1731
    • [delivered] 36U Side Panel Kit $199.99 P/N: 102-1775
  • Rack shelf
    • [delivered] 1 RMS 19 X 15 SINGLE SIDED NON-VENTED SHELF 70121637
  • Work bench, Stools
    • [not yet] 72"L X 30"W Production Bench - Phenolic Resin Square Edge-Blue Form attached WB237381LBL    
    • [not yet] 72"W Lower Shelf For Bench - 15"D- Blue Form attached WB606951    
    • [not yet] ESD-Safe Vinyl Clean Room Stool with Nylon Base with Drag Chain Blue Form attached WBB560852    
  • P Touch
    • [delivered] Brother PT-2030 Desktop Office Labeler Punch-out product 672828    
    • [delivered] Brother(R) TZe-241 Black-On-White Tape, 0.75 x 26.2 Punch-out product 239384    
    • [delivered] Brother(R) TZe-231 Black-On-White Tape, 0.5 x 26.2 Punch-out product 239400    
      
  • UV light guide
    • [delivered] Fiber Optic Single Light Guide 5mm OD X 3mm ID X 1M L Note: This light guide can be used with MKIII UV Cure unit. OLB1081
  • Gloves (7.5, 8.0)
    • [delivered] GLOVE ACCTCH NR-LTX SZ7.5 PK25 Punch-out product 79999-306
    • [delivered] GLOVE ACCTCH NR-LTX SZ8 PK25 Punch-out product 79999-308
  • Lab coat (L,XL), Sticky Mat, Shoe Covers (L, XL), Cap, Mask
    • [delivered] LAB XP WH EL WR.COLL. NP L30EA Punch-out product 82007-618
    • [delivered] LAB XPWH EL WR.COLL. NP XL30EA Punch-out product 82007-620    
    • [delivered] VWR MAT ADHESIVE 30L 18X36 BLU Punch-out product 21924-110 (This was too small)
    • [delivered] VWR SHOECVR NSKID AP 2XL 150PR Punch-out product 414004-651    
    • [delivered] VWR SHOECVR NSKID AP XL 150PR Punch-out product 414004-650    
    • [delivered] CAP BOUFFANT 24IN RAYON CS500 Punch-out product 10843-053    
    • [delivered] MASK VLTC TIES N/STRL PK50 Punch-out product 10869-020
      
  • VWR
    • [delivered] FACE SHIELD UVC-803 Supplier: UVP 33007-151
       
  • [Delivered] Laser safety glasses
    
    • 35-200 Laser Glasses (PN 100-35-200) Qty.2 Price 189.00 ea
      http://www.lasersafetyindustries.com/35_200_Laser_Safety_Glasses_p/35-200.htm
    • Black Sport-wrap Laser Glasses 950-3600 nm (PN 100-38-200) Qty.1 Price 169.00 ea
      http://www.lasersafetyindustries.com/Black_Sport_wrap_Glasses_Diode_Nd_YAG_Er_YAG_p/100-38-200.htm

• Work in progress
  
  • 
     
• Work to be done
  • Replacing a file cabinet next to the south wall by a lockable cabinet
  • Laser sign
  • Safety glass holder/rack/shelf
  • Prepare clean supplies ~ glove 8.5,9,9.5
  • Ion gun safety issues: https://dcc.ligo.org/cgi-bin/private/DocDB/ShowDocument?docid=88631
     　
• Design
  • Optical layout - Laser SOP
  • Additional HEPA stage
     
• Test
  • Confirm particle level
     
• Note: Optical Table W96" x D48" x H27"

Beaurocracy

• Laser SOP
• HV use?
• UV?

Mechanics

• Ongoing Work 
  • Cone-shaped wire clamp design (at the OMC end) - Jeff
     
• Design
  • Wire preparation fixture - Jeff
  • How do we hold the PDs, QPDs, and black glass - we put 2 PDs and 2 QPDs on the PD mounting blacket. - Jeff
  • Integrated solidwork model - Derek
    • Q: How the wires are clamped at the top side?
    • Q: How much the length of the wire should be?
    • Q: Locations of the wire mounts on the plate
  • Cabling investigation:
    • Where do the cables from the feed-thrus anchored?
    • List of the current internal cables and their lengths
    • List of the required internal cables and their lengths
    • Can we route the intermediate stage of the suspension? Do we need new cables?
  • Dummy intermediate stage structure
     
  • Metal templates
    • First, decide an optical design
    • takes at least a month
       
  • Weights how heavy / how many
     
  • Earthquake stop design (Sam B)
     
• Test
  • Cone-shaped wire clamp test - Jeff/Koji 
  • Balancing the plates
    • The Faraday isolator cage isn't clean
  • Dummy metal payload test at the sites???
     
