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ID Dateup Author Type Category Subject
  252   Wed Dec 21 14:32:41 2016 GabrieleGeneralMeasurementsS1600457 after cleaning

2016-12-21

  • 2:22pm, in chamber, balanced
  • 2:23pm, roughing pump on
  • 2:33pm, turbo pump on
  • 5:00pm, clean air filters off
  • Excitations:
    • Quiet time before excitation: 1166403765
      Excitation (broad band) at 1166403798 (120 s)
      Quiet time after excitation: 1166403920

    • Quiet time before excitation: 1166404850
      Excitation (broad band) at 1166404882 (120 s)
      Quiet time after excitation: 1166405004

    • Quiet time before excitation: 1166405934
      Excitation (broad band) at 1166405966 (120 s)
      Quiet time after excitation: 1166406088

    • Quiet time before excitation: 1166407018
      Excitation (broad band) at 1166407050 (120 s)
      Quiet time after excitation: 1166407172

    • Quiet time before excitation: 1166408103
      Excitation (broad band) at 1166408136 (120 s)
      Quiet time after excitation: 1166408258

2016-12-22

  • 8:56am, pumps off
  253   Thu Dec 22 09:47:58 2016 GabrieleGeneralMeasurementsS1600458 after cleaning

 

2012-12-22

  • 9:46am, in chamber, balanced, removed ND0.3
  • 9:48am, roughing pump on
  • 9:59am turbo pump on
  • Excitations:
    • Quiet time before excitation: 1166473512
      Excitation (broad band) at 1166473544 (60 s)
      Quiet time after excitation: 1166473606

    • Quiet time before excitation: 1166474536
      Excitation (broad band) at 1166474568 (60 s)
      Quiet time after excitation: 1166474630

    • Quiet time before excitation: 1166475561
      Excitation (broad band) at 1166475593 (60 s)
      Quiet time after excitation: 1166475655

    • Quiet time before excitation: 1166476585
      Excitation (broad band) at 1166476618 (60 s)
      Quiet time after excitation: 1166476680

  • Another excitation with HF boost (zeros 2x2000Hz / poles 2x5000Hz)
    • Quiet time before excitation: 1166477610
      Excitation (broad band) at 1166477642 (60 s)
      Quiet time after excitation: 1166477704

2016-12-27

  • Excitations:
    • Quiet time before excitation: 1166897529
      Excitation (broad band) at 1166897561 (60 s)
      Quiet time after excitation: 1166897623

    • Quiet time before excitation: 1166898553
      Excitation (broad band) at 1166898585 (60 s)
      Quiet time after excitation: 1166898647

    • Quiet time before excitation: 1166899577
      Excitation (broad band) at 1166899609 (60 s)
      Quiet time after excitation: 1166899671

    • Quiet time before excitation: 1166900601
      Excitation (broad band) at 1166900633 (60 s)
      Quiet time after excitation: 1166900695

    • Quiet time before excitation: 1166901625
      Excitation (broad band) at 1166901658 (60 s)
      Quiet time after excitation: 1166901720

2017-01-03

  • Quiet time before excitation: 1167513943
    Excitation (broad band) at 1167513975 (60 s)
    Quiet time after excitation: 1167514037
  • Quiet time before excitation: 1167514967
    Excitation (broad band) at 1167515000 (60 s)
    Quiet time after excitation: 1167515062
  • Quiet time before excitation: 1167515992
    Excitation (broad band) at 1167516025 (60 s)
    Quiet time after excitation: 1167516087
  • Quiet time before excitation: 1167517017
    Excitation (broad band) at 1167517050 (60 s)
    Quiet time after excitation: 1167517112
  • Quiet time before excitation: 1167518042
    Excitation (broad band) at 1167518074 (60 s)
    Quiet time after excitation: 1167518136

2017-01-05

  • 11:30am, sample removed from chamber
  254   Wed Jan 4 14:28:03 2017 GabrieleElectronicsConfigurationReal time models for new measurement system
  • changed the name of the test chamber real time model from CR1 to CR0. Updated all MEDM screens and scripts (autocenter.py, auto_excite.py, crime.py)
  • created new real time models CR1, CR2, CR3, CR4 to be used for the new chamber system. Created MEDM screens and updated all EPICS values
     
  255   Fri Jan 6 11:23:10 2017 GabrieleGeneralMeasurementsMark Optics 4

This is one of the samples we got from the first batch, no flats, edge not polished

2017-01-06

  • 11:10am, in chamber, balanced
  • 11:11am, roughing pump on
  • 11:23am, turbo pump on
  • Excitations:
    • Quiet time after excitation 1167770663
    • Quiet time before excitation: 1167781499
      Excitation (broad band) at 1167781532 (60 s)
      Quiet time after excitation: 1167781594

    • Quiet time before excitation: 1167792424
      Excitation (broad band) at 1167792457 (60 s)
      Quiet time after excitation: 1167792519

