40m QIL Cryo_Lab CTN SUS_Lab TCS_Lab OMC_Lab CRIME_Lab FEA ENG_Labs OptContFac Mariner WBEEShop
  40m Log, Page 333 of 344  Not logged in ELOG logo
ID Date Authorup Type Category Subject
  12836   Fri Feb 17 10:56:12 2017 steveUpdatePEMparticle counter moved into PSL enclousure

The MET#1 particle counter was moved from CES wall at ITMX to PSL enclousure south west corner at 11am.

The HEPA filter speed at the Variac was turned down to 20V from 40

This counter pumps air for 1 minute in every 20 minutes. Soft foam in bags used to minimize this shaking as it is clamped.


Attachment 1: from_here.jpg
Attachment 2: to_here.jpg
Attachment 3: PSL_particles.png
  12841   Tue Feb 21 10:08:35 2017 steveUpdatePEMnoisy morning

Our new janitor Francisco is started working in IFO room today.


The MET#1 particle counter was moved from CES wall at ITMX to PSL enclousure south west corner at 11am.

The HEPA filter speed at the Variac was turned down to 20V from 40

This counter pumps air for 1 minute in every 20 minutes. Soft foam in bags used to minimize this shaking as it is clamped.


Large film crews are working just out side  the north west corner of the lab. They started around ~ 5:30am  Do not plan on working late tonight.

ETMX sus damping restored.

C1:PSL-FSS_RMTEMP, C1:PSL-PMC_PMCTRANSPD and C1:PEM-count_temp channels are not reading since Friday


Attachment 1: outside_activity.png
  12844   Wed Feb 22 08:54:17 2017 steveUpdatePEM PSL enclousure particle count

ETMX sus damping recovered.  PSL enclousure is dusty at 20V rotation speed. Rainy days as outside condition.


The MET#1 particle counter was moved from CES wall at ITMX to PSL enclousure south west corner at 11am.

The HEPA filter speed at the Variac was turned down to 20V from 40

This counter pumps air for 1 minute in every 20 minutes. Soft foam in bags used to minimize this shaking as it is clamped.



Attachment 1: dusty__PSL.png
  12855   Tue Feb 28 08:04:48 2017 steveUpdatePEMETMX damping recovered

ETMX sus damping recovered.

Note: The giant metal garbage container was moved from the south west corner of CES months ago.


ETMX sus damping recovered.  PSL enclousure is dusty at 20V rotation speed. Rainy days as outside condition.



Attachment 1: ETMX.png
  12895   Mon Mar 20 17:12:08 2017 steveUpdatePEMparticle counter inside of PSL enclousure

The logging script is multiplying by 100 instead of 10 !


The MET#1 particle counter was moved from CES wall at ITMX to PSL enclousure south west corner at 11am.

The HEPA filter speed at the Variac was turned down to 20V from 40

This counter pumps air for 1 minute in every 20 minutes. Soft foam in bags used to minimize this shaking as it is clamped.



Attachment 1: enclousure_partical_count.png
  13181   Thu Aug 10 09:10:55 2017 steveUpdateGeneraldataviewer is recovering

It can look back 7 days trends now. There is still no vacuum channels. I can bring back the channels through the restore directory, but there are no data.

Attachment 1: 7dm.png
  13261   Mon Aug 28 10:51:21 2017 steveUpdateSUSETMX damping recovered
Attachment 1: ETMX_restored.png
  13695   Wed Mar 21 10:00:35 2018 steveUpdateGeneralprojector light bulb replaced

Light bulb replaced.


Bulb went out ~10am today. Looks like the lifetime of this bulb was <100 days.

Steve: bulb is arriving next week


  13861   Fri May 18 07:41:01 2018 steveUpdateSUSclipping ITMX oplev

The ITMX oplev still clipping


The ITMX oplev beam is clipping. It will be corected with locked arm



  14048   Tue Jul 10 14:20:09 2018 steveUpdateGeneralprojector light bulb replaced

Bulb replaced at day 110  We have now spare now.


  4963   Tue Jul 12 17:30:24 2011 steve,UpdateSUSBS oplev spectra


Healthy BS oplev

 I repeated the BS oplev spectrum today and I do not understand why it does look different. I did it as Kiwamu describes it in entry#4948  The oplev servo was left ON!

