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

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

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

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.

• 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.

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!

• 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)

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

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

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.

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

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.

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

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

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.

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:

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

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.

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

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.

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.

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

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

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

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

     

     

     

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

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

• 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
   

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

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

2016-12-21

• 8:59am, in chamber, balanced
• 9:00am, roughing pump on
• 9:11am, turbo pump on
• Excitations:

  • Quiet time before excitation: 1166383869
    Excitation (broad band) at 1166383902 (120 s)
    Quiet time after excitation: 1166384024

  • Quiet time before excitation: 1166384954
    Excitation (broad band) at 1166384986 (120 s)
    Quiet time after excitation: 1166385108

  • Quiet time before excitation: 1166386038
    Excitation (broad band) at 1166386070 (120 s)
    Quiet time after excitation: 1166386192

  • Quiet time before excitation: 1166387123
    Excitation (broad band) at 1166387155 (120 s)
    Quiet time after excitation: 1166387277

  • Quiet time before excitation: 1166388207
    Excitation (broad band) at 1166388239 (120 s)
    Quiet time after excitation: 1166388361

• 1:15pm, pumps off

2016-12-20

• 3:50pm, in chamber, balanced. ND0.3 installed back
• 3:51pm, roughing pump on
• 4:02pm, turbo pump on
• Excitations:

  • Quiet time before excitation: 1166324097
    Excitation (broad band) at 1166324129 (120 s)
    Quiet time after excitation: 1166324251

  • Quiet time before excitation: 1166325481
    Excitation (broad band) at 1166325513 (120 s)
    Quiet time after excitation: 1166325635

  • Quiet time before excitation: 1166326865
    Excitation (broad band) at 1166326897 (120 s)
    Quiet time after excitation: 1166327019

  • Quiet time before excitation: 1166328249
    Excitation (broad band) at 1166328282 (120 s)
    Quiet time after excitation: 1166328404

  • Quiet time before excitation: 1166329634
    Excitation (broad band) at 1166329666 (120 s)
    Quiet time after excitation: 1166329788

• 8:45pm, air filters off

• More excitations:

  • Quiet time before excitation: 1166331404
    Excitation (broad band) at 1166331436 (120 s)
    Quiet time after excitation: 1166331558

  • Quiet time before excitation: 1166332788
    Excitation (broad band) at 1166332820 (120 s)
    Quiet time after excitation: 1166332942

  • Quiet time before excitation: 1166334172
    Excitation (broad band) at 1166334204 (120 s)
    Quiet time after excitation: 1166334326

  • Quiet time before excitation: 1166335556
    Excitation (broad band) at 1166335589 (120 s)
    Quiet time after excitation: 1166335711

  • Quiet time before excitation: 1166336941
    Excitation (broad band) at 1166336973 (120 s)
    Quiet time after excitation: 1166337095

2016-12-21

• 7:55am, pumps off
• 8:08am, air filters on

2016-12-20

• 9:58am, in chamber, balanced. Removed ND0.3
• 10:00am, roughing pump on
• 10:12am, turbo pump on
• Excitations:

  • Quiet time before excitation: 1166299404
    Excitation (broad band) at 1166299436 (120 s)
    Quiet time after excitation: 1166299558

  • Quiet time before excitation: 1166306789
    Excitation (broad band) at 1166306821 (120 s)
    Quiet time after excitation: 1166306943

• 3:08pm, pumps off

Here's a comparison of the measured Q values before and after being shipped to Montreal and back. No significant differences.

