40m QIL Cryo_Lab CTN SUS_Lab TCS_Lab OMC_Lab CRIME_Lab FEA ENG_Labs OptContFac Mariner WBEEShop
  40m Log, Page 141 of 341  Not logged in ELOG logo
ID Date Author Typeup Category Subject
  5068   Sat Jul 30 07:07:28 2011 kiwamuUpdateASCMCASS status

Since we will measure (and hopefully adjust) the spot positions on the MC suspensions prior to the vent, MCASS is necessary for it.

 

#######################

Here is the MCASS status so far:

  + Valera worked on MCASS on the last February, and basically no progress after he left.

  + The MCASS model had been completed in C1IOO.mdl.

  + He made some useful scripts, including mcassup, mcassOn/Off, senseMCdecenter, senseMCmirrro and senseMCdofs.

       Summary of those scripts can be found in his entry #4355.

  + We haven't closed the MCASS loops.

  + The control filters are still blank.

  + We haven't put any elements on the input and output matrices.

  + Some parameters for the dithering oscillators and demodulation systems were properly set.

     So we can get the demodulated signals by simply running mcassUp and mcassOn. (This essentially corresponds to the A2L measurement.)

  + The PIT motions are driven at 10, 11 and 12 Hz for MC1, 2 and 3 respectively. For YAW, the frequencies were chosen to be 11.5, 12.5 and 13.5 Hz.

  + Some medm windows were prepared but not as refined as that of ASS.

  + Valera performed a measurement of the spot positions by using MCASS. The results are summarized in #4660.

  + We made an estimation about the beam clearance on the Faraday based on the measured spot positions (#4674)

 

#########################

So, it seems we should be able to at least measure the spot positions soon by using his scripts.

  5069   Sat Jul 30 10:01:35 2011 JennyUpdatePSLPSL table work

I've been working on the PSL table to put together a setup so that I can measure the reference cavity's response to a temperature step increase at the can surrounding it. My first step was to mode match the beam coming from the AP table to the cavity.

I implemented my mode matching solution. I ended up using a different one from the one I last elogged about. Here is the solution I used:

Two lenses: f = 1016.7.6 mm at -0.96 m and f = 687.5 mm at -0.658 m. (I set my origin at the polarizing beam splitter--the spot where I want my beam to match the beam coming from the PMC, so all waists are behind that point). Below is what it should look like.

modematchpic.pngmodematchinfo.png

What I did on the table:

  • Before placing lenses I aligned the beam and added a 1/2-wave plate between the two polarizing beam splitters to change the polarization of the beam from S to P.
  • I aligned the beam so that it reflected off of the cavity opening (monitoring the reflected power with a photodetector connected to an oscilloscope and tweaking the alignment to maximize the reflected signal). 
  • I then placed the lenses at -0.93 and -0.64 mm because the exact spots were blocked by optics being used in another setup.
  • I reasoned that since the fitting for the initial waist is so uncertain, the lens position being off by a few cm will not produce the dominating source of error. I am now driving the laser frequency using a lock-in as a function generator to drive the laser temperature at ~1 Hz. I'm then monitoring the power transmitted by the reference cavity with a camera connected to a TV monitor. I will use this setup to improve my mode matching.

Here's a picture of the PSL table with the lenses and mirror I added. The beam is redirected by a mirror and then a polarizing beam splitter. Past the beam splitter is another lens (f=286.5 mm), which was already in place from the mode matching of the beam from the PMC to the reference cavity.

modematch_setup_pic.png

Here is a block diagram of my intended experimental setup:

LIGO_block_diagram.png

I am going to try to lock the laser to the cavity given my preliminary mode matching and then go back and improve it later. My next step is to find a frequency range for dithering the voltage sent to the PZT. To do this I will:

  • Measure the transfer function (amplitude response) of the PZT using a photodiode. The power outputted by the laser varies with driving frequency.
  • Find a frequency region in which the amplitude response is low.
Attachment 3: LIGO_block_diagram.png
LIGO_block_diagram.png
  5070   Sat Jul 30 10:03:32 2011 JennyUpdateComputer Scripts / ProgramsMode matching

I ended up having to switch to a different mode-matching solution, because I was unable to find the f = 572.7 mm lens. See my next elog entry (5069).

