 Tue May 23 16:30:09 2023, Thejas , Electronics, Characterization, A+ OMC Piezos LA coupling 
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Oplev setup was built: arm length about 2 m
As the PZT 44 was actuated with a drive voltage 0-150 V signal was observed on the Spectrum Analyser.
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Fri May 19 16:09:31 2023, Stephen, General, General, A+ OMC Build Progress, Week of 2023.05.15
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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 |
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Wed Apr 26 13:23:00 2023, Stephen, Optics, Characterization, PZT DC Response with Shadow Sensor - QPD Calibration
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[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 |
 Mon May 1 13:30:40 2023, Stephen, Optics, Characterization, PZT DC Response with Shadow Sensor - PD Calibration
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[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: |
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Tue May 2 12:49:43 2023, Stephen, Optics, Characterization, PZT DC Response with Shadow Sensor - First measurement attempt
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[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 |
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Thu May 4 11:39:19 2023, Stephen, Optics, Characterization, PZT DC Response with Shadow Sensor - First measurement attempt
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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 |
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Fri May 5 18:37:31 2023, Stephen, Optics, Characterization, PZT DC Response with Shadow Sensor - First measurement attempt
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[Thejas, Camille, Stephen]
In Downs 227 on 05 May 2023
We took the following actions: |
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Tue May 16 13:07:11 2023, Stephen, Optics, Characterization, PZT DC Response with Shadow Sensor - DC Response Qualitative Results, Batch 1
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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. |
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Thu May 4 15:12:14 2023, Koji, General, Characterization, OMC (004): Final Testing
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FSR measurement (dip) - done May 3, 2023
FSR measurement (RFAM injection) - done May 3, 2023
TMS
measurement with PZT1/2 swept from 0V~200V
Mirror cleaning / Power budget - done [OMC
ELOG 530]
PZT response DC / AC
DCPD shim height adjustment
QPD alignment / shim height adjustment
Alignment: |
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Tue May 16 10:26:12 2023, Koji, General, Characterization, OMC (004): Final Testing
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FSR measurement (dip) - done May 3, 2023
FSR measurement (RFAM injection) - done May 3, 2023
TMS
measurement with PZT1/2 swept from 0V~200V
Mirror cleaning / Power budget - done [OMC
ELOG 530]
PZT response DC / AC done May 11, 2023 [OMC ELOG 537]
DCPD |
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Mon May 15 14:20:03 2023, Thejas , Optics, Characterization, A+ OMC ROC 21x
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Herewith attached are the results of curved mirror radius of curvature characterization.
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Mon May 15 14:24:41 2023, Thejas , Optics, Characterization, A+ OMC ROC
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Koji's mirror measurement result attached herewith for comparison.
Quote:
Herewith attached are |
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Wed Apr 26 14:43:44 2023, Stephen, General, Loan / Lending, Borrowed Items for PZT DC Response Shadow Sensor Setup
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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 |
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Fri May 12 10:00:06 2023, Camille Makarem, General, Loan / Lending, Borrowed Items for PZT DC Response Shadow Sensor Setup
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The ThorLabs MDT694B piezo driver was returned to the OMC lab.
Quote:
Borrowed for PZT DC Response |
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Thu May 11 10:46:17 2023, Thejas , General, Characterization, aLIGO OMC
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[Thejas, Camille, Koji]
We aligned the laser beam to the cavity and drove the OMC cavity PZTs (0 to 5 V from signal generator with 15x amp from the piezo driver) with
a ramp signal and logged the transmission mode spectrum. The drive PZT voltage changes from 3.4 V to 7 V for one fringe shift or half wavelength change |
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Fri Apr 28 14:24:03 2023, Thejas , Optics, Characterization, A+ OMC Matching
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[Thejas, Camille, Stephen]
Here are some notes on how I plan to approach matching of the PZTs, mounting prisms and curved optics.