Attachment 1: BS_oplev.jpg
  4966   Thu Jul 14 09:38:50 2011 steve,UpdateSUSBS oplev spectra



Healthy BS oplev

 I repeated the BS oplev spectrum today and I do not understand why it does look different. I did it as Kiwamu describes it in entry#4948  The oplev servo was left ON!

 It is working today! Finally I repeated the BS spectra, that we did with Kiwamu last week

Attachment 1: BS_oplev.jpg
  4967   Thu Jul 14 15:27:08 2011 steve,UpdateSUSSUS oplev spectras




Healthy BS oplev

 I repeated the BS oplev spectrum today and I do not understand why it does look different. I did it as Kiwamu describes it in entry#4948  The oplev servo was left ON!

 It is working today! Finally I repeated the BS spectra, that we did with Kiwamu last week

 The optical levers were centered during these measurements  without the reference of locked cavities.  They have no reference value now.

SRM sus need some help. ITMX is showing pitch/yaw modes of the pendulum .....OSEM damping is weak?

Attachment 1: BS_oplev.jpg
Attachment 2: PRM_oplev.jpg
Attachment 3: ITMX_oplev.jpg
Attachment 4: ETMX_oplev.jpg
Attachment 5: ETMY_oplev.jpg
Attachment 6: SRM_oplev.jpg
Attachment 7: ITMY_oplev_b.jpg
  1964   Thu Sep 3 10:19:35 2009 steve, albertoUpdatePEMparticle counts and burning hillsides

The San Gabriel mountain has been on fire for  6 days. 144,000 acres of beautiful hillsides burned down and it's still burning.  Where the fires are.

The 40m lab particle counts are more effected by next door building-gardening activity than the fire itself.

This 100 days plot shows that.

Attachment 1: fire6d.jpg
Attachment 2: 40mgarden.JPG
Attachment 3: 40mgarden2.JPG
Attachment 4: RBLOG-FIRE-SKY.JPG
  4947   Wed Jul 6 16:44:37 2011 steve, kiwamuUpdateSUSBS oplev spectra

Healthy BS oplev

Attachment 1: BS.jpg
  5590   Fri Sep 30 18:35:42 2011 steve, kiwamuUpdateVACvacuum set for poweroutage

We did the following:

1, closed V1, VM1,  annuloses: VASE, VASV, VABS, VAEV,  VAEE and VA6

2, stop rotation of Maglev-TP1, waited to decellerate and turned off power to it

3, closed V4,  stoped rotation of TP2, waited to decellerate and turned power off

4, opened VM3 to RGA that is still running


I will come in tomorrow 9-10am to restart pumping.

Attachment 1: prepforpoweroutage.png
  3138   Tue Jun 29 17:10:49 2010 steve, ranaUpdateVACslow pumpdown started

The folding crane was fixed and tested this morning by the NNN rigging company. Pictures will be posted by Steve in the morning.

Afterwards, the ITM-east door was installed, jam-nuts checked. No high voltage was on for the in-vac PZTs.

The annulus spaces were roughed down to 350mTorr by Roughing Pump RP1. For this operation, we removed the low flow valve from the RP1 line.

After the spaces came down to ~400 mTorr, we closed their individual valves.

Warning: The VABSSC1 and VABSSC0 valves are incorrect and misleadingly drawn on the Vacuum overview screen.

We then:

  1. Closed V6 (valve between RP1 and the annulus line).
  2. Turned off RP1 from the MEDM screen.
  3. Installed the soft -starting butterfly valve.
  4. Turned on RP1.
  5. Opened V3.
  6. Closed VV1 (at the last minute - this is a vent valve and must be checked before each pumpdown)
  7. and pumpdown was started with a 3/4 turn opening of manual valve RV1.

Our idea is to have a much slower pumpdown this time than the last time when we had a hurricane kick up the dust. Looks like it worked, but next time we should do only 1/2 turn.

  3140   Tue Jun 29 23:49:18 2010 steve, ranaUpdateVACslow pumpdown started


The pumpdown started at 4 PM (2300 UTC). At 10 PM, we (Jenne, Jan, and I) opened up the RV1 valve to full open. That's the second inflection point in the plot.

  3169   Wed Jul 7 17:05:30 2010 steve, ranaUpdateSAFETYSummary of Crane Damage/Malfunction

The 1 Ton yellow crane support beam jammed up at Friday morning, June 25.