  5071   Sat Jul 30 19:06:25 2011 ryan, ranaUpdatePSLReturn of the PSL temperature box

Quote:

The PSL temperature box has returned to service, with some circuit modifications. The 1k resistors on all the temp. sensor inputs (R3, R4, R7, R8, R12, R12) were changed to 0 Ohm. Also, the 10k resistors R26, R28, R29, and R30 were changed to 10.2k metal film. The DCC document will be updated shortly. There is now an offset in the MINCOMEAS channel compared to the others, which will be corrected in the morning after looking at the overnight trend.

 Forgot to do this in May. Have just changed the values in the psl.db file now as well as updating them live via Probe.

To make the appropriate change, I took the measured offset (5.31 deg) and added 2x this to the EGUF and EGUL field for the MINCO_MEAS channel. (see instructions here)

Committed the .db file to the SVN.

attached plot shows 8 days of trend with 5.31 degC added to the black trace using the XMGRACE Data Set Transformations

Attachment 1: rctempbox.png
rctempbox.png
  5072   Sat Jul 30 20:41:50 2011 ranaUpdatePSLRefCav Stabilization back on

 Untitled.png

I turned the RefCav heater and servo back on a couple days ago. At first it was stabilizing again at a low setpoint, but in reality the right temperature (~40 C). After fixing the in-loop signal offsets, the setpoint now correctly reflects the actual temperature.

Jenny is going to calibrate the sensors using some kind of dunking cannister next week.

  5073   Sat Jul 30 21:04:23 2011 kiwamuUpdateASCY arm ASS fixed

The X arm ASS was also fixed. So both X and Y arm ASS are now back to normal.

Now we can align the arms any time from the buttons on the C1IFO_CONFIGURE window.

 

(notes)

The reason why the servo didn't work was that the sign of some control gains had been flipped.

This was exactly the same situation as that in the Y arm ASS (#5067).

Quote from #5067

The servos of C1ASS for the Y arm and the beam axis alignments were fixed.

  5074   Sun Jul 31 00:05:52 2011 kiwamuUpdateLSCscript for loss measurement : modified

I modified the script armloss so that the channel names in the script are properly adopted to the new CDS.

Additionally I disabled the ETMX(Y)_tickle command in the script.

The tickle command puts some offsets on the LSC signal to let the arms pass through a fringe until it gets locked, but apparently we don't need it because the arms are loud enough.

A brief check showed that the script ran fine.

I will measure the loss on the X and Y arm cavity tomorrow.

Quote from #5067

Next : Health-check for the X arm ASS, the loss measurements.

 

  5075   Sun Jul 31 00:37:57 2011 kiwamuUpdatePSLRe : PSL table work

I think you made a simple mistake in your diagram -- the mixer must be replaced by a summer circuit. Otherwise you cannot do the PDH lock.

Quote from #5069

LIGO_block_diagram.png

  5077   Sun Jul 31 22:35:35 2011 kiwamuUpdateLSCarm loss measurement : done

I did the measurement of the arm loss on both X and Y arm by running the armLoss script.

The results will be posted later.

Quote from #5074

I will measure the loss on the X and Y arm cavity tomorrow.

 

  5079   Mon Aug 1 04:08:24 2011 kiwamuUpdateABSLArm length measurement : cavity kick technique

I made some attempts to measure the current length of the arm cavities by using the mass-kicking technique.

However unfortunately I am running out my energy to complete the measurement,

so I will finish the measurement at some time today.

I still have to set an appropriate kick amplitude. Right now I am injecting AWG into ETMY_LSC_EXC at 0.2 Hz with amplutde of 400 cnts.

I guess it needs a little bit more amplitude to get more psuedo-constant velocity.

Volunteers are always welcome !

 

(some notes)

The procedure was well-described in entry #555 by Dr.Stochino.

Here is just an example of the time series that I took today showing how the time series looks like.

ETMY_kick.png

  5080   Mon Aug 1 08:52:37 2011 steveUpdateVACpreparation to vent

Both arms locked easely around 1V transmited.  We should recenter oplevs.

Attachment 1: pztsteering.png
pztsteering.png
Attachment 2: vac1Aug2011.png
vac1Aug2011.png
Attachment 3: PEM200d.jpg
PEM200d.jpg
  5082   Mon Aug 1 16:06:05 2011 steveUpdateSUSoplevs are centered

Kiwamu, Koji and Steve,

Arm aligned separatly and oplev qpds were centered  including BS. Than we realigned manually DRM and centered their qpds.

ALL SUS oplevs were centered to resonating cavities.