2016-12-19

• 10:27am: in chamber, balanced
• 10:28am, roughing pump on
• 10:40am, turbo pump on
• Excitations:

  • Quiet time before excitation: 1166214597
    Excitation (broad band) at 1166214629 (60 s)
    Quiet time after excitation: 1166214691

  • Quiet time before excitation: 1166215921
    Excitation (broad band) at 1166215954 (60 s)
    Quiet time after excitation: 1166216016

  • Quiet time before excitation: 1166217246
    Excitation (broad band) at 1166217278 (60 s)
    Quiet time after excitation: 1166217340

  • Quiet time before excitation: 1166218570
    Excitation (broad band) at 1166218603 (60 s)
    Quiet time after excitation: 1166218665

  • Quiet time before excitation: 1166219895
    Excitation (broad band) at 1166219927 (60 s)
    Quiet time after excitation: 1166219989

• More excitations

  • Quiet time before excitation: 1166227570
    Excitation (broad band) at 1166227602 (120 s)
    Quiet time after excitation: 1166227724

  • Quiet time before excitation: 1166228954
    Excitation (broad band) at 1166228987 (120 s)
    Quiet time after excitation: 1166229108

  • Quiet time before excitation: 1166230338
    Excitation (broad band) at 1166230371 (120 s)
    Quiet time after excitation: 1166230493

  • Quiet time before excitation: 1166231723
    Excitation (broad band) at 1166231755 (120 s)
    Quiet time after excitation: 1166231877

  • Quiet time before excitation: 1166233107
    Excitation (broad band) at 1166233139 (120 s)
    Quiet time after excitation: 1166233261

2016-12-20

• 8:46am, pumps off

2016-12-18

• 2:29pm, in chamber, balanced
• 2:30pm, roughing pump on
• 2:42pm, turbo pump on
• Excitations:

  • Quiet time before excitation: 1166146273
    Excitation (broad band) at 1166146305 (60 s)
    Quiet time after excitation: 1166146367
    X3:CR1-AUTOCENTER => 1

  • Quiet time before excitation: 1166147597
    Excitation (broad band) at 1166147630 (60 s)
    Quiet time after excitation: 1166147692

  • Quiet time before excitation: 1166148922
    Excitation (broad band) at 1166148954 (60 s)
    Quiet time after excitation: 1166149016

  • Quiet time before excitation: 1166150246
    Excitation (broad band) at 1166150278 (60 s)
    Quiet time after excitation: 1166150340

  • Quiet time before excitation: 1166151570
    Excitation (broad band) at 1166151603 (60 s)
    Quiet time after excitation: 1166151665

​2016-12-19

• 8:55am, pumps off

2016-12-17

• 12:54pm, in chamber, balanced. Added a ND0.3 to avoid QPD saturation
• 12:55pm, roughing pump on
• 1:05pm: turbo pump on
• Excitations:

  • Quiet time before excitation: 1166054813
    Excitation (broad band) at 1166054845 (60 s)
    Quiet time after excitation: 1166054907

  • Quiet time before excitation: 1166056137
    Excitation (broad band) at 1166056170 (60 s)
    Quiet time after excitation: 1166056232

  • Quiet time before excitation: 1166057463
    Excitation (broad band) at 1166057495 (60 s)
    Quiet time after excitation: 1166057557 

  • Quiet time before excitation: 1166060112
    Excitation (broad band) at 1166060144 (60 s)
    Quiet time after excitation: 1166060206

2016-12-18

• 8:12am, pumps off

2016-12-16

• 1:41pm: in chamber, balanced (coating facing up)
• 1:42pm: roughing pump on
• 1:54pm: turbo pump on
• Excitations:
  • Quiet time before excitation 1165963531
    Broad band excitation (6kV, 60s)
    Quiet time after excitation 1165963649
  • Quiet time before excitation: 1165964693
    Excitation (broad band) at 1165964725 (60 s)
    Quiet time after excitation: 1165964787
  • Quiet time before excitation: 1165966017
    Excitation (broad band) at 1165966050 (60 s)
    Quiet time after excitation: 1165966112
  • Quiet time before excitation: 1165967342
    Excitation (broad band) at 1165967375 (60 s)
    Quiet time after excitation: 1165967437

2016-12-17

• 12:16pm: pumps off

I find sometimes that the probe configuration can give these distorted signals. For the Tektronix probes, its best to use a 500 MHz probe instead of the BNC clip leads. The probe also should be compensated by attaching to the gold fingers square wave generator on the scope front and adjusting the capacitor in the probe with a little screwdriver until the square wave becomes perfect.