Step 1: Match the prisms and the PZTs such that resulitng 18 combiations will have minimum vertical wedging. |
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Fri Apr 28 13:25:40 2023, Thejas , Optics, General, aLIGO OMC Unit-4
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[Camille, Koji, Thejas]
Yesterday, we cleaned the cavity optics with first contact, aligned the input laser beam to the cavity and measured the power at different
terminals on the cavity breadboard. |
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Mon Apr 24 15:29:48 2023, Camille Makarem, Optics, , summary of zygo setups 6x
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Summary of Zygo setups
Initial Zygo Setup:
Our initial Zygo setup consisted of a flat transmission sphere with the 0.5" curved mirror mounted against a 1" flat mirror. |
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Tue Apr 11 16:18:25 2023, Thejas, Optics, Characterization, A+ OMC Curved mirror radius of curvature
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Curved mirror radius of curvature raw data can be found in the DCC document: T2300050
The input beam falling on the curved optic was characterized. The beam waist and it's position was found by curve fitting gaussian beam
propagation formula in near field: |
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Wed Apr 19 14:28:08 2023, Thejas, Optics, Characterization, A+ OMC Curved mirror radius of curvature
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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. |
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Tue Apr 18 07:59:46 2023, Madeline Lesovsky, General, General, Test Cure Bake - Curved Mirror Subassembly Bonding 6x
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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. |
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Mon Apr 17 17:56:25 2023, Thejas , Optics, Characterization, A+ OMC Piezos wedge angle 19x
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PZT dimension analyzed and characterized. The blue dot in the images represents the position of the cathode. The length of the arrows indicates the amount
of wedging.
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Fri Apr 14 15:52:53 2023, Camille Makarem, Optics, Characterization, Determining the curvature bottom of the curved mirrors
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[Camille, Thejas]
We repeated Zygo measurements (using the same setup and method as below) for curved mirrors sn07, sn11, sn12, sn18, sn19, sn25, sn26, and sn30.
sn11 and sn25 still show a large spread in angular measurements (see attached.) This is attributed to the low decentering values for these two |
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Fri Apr 14 16:36:29 2023, Thejas, Optics, Characterization, Determining the curvature bottom of the curved mirrors 21x
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Attached here with are relevant plots.
Quote:
[Camille, Thejas] |
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Thu Apr 13 07:47:28 2023, Camille Makarem, Optics, Characterization, Zygo setup for curved mirror measurements
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[Camille, Thejas, Stephen]
We modified the Zygo setup for measuring the sagitta of the curved mirrors. A mirror at 45deg was used to reflect the interferometer beam down
towards the surface of the table (see picture). A fused silica flat was placed horizontally with the surface of the table and was used as our reference |
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Wed Apr 5 22:09:30 2023, Koji, Facility, General, HEPA Enclosure extension
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| Chub finished the HEPA enclosure extension project. |
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Tue Apr 4 16:14:06 2023, Koji, Optics, Loan / Lending, C7 mirror to Downs
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| I handed Camille the C7 mirror for the cross-calibration of the ROC characterization techniques. |
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Mon Apr 3 11:06:47 2023, Thejas , Optics, Characterization, Flat mirror flatness
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Data can be found in DCC document T2300050.
On Friday. Camille and I measured the flatness of the flat mirror. Tilt values (without subtracting tilt) were less than 100 nm and PV |
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Tue Mar 28 11:21:27 2023, Camille Makarem, Optics, Characterization, Sagitta measurements of curved mirrors
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[Camille, Stephen, Thejas]
Curved mirror sn02 was used to test the method for collecting Zygo measurements on the curved mirrors. The curved mirror was mounted with its back |
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Fri Mar 24 07:47:37 2023, Camille Makarem, Optics, Characterization, ROC measurements of the curved mirrors
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[Camille]
22 March 2023
Beam profile measurements were continued for more of the curved mirrors. |
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Fri Mar 24 07:38:54 2023, Camille Makarem, Optics, Characterization, ROC measurements of the curved mirrors
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[Thejas, Camille]
21 March 2023
We made slight adjustments to the beam expander lenses in the ROC setup. The position of the second lens was moved slightly (a few mm) to improve |
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Tue Mar 14 18:24:03 2023, Thejas , Optics, Characterization, A+ OMC Curved mirror radius of curvature
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Today, I tried to measure the radius of curvature of the curved mirror using the input beam for the OMC test set-up. It was noticed that the half inch
curved optic (ROC=2.5 m), when placed within the Rayleigh range of the beam waist, did not focus the beam. This is probably becasue the beam diameter is
small for this optic's radius of curvature to produce any focussing. This can be illustrated even further using the JAMMT software by replacing |
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Tue Mar 14 20:06:03 2023, Koji , Optics, Characterization, A+ OMC Curved mirror radius of curvature
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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.