  5083   Mon Aug 1 17:47:37 2011 steveUpdateASCwhat is not working

SUS-ETMY_QPD is not responding. It is reading zero in dataviewer and 4,400 counts on QPD MEDM screen.......must be wrong cable connected

IP-POS is sick. Last time alive 7-19-2011

IP-ANG beam is clipping on pick-up mirror at ETMY chamber. This will have to be fixed at the vent. The qpd itself is responding to light.

  5084   Mon Aug 1 20:21:05 2011 kiwamuUpdateGreen LockingY arm green beam axis : aligned

The beam axis of the Y green light has been aligned.

Now I can see TEM00 mode is flashing on the ETMY camera.

 

-- (What I will do tonight)

The next step is to refine some electronics in the PDH loops to get the green light locked to the Y arm cavity.

If the beam isn't locked, I guess the in-vac-work will be so difficult because of the low intensity of the green light.

According to a brief check on the circuits, a low pass filter after the demodulation mixer is in a sad situation.

It doesn't pass any signals and in fact it behaves more like an absorber.

On the other hand, the modulation system looks fine to me because I was able to see the 270 kHz sideband converted into AM due to the fringing.

Quote from #5078

  (not yet) Alignment of the Y green beam (#5066)

  5086   Mon Aug 1 23:26:32 2011 KojiUpdateLSCREFL33 PD

Old MZ PD (InGaAs 2mm, @29.5MHz) has been modified for REFL33.
There has been no choice for the 11MHz notch other than putting it on the RF preamp
as the notch in parellel to the diode eats the RF transimpedance at 33MHz.

I wait for judgement of Rana if the notch at the MAX4107 feedback is acceptable or not.

P8011390.JPG

Attachment 1: REFL33_schematic_110801_KA.pdf
REFL33_schematic_110801_KA.pdf
  5087   Mon Aug 1 23:29:24 2011 Manuel, IshwitaUpdateWienerFilteringGetting Data by matlab

We tried to acquire data from the seismometers and the mode cleaner using the Matlab function

datalist = NDS2_GetData({'C1:PEM-SEIS_GUR1_X_IN1_DQ'}, 996258376 , 10, CONFIG.nds.C)

and encountered the following error

Warning: daq_request_data failed
 
??? Error using ==> NDS2_GetData
Fatal Error getting channel data.

The same error was obtained with the following other channels

C1:PEM-SEIS_GUR2_X_IN1_DQ

C1:PEM-SEIS_STS_1_X_IN1_DQ

But we are able to get data from channel

C1:LSC-MC_OUT_DQ

for the same gps time.

We checked with Dataviewer that the data are saved (we viewed data of last 24h) for every channel.

  5088   Tue Aug 2 02:20:09 2011 kiwamuUpdateGreen LockingY arm green beam axis : done

I succeeded in locking the green light to the Y arm cavity, but it wasn't so robust. Something is unhealthy in the electronics.

I am leaving the Y green system as it is because I already can see a plenty of the green light flashing in the BS chamber.

So just a flashing of the green light is good enough for the in-vac-work.

DONE.

Quote from #5084

The next step is to refine some electronics in the PDH loops to get the green light locked to the Y arm cavity. 

 

  5089   Tue Aug 2 02:35:23 2011 kiwamuUpdateGeneralpreparation of the vent : status and plan

The vent will take place on Wednesday.

Plan for Tuesday :

  (Morning) Preparation of necessary items for the low power MC (Steve / Jamie)

  (Daytime) Measurement of the MC spot positions (Suresh)

  (Daytime) Arm length measurement (Jenne)

  (Nighttime) Locking of the low power MC (Kiwamu / Volunteers)

 

Plan for Wednesday :

  (Early morning) Final checks on the beam axis, all alignments and green light (Steve / Kiwamu / Volunteers )

  (Morning) Start the vent (Steve)

  (daytime-nighttime) Taking care of the Air/Nitrogen cylinders (Everybody !!)

 

Status of the vent preparation :

 

  (not yet) Low power MC

  (ongoing) Measurement of the arm lengths

  (ongoing) Measurement of the MC spot positions

  (80% done) Estimation of the tolerance of the arm length (#5076)

  (done) Alignment of the Y green beam (#5084)

  (done) Preparation of beam dumps (#5047)

  (done) Health check of shadow sensors and the OSEM damping gain adjustment (#5061)

  (done) Alignment of the incident beam axis (#5073)

  (done) Loss measurement of the arm cavities (#5077)

  5091   Tue Aug 2 11:02:52 2011 JenneUpdateSUSPRM Watchdog tripped

I found PRM watchdog tripped.  It's all better now.