The disks coated at Montreal are hold with three small clips. Therefore there are three small regions close to the edge that are not coated. See the picture below to see one of the samples with the clips.

To check the effect of the clip fingerprints on the dilution factor, I set up a COMSOL simulation. For simplicity, I started with only two small clips as shown below:

The result is that they have a very small effect. The first plot below compares the dilution factor (energy in the coating over total energy) with and without the fingerprints:

Another way to look at it is given below: the plot shows the percentage difference in the computed dilution factor. It's always smaller than 1%, so completely neglegible. In conclusion: we don't need to model the clips.

The plot below shows the best loss angle we expect foer our samples, based on Steve Penn's model of surface and volume losses (Phys. Lett. A 352, 3). That paper contains data only for Suprasil 2 and Suprasil 312, so it might be a bit wrong for our Corning 7980. The two experimental data sets are for samples that have been laser polished.

2016-12-12

• 4:32pm, in chamber, balanced
• 4:33pm, roughing pump on
• 4:46pm, turbo pump on

2016-12-13

• Excitation:
  • Quiet time before excitation: 1165689679
    Excitation brodband (3 kV, 60s)
    Quiet time after excitation: 1165689920

I swapped the DAC with another one, but I see the same behavior in the output signal. Here's a spectrum of the DAC output, with and without output.

Following the model from R. Nawrodt et al. Investigation of mechanical losses of thin silicon flexures at low temperatures, CQG 30 (2013) 115008, I predicted the thermo-elastic losses in the Si sample. The model matches quite well the measurements:

Here are some details on the model, eq. 1 and 2 of the cited paper:

where:

• alpha  = thermal expansion coefficient 2.6e-6/K
• Y = Young's modulus 150 GPa
• T = temperature 300 K
• C_P = specific heat 705 J/kg/K
• rho = density 2329 kg/m^3
• t_f = sample thickness 400 um
• k = thermal conductivity 130 W/m/K

The model is for a cantilever, but it fits well enough for our disk too.

Silicon wafer from WRS materials, diameter 3", thickness 356-406 microns.

2016-12-09

• 1:00pm, retaining ring and pins installed back, optical system realigned to horizontal reference
• 1:08pm, in chamber, balanced. Since silicon reflection is higher than silica, installed a ND0.3 to avoid QPD saturation
• 1:10pm, roughing pump on
• 1:23pm, turbo pump on
• Excitations

  • Quiet time before excitation: 1165359305
    Excitation (broad band) at 1165359337 (60 s)
    Quiet time after excitation: 1165359399

2016-12-12

• Excitation:
  • Quiet time before excitation: 1165611248
    Broadband excitation
    Quiet time after excitation: 1165611382
  • Quiet time before excitation: 1165611540
    100-1000 Hz excitation
    Quiet time after excitation: 1165611619
• 2:05pm, pumps stopped