    • Quiet time before excitation: 1167803349
      Excitation (broad band) at 1167803381 (60 s)
      Quiet time after excitation: 1167803443

    • Quiet time before excitation: 1167814274
      Excitation (broad band) at 1167814306 (60 s)
      Quiet time after excitation: 1167814368

2017-01-10

  • 10:15am pumps stopped

​Results

2017-01-06A

2017-01_06B

2017-01-06C

2017-01-06D

  256   Fri Jan 6 12:19:22 2017 Alena, Bob, Stephen and CalumGeneralDaily ProgressSecond vacuum chamber

Cleaning and baking (200 C air foe SS and 120 for Al) parts for the new vacuum chamber

  257   Tue Jan 10 11:29:23 2017 GabrieleGeneralMeasurementsS1600459 post deposition

Note:Coated with tantala at 400C

2017-01-10

  • 11:15am in chamber, balanced, added ND0.3 to reduce power on QPD and avoid saturation (got 195 uW total)
  • 11:16am roughing pump on
  • 11:29am turbo pump on
  • Excitations
    • Quiet time before excitation: 1168122715
      Excitation (broad band) at 1168122748 (60 s)
      Quiet time after excitation: 1168122810

    • Quiet time before excitation: 1168124040
      Excitation (broad band) at 1168124072 (60 s)
      Quiet time after excitation: 1168124134

    • Quiet time before excitation: 1168125364
      Excitation (broad band) at 1168125397 (60 s)
      Quiet time after excitation: 1168125459

    • Quiet time before excitation: 1168126689
      Excitation (broad band) at 1168126721 (60 s)
      Quiet time after excitation: 1168126783

    • Quiet time before excitation: 1168128013
      Excitation (broad band) at 1168128045 (60 s)
      Quiet time after excitation: 1168128107

    • Quiet time before excitation: 1168129337
      Excitation (broad band) at 1168129369 (60 s)
      Quiet time after excitation: 1168129431

       

       

       

  258   Tue Jan 10 16:50:20 2017 GabrieleGeneralMeasurementsS1600461 post deposition

Note:Coated with tantala at 400C

2017-01-10

  • 4:48pm, in chamber, balanced
  • 4:49pm, roughing pump on
  • 5:02pm, turbo pump on
  • Excitations
    • Quiet time before excitation: 1168141883
      Excitation (broad band) at 1168141915 (60 s)
      Quiet time after excitation: 1168141977

    • Quiet time before excitation: 1168145607
      Excitation (broad band) at 1168145639 (60 s)
      Quiet time after excitation: 1168145701

    • Quiet time before excitation: 1168149331
      Excitation (broad band) at 1168149363 (60 s)
      Quiet time after excitation: 1168149425

    • Quiet time before excitation: 1168153055
      Excitation (broad band) at 1168153088 (60 s)
      Quiet time after excitation: 1168153150

    • Quiet time before excitation: 1168156780
      Excitation (broad band) at 1168156813 (60 s)
      Quiet time after excitation: 1168156875

    • Quiet time before excitation: 1168160505
      Excitation (broad band) at 1168160538 (60 s)
      Quiet time after excitation: 1168160600

2017-01-11

  • 8:22am, pumps off
  259   Wed Jan 11 09:01:59 2017 GabrieleGeneralMeasurementsS1600448 post deposition

Note: coated with tantala at 480C

2017-01-11

  • 9:00am in chamber, balanced
  • 9:01am, roughing pump on
  • 9:12am turbo pump on
  • Excitations:
    • Quiet time before excitation: 1168213704
      Excitation (broad band) at 1168213737 (60 s)
      Quiet time after excitation: 1168213799
       
    • Quiet time before excitation: 1168215629
      Excitation (broad band) at 1168215662 (60 s)
      Quiet time after excitation: 1168215724
    • Quiet time before excitation: 1168217554
      Excitation (broad band) at 1168217586 (60 s)
      Quiet time after excitation: 1168217648

    • Quiet time before excitation: 1168219478
      Excitation (broad band) at 1168219510 (60 s)
      Quiet time after excitation: 1168219572

    • Quiet time before excitation: 1168221402
      Excitation (broad band) at 1168221435 (60 s)
      Quiet time after excitation: 1168221497

    • Quiet time before excitation: 1168223327
      Excitation (broad band) at 1168223359 (60 s)
      Quiet time after excitation: 1168223421

​2017-01-12

  • 8:37am, pumps off
  260   Thu Jan 12 10:09:41 2017 GabrieleGeneralMeasurementsS1600453 post deposition

Note: coated with tantala at 480 C

2017-01-12

  • 10:07am in chamber, balanced
  • 10:09am, roughing pump on
  • 10:22am, turbo pump on
  • Excitations:
    • Quiet time before excitation: 1168291819
      Excitation (broad band) at 1168291851 (60 s)
      Quiet time after excitation: 1168291913