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Wed Mar 15 15:28:24 2023, Thejas , Optics, Characterization, A+ OMC Curved mirror radius of curvature
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Thanks for teh comment Koji. Yes, I did see this effect by comparing the beam sizes with and without the curved mirror. But the observation did not conform
with the expectation that the beam should focus at a distance of 1.25 m from the curved mirror (as seen in the software images). So, I plan to
use some lenses to increase the beam waist and perform the measurement. |
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Wed Mar 15 17:07:35 2023, Koji , Optics, Characterization, A+ OMC Curved mirror radius of curvature
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| 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. |
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Fri Mar 17 15:01:21 2023, Koji , Optics, Characterization, A+ OMC Curved mirror radius of curvature
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Thanks Koji, the lenses available in the cabinet in the lab actually sufficed.
Quote:
I hope you can find useful |
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Tue Mar 14 10:41:06 2023, Thejas , Optics, Characterization, A+ OMC curved mirror characterization
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[Camille, GarriLynn, Stephen, Thejas]
Folllowing the replacement of the spherical transmission / reference mirror with a flat mirror, on Friday we were able to observe fringes that
facilitated characterization of the curvature minimum. |
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Tue Mar 14 12:12:41 2023, Koji , Optics, Characterization, A+ OMC curved mirror characterization
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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. |
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Fri Mar 10 11:12:57 2023, Thejas , Optics, Characterization, A+ OMC Curvature minimum of curved optics
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[GariLynn, Stephen, Thejas]
Yesterday, we placed an iris (borrowed from OMC Lab) infront of the spherical transmission sphere to limit the spot size, on the other end of
the cavity, to only the curved optic. This produced a crisp boundary for the interference pattern. We obtained some data at different imaging focal planes. |
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Fri Mar 10 10:23:08 2023, Thejas, Optics, Characterization, A+ OMC curved mirror radius of curvature
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OMC test set-up
Yesterday, laser beam output from the fibre follwoing teh mode-matching lenses was picked off and beam profile was characterized using beam profiler Thorlabs
BP209-VIS. |
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Wed Mar 8 17:27:51 2023, Thejas , Optics, Characterization, A+ OMC Curvature minimum of curved optics
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[Stephen, Thejas]
Today, a more rigorous effort was made to re-measure the position of the optics forming the Fizeau cavity and re-position the curved optic to
get more contrasting fringes. Distance measurements were made using a Fluke laser displacement sensor. We obtained a contrasting fringe pattern but the |
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Tue Mar 7 23:00:16 2023, Thejas , Optics, Characterization, OMC Lab clean up
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Today, Koji and I cleaned up the the lab space and made some space on the optical table for radius of curvature measurement of the A+ OMC curved
mirrors.
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Tue Mar 7 10:20:55 2023, Thejas , Optics, Characterization, A+ OMC Curved mirror radius of curvature
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[Camille, Stephen, Thejas]
Stephen returned the curved mirror #6 to Liyuan for point transmission measurement. We are now using #5 for to setup/align the ZYGO Fizeau
interferometer setup to characterize the curvature center of the mirrors. It was setup such that the focal point of the input reference sphere was coincident |
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Mon Mar 6 16:02:56 2023, Thejas , Optics, General, OMC test setup locking
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On Feb 16, Camille and I attampted at locking the OMC cavity. It was quick to re-align the beam to the cavity (by using only the fine adjustment
of the output fibre couple). This was done by looking to minimize the power reflected from the cavity and observing the mode shapes on the CCD.