The 40m vertex crane has a folding I-beam support to reach targeted areas. The rotating I-beam is 8 ft long. The folding extension arm gives you another 4 ft.

The 12 ft full reach can be achieved by a straightening of the 4 ft piece. There is a spring loaded latch on the top of the I-beam that locks down when the two I-beams align.

This lock joins the two beams into one rigid support beam for the jib trolley to travel.  The position of this latch is visible when standing below, albeit not very well.

To be safe it is essential that this latch is locked down fully before a load is put on the crane.


We were preparing to pump down the 40m vacuum system on Friday morning. The straight alignment of the 8 and 4 ft piece made us believe that

the support beams were locked. In reality, the latch was not locked down. The jib trolley was driven to the end of the 12 ft I-beam. The 200 lbs ITM-east door was lifted

when the 4 ft section folded 50 degrees around the pivot point. This load of door + jib-trolley + 4 ft I-beam made the support beam sag about 6 inches

The door was removed from the jib hoist with the blue Genie-lift. The sagging was reduced to ~3".


The Genie-lift platform was raised to support the sagging crane jib-trolley. The lab was closed off to ensure safety and experts were called in for consultation. It was decided to bring in professional riggers.


Halbert Brothers, Inc. rigging contractor came to the lab Tuesday morning to fix the crane. The job was to unload the I-beam with safety support below. They did a very good job.


The static deformation of I-beams sprung back to normal position. There are some deformation of the I-beam ~2 mm where the beams were jammed under load.

It is not clear if this is a new deformation or if the crane sections have always been mis-aligned by a couple of mm.


The crane was tested with 450 lbs load at 12 ft horizontal travel position. The folding of I-beams were repeatedly tested for safe operation. Its a 1 ton crane, but we tested it with 450 lbs because that's what we had on hand.


We're working on the safety upgrade of this lift to prevent similar accident from happening.

Pictures below:

Atm 1)   load testing 2007

Atm 2)   jammed-sagging under ~400 lbs, horizontal          

Atm.3)   jammed-folded 50 degrees, vertical     

Atm.4)   static deformation of I-beams

Atm.5)   unloading in progress with the help of two A-frames          

Atm.6)   it is unloaded

Atm.7-8) load testing        

Atm.9)   latch locked down for safe operation            

Atm.9)   zoom in of the crane sections misalignment    

Attachment 1: DSC_0026_00.JPG
Attachment 2: P1060408.JPG
Attachment 3: P1060415.JPG
Attachment 4: P1060413.JPG
Attachment 5: P1060421.JPG
Attachment 6: P1060423.JPG
Attachment 7: P1060441.JPG
Attachment 8: P1060436.JPG
Attachment 9: P1060425.JPG
Attachment 10: P1060432.JPG
  1857   Fri Aug 7 16:11:11 2009 steve, robConfigurationVACIFO pressure rose to 2.3 mTorr


IFO pressure was 2.3 mTorr this morning,

The Maglev's foreline valve  V4 was closed so P2 rose to 4 Torr. The Maglev was running fine with V1 open.

This is a good example for V1 to be closed by interlock, because at 4 Torr foreline pressure the compression ratio for hydrocarbones goes down.

V4 was closed by interlock when TP2 lost it's drypump. The drypump's AC plug was lose.

To DO: set up  interlock  to close V1 if P2 exceeds 1 Torr




We added C1:Vac-CC1_pressure to the alarm handler, with the minor alarm at 5e-6 torr and the major alarm at 1e-5 torr.

  4301   Tue Feb 15 11:57:06 2011 steve, valeraConfigurationPSLPMC swap

 We swapped the PMC s/n 2677 for s/n lho006.

The table below summarizes the power levels before and after the PMC swap.

  old new
Ptrans 1.32 W 1.42 W
Transmission 85 % 91.5 %
Refl PDDC locked/unlocked 5.0 %  4.3 %
Loss 7-8 % 2-3 %
Leakage out of the back 10 mW 0.3 mW


- The power into the PMC (1.67 W) was measured with Scietech bolometer before the first steering PMC mirror. The leakage through the steering mirrors was measured with Ophir power meter to be 12+8 mW. There is also a lens between the mirrors which was not measured. 

- The power through the PMC was measured after the doubler pick off (105 mW), steering mirror (4 mW), and lens (not measured).

- The estimated reflection from four lens surfaces is 1-2% hence 1% uncertainty in the losses in the table.