  5093   Tue Aug 2 15:41:06 2011 kiwamuUpdateIOOMeasurement of MC spot positions : done

[Suresh / Kiwamu]

 The measurement of the spot positions on the MC mirrors are DONE.

Surprisingly the spot positions are not so different from the ones measured on May.

    Feb 26 2011      May 08 2011 (New !) Aug 2 2011
MC1 pit [mm]   1.6   1.9  1.93
MC2 pit [mm]   6.4   9.0 9.03
MC3 pit [mm]   1.4   2.0 2.01
MC1 yaw [mm]   -1.5   -1.7 -1.72
MC2 yaw [mm]   1.0   0.2 0.178
MC3 yaw [mm]   -1.3   -1.9 -1.87

 

(some notes)
We used Valera's script senseMCdecenter to estimate the spot positions ( see his entry).

It returns so many EPICS error messages and sometime some measured values were missing. So we had to throw away some of the measurements.

Anyways we gave the resultant ASCII file to Valera's matlab file sensmcass.m to get the actual amount of off-centering in milli-meter.

The attached file is the resultant plot from his matlab code.

Attachment 1: MCdecenter.png
MCdecenter.png
  5094   Tue Aug 2 16:43:23 2011 jamieUpdateCDSNDS2 server on mafalda restarted for access to new channels

In order to get access to new DQ channels from the NDS2 server, the NDS2 server needs to be told about the new channels and restarted.  The procedure is as follows:

ssh mafalda
cd /users/jzweizig/nds2-mafalda
./build_channel_history
./install_channel_list
pkill nds2
# wait a few seconds for the process to quit and release the server port
./start_nds2

This procedure needs to be run every time new _DQ channels are added.

We need to set this up as a proper service, so the restart procedure is more elegant.

An additional comment from John Z.:

    The --end-gps parameter in ./build_channel_history seems to be causeing
    some trouble. It should work without this parameter, but there is a
    directory with a gps time of 1297900000 (evidently a test for GPS1G)
    that might screw up the channel list generation. So, it appears that
    the end time requires a time for which data already exists. this
    wouldn't seem to be a big deal, but it means that it has to be modified
    by hand before running. I haven't fixed this yet, but I think that I
    can probably pick out the most recent frame and use that as an end-time
    point. I'll see if I can make that work...

  5095   Tue Aug 2 16:55:21 2011 ranaUpdateABSLArm length measurement : cavity kick technique

Quote:

I made some attempts to measure the current length of the arm cavities by using the mass-kicking technique.

 Why not just scan the Green laser to measure the arm lengths instead? The FSR of the arm is ~3.75 MHz and so all you have to do is lock the arm green and then sweep the PZT until the resonance is found at 3.75 MHz.

L.png

  5096   Tue Aug 2 17:40:04 2011 JennyUpdatePSLReducing beam intensity incident on photodiode

I am using a PDA255 photodiode to measure the power outputted by the NPRO beam on the PSL table. (I'm going to then use a network analyzer to measure the amplitude response of the PZT to being driven at a range of frequencies. I'll detect the variation in in response to changing the driving frequency using this PDA255.)

The PDA255 has an active area of 0.8mm^2 and a maximum intensity for which the response is linear of 10mW/cm^2. This means that a beam I focus on the PD must have a power less than 0.08 mW (and even less if the spot size is smaller than the window size).

I used a power meter to measure the beam power and found it was 0.381 mW.

The second polarizing beam splitter in the setup transmits most of the beam power, but reflects 0.04 mW (according to the power meter). I'm going to place the photodiode there in the path of the reflected beam.

  5097   Tue Aug 2 19:05:13 2011 kiwamuUpdateIOOpeparation for low power MC : HWP+PBS installed

[Steve / Kiwamu]

  An attenuator, consisting of two HWPs and a PBS, has been installed on the PSL table for the MC low power state.

Those items allow us to reduce the amount of the incident power going into the MC.

We haven't decreased the power yet because we still have to measure the arm lengths.

After we finish the measurement we will go to the low power state.

We have adjusted the polarization after the last HWP using another PBS. Now it is S-polarizing beam.

After the installation of the attenuator the beam axis has changed although we were immediately able to lock the MC with TEM00 mode.

I touched two steering mirrors on the PSL table to get the transmitted power of MC higher. At the moment the transmitted power in MC_TRANS is at about 30000 cnts.

 

The attached picture is the setup of the attenuator on the PSL table.