• Procedures to be decided
  • PZT alignment
  • Prototyping with metal parts?
  • UV glue? (heat) / gluing test
  • Balance

Optics

• Things ordered
  
  • Newport LB servo
  • Halogen Lamp
  • N2 cylinder/lines/filter
• Ongoing Work 
  
  • Mirrors to be delivered ~Aug
     
  • Design down select - Between "Single output & BS" vs "Two outputs & no BS"
  • Down selecting procedure:
    
    1. Assume ELIGO beam component
    2. Assume amount of 9MHz / 45MHz sidebands at the OMC input
    3. Calculate transmitted power
    4. Require HOM to be smaller than the TEM00 offset 
        
  • UV cured epoxy (Quate obtained)
    
    • Electronic Materials Inc.'s Optocast 3553LV-UTF-HM
      (A Low Viscosity, Ultra Thin Film epoxy with Heat Mechanism. The assembly/cure procedure includes both a UV binding step and a 120 degree cure for 24 hours.)
    • Ref1: Dennis Coyne, LIGO-E960050-v11,
      https://dcc.ligo.org/cgi-bin/private/DocDB/ShowDocument?docid=3879
    • Ref2: Tobin Fricke, LIGO Document P1000010-v1, Homodyne detection for laser-interferometric gravitational wave detectors
      https://dcc.ligo.org/cgi-bin/private/DocDB/ShowDocument?docid=8443
    • Ref3: OMC Construction Wiki https://awiki.ligo-wa.caltech.edu/aLIGO/OMC_Construction
    • The glue should be stored at T<0degC ==> Freezer in a lab
       
• Design
  
  • Mode design for HAM6 layout
  • Finalization of scattering paths
     
• Tests
  • Measurement of PD angles
  • R&T of each mirror
  • Curvature of the curved mirrors
  • Cavity ref/trans/finesse
  • PD Q.E. & Reflectivity measurement vs incident angle
     
• Things to be decided / confirmed
  • How to handle optics / assemblies (Talk to the prev people)
  • First contact? (Margot: applicable to a short Rc of ~2.5m)
  • Gluing templates to be designed (how to handle it?)
     
• PDs
  • Primary choice for DC PD: Exelitas C30665GH 3mm
    Peter has plenty of them
    0.76A/W => Q.E. 0.88
    http://www.excelitas.com/downloads/dts_pe_pd_14_ingaasandsipindiodes.pdf
     
  • Primary choice for DC QPD: OSI FCI-InGaAs-Q3000
     
• Misc
  • CCD beam analyzer (Zach: It is fixed.)
  • Are two PZTs used?
    • YES, for redundancy, range, upconversion tests.
       
• Things to buy
  
  • Black Glass / Black Glass holder
  • Acetone.
  • N2 cylinder: 4N - UHP or 5N - Research Grade.
  • Paper lens tissue
  • Lint free cloth
  • The ionized gun used in the clean room at Downs: made by Terra Universal.com
    http://www.terrauniversal.com/static-control/ionizing-blow-off-guns.php
  • Flow path: N2 cylinder - Filter - Gun
  • Freezer
  • Clean tools, tray, storage

• Need to buy a fiber for mode cleaning?
  
• Mode content of the ELIGO dark beam?
• Jitter noise?
• How to determine the design?
• Why Fused Silica? (How much is the temp fluctuation in the chamber?)
• How to align the cavity mirrors, input mirrors, QPDs, PDs, beam dumps.
• PZTs @LLO
   

Electronics

• Thorough scrutinization of cabling / wiring / electronics
  • ELIGO OMC Wiring diagram D070536-A2
    • Occupies 2 DB25s -> They were anchored on the sus cage
    • Preamps for DCPDs will be fixed on the ISI table
      -> DB25 for the DCPDs will be anchored on the table
    • Use longer thin cables for the DCPDs in order to route them through the suspension stages
    • Turn the heater cable to the one for the other PZT
• Electronics / CDS electronics / software
• Things to be tested
  • QPD/PD pre-selections (QE/noise)
  • PD preamp design (Rich)
  • Functionality test of QPD/PD/PZT

Shipping, storage etc

• Shipping cage drawing
  https://dcc.ligo.org/cgi-bin/private/DocDB/ShowDocument?docid=70209

Jun/July
    - Lab renovation
Aug
    - Mechanics design
    - Mirror delivery
Sept
    - Basic optics test
    - Glue training
Oct
    - Cavity test
Nov
    - Suspending test
Dec
    - Shipping to LLO

Open questions
    Two optical designs
    Procedure
    Modeling
    Clamp design / stencil design
    gluing-installation procedure

- The floor of the room was cleaned and waxed!

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

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

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

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