- The beams into the PMC and on REFL PD were realigned. The beams downstream of the PMC are blocked as we did not realigned the PMC and doubler paths.

- The trans PD ND filters were removed. The VDC=1.28 V now.

- The NPRO current is 2.102 A


Atm 1 old

Atm2  new

Attachment 1: P1070421.JPG
Attachment 2: P1070423.JPG
  3148   Wed Jun 30 15:24:04 2010 steve,kiwamuUpdateVACslow pumpdown copmlete



The pumpdown started at 4 PM (2300 UTC). At 10 PM, we (Jenne, Jan, and I) opened up the RV1 valve to full open. That's the second inflection point in the plot.

 Atm 2 is showing the butterfly valve that closes down down the orifice at higher pressure to slow down the pumping speed.

 See elog entry #2573


Attachment 1: slowpd.jpg
Attachment 2: butterfly.JPG
  539   Wed Jun 18 16:37:54 2008 steve,ranaUpdateSAFETYCO2 test in the east arm
The CO2 laser and table are in the east arm for characterization of the mechanics. We
will not be operating it until we have an SOP (which is being written). No worries.
Attachment 1: co2.png
  549   Fri Jun 20 08:30:27 2008 stivUpdatePhotos40m summer line up 2008
atm1: John, Alberto, Yoichi, Koji, Masha, and Sharon

atm2: surf students Max of CIT, Sharon of MIT, Masha of Harvard, Eric of CIT not shown
Attachment 1: P1020559.png
Attachment 2: P1020560.png
  14008   Fri Jun 22 15:22:39 2018 sudoUpdateCDSDTT working

Seems like DTT also works now. The trick seems to be to run sudo /usr/bin/diaggui instead of just diaggui. So this is indicative of some conflict between the yum installed gds and the relic gds from our shared drive. I also have to manually change the NDS settings each time, probably there's a way to set all of this up in a more smooth way but I don't know what it is. awggui still doesn't get the correct channels, not sure where I can change the settings to fix that.


  4371   Wed Mar 2 22:57:57 2011 sureshSummaryGeneralStuff from LLO

Here is a partial list of stuff which is being packed at LLO to be shipped to CIT.  The electronics ckt boards are yet to be added to this list.  Will do that tomorrow.



Attachment 1: eLIGO_items_from_LLO_for_Caltech.xls
  4381   Mon Mar 7 17:58:14 2011 sureshSummaryGeneralStuff from LLO

Here is the updated list. These lists were used as packing lists and therefore are organised by Box #.
Attachment 1: eLIGO_items_from_LLO_for_Caltech_Sheet1.pdf
eLIGO_items_from_LLO_for_Caltech_Sheet1.pdf eLIGO_items_from_LLO_for_Caltech_Sheet1.pdf eLIGO_items_from_LLO_for_Caltech_Sheet1.pdf eLIGO_items_from_LLO_for_Caltech_Sheet1.pdf eLIGO_items_from_LLO_for_Caltech_Sheet1.pdf eLIGO_items_from_LLO_for_Caltech_Sheet1.pdf
  4548   Wed Apr 20 22:29:07 2011 sureshUpdateRF SystemPlan for LSC rack

The suggested layout of the 1Y2 Rack is shown below.

To simplify the wiring, I have largely kept demod boards with the same same LO frequency close to each other. 

The Heliax cables land on the top and bottom of the of subracks.  These are currently flexible plastic sheets.  Steve has agreed to replace them with something more rigid.  It would be good to have eight N-type connectors on the top and eight  at the bottom.  As  demod boards occur in sets of eight per subrack.  So it would be convenient if the 11 and 55 Mhz Heliax cables land on the top and the rest at the bottom.  In the layout I have shown the current situation. 

The LO signals to the boards come from the RF Distribution box and this is kept in the middle so that cables to both the subracks can be kept short.

The outputs of the AA filter boards from both subracks  have to be connected to the SCSI Interface board with a twisted pair ribbon cable. 


  5002   Wed Jul 20 17:43:33 2011 sureshUpdateComputersrestarted the frame builder

I restarted the frame builder in the last 15mins. 

I was making a change to a DAC channel in the C1IOO model.

  5013   Thu Jul 21 16:05:15 2011 sureshUpdateIOOPSL beam into MC realigned

 I realigned the PSL beam going into the MC.