Attachment 1: attenuator.png
attenuator.png
  5098   Tue Aug 2 23:02:48 2011 NicoleUpdateSUSFixed Accelerometer


 

The EM shaker was broken (the input terminals (banana inputs) had snapped off. To fix this, I have mounted two banana input mounting posts to a metal mount that Steve attached to the shaker.

shakerposts.jpgclipstoamplifier.jpg

However, because bananas do not provide a secure connection (they easily fall out), I have made special wires to connect the banana inputs of the shaker to the mounted banana inputs of the amplifier I am using (along with the sine generating function of the HP 3563A signal analyzer). Upon Koji's suggestion, I have made C-shaped clips to attach to the banana post mounts. These clips are made from insulated ring terminals.

 newclips.jpg

Today I tested the  shaker and it works! WOOT! I currently have the shaker attached to the horizontal sliding platform (without the TT suspension on it).

Using a 750mHz signal from the HP 3563A with an amplitude of 500 mV amplified to 0.75V, I have gotten the shaker to displace the platform (without the TT suspension on it) 1 mm.

  5099   Tue Aug 2 23:14:21 2011 NicoleUpdateSUSCorrected Screw Alignment in TT Suspension Base

The TT suspension base was not able to be securely mounted to the optical table (i.e. mounted with 4 screws)

because the spacing between the screw holes in the base did not have the correct spacing for mounting on a table with a 1 inch pitch.

newholes.jpg

We have carefully removed the suspension from the problematic base. PLEASE BE VERY CAREFUL AROUND THE TABLE NEXT TO THE MC-2 CHAMBER! THE TT SUSPENSION IS RESTING THERE WITHOUT THE BASE! I will reattach it to the base tomorrow morning when I am less tired and more careful!

We measured the base to be about 4.882" x 3.774". The screw hole spacing is about 3.775" and 2.710" respectively. I have changed the diameter of the screw holes from 0.26" to 0.315" and have been able to successfully mount the suspension to the 1 inch pitch table next to the MC-2 chamber.

 

mountedmirrorflash.jpg

Now that the TT suspension can be mounted, I am going to be aligning a 670nm LED laser and balancing the mirror on the TT tomorrow morning. I will be using a beam blocker but please still be careful.

  5100   Wed Aug 3 01:30:04 2011 JenneUpdateLSCAbsolute length of Xarm and Yarm measured

So far, this is just preliminary, because I haven't done full error analysis to determine the error on my measurements.  That will hopefully be done by tomorrow afternoon (so before we start taking off doors).

I find that the length of the Xarm is:  37.5918 meters.

I find that the length of the Yarm is:   37.5425 meters.

I used the mass-kicking technique, as summarized by Kiwamu, and fully described by Alberto.  More words / description to follow with the full error analysis.

  5101   Wed Aug 3 02:20:33 2011 KojiUpdateLSCREFL165 PD

REFL165 PD has been made from the old 166MHz PD.
As the required inductance was ~10nF level, the stray inductance of the circuit pattern was significant.
So, I am not so confident with the circuit functionality before the optical transfer function test.

I will test REFL33 and REFL165 with the Jenne laser to see how they work.

P8031393.JPG

P8031391.JPG

Attachment 1: REFL165_schematic_110802_KA.pdf
REFL165_schematic_110802_KA.pdf
  5102   Wed Aug 3 02:28:08 2011 Manuel, IshwitaUpdateWienerFilteringWiener Filtering in X-arm

Wiener Filtering was applied on the data collected from the X-arm during the time: GPS time-996380715 (Aug 02, 2011. 21:25:00. PDT) to GPS time-996382215 (Aug 02, 2011. 21:50:00. PDT) for a duration of 1500 seconds. During this time the X-arm was locked, we checked it by acquiring data from channel C1:LSC-TRX_OUT_DQ .

The seismometers were near the beam splitter (guralp2) and near MC2 (guralp1).

Target data was obtained from channel C1:LSC-XARM_IN1_DQ.

Schermata-6.png

Schermata-7.png

Following graphs were obtained after applying the Wiener filter:

 

      1.Seismic data acquired from Guralp1 (X and Y) and Guralp2 (X and Y)                              2.Seismic data acquired from Guralp2 X                                                              3.Seismic data acquired from Guralp2 Y 

WFgur1X1Y2X2YN20000srate2048.pngWFgur2XN20000srate2048.pngWFgur2YN20000srate2048.png

These graphs were obtained with srate = 2048 (sample rate) and N = 20000 (order of the filter).

Graph 1 is the best because the black (residual) line is below the red (target) line for low frequencies since we used seismic data from 4 channels. Graph 3 is the worst because we used seismic data from only one Y channel (Y axis of Guralp2) that is less related with the X-arm mirrors' motion since they are oriented orthogonally.