    • Quiet time before excitation: 1168293743
      Excitation (broad band) at 1168293775 (60 s)
      Quiet time after excitation: 1168293838

    • Quiet time before excitation: 1168295668
      Excitation (broad band) at 1168295701 (60 s)
      Quiet time after excitation: 1168295763

    • Quiet time before excitation: 1168297593
      Excitation (broad band) at 1168297625 (60 s)
      Quiet time after excitation: 1168297687

    • Quiet time before excitation: 1168299517
      Excitation (broad band) at 1168299549 (60 s)
      Quiet time after excitation: 1168299611

    • Quiet time before excitation: 1168301442
      Excitation (broad band) at 1168301474 (60 s)
      Quiet time after excitation: 1168301536

  • More excitations:
    • Quiet time before excitation: 1168314406
      Excitation (broad band) at 1168314438 (60 s)
      Quiet time after excitation: 1168314500

    • Quiet time before excitation: 1168316330
      Excitation (broad band) at 1168316362 (60 s)
      Quiet time after excitation: 1168316424

    • Quiet time before excitation: 1168318254
      Excitation (broad band) at 1168318287 (60 s)
      Quiet time after excitation: 1168318349

    • Quiet time before excitation: 1168320179
      Excitation (broad band) at 1168320212 (60 s)
      Quiet time after excitation: 1168320274

    • Quiet time before excitation: 1168322104
      Excitation (broad band) at 1168322136 (60 s)
      Quiet time after excitation: 1168322198

    • Quiet time before excitation: 1168324028
      Excitation (broad band) at 1168324060 (60 s)
      Quiet time after excitation: 1168324122

2017-01-13

  • 2:11pm, pumps off

 

 

 

  261   Thu Jan 12 10:36:47 2017 GabrieleElectronicsConfigurationAdded ESD bias path to model CR0

I added to the model CR0 an additional bias path for the ESD driver:

Some funny RGC idiosyncrasy: if you have a filter bank named "SUM", you can't add a summation block: if you do you get a name conflict at compilation time. That's why I used a matrix

Updated the MEDM screen accordingly

A quick test shows that working with a bias does not improve the ability to excite the modes. The DAC saturates at +-32k, which corresponds to +-10V out of the ADC, matched to the input range of the HV amplifier. The largest excitation of high frequency modes is obtained by using white noise, no bias, and maximum amplitude.

  262   Wed Jan 18 14:02:56 2017 GabrieleGeneralMeasurementsS1600466 control sample

2017-01-18

  • 2:01pm, in chamber, balanced, removed ND
  • 2:02pm, roughing pump on
  • 2:14pm, turbo pump on
  • Excitations:
    • Quiet time before excitation: 1168833851
      Excitation (broad band) at 1168833883 (60 s)
      Quiet time after excitation: 1168833945

    • Quiet time before excitation: 1168844775
      Excitation (broad band) at 1168844808 (60 s)
      Quiet time after excitation: 1168844870

    • Quiet time before excitation: 1168855700
      Excitation (broad band) at 1168855732 (60 s)
      Quiet time after excitation: 1168855794

2017-01-19

  • 10:29am, pumps off

​Results

The plot below compare the measured Q before and after the sample was sent to Montreal. The Q values measured after are systematically lower. According to the notes received from the Montreal group, this sample has been through quite many things, see below.

Attachment 2: Screen_Shot_2017-01-19_at_9.33.33_AM.png
Screen_Shot_2017-01-19_at_9.33.33_AM.png
  263   Wed Jan 18 14:29:16 2017 AlenaGeneralAnnealingAnnealing run (489-490) on 3" wafers - Crime 01/18/2017


Started annealing run Annealing run (489-490) on 3" wafers - Crime 01/18/2017 https://dcc.ligo.org/T1700027 using new hardware

 

  264   Thu Jan 19 07:32:33 2017 AlenaGeneralVacuumNew chamber first pimp down

The new chamber was build. The first attempt to pump down was unsuccessful because of dislocated lid. After the lit was placed properly, the chamber was pumped down to 0.1 torr within 8 min. In future a sky hook will be used to help placing the lid properly. The clamps should not be placed on the lid before the roughing pump turned on.

The turbo pump controller failed. Error code 698 – call the vendor.

  265   Thu Jan 19 12:49:17 2017 GabrieleFacilityVacuumSkyhook installed

The SkyHook has been put in place and bolted down to the floor.

Attachment 1: IMG_4241.JPG
IMG_4241.JPG
Attachment 2: IMG_4241.JPG
IMG_4241.JPG
Attachment 3: IMG_4241.JPG
IMG_4241.JPG
  266   Thu Jan 19 14:16:53 2017 GabrieleMechanicsDesignNew concept for retaining ring motion

Since my experiment with coil and magnets didn't work out very well, here's a new concept for the motion of the four retaining rings (all together) using a translation stage and a picomotor. This follows the same idea put forward by Steve Penn. The translation stage is a Newport 9066-COM-V and the picomotor (which we already have) is a Newport 8301-V. Both stage and picomotor are vacuum compatible (rated at 1e-6 Torr) and tested down to 1e-8 Torr by Steve.