The MC beam was realigned so as to maximise the power in the MC.  I minimised the MC_RFPD_DCMON dial on the MC_ALIGN screen while adjusting the two zig-zag mirrors at the end of the PSL table.

  6016   Sat Nov 26 07:22:20 2011 sureshUpdateComputers 

c1sus has been shutdown so that the optics dont bang around.  This is because the watch dogs are not working.

  6438   Thu Mar 22 17:41:15 2012 sureshUpdateCDSc1scx and c1scy not properly running


It seems that neither c1scx nor c1scy is working properly as their ADC counts are showing digital-zeros.

Quote from #6434

The power was turned back on at 4pm It took some time for Suresh to restart the computers. We have damping but things are not perfect yet. Auto BURTH did not work well.

 When Steve and I restarted the c1iscex and c1iscey computers after the power shutdown, the models within them did not start-up automatically.  I had to start them manually from a terminal in the control room. 

I also tried rebooting the FB a couple of times.  Did not make any difference.

Manually starting the c1x05, c1scy and c1x01, c1scx models (with the Burt Restore button ON) did not resolve the issue of zeros in the epics screens.  though it did re-establish timing. 

  7950   Mon Jan 28 21:36:44 2013 tall guyFrogsGeneralsmall people on notice

If I catch anyone putting small booties into the large bootie bin, I will make said person eat small booties.

  3812   Thu Oct 28 19:10:26 2010 taraUpdateElectronicsTTFSS for 40m

I keep a set of new TTFSS for 40m in electronic cabinet along the North arm.

The set number is #6. It is working and has not been modified by me.

Other two sets,# 5 and #7, are kept at PSL lab.

  4512   Mon Apr 11 20:03:05 2011 taraUpdateElectronicsTTFSS for 40m

I brought TTFSS set #7 to 40m and kept it in the electronic cabinet.

note that Q4 transistor has not been replaced back to PZT2907A yet. It's still GE82.

Q3 is now pzt3904, not PZT2222A.


  6514   Tue Apr 10 11:08:29 2012 taraUpdatePSLcurved mirror behind AOM removed

We removed the curved mirror behind the AOM (ROC=0.3m) on PSL table. The mirror is now in PSL lab. See PSL:905 for more detail.

  7904   Wed Jan 16 10:57:37 2013 taraSummaryIOONoise budget for MC

I calculated thermal noise in mode cleaner (MC) mirrors and compared it with the measured MC noise. Thermal noise won't be a significant noise source for MC.

== Motivation==

 There is an idea of using MC and a refcav to measure coating thermal noise. One laser is frequency locked to MC, another laser is locked to an 8" refcav. Then the two transmitted beams are recombined so that we can readout the frequency noise. In this case, the transmitted beam from MC is a better reference (less frequency noise) than the beam from refcav. However, we need to make sure that we understand the noise sources, for example brownian noise, thermoelastic noise in both substrates and coatings, in MC more thoroughly.


I used Rana's code for MC's technical noise sources from, svn. The same plot can be found in appendix C of his thesis. Then I added my calculation to the plot.  Jenne pointed me to 40m:2984 for the spot size and the cavity length. The spot radius on MC1 and MC3 is ~ 1.5mm, and ~3.4 mm@MC2, The round trip length is ~27m, thus the frequency fluctuation due to thermal noise is lower than that of refcav by 2-3 orders of magnitude. I calculated Brownian noise in coatings, Brownian noise in substrate, Thermoelastic noise in substrate. I assumed that the coatings are SiO2/Ta2O5, quarter stacks, coatings thickness for MC1/3 = 5um, for MC2 = 8um. The code can be found in the attachment.



Total thermal noise on MC (Brownian + Thermoelastic on substrate and coatings of MC1-MC3) is plotted in dashed red. It is already below 10^-5 Hz/rtHz at ~20 Hz. This is sufficiently low compared to other noise sources. Beat signal from CTN measurement with 8" cavities is plotted in pink, the estimated coating brownian noise is plotted in a yellow strip. They are well above the measured MC noise between 100 Hz to a few kHz. Measuring coating thermal noise on 8" refcav seems plausible with this method. We can beat the two transmitted beams from IMC and refcav and readout the beat signal to extract the displacement noise of refcav. I'll discuss this with Koji if this is a good surf project.


[the internal thermal noise in the original plotted is removed and replaced with the total thermal noise plot instead]

 note:I'm not sure about the current 40m MC configuration. The parameters used in this calculation are summarized in mcnoiseS2L1.m (in the svn page).