After we achieved locking we placed the lid of the OMC back and turned off the laser. |
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Mon Mar 6 12:25:08 2023, Koji, Facility, General, HEPA Enclosure improvement
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| Chub, JC, and co worked on the HEPA enclosure improvement. |
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Wed Mar 1 10:23:10 2023, Thejas , Optics, Characterization, A+ OMC curved mirror characterization
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[Camille, Thejas, Stephen]
Yesterday, efforts were made to measure ROC of curved mirrors (#6) in the ZYGO lab using a Fizeau Interferometer. Peculiar observation: Stray
fringes were seen that dominated the fringes that conformed with the expectation. The origin of these fringes is still not accounted for (see attached |
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Mon Feb 27 17:40:27 2023, Thejas , Optics, Characterization, A+ OMC curved mirror characterization
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[Camille, Stephen, Thejas]
Today, before the ZYGO lab was cleaned and prepared for the cureved mirrors' radius of curvature (ROC) characterization, Mirror no. 6 was
mounted into one of the half inch mirror holders. The cleanliness of the envoronment and handling was not satisfactory. Tomorrow efforts will |
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Fri Feb 17 17:41:57 2023, Thejas , Electronics, Characterization, A+ OMC Piezos wedge angle
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[Camille, Stephen, Thejas]
PZT model: Noliac 2124
Qty: 18 (Sr. No. 30 - 48) |
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Fri Feb 17 17:25:39 2023, Thejas , Optics, Characterization, A+ OMC Breadboard measuerements
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Yesterday we also measured weight and dimensions of breadboard. Error for the following measurements is same as the least count of the instruments used.
26
6149 g |
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Fri Feb 17 17:11:28 2023, Thejas , Optics, Characterization, A+ OMC beam-splitter prisms wedge angle measurement 11x
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[Camille, Stephen, Thejas]
Yesterday we measured wedge angle of the beamsplitter (BS) prisms. I reckon these measurements are not as important as the BSs will be used |
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Wed Feb 15 17:40:21 2023, Thejas , Optics, Characterization, A+ OMC perpendicularity of hole prisms 20x
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[Camille, Stephen, Thejas]
Contnuing the efforts to measure and check perpendicularity: tombstone prisms with holes/ hole prisms (HP).
Note: Veritcal crosshair splitting can be seen in the some of the image. This is probably because the horizontal of the Al flat |
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Sat Feb 4 03:30:02 2023, Koji, Electronics, General, OMC cables #4 arrived
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The OMC cables #4 arrived on Feb 3rd. (See Attachment)
This shipment included two DCPD cables and two QPD cables. It means that the direct wiring from the PZT to the mighty mouse connectors was not
included in the shipment. |
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Wed Feb 15 16:00:46 2023, Stephen, Electronics, General, OMC cables #4 inspected
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Inspection
Updated ICS (Shipment-12578) and moved those parts to Storage-9482.
Inspection showed the following: |
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Tue Feb 14 22:52:35 2023, Thejas , Optics, Characterization, A+ OMC Prism perpendicularity of HR Prisms and BS 18x
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[Camille, Stephen, Thejas]
Continuing with the efforts to measure the perpndicularity.
Prism 15 |
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Tue Feb 14 10:45:00 2023, Thejas , Optics, Characterization, A+ OMC Prism perpendicularity 27x
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[Camille, Stephen, Thejas]
Following the wedge angle measurements of the prisms, perpendicularoty of their bottom surface with respect to their HR surface was measured
usign the autocollimator. More info. about the procedure can be found in the OMC testing document. We want to set the requiremetns for perpendicularity |
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Thu Feb 9 15:54:41 2023, Thejas , Optics, Characterization, A+ OMC, Parallelism of HR Prisms 19x
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[Camille, Thejas, Stephen]
Continuing yesterday's efforts to measure the wedge angle of the back surface of the prisms. We completed measurement for all the 18 prisms.
The images below accompanying the readings represent the S2 crosshair image on top of the reticle, alighned for yaw. |
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Wed Feb 8 16:10:52 2023, Stephen, Optics, Characterization, A+ OMC, Parallelism of HR Prisms 7x
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[Camille, Thejas, Stephen]
We set up the white light autocollimator in the Downs B119 cleanroom. (Nippon Kogaku, from Mike Smith).
|
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Sat Feb 4 03:33:22 2023, Koji, General, General, OMC Lab Inventory
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Attachment 1: North Cabinet 2nd from the left
Attachment 2: North Cabinet 3rd from the left
Attachment 3: South Cabinet (right) |
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Sat Feb 4 03:22:46 2023, Koji, Facility, General, Ready for the HEPA enclosure expansion
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HEPA is quite low for a tall person and also the curtain on the back of us is always heavy. It's very tough for anyone to work with. (See Attachment
1)
I did the lab and table organization so that the HEPA expansion work can be resumed. |
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Thu Jan 19 23:45:44 2023, Koji, Optics, General, OMC #4: cavity mirror bonding
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[Koji, Camille]
We worked on the bonding of the flat mirrors for the OMC cavity with UV epoxy.