Here's the jig integrated in the full system:

 

  267   Thu Jan 19 14:27:02 2017 AlenaGeneralVacuumFirst vacuum test new chamber

Turbo pump controller (new chamber) was configured. Need to reduce the frequency or setup a standby mode. First pump down: E-7 range reached within about an hour. See plot: blue - old crime chamber, pink - new crime chamber.

  268   Fri Jan 20 11:24:39 2017 GabrieleGeneralMeasurementsS1600489

2017-01-20

  • 10:58am, in chamber, balanced
  • 10:59am, roughing pump on
  • 11:24, turbo on
  • Excitations
    • Quiet time before excitation: 1168999600
      Excitation (broad band) at 1168999633 (60 s)
      Quiet time after excitation: 1168999695

    • Quiet time before excitation: 1169010525
      Excitation (broad band) at 1169010557 (60 s)
      Quiet time after excitation: 1169010619

    • Quiet time before excitation: 1169021449
      Excitation (broad band) at 1169021482 (60 s)
      Quiet time after excitation: 1169021544

    • Quiet time before excitation: 1169032374
      Excitation (broad band) at 1169032406 (60 s)
      Quiet time after excitation: 1169032468

2017-01-21

  • 2:14pm, pumps off
  269   Fri Jan 20 16:00:36 2017 AlenaGeneralAnnealingAnnealing run (491-496) on 3" wafers - Crime 01/20/2017

 Started Annealing run (491-496) on 3" wafers - Crime 01/20/2017 https://dcc.ligo.org/LIGO-T1700036 Will be done by Monday

  270   Fri Jan 20 17:20:20 2017 GabrieleOpticsDaily ProgressInput part of the optical lever setup installed and aligned

Today I installed and aligned part of the optical components for the optical lever of the new setup. For the moment being I installed only the input components, and aligned the beams into the vacuum chamber. Since I don't have any in-vacuum optics yet, there's nothing more that can be done now.

  271   Sat Jan 21 15:55:04 2017 GabrieleGeneralMeasurementsS1600490

2017-01-21

  • 3:43pm, in chamber, balanced
  • 3:44pm, roughing pump on
  • 3:55pm turbo pump on
  • Excitations:
    • Quiet time before excitation: 1169095612
      Excitation (broad band) at 1169095644 (60 s)
      Quiet time after excitation: 1169095706

    • Quiet time before excitation: 1169106536
      Excitation (broad band) at 1169106568 (60 s)
      Quiet time after excitation: 1169106630

    • Quiet time before excitation: 1169117460
      Excitation (broad band) at 1169117492 (60 s)
      Quiet time after excitation: 1169117554

    • Quiet time before excitation: 1169128385
      Excitation (broad band) at 1169128417 (60 s)
      Quiet time after excitation: 1169128479

2017-01-23

  • 8:53am, pumps off
  272   Mon Jan 23 16:29:52 2017 GabrieleOpticsDaily ProgressInput part of the optical lever setup installed and aligned

Today I cabled and installed the four QPD, in a temporary position. I also assembled four picomotor mounts that will be used for the auto-centering.

Quote:

Today I installed and aligned part of the optical components for the optical lever of the new setup. For the moment being I installed only the input components, and aligned the beams into the vacuum chamber. Since I don't have any in-vacuum optics yet, there's nothing more that can be done now.

 

  273   Mon Jan 23 17:04:47 2017 GabrieleGeneralMeasurementsS1600491

2017-01-23

  • 4:51pm in chamber, balanced
  • 4:52pm, roughing pump on
  • 4:54pm, turbo pump on
  • Excitations
    • Quiet time before excitation: 1169273022
      Excitation (broad band) at 1169273054 (60 s)
      Quiet time after excitation: 1169273116

    • Quiet time before excitation: 1169283946
      Excitation (broad band) at 1169283978 (60 s)
      Quiet time after excitation: 1169284040

    • Quiet time before excitation: 1169294870
      Excitation (broad band) at 1169294902 (60 s)
      Quiet time after excitation: 1169294964

    • Quiet time before excitation: 1169305794
      Excitation (broad band) at 1169305827 (60 s)
      Quiet time after excitation: 1169305889

 

2017-01-24

  • 9:32am, pumps off

 

  274   Tue Jan 24 11:01:58 2017 GabrieleGeneralMeasurementsS1600492

2017-01-24

  • 11:00am, in chamber, balanced
  • 11:02am, roughing pump on
  • 11:13am, turbo pump on
  • Excitations
    • Quiet time before excitation: 1169335400
      Excitation (broad band) at 1169335432 (60 s)
      Quiet time after excitation: 1169335494

    • Quiet time before excitation: 1169346908
      Excitation (broad band) at 1169346940 (60 s)
      Quiet time after excitation: 1169347002