​Results

% Freq        Q                Q (C.I. 95%)        Q (C.I. 95%)
2043.9        6.5333e+03        6.5061e+03        6.5607e+03
2307.9        1.6958e+04        1.6895e+04        1.7022e+04
3671.0        2.7458e+04        2.7324e+04        2.7595e+04
4909.0        4.1605e+04        4.1322e+04        4.1892e+04
5268.1        2.5236e+04        2.5186e+04        2.5286e+04
6079.0        2.6835e+04        2.6311e+04        2.7382e+04
7317.4        5.1946e+04        5.1799e+04        5.2095e+04
7391.0        1.3702e+04        1.3441e+04        1.3973e+04
8586.6        5.3491e+04        5.2271e+04        5.4769e+04
8719.9        5.4501e+04        5.3904e+04        5.5111e+04
9600.4        6.6514e+04        6.6390e+04        6.6639e+04
9622.1        3.0667e+04        3.0505e+04        3.0830e+04
10507.0        8.1040e+04        8.0965e+04        8.1115e+04
11053.9        6.0651e+04        5.9853e+04        6.1471e+04
11397.5        5.2873e+04        5.2242e+04        5.3520e+04
11950.0        3.2045e+04        3.1514e+04        3.2593e+04
12083.0        8.8181e+04        8.7571e+04        8.8800e+04
12330.6        4.9761e+04        4.8997e+04        5.0549e+04
13799.0        4.8752e+04        4.7609e+04        4.9951e+04
14911.9        8.7301e+04        8.6550e+04        8.8066e+04
15849.6        3.7500e+04        3.6882e+04        3.8139e+04
17381.4        7.5930e+04        7.4582e+04        7.7328e+04
17585.0        9.7947e+04        9.6811e+04        9.9110e+04
17597.0        2.8465e+04        2.7318e+04        2.9712e+04
18310.4        9.0019e+04        8.9175e+04        9.0879e+04
18542.1        6.8287e+04        6.7506e+04        6.9088e+04
18547.5        1.4131e+05        1.4017e+05        1.4248e+05
18774.9        1.0588e+05        1.0490e+05        1.0687e+05
19066.6        8.0216e+04        7.8924e+04        8.1551e+04
20253.5        9.6914e+04        9.4540e+04        9.9411e+04
20463.0        1.0020e+05        9.9323e+04        1.0109e+05
21188.2        1.1931e+05        1.1851e+05        1.2012e+05
21828.5        1.4420e+05        1.4290e+05        1.4552e+05
21837.5        1.5768e+05        1.5639e+05        1.5899e+05
22976.0        5.6472e+04        5.6229e+04        5.6717e+04
23356.5        1.2871e+05        1.2729e+05        1.3017e+05
23398.5        1.4698e+05        1.4422e+05        1.4984e+05
23455.0        1.1209e+05        1.0950e+05        1.1479e+05
23457.7        1.0716e+05        1.0509e+05        1.0932e+05
23496.0        1.4477e+05        1.4295e+05        1.4665e+05
23703.5        1.5954e+05        1.5695e+05        1.6222e+05
23993.0        1.3344e+05        1.3183e+05        1.3510e+05
24758.2        1.4752e+05        1.4655e+05        1.4850e+05
24952.6        1.3025e+05        1.2972e+05        1.3077e+05
25139.0        3.3941e+04        3.3575e+04        3.4316e+04
25298.5        1.0825e+05        1.0603e+05        1.1056e+05
25387.1        1.3101e+05        1.3055e+05        1.3148e+05
25391.7        1.2021e+05        1.2011e+05        1.2032e+05
26752.9        1.0624e+05        1.0595e+05        1.0653e+05
26762.0        1.8838e+05        1.8490e+05        1.9200e+05
26838.0        6.9555e+04        6.7066e+04        7.2237e+04
27147.7        1.0675e+05        1.0571e+05        1.0780e+05
27698.0        8.3204e+04        8.1975e+04        8.4471e+04
28101.4        1.7792e+05        1.7748e+05        1.7836e+05
28109.4        8.9486e+04        8.8527e+04        9.0466e+04
28480.6        1.1985e+05        1.1934e+05        1.2037e+05
28972.0        4.5087e+04        4.3490e+04        4.6806e+04
28979.3        1.3823e+05        1.3750e+05        1.3897e+05
29044.6        1.7261e+05        1.7177e+05        1.7347e+05
29166.4        1.7820e+05        1.7785e+05        1.7855e+05
29222.0        1.8986e+05        1.8640e+05        1.9345e+05
29451.0        3.4557e+04        3.3927e+04        3.5211e+04
30284.4        1.9755e+05        1.9701e+05        1.9810e+05
30691.3        9.7139e+04        9.6728e+04        9.7553e+04
31228.6        1.2060e+05        1.2028e+05        1.2092e+05
32159.5        2.0041e+05        1.9800e+05        2.0288e+05
32226.8        7.3880e+04        7.3119e+04        7.4658e+04
32366.0        2.0220e+05        2.0185e+05        2.0255e+05

My previous test showed that the timing drift was somehow related to the output of the signal generator being connected to the DAC.