  5103   Wed Aug 3 04:29:48 2011 kiwamuUpdateIOOpeparation for low power MC : HWP+PBS installed

[Suresh / Kiwamu]

 The incident beam power going into MC was decreased down to 20 mW by rotating the HWP that we set yesterday.

A 10% beam splitter which was sitting before MCREFL_PD was replaced by a perfect reflector so that all the power goes into the PD.

And we confirmed that MC can be still locked by increasing C1IOO-MC_REFL_GAIN. Some modifications in the Autolocker script need to be done later.

Also we opened the aperture of the MC2F camera to clearly see the low power beam spot.

 

WE ARE READY FOR THE VENT !!

Power after the EOM = 1.27 W

Power after the HWPs and PBS = 20.2 mW

Power on MCREFL = 20 mW (MC unlocked)

MCREFL_DC = 0.66 V (with MC locked)

 

Quote:

After we finish the measurement we will go to the low power state.

 

  5104   Wed Aug 3 09:40:13 2011 steveUpdateVACvent

The vacuum system is coming up to atm. The vent was started with slow N2 flow. The PSL output is blocked 2 places on the table.

Attachment 1: pzt2011Aug3.png
pzt2011Aug3.png
  5105   Wed Aug 3 11:34:59 2011 kiwamuUpdateVACRe: vent

An important rule during the in-vac work :

   Do not change the incident axis of the X and Y green beams.

Because of the air flows and unusual pressure in the chambers, the DC alignment of the suspensions become less reliable in terms of the beam pointing reference.

The green beams will be considered as references during the vent.

Quote:

The vacuum system is coming up to atm. The vent was started with slow N2 flow.

  5106   Wed Aug 3 12:24:08 2011 Manuel, IshwitaUpdateWienerFilteringWeekly summary

Last Friday (Jul 29) we reinstalled the blue breakout box, and changed the names of the C1:PEM channels. Elog Reference

We continued the work on the simulation ad applied wiener filter on the simulated ground motion, but the result is unsatisfactory, yet. We will post reasonable results soon.

We did wiener filtering for the first time on real data from the Xarm while it was locked. Elog Reference

  5109   Wed Aug 3 14:20:49 2011 steveUpdateSUSITMX and PRM damping restored

ITMX watchdog tripped around 5 Torr  and the PRM around 450 Torr of this vent. They were restored than.

We are at 580 Torr now.

  5111   Wed Aug 3 16:18:30 2011 steveUpdateVACvent is almost finished

P1 at 750 Torr,  Vent valve VV1 is left open to atm. It will reach equilibrium in an hour. The PSL power is not turned down yet. The beam path is blocked at two places inside the enclosure.

The low power 20 mW  input  MC can be locked tonight.

 

Next day's - Thursday notes:

We  reached 760 Torr of atm in 8 hrs at  1.7 Torr/ min with 5 cylinders of  instrument grade air.

Used 500 PSI of nitrogen to get to 20 Torr at first.  This flow  and the first cylinder of N2  has to be slower next time.

 

We did the following:

1, oplevs were centered on locked caveties 2 days ago

2, just before vent we rechecked arms  pointing, they wre still locking

3,eloged strain gages  and turned HVs off at PZT-steering   at 1Y3 rack and OMC-PZT ps at 1X2 aux rack. They were actually off.

4,,checked jam nuts 6 places x 3

5, turned oplev servos off

6, eloged SUS summery page

7, checked particle counts at ITMY: 1 micron 300,  0.5 micron 3K,  0.3 micron  30K particles / cft-min. All three cranes were wiped 2 days ago.

8, blocked laser into IFO: main 1064 in 1.25W were blocked by manual 2 blocks on PSL table. The PSL output shutter was left open to be triggered by interlock  at P1 3 mTorr. It did!

    Aux NPRO-AP and green light  input at both ends were blocked.

Attachment 1: vent8h.jpg
vent8h.jpg
  5112   Wed Aug 3 22:22:47 2011 KojiUpdateLSCREFL165 PD

This REFL165 was good in terms of RF, but I forgot to make the DC path functioning.

I will try some ideas to fix this tomorrow.

  5113   Wed Aug 3 22:31:38 2011 KojiUpdateLSCREFL33 PD

REFL33 is ready for the installation

Characterization results of REFL33 is found in the PDF attachment.