    • Quiet time before excitation: 1169357832
      Excitation (broad band) at 1169357864 (60 s)
      Quiet time after excitation: 1169357926

    • Quiet time before excitation: 1169368756
      Excitation (broad band) at 1169368788 (60 s)
      Quiet time after excitation: 1169368850

    • Quiet time before excitation: 1169379680
      Excitation (broad band) at 1169379713 (60 s)
      Quiet time after excitation: 1169379775

 

2017-01-25

  • 9:05am, pumps off

 

 

  275   Tue Jan 24 11:45:55 2017 GabrieleElectronicsConfigurationPicomotor drivers
  • Changed the library Picomotor8752.py to add a third axis 'r' that will allow moving the in-vacuum retaining ring. The controller remains connected to the workstation through a serial cable
  • Tested a new NewFocus 8741 controller with USB and ethernet. The USB driver works only on Windows, so I tested it by running a Windows virtual machine. I used this trick to get the IP address of the controller. Then I wrote another library Picomotor8742.py that uses TCP/IP sockets to communicate with the driver via ethernet. Tested and working. Each driver can control up to four axis, so the user can choose which QPD centering mirror to move (1/2 or 3/4) and which axis (x or y)
  276   Wed Jan 25 10:02:23 2017 GabrieleElectronicsDaily ProgressHigh voltage system in place

This morning I installed in the clean room the high voltage amplifier and the high voltage relays. Everything is cabled as planned. No way to test it yet, since there's nothing in the chamber!

  277   Wed Jan 25 16:12:05 2017 GabrieleGeneralDaily ProgressSome assembly
  • assembled the four in-vacuum periscopes (no mirrors yet)
  • soldered kapton wires to the four ESD board; the vacuum side HV connectors are installed
  • installed the picomotor into the traslation stage, and soldered the two picomotor wires to a twisted kapton pair. Note: the white wire is connected to the kapton wire which is twisted on the other side.
  278   Thu Jan 26 17:06:59 2017 GabrieleGeneralDaily ProgressFour fold measurement system installation

Today I installed the four GeNS systems into the chamber, connected the ESD to the HV feedthrough and put the periscopes in place.

Note 1: the lens holders have been remachined to solve a dimension problem, by removing completely the two lips against which the lens was supposed to be sitting. To recover a reasonable centering of the lens, I added two small shims inside each holder. They are made out of wrapped aluminum foil.

Note 2: I added some small shims (again made of wrapped aluminum foil) below the base plate, to make it as close to horizontal as possible

Finally, I managed to align the optical level beam for the QPD1, using as usual a small container with water to get the horizontal reference.

Some pictures below.

Attachment 3: 2017-01-26_14.04.06.jpg
2017-01-26_14.04.06.jpg
  279   Fri Jan 27 10:40:03 2017 GabrieleGeneralMeasurementsS1600493

2017-01-27

  • 10:38am, in chamber, balanced
  • 10:39am, roughing pump on
  • 10:53am, turbo pump on
  • Excitations:
    • Quiet time before excitation: 1169592263
      Excitation (broad band) at 1169592295 (60 s)
      Quiet time after excitation: 1169592357

    • Quiet time before excitation: 1169603187
      Excitation (broad band) at 1169603219 (60 s)
      Quiet time after excitation: 1169603281

    • Quiet time before excitation: 1169614111
      Excitation (broad band) at 1169614143 (60 s)
      Quiet time after excitation: 1169614205

    • Quiet time before excitation: 1169625035
      Excitation (broad band) at 1169625067 (60 s)
      Quiet time after excitation: 1169625129

    • Quiet time before excitation: 1169664828
      Excitation (broad band) at 1169664861 (60 s)
      Quiet time after excitation: 1169664923

 

2017-01-28

  • 1:32pm pumps off

 

  280   Fri Jan 27 14:56:55 2017 GabrieleOpticsDaily ProgressOptical lever setup completed

The four optical levers are completely installed and aligned to a horizontal reference.

  281   Sat Jan 28 15:39:30 2017 GabrieleGeneralMeasurementsS1600494

2017-01-28

  • 3:38pm, in chamber, balanced
  • 3:39pm, roughing pump on
  • 3:50pm, turbo pump on
  • Excitations
    • Quiet time before excitation: 1169700428
      Excitation (broad band) at 1169700460 (60 s)
      Quiet time after excitation: 1169700522

    • Quiet time before excitation: 1169711352
      Excitation (broad band) at 1169711384 (60 s)
      Quiet time after excitation: 1169711446

    • Quiet time before excitation: 1169722276
      Excitation (broad band) at 1169722308 (60 s)
      Quiet time after excitation: 1169722370

    • Quiet time before excitation: 1169733200
      Excitation (broad band) at 1169733232 (60 s)
      Quiet time after excitation: 1169733294

    • Quiet time before excitation: 1169744124
      Excitation (broad band) at 1169744156 (60 s)
      Quiet time after excitation: 1169744218