Attachment 2: mc_nb_TN.png
Attachment 3: mc_nb_TN.fig
Attachment 4: MC_nb.m.zip
  3163   Wed Jul 7 00:15:29 2010 tara,RanaSummaryPSLpower spectral density from RefCav transmitted beam

I measured the RC transmitted light signals here at the 40m. I made all connections through the PSL patch panel.

Other than two steering mirrors in front of the periscope, and the steering mirror for the RFPD which were used to steer

the beam into the cavity and the RFPD respectively, no optics are adjusted.

We re-aligned the beam into the cavity (the DC level increased from 2 V to 3.83V) (Fig2) (We could not recover the power back to what it was 90 days ago)

and the reflected beam to the center of the RFPD.


I measured the spectral density of the signal of the transmitted beam behind RefCav in both time and frequency domain.

This will be compared with the result from PSL lab later, so I can see how stable the signal should be.

I did not convert Vrms/rtHz to Hz/rtHz because I only look at the relative intensity of the transmitted beam which will be compared to the setup at PSL lab. 



 We care about this power fluctuation because we plan to measure

 photo refractive noise on the cavity's mirros

(this is the noise caused by dn/dT in the coatings and the substrate,

the absorption from fluctuating power on the coating/mirror changes

the temperature which eventually changes the effective length of the cavity as seen by the laser.)


      The plan is to modulate the power of the beam going into the cavity,

the absorption from ac part will induce frequency noise which we want to see.

Since the transmitted power of the cavity is proportional to the power inside the cavity.

 Fluctuations  from other factors, for example, gain setting,  will limit our measurement. 

That's why we are concerned about the stability of the transmitted beam and made this measurement.


Attachment 1: RIN_rftrans.png
Attachment 2: tara.png
  3210   Tue Jul 13 21:04:49 2010 tara,ranaSummaryPSLTransfer function of FSS servo

 I measured FSS's open loop transfer function.

For FSS servo schematic, see D040105-B.  

4395A's source out is connected to Test point 2 on the patch panel.

Test Point 2 is enabled by FSS medm screen.

"A" channel is connected to In1, on the patch panel.

"R" channel is connected to In2, on the patch panel.

the plot shows signal from A/R.

Note that the magnitude has not been corrected for the impedance match yet.

So the real UGF will be different from the plot.



4395A setup


network analyzer mode

frequency span 1k - 10MHz

Intermediate frequency bandwidth 100Hz

Attenuator: 0 for both channels

Source out power: -30 dBm

sweep log frequency


medm screen setup


TP2: enabled

Common gain -4.8 dB

Fast Gain 16 dB

Attachment 1: TF_FSS_ser.png
  3570   Mon Sep 13 22:51:07 2010 tara,valeraConfigurationPSLbeam scan for RCAV

On Friday, Valera and I calculated the modematching for reference cavity from AOM.

We scan the beam profile where the spot should be.

The first beam waist in the AOM is 103 um, the lens (f= 183 mm, I'm not sure if I have the focal length right) is 280 mm away.

The data is attached. The first column is marking on the rail in inches,

the second column is distance from the lens, the third and fourth column are

vertical and horizontal spot radius in micron. Note that the beam is very elliptic because of the AOM.

Attachment 1: 2010_09_10_w.mat
  14105   Thu Jul 26 01:52:01 2018 terraUpdateThermal Compensationheater work update

Just a quick update: over the past few days we've taken (at least) 5 scans around each peak [carrier - HOM3] at 9.4V/0.8A, 4 scans around [carrier - HOM5] at 12V/0.9A hot state with the reflector setup. We also have (at least) 5 scans of carrier - HOM5 in cold state. I attach a rough overview of the peak magnitude shifts in the first attachment. Analysis ongoing. All data stored in annalisa/postVent/{date}

Initial shifts just based on rought peak placement in the meantime:

            [9.4V/0.8A]   [12V/0.9A]

HOM1    10 kHz         20 kHz

HOM2    18 kHz         28 kHz

HOM3     30 kHz        40 kHz

HOM4     N/A             26 kHz

HOM5     N/A             35 kHz

I also attach the heating thermal transient from today (12V/0.9A) as seen by the opLevs. We see a shorter time constant for pitch, longer for yaw, preceeded by a dip in yaw. Similar behavior yesterday for slightly less heating, though less pronounced pre-dip. The heater is offcentered on the optic horizontally; likely this is part of the induced yaw. The spikey stuff i removed is from people walking around inside during the transient.