Resonance at 33.18MHz
Q of 6.0, transimpedance 2.14kOhm
shotnoise intercept current = 0.52mA (i.e. current noise of 13pA/rtHz)

Notch at 10.97MHz
Q of 22.34, transimpedance 16.2 Ohm

Notch at 55.60MHz
Q of 42.45, transimpedance 33.5 Ohm

 

Attachment 1: REFL33_test_110801_KA.pdf
REFL33_test_110801_KA.pdf REFL33_test_110801_KA.pdf REFL33_test_110801_KA.pdf REFL33_test_110801_KA.pdf
  5114   Thu Aug 4 00:04:52 2011 JennyUpdatePSLNetwork analyzer and PD set up to measure amplitude response of PZT

Today I placed the PDA255 photodiode on the PSL table to catch the small amount of beam power reflected by the second polarizing beam splitter in my setup. I plugged the PD output to the oscilloscope to measure the voltage output and positioned the PD such that the voltage output was maximized. At best I was able to achieve a 300 mV DC output voltage from the PD, (which seems a bit low, as the PD is specified to go from 0 to 5 V and the specifications say that the response becomes nonlinear after 10 mW/cm^2 and my beam has an intensity of approximately 5 mw/cm^2. I would therefore expect to get more beam power but after over an hour of maneuvering, 300 mV was the highest voltage output I could get).

I am planning, tomorrow afternoon, to take a measurement of the amplitude response of the PZT driving the NPRO laser. I moved the 4395 spectrum/network analyzer to near the PSL table and connected the RF output to an RF splitter. I fed one output of that into the PZT and the other output into the R port on the network analyzer. I fed the PD output into the A port. I plan to measure A/R as a function of driving frequency, sweeping from 10 Hz to 30 mHz.

I also worked to improve the mode matching of the NPRO beam coming from the AP table to the reference cavity. I drove the temperature of the NPRO at 0.100 Hz with an amplitude of 0.300 V, which Koji told me corresponds to a 1GHz change in the laser frequency. The transmission from the cavity is being monitored by a camera connected to a TV monitor, and also by a PD connected to an oscilloscope. I then repositioned the second lens in my mode matching setup in an attempt to increase the transmission peaks from the zeroth order spacial mode and decrease the transmission peaks from higher order modes. I may have improved the mode matching slightly but I was unable to improve it significantly.

  5115   Thu Aug 4 01:49:08 2011 SureshUpdateIOOMC is locked

I measured the power transmitted from the PSL to the MC. It is 19mW.

The MC is now locked.  The MC Autolocker script cannot be used now since the tigger conditions are not met.  It has been disabled on the C1IOO-LOCK_MC screen.  The boost switch also is set to zero.  Increasing the boost results in MC unlocking. 

The C1:IOO-MC_RFPC_DCMON was going from 1.4 (MC Unlocked) to 0.66 (MC_locked).  I thought we ought to have a factor of ten drop in this since under high power conditions we used to have a drop of about 5.6 to 0.6.   So I adjusted the zig-zag at the end of the PSL table to improve the alignment.  It now goes from 1.4 to 0.13 when the MC is locked.   The lock is also much more stable now.  It still does not tolerate any boost though.

I checked to make sure that the beam centering on MC_REFL PD is optimal since I touched the zig-zag.  The RFPD output is now 0.7V (MC unlocked).  This matches well with the fact that we used to have 3.5V on it with the MC unlocked.  And we have cut the down the power incident on this by a factor of 5.  Because 1W -> 20mW at the PSL table  and 10% BS -> 100% Y1-...

 

 

  5116   Thu Aug 4 08:25:51 2011 steveUpdateSUSsus at atm

ITMX and PRM moved alot.  BS and   ITMY just a little based on oplev reference.

Attachment 1: SUSatm.png
SUSatm.png
Attachment 2: oplevsaftervent.png
oplevsaftervent.png
  5117   Thu Aug 4 09:42:19 2011 KojiUpdateABSLABSL Laser shutter closed

The shutter of the ABSL laser is closed for the vent work.

  5118   Thu Aug 4 11:18:12 2011 ranaUpdateSUSsus at atm

Remember that the Oplevs are not good references because of the temperature sensitivity. The week long trend shows lots of 24 hour fluctuations.