    • Quiet time before excitation: 1169755048
      Excitation (broad band) at 1169755080 (60 s)
      Quiet time after excitation: 1169755142

​2017-01-30

  • 7:59am pumps off

 

  282   Mon Jan 30 15:16:54 2017 GabrieleGeneralDaily ProgressFour samples in chamber
  • checked that the high voltage paths are working:
    • the DAC signal is properly received and amplified by the Trek 2220 HV amplifier
    • the HV switch box is working as expected: I can switch on and off each path individiually using the DAC signals
  • installed four samples (refer to the optical drawing for the numbering)
    • S1600472 in bay 1
    • S1600478 in bay 2
    • S1600473 in bay 3
    • S1600480 in bay 4

  • balanced all samples and centered all optical levers. There is a problem with the fifth connector in the ADC interface board (or maybe with one ADC channel). So one of the quadrants of QPD4 was not working. I moved the connector to number 6 and updated the model. Everything looks fine now.
  • the power in the four QPD is quite diverse: this is not unexpected, since it depends on the interference of the reflection from the two surfaces of the disk

  • installed the picomotor controllers on the bench, connected them to the net using the switch on the top of the clean room. For the moment being they are using DHCP.
  • connected all picomotors to the controllers.
    • Bottom controller, from left to right: QPD1x, QPD1y, QPD2x, QPD2y
    • Top controller, from left to right: QPD3x, QPD3y, QPD4x, QPD4y
  • tested the remote control and motion of all picomotors

  283   Tue Jan 31 09:03:12 2017 GabrieleElectronicsConfigurationAuto centering script for the new setup

I wrote an autocenter script for the four QPD in the new setup (autocenter14.py) and renamed the script for the old chamber (autocenter0.py).

Tested and working properly, with network connection to the picomotor controllers. Be aware that if the picomotor controllers are switched off, their IP address might change.

  284   Tue Jan 31 11:21:44 2017 GabrieleMechanicsDaily ProgressRetaining ring mechanics

All parts for the motion of the retaining rings have been received and are ok. We're going to clean and bake them. 

  285   Tue Jan 31 16:50:55 2017 Gabriele, AlenaGeneralVacuumFirst pump-down with setup

This afternoon we started the pump-down with all the system installed into the chamber. Unfortunately the IGM vacuum gauge isn't working, so we can't be sure what the pressure is. To be fixed

  286   Tue Jan 31 16:55:17 2017 GabrieleGeneralDaily ProgressImproved autocenter, excitation not working, wandering line

The autocenter script wasn't working in a very robust way (sometimes the socket connection to the controller failed, some times no motion was obtained after issuing a command). So I rewrote the interface to the Newport controller using the http server interface. The code is in picomotor8742_http.py. This version seems much more robust.

There is a large wandering line that spans all frequencies. Not sure what the origin is, but it will need some noise hunting. Here are spectrograms of all four QPD X signals. The line is visible in all of them, at the same frequency. So it's definitely something external coupling into the light or the QPD electronics. It's not visible in the sum of the QPD quadrants, but maybe just because it's buried in noise.

Finally, I tried to excite the disks, but I couldn't get any motion of the optical lever beams. To be investigated, there might simply be some cables disconnected.

 

Attachment 1: wandering_line.png
wandering_line.png
  287   Wed Feb 1 15:23:42 2017 GabrieleOpticsNoise huntingWandering line is due to the laser

The wandering line I mentioned in my previous elog, which is spoiling most of the sensitivity, turns out to be power noise of the laser. 

I used a Thorlabs PDA100 and a SR785 to measure the power noise out of the laser directly, and saw a huge forest of peaks above 20kHz. Among them, a couple of peaks are moving up and down in frequency very fast. The plot below compares two different times of the Thorlabs HNL210L laser (the new one, 21 mW) with the old JTSU laser we are using for the test setup:

The noise of the new laser is cleary much larger (even after the laser has been on for some time) and non stationary. This is a big issue for us. I will contact Thorlabs to inquire if this behavior is normal.

The attached video file shows the peaks dancing around on the SR785 screen.

Attachment 2: Untitled.avi
  288   Wed Feb 1 15:35:30 2017 GabrieleGeneralDaily Progressexcitation not working - FIXED

My bad, a cable was disconnected.

Quote:

 

Finally, I tried to excite the disks, but I couldn't get any motion of the optical lever beams. To be investigated, there might simply be some cables disconnected.

  289   Wed Feb 1 16:58:10 2017 GabrieleGeneralCharacterizationExcitation tests

The excitation is working fine. However, there is a large cross coupling in the excitation between channels: so if I switch on only one of the ESD paths, I actually excite all other disks too.  It might be due to the common ground or to the fact that the cables run close to each other. This needs some investigation, but it's not a big issue for the moment being.

On the other hand, the optical levers are very well decoupled: each one sees a different set of modes. So there is no measurable cross coupling between the disks or the readout.