- Prepared the UV illumination setup. Cleaned up the table a bit to spare some space for the illuminator. |
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Mon Jan 23 19:51:20 2023, Koji, Optics, General, OMC #4: cavity mirror bonding
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[Camille, Koji]
We continued to bond two CM mirrors and the other two steering mirrors for QPD2.
Before the bonding work, the FSR and TMSs were checked again. |
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Thu Jan 26 22:57:19 2023, Koji, Optics, General, OMC #4: One Invar block bonded with tilt
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[Camille, Koji]
The bottom side template was separated into two pieces and successfully removed from the breadboard. The template was assembled together again
and bagged to store it in a cabinet. |
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Thu Feb 2 03:09:41 2023, Koji, Optics, General, OMC #4: One Invar block bonded with tilt
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[Camille, Thejas, Koji]
We added a reinforcement bar at the back of the invar block which had the tilt issue.
The reinforcement bar was added to the backside rather than the side or front such that the DCPD housing does not interfere with the reinforcement |
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Sat Feb 4 03:16:10 2023, Koji, Optics, General, OMC #4: One Invar block bonded with tilt
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The attached photo shows the resulting bond spread.
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Wed Feb 1 01:44:14 2023, Koji, General, General, OMC (004) plan
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2/1 2:30PM~ Bonding reinforcement (Last EP30-2 gluing)
2/2 1:00PM~ Peripheral attachment / Optical testing setup |
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Wed Feb 1 01:39:41 2023, Koji, Mechanics, General, DCPD housing / QPD housing
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| Inserted 4-40 and 2-56 helicoils into the DCPD/QPD housings for the 4th OMC. The retainer caps were also fastened to the housings. |
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Mon Nov 9 22:06:18 2020, Koji, Mechanics, General, 5th OMC Transport Fixture
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I helped to complete the 5th OMC Transport Fixture. It was built at the 40m clean room and brought to the OMC lab. The fixture hardware (~screws) were
also brought there. |
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Wed Feb 1 01:33:03 2023, Koji, Mechanics, General, 5th OMC Transport Fixture
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| The transport fixture was brought to the 40m clean room to use as an assembly reference. |
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Sat Jan 28 00:46:21 2023, Koji, Mechanics, General, OMC #4: Replaced the locks of the transport fixture
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Yesterday, we noticed that we could not close the transport fixture for OMC #4. We could not fully rotate the knobs of the locks. Today, I took the hooks
from the functioning locks of the spare transport fixture.
It turned out that the default dimension of the lock seemed too tight. The functioning one has the through holes elongated by a file or something. |
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Sat Jan 28 00:38:56 2023, Koji, Mechanics, General, OMC #1 cable bracket replacement / OMC #1 repair completed
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The AL metal bracket was replaced with a PEEK version.
Attachments 1/2: Before the replacement. The photos show how the cables are arranged.
Attachment 3: How the replacement work is going. The 1/4-20 screws were super tight. Once the connectors were removed, an Allen key was inserted |
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Tue Nov 15 07:46:58 2022, Camille Makarem, Optics, General, cleaning OMC #1
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Monday, November 14, 2022
Camille and Koji did a "deep cleaning" of OMC#1:
1) Applied First Contact to the mirror surfaces. Removed first contact after ~10 minutes. |
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Tue Nov 15 10:58:53 2022, Koji, Optics, General, OMC #1 damaged black glass removal
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[Camille, Koji]
The damaged black glass was removed from the OMC breadboard leaving the glass base.
The black glass pieces were bonded very tightly on the FS base with EP30-2. The apparent amount of the bond was not so much but it was such hard |
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Tue Nov 15 11:12:24 2022, Koji, Optics, General, OMC #1 fogging on the AR side of BS1 cleaned
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[Camille, Koji]
Photo of the BS1 AR cleaning process
Attachment 1: Before cleaning. Foggy surface is visible. |
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Thu Jan 26 23:46:13 2023, Koji, Optics, General, OMC #1 input beam dump bonding
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A beam dump was stacked on the base of the previous beam dump. The angle was determined so that the main transmission goes through while the stray OMC
reflection is blocked without clipping at the edge.
The resulting alignment of the beam dump is shown in Attachment 1. |