Some more findings follow. When the CyMAC is powered down, the timing sent to the DAC is highly distorted. It stays the same even when I power the CyMAC up again, and it gets better only after the IOP process is started. My guess is this has something to do with the DAC board initialization. In the following: first trace is the timing signal with CyMAC off; second with the CyMAC powering on, but IOP not yet started; third when the IOP process is running.

A small residual distortion around the transitions is visible. This is not present on the original signal, or even if the ADC only is connected to the timing.

To try to debug the problem, I set up a second signal generator (not locked to the first one) and used it to provide the DAC timing. In this way ADC and DAC get their timing from two different signal generators.

I still see the same small distortion on the DAC timing. More important, I noticed that the signals generated by the DAC (here a 1kHz sinusoid) are very noisy: there is a very large glitch at every clock transition. Is this a sign that tha DAC is malfunctioning? I don't recall seeing anything like that in any other case. In both screeshots, the purple trace is the DAC output (1 kHz sinusoid) and in the second screenshot the blue trace is the DAC timing. It's clear that there is a glitch every time the clock signal transitions.

For the last ~day the difference between the frontend GPS time and the machine GPS time remained constant between -1 and -2 seconds

I reconnected the DAC timing cable at

PST: 2016-12-08 09:23:06.934999 PST
UTC: 2016-12-08 17:23:06.934999 UTC
GPS: 1165253003

After that, the timing started to drift at a rate of about 1 second every 2300 seconds (4.35e-4). So the conclusion is that the culprit for the timing issue is on the DAC connection side.

I put back the Stanford Reserch signal generator. On a scope, the timing signal looks good. There is a small ripple and some noise in the flat parts. I found that when I unplug the DAC timing cable, the ripple and the noise goes away. 

I'm leaving the DAC timing unplugged for the night, and I'm using a script to track the difference between the machine time and the front-end time.

2016-12-07

• Removed retaining ring and pins, aligned optical setup to horizontal reference
• 9:59am, in chamber, balanced
• 10:00am, roughing pump on
• 10:12am, turbo pump on

As visible in th second picture, the distance between the disk and the ESD is about 1.5 mm

• Excitations:

  • Quiet time before excitation: 1165178719
    Excitation (broad band) at 1165178751 (60 s)
    Quiet time after excitation: 1165178813

  • Quiet time before excitation: 1165180007
    Excitation (broad band) at 1165180039 (60 s)
    Quiet time after excitation: 1165180101

  • Quiet time before excitation: 1165181331
    Excitation (broad band) at 1165181363 (60 s)
    Quiet time after excitation: 1165181425

• 2:39pm, pumps off

​Results

2016-12-07 A

% Freq        Q               Q (C.I. 95%)        Q (C.I. 95%)
251.8        2.9528e+04        2.9325e+04        2.9732e+04
323.4        6.9039e+04        6.5071e+04        7.3509e+04
328.7        5.5337e+04        5.5222e+04        5.5453e+04
692.8        2.4543e+04        2.4515e+04        2.4571e+04
705.5        2.7474e+04        2.7356e+04        2.7592e+04
1128.5        2.1332e+04        2.1268e+04        2.1395e+04
1242.4        1.2258e+04        1.2079e+04        1.2442e+04
1318.0        2.4548e+04        2.4419e+04        2.4678e+04
1800.7        2.6692e+04        2.6451e+04        2.6937e+04
1933.3        9.2002e+03        8.9167e+03        9.5022e+03
1937.7        8.5766e+03        8.5339e+03        8.6198e+03
2124.0        2.4927e+04        2.4872e+04        2.4982e+04
2799.2        8.1222e+03        7.9880e+03        8.2609e+03
2924.5        8.1070e+03        8.0349e+03        8.1804e+03
2964.4        8.2661e+03        8.1772e+03        8.3570e+03
4692.7        4.5716e+04        4.4885e+04        4.6578e+04