There seems to be something fishy with the Y picomotor of QPD3: it doesn't always move in the same direction for the same set of steps. Some investigations needed here too. Autocentering might fail, but it's still possible to center it manually.

Excitation at 4:56pm (quiet time before excitation 1170032165, quiet time after excitation 1170032234).

Another excitation at 8:30am (2017-02-02) (quiet time before excitation 1170088185, quiet time after excitation 1170088373)

  290   Mon Feb 6 08:37:54 2017 GabrieleGeneralMeasurementsS1600495

2017-02-06

  • 8:35am in chamber, balanced
  • 8:36am roughing pump on
  • 8:50am tubo pump on
  • Excitations: (they didn't work, I forgot to switch on the noise!!)
    • Quiet time before excitation: 1170460053
      Excitation (broad band) at 1170460085 (60 s)
      Quiet time after excitation: 1170460147

    • Quiet time before excitation: 1170470977
      Excitation (broad band) at 1170471010 (60 s)
      Quiet time after excitation: 1170471072

    • Quiet time before excitation: 1170481902
      Excitation (broad band) at 1170481935 (60 s)
      Quiet time after excitation: 1170481997

    • Quiet time before excitation: 1170492827
      Excitation (broad band) at 1170492860 (60 s)
      Quiet time after excitation: 1170492922

    • Quiet time before excitation: 1170503752
      Excitation (broad band) at 1170503785 (60 s)
      Quiet time after excitation: 1170503847

    • Quiet time before excitation: 1170514677
      Excitation (broad band) at 1170514710 (60 s)
      Quiet time after excitation: 1170514772

2017-02-07

  • 09:36am pumps off

 

 

  291   Mon Feb 6 11:19:13 2017 GabrieleOpticsDaily ProgressLaser swap

The Thorlabs laser has been misbehaving for the whole weekend. Even after many days being continuosly on, the wandering line is still moving all over the frequencies.

So this morning I swapped in a JDSU 1125P borrowed from the 40m lab, which provides about 6.8 mW of power. I tested it over the weekend on a separate test table, and after one day or so of operation the power looks reasonably stable. Now it's been on for a few hours: there is still a line moving around, but it's slowing down and hopefully setting down in a good place.

I started a series of test measurements on the samples that were already installed.

  • Quiet time before excitation: 1170443490
    Excitation (broad band) at 1170443523 (60 s)
    Quiet time after excitation: 1170443586

 

  292   Mon Feb 6 14:09:07 2017 GabrieleGeneralMeasurementsFirst set of parallel measurements completed

The new laser is still acting up a bit, with a wandering line moving sometimes inside the band. Nevertheless, I could perform the first complete measurement of four samples in parallel.

Everything went as expected, there is no visible cross coupling between modes of different disks. The MATLAB code for the analysis is ready and working.

Here are the results:

Attachment 1: results_06-Feb-2017.png
results_06-Feb-2017.png
  293   Mon Feb 6 16:22:47 2017 GabrieleGeneralMeasurementsS1600472 S1600478 S1600473 S1600480
  • In the new chamber
  • Excitations:
    • Quiet time before excitation: 1170443490
      Excitation (broad band) at 1170443523 (60 s)
      Quiet time after excitation: 1170443586

    • Quiet time before excitation: 1170454416
      Excitation (broad band) at 1170454449 (60 s)
      Quiet time after excitation: 1170454512

    • Quiet time before excitation: 1170465342
      Excitation (broad band) at 1170465375 (60 s)
      Quiet time after excitation: 1170465438

 

2017-02-07

  • 9:36am gate valve closed, pumps off

 

 

 

  294   Tue Feb 7 10:03:35 2017 GabrieleGeneralMeasurementsS1600496

2017-02-07

  • 10:02am in chamber, balanced
  • 10:03am roughing pump on
  • 10:30am turbo pump on
  • Excitations (they didn't work, I forgot to switch on the noise!!)
    • Quiet time before excitation: 1170548335
      Excitation (broad band) at 1170548367 (60 s)
      Quiet time after excitation: 1170548429

    • Quiet time before excitation: 1170559259
      Excitation (broad band) at 1170559291 (60 s)
      Quiet time after excitation: 1170559353

    • Quiet time before excitation: 1170570183
      Excitation (broad band) at 1170570216 (60 s)
      Quiet time after excitation: 1170570278

    • Quiet time before excitation: 1170581108
      Excitation (broad band) at 1170581140 (60 s)
      Quiet time after excitation: 1170581202

    • Quiet time before excitation: 1170592032
      Excitation (broad band) at 1170592064 (60 s)
      Quiet time after excitation: 1170592126

    • Quiet time before excitation: 1170602956
      Excitation (broad band) at 1170602989 (60 s)
      Quiet time after excitation: 1170603051

  • Excitations:

    • Quiet time before excitation: 1170638328
      Excitation (broad band) at 1170638360 (60 s)
      Quiet time after excitation: 1170638422