  5119   Thu Aug 4 20:05:23 2011 NicoleUpdateSUSNew Horizontal Sliding Base Mount for TT suspension testing

In order to more-securely mount the TT supsion to the horizontal sliding base, I have made a sub-mounting plate (upon Koji's suggestion) to go in between the horizontal sliding base and the TT suspension base. I made many mistakes in this once-pristine aluminum board. I learned that using a ruler is not good enough for determining where to make holes. Upon Koji's suggestion, I have completed the mounting plate by first making a full-scale diagram on Solid Works, printing it out, and then using the diagram to determine where to make my punch holes. Thank you also to Manuel for helping me drill and to Suresh for teaching me how to use the taps!

topplateview.jpgplatform.jpg

I have been able to successfully mount the plate to the horizontal sliding platform. The TT suspension base is mounted to the front of the mounting plate (there are counter-sink screws at the front connecting the platform to the slider so that the screw heads do not obstruct the TT base). I have been able to successfully mount the TT suspension base to the mounting plate. I have also reattached the TT suspension frame to its original base (the one that I modified so that the TT could be mounted to a 1 inch pitch surface). Currently, the TT suspension is mounted to the optical table I have been working on (next to the MC-2 chamber). I am working on balancing the mirror. I am going to balance the mirror using a 670nm LED laser.

Below is a picture of the laser and the laser block I am using. After I took this photo, I have mounted the laser and the block to the optical table next to the MC-2 chamber.

 

lasersetup.jpg

I have already leveled the laser and I will plan to work on balancing the mirror tomorrow morning (my hands were shaking a lot this afternoon/evening, so I think it would be best to wait until the morning when I will be more careful). I am now going to work on the second half of my photosensor circuit box and second sensor head.

 

Please do not touch the 670nm laser on the optical table next to the MC-2 chamber! It has been leveled. Please also be careful around the optical table, since the TT suspension is mounted to the table!

  5121   Fri Aug 5 04:03:16 2011 KojiUpdateLSCREFL165 PD

REFL165 PD was made and tested. The characterization results are in the PDF file.

Resonance at 166.12MHz
Q of 7.3, transimpedance 667Ohm (Series Resistance = Z/Q2 = 2.5Ohm)
shotnoise intercept current = 4.3mA (i.e. current noise of 36pA/rtHz) 


As the circuit pattern had ~10nH level strain inductance, some technique was needed.

  • The diode was pushed in so as to reduce the lengths of the legs as short as possible.
  • The inductor for the resonant circuit has been located as close to the photodiode as possible
  • The other side of the inductor was needed to be bypassed by a large (0.1uF) capacitor, as the original circuit pattern (D1-L5-C33//R22) was too skinny and long.
  • C32 is also moved next to the diode.
  • The path of the photo current circuit was made thicker by Cu tapes.

Now the size of the loop for the resonant circuit is comparable with the size of SOIC-8 opamp.
(Left-Top corner of the photo)

This improved the resonant gain by factor of 8.5dB at the test with TEST INPUT. (Analyzer photo)

There is no tunable component.
The resonant freq was adjusted by a parallel inductance (270nH) to the main inductor (15nH).

P8041394.JPG

P8041395.JPG

Attachment 3: REFL165_test_110804_KA.pdf
REFL165_test_110804_KA.pdf REFL165_test_110804_KA.pdf REFL165_test_110804_KA.pdf REFL165_test_110804_KA.pdf
  5123   Fri Aug 5 13:51:51 2011 steveUpdateSUScross coupling

We need a plan how to minimize cross coupling in the OSEMs now

  5124   Fri Aug 5 14:03:12 2011 steveUpdateGeneralmalfunctioning crane at ETMY

The horizontal trolley drive stopped working  at the east end this morning. It is working intermittently. In the worst case we can take the door off with the manual -Genie- lift.

I'm working with Konecrane to solve  the wormgear drive problem.

  5125   Fri Aug 5 15:11:24 2011 kiwamuUpdateSUSRe: cross coupling

There is a page on the 40m wiki explaining the procedure.

  http://blue.ligo-wa.caltech.edu:8000/40m/OSEM_adjustment_proceedure

 

Additionally there are several old elogs about the cross-coupling minimization, which can be useful for us:

[1] "SUS ranking from measured data", iLog by Osamy (Aug.22 2005)

[2] "TF from position to sensors for ETMX ", iLog by Osamu (Aug.25 2005)

[3] "Further OSEM tweaking", iLog by Rana (Oct.3 2006)

Quote from #5123

We need a plan how to minimize cross coupling in the OSEMs now

 

  5126   Fri Aug 5 18:29:35 2011 JennyUpdatePSLNetwork analyzer and PD set up to measure amplitude response of PZT

Quote:

Today I placed the PDA255 photodiode on the PSL table to catch the small amount of beam power reflected by the second polarizing beam