2016-12-07 B

% Freq        Q                Q (C.I. 95%)        Q (C.I. 95%)
251.7        2.8324e+04        2.8084e+04        2.8567e+04
329.0        5.4343e+04        5.4182e+04        5.4504e+04
692.7        2.4556e+04        2.4524e+04        2.4588e+04
705.5        2.7344e+04        2.7229e+04        2.7461e+04
1128.3        2.0844e+04        2.0548e+04        2.1148e+04
1242.1        1.2091e+04        1.1999e+04        1.2185e+04
1317.8        2.4709e+04        2.4659e+04        2.4760e+04
1322.0        2.8932e+04        2.6985e+04        3.1179e+04
1800.6        2.6879e+04        2.6691e+04        2.7069e+04
2123.6        2.4719e+04        2.4619e+04        2.4820e+04
2798.1        9.5908e+03        9.2072e+03        1.0008e+04
2841.0        1.1254e+04        1.0614e+04        1.1976e+04
2924.0        1.1666e+04        1.0395e+04        1.3291e+04
2963.1        9.7910e+03        9.3703e+03        1.0251e+04
3427.6        8.7265e+03        8.2911e+03        9.2102e+03
3700.2        1.4646e+04        1.3418e+04        1.6120e+04
4691.8        5.0056e+04        4.7715e+04        5.2638e+04

2016-12-07 C

% Freq        Q               Q (C.I. 95%)        Q (C.I. 95%)
251.8        2.8868e+04        2.8741e+04        2.8997e+04
313.8        4.8299e+04        4.4161e+04        5.3275e+04
658.0        4.5409e+04        4.4859e+04        4.5971e+04
692.6        2.4089e+04        2.3929e+04        2.4251e+04
705.4        2.7821e+04        2.7639e+04        2.8006e+04
1128.2        2.1583e+04        2.1087e+04        2.2103e+04
1242.1        1.2540e+04        1.2303e+04        1.2786e+04
1317.9        2.4663e+04        2.4626e+04        2.4700e+04
1571.0        1.4941e+04        1.4265e+04        1.5685e+04
1800.4        2.8559e+04        2.8113e+04        2.9019e+04
2123.4        2.7042e+04        2.6498e+04        2.7608e+04
2452.3        2.9667e+04        2.8231e+04        3.1256e+04
2797.4        8.7540e+03        8.0589e+03        9.5802e+03
2840.2        1.3484e+04        1.2967e+04        1.4043e+04
3706.5        1.0864e+04        1.0328e+04        1.1457e+04
4107.6        1.5757e+04        1.5573e+04        1.5946e+04
4690.7        4.8903e+04        4.7899e+04        4.9949e+04

2016-12-07 D

% Freq        Q               Q (C.I. 95%)        Q (C.I. 95%)
251.8        2.9311e+04        2.9189e+04        2.9434e+04
323.2        2.7246e+04        2.4352e+04        3.0908e+04
692.6        2.4309e+04        2.4226e+04        2.4392e+04
698.0        1.7009e+04        1.5425e+04        1.8954e+04
702.0        2.7209e+04        2.6645e+04        2.7796e+04
705.5        3.0025e+04        2.9300e+04        3.0785e+04
1127.6        2.0285e+04        1.9811e+04        2.0781e+04
1317.3        2.5325e+04        2.5209e+04        2.5442e+04
1800.3        3.2511e+04        3.1223e+04        3.3909e+04
1935.2        6.5014e+03        4.9517e+03        9.4607e+03
2122.5        2.8808e+04        2.7758e+04        2.9940e+04
2795.4        1.0237e+04        8.7193e+03        1.2393e+04
4688.8        4.9909e+04        4.1120e+04        6.3475e+04
6847.5        7.9848e+03        7.7352e+03        8.2510e+03

I modified the autocenter script. Now while the picomotor is moving, the variable X3:CR1-AUTOCENTER takes the value 1, otherwise it is 0.

Unfortunately, this morning the model time is again wrong...