I've left the heater and LSC off for the night. Heater off at 2:07 am local time.

Please don't touch the oplevs; we're taking a cool down measurement.

Attachment 1: OpLev_thermal_drift.pdf
Attachment 2: hotColdAll.pdf
  14110   Sat Jul 28 00:45:11 2018 terra, sandrineSummaryThermal CompensationHeater measurements overview

[Sandrine, Koji, Terra]

Summary: We completed multiple scans at different heating powers for the reflector set up, observing unique HOM peak shifts of tens of kHz. We also observed HOM5 shifts with the cylinder set up. Initial Lorentzian fittings of the magnitude give tens of Hz resolution. I summarize the main week's work below. 


Heater set-up is described in several previous elogs, but attachments #1 and #2 show the full heater set-up and wiring/pinouts in and out of vacuum, since we're all intimately aware of how confusing in-vacuum pinouts can be. We are not using the Sorenson power supply (as described in 14071); we just have the BKPrecision power supply 1735 sitting next to the ETMY rack and are manually going out to turn on/off. 

We've continued to use the scan setup described in elog 14086, which is run using /users/annalisa/postVent/AGfast.py. Step by step notes for setting up the scan, running the scans, and processing the scans are attached in notes.txt.

Inducing/witnessing HOMs

The aux input beam was already clipped and on wednesday (after Trans was centered, 14093) we also clipped the output aux beam with razor blade (angled vertically and horizontally, elog 14103) before PDA255; we clipped ~1/3 of the output beam. Attachment #3 shows before and after clipping output, where orange 'cold' == unclipped, black 'mean' == clipped (all in cold state). Up to HOM5 is visible. 


Below is a summary of the available scan data. We also have cold (0A) scans CAR-HOM5 and full FSR scans for most configurations. 

Elliptic Reflector
current[A] voltage[V] power[W] scans
0.4 2 0.8 CAR-HOM3(x1)
0.5 3.4 1.7 CAR-HOM3(x1)
0.6 5 3.0 CAR-HOM3(x1)
0.8 9.4(9.7) 7.5(7.8) CAR-HOM5(>x5)
0.9 12 10.8 CAR-HOM5(x4)
1.09 17 18.5 CAR-HOM3








Cylinder + Lenses
current[A] voltage[V] power[W] scans
0.9 15 13.5 CAR-HOM5(odds x4)

We tried the cylinder set-up again tonight for the first time since inital try and can see shifts of HOM5 - see attachment #5; we haven't looked in detail yet, but it looks like odd modes are more effected, suggesting the ring heat pattern is off centered from the beam axis. 

Scan data is saved in the following format: users/annalisa/postVent/scandata/{reflector,cylinder}/{parsed,unparsed}/{CAR,HOM1,HOM2,HOM3,HOM4,HOM5}{_datetime}{_parsed,_unparsed}.{txt,pdf}

Minimum heating

On 7/26 we increased the power to the elliptical reflector heater in steps to find the minimum heater power required to see frequency shifts with our measurement setup. Lowest we can resolve is a shift in HOM3 with 1.7W (0.5A/3.4V). According to Annalisa's measurements in elog 14050, this would be something like 30-60 mW radiated power hitting the test mass. We only looked at CAR - HOM3 for this investigation; data for scans at 0.4A, 0.5A, 0.6A is available as indicated above.

Lorentizian Fitting

The Lorentzian fitting was done using the equation a + b / sqrt(1+((x-c)/d*2), where a = constant background, b = peak height above background, c = peak frequency, d = full width at half max. 

The fitting is still being edited and optimized. We will crop the data to zoom in around the peak more.

The Lorentzian fit of the magnitude shows ~10Hz of resolution. (See attachment 6 for the carrier at 8A and attachment 7 for HOM 1 at 9A)

We're working on fitting the full complex data.