    • Quiet time before excitation: 1170649252
      Excitation (broad band) at 1170649285 (60 s)
      Quiet time after excitation: 1170649347

    • Quiet time before excitation: 1170660177
      Excitation (broad band) at 1170660209 (60 s)
      Quiet time after excitation: 1170660271

    • Quiet time before excitation: 1170671101
      Excitation (broad band) at 1170671133 (60 s)
      Quiet time after excitation: 1170671195

    • Quiet time before excitation: 1170682025
      Excitation (broad band) at 1170682057 (60 s)
      Quiet time after excitation: 1170682119

 

2017-02-09

  • 4:11pm, pumps off

 

  295   Tue Feb 7 16:16:37 2017 GabrieleOpticsDaily ProgressLasers

The high power lasers I tested so far (the Thorlabs 21mW and the JDSU 1125P) are noisy: they both have wandering lines that from time to time are alised down into the base band, destroing the measurement. 

I have three JDSU 1103P units: two of them dlived about 2.5 mW, the third one delivers about 1.4 mW. One of the 2.5mW was installed in the test setup. I swapped it out with the 1.4 mW, so now I have two good 2.5 mW laser. My plan is to modify the new setup to use those two lasers in parallel, splitting each one in two, for a total of four beams of about 1.2 mW each.

The new optical layout is atttached.

Attachment 1: crime_v3.pdf
crime_v3.pdf
  296   Wed Feb 8 17:01:01 2017 GabrieleOpticsDaily ProgressTwo laser installed, setup aligned

Today I swapped out the 8mW laser and installed two 2.5 mW lasers. I rebuilt the input part of the optical levers and re-aligned everything. See below for a picture of the new setup: red beams are input, yellow beams are output. I also installed a protective screen all around the table, to abvoid any suprios beam to get out.

  297   Wed Feb 8 17:06:11 2017 Gabriele, LarryElectronicsConfigurationPrivate network

This morning Larry set up a network switch to create a local network for the power strip and the two Newport picomotor controllers. The laboratory workstation serves as gateway between the networks.

I still have to configure the power strip and the picomotor controllers to use the new static IP address.

  298   Thu Feb 9 08:35:24 2017 GabrieleElectronicsConfigurationRemoved ESD bias path to model CR0

Removed, since iit was not useful to improve the actuation authority.

Quote:

I added to the model CR0 an additional bias path for the ESD driver:

 

  299   Thu Feb 9 09:10:17 2017 Gabriele, LarryElectronicsConfigurationPrivate network

I reconfigured the powerstrip and the two Newport controllers to use static IP address in the new 10.10.10.X network, using the workstation as gateway. All scripts updated and working

Quote:

This morning Larry set up a network switch to create a local network for the power strip and the two Newport picomotor controllers. The laboratory workstation serves as gateway between the networks.

I still have to configure the power strip and the picomotor controllers to use the new static IP address.

 

  300   Thu Feb 9 09:30:52 2017 GabrieleOpticsDaily ProgressTwo laser installed, setup aligned

The lasers are behaving well, there is no high noise or wandering lines. The spectrum below is taken in air: that explains the excess of noise in the few kHz region.

Quote:

Today I swapped out the 8mW laser and installed two 2.5 mW lasers. I rebuilt the input part of the optical levers and re-aligned everything. See below for a picture of the new setup: red beams are input, yellow beams are output. I also installed a protective screen all around the table, to abvoid any suprios beam to get out.

 

  301   Thu Feb 9 11:35:27 2017 GabrieleOpticsConfigurationQPD calibration

This morning I measured the beam profiles at the QPD positions. As expected, the beams are not gaussian there, since we are seeing the interference of the reflections from the two faces of the disks. Nevertheless, the measured sizes are

  Beam radius [microns]
QPD1 302
QPD2 338
QPD3 270
QPD4 401

Here are the images of the beams:

The arm lever lengths (distance from the disk surface to the QPD) can be estimated from the optical drawing:

  Distance disk to QPD [mm]
QPD1 1540
QPD2 1813
QPD3 1587
QPD4 1652

The optical gain (normalized QPD signal over disk surface angle) is given by

g = \frac{4 L}{w} \sqrt{\frac{2}{\pi}}

  Gain 1/rad
QPD1 16300
QPD2 17100
QPD3 18800
QPD4 13150

The uncertaint in those numbers is quite large, both from the beam size and from the arm lever. Anyhow, I'm using the average to have a rough calibration of the QPD signals in terms of disk surface angular motion. The value I plugged in into the X_NORM filter banks is 16300 /rad. Therefore now the signals *NORM_OUT_DQ are calibrated in radians (deflection of the disk surface).

Finally, I also measured the profiles of the beams going into the chamber, somewhere before the 2" folding mirror. They have nice gaussian shapes

Attachment 1: qpd1.bmp
Attachment 9: IN3.png
IN3.png
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