Attachment 1: heater_setup.jpg
Attachment 2: heater_wiring.jpg
Attachment 3: notes.txt
Notes for running scans:
1. when first turning on Agilent, set initial stuff
    > cd /users/annalisa/postVent/20180718
    > AGmeasure TFAG4395Atemplate.yml
2. tweak arm alignment and offset PLL
    > sitemap (then IFO --> ALIGN and also PSL --> AUX)
    > to increase 
3. make sure X-arm is misagligned (hit '! Misalign' button for ITMX, ETMX) 
3. run scan
    > python AGfast.py startfreq stopfreq points
... 36 more lines ...
Attachment 4: FSR_clipped.pdf
Attachment 5: cylinderHOM5.pdf
Attachment 6: pt8A_CAR.pdf
Attachment 7: pt9A_HOM1.pdf
  340   Sun Feb 24 10:51:58 2008 tfFrogsEnvironment40m in phdcomics?
  28   Mon Oct 29 23:25:42 2007 tobinSoftware InstallationCDSframes mounted
I mounted the frames directory on mafalda and linux3. It's intentionally not listed in the /etc/fstab so that an fb crash won't prevent the controls machines from booting. The command to mount the frames directory is:

mount fb40m:/frames/frames /frames
  31   Tue Oct 30 16:55:40 2007 tobinRoutine Drag-wiping perfected
Steve, Tobin

Steve procured an assortment of syringes from the bio storeroom and we practiced drag-wiping the SOS in the flow bench. Using a 50 microliter Hamilton syringe to deliver 16 microliters of methanol seems perfect for drag-wiping the small optics. Drag-wiping in the downward direction seems to work very well, since we can squirt the optic directly in the center, and the (half) piece of kodak lens tissue fits easily between the bottom two earthquake stops.
  32   Tue Oct 30 19:32:13 2007 tobinProblem FixedComputersconlogger restarted
I noticed that the conlogger wasn't running. It looks like it hasn't been running since October 11th. I modified the restart_conlogger script to insist that it run on op340m instead of op440m, and then ran it on op340m.
  33   Tue Oct 30 20:15:24 2007 tobinOtherEnvironmentearthquake
Rana, Tobin

Largish (M5.6) earthquake in San Francisco sent our optics swinging.
  39   Wed Oct 31 15:02:59 2007 tobinRoutineIOOMode Cleaner Mode Tracking
I processed the heterodyned mode cleaner data yesterday, tracking the three 28 kHz modes corresponding to MC1, MC2, and MC3. Unfortuntately the effect of our MC power chopping is totally swamped by ambient temperature changes. Attached are two plots, one with the tracked mode frequencies, and the other containing dataviewer trends with the MC transmitted power and the room temperature. Additionally, the matlab scripts are attached in a zip file.
Attachment 1: mode-track.pdf
Attachment 2: trends.pdf
Attachment 3: mcmodetrack.zip
  45   Thu Nov 1 11:45:30 2007 tobinConfigurationIOOMode cleaner drag-wiping
Andrey, Bob, David, John Miller, Rana, Rob, Steve, Tobin

Yesterday we vented the vacuum enclosure and opened up the chamber containing MC1 & MC3 by removing the access connector between that chamber and the OMC chamber. Rana marked MC1's location with dogs and then slid the suspension horizontally to the table edge for easy drag-wiping access. The optic was thoroughly hosed-down with the dionizer, in part in an effort to remove dust from the cage and the top of the optic. Drag-wiping commenced with Rob squirting (using the 50 microliter syringe) and Tobin dragging (using half-sheets of Kodak lens tissue). We drag-wiped the optic many (~10) times, concentrating on the center but also chasing around various particles and a smudge on the periphery. There remains one tiny speck at about the 7:30 position, outside of the resonant spot area, that we could not dislodge with three wipes.

Today we drag-wiped MC3. First we slid MC1 back and then slid MC3 out to the edge of the table. We disconnected the OSEM cables in the process for accessibility, and MC1 is perched at an angle, resting on a dog. We did not blow MC3 with the deonizer, not wanting to blow particles from MC3 to the already-cleaned MC1. We drag-wiped MC3 only three times, all downward drags through the optic center, with Steve squirting and Tobin dragging. Some particles are still visible around the periphery, and there appears to be a small fiber lodged near the optic center on the reverse face.

Andrey and Steve have opened up MC2 in preparation for drag-wiping that optic after lunch.
  71   Tue Nov 6 16:48:54 2007 tobinConfigurationComputersscopes on the net
I configured our two 100 MHz Tektronix 3014B scopes with IP addresses: (scope0) and (scope1). Let the scripting commence!

There appears to be a Matlab Instrument Control Toolbox driver for this scope.
ELOG V3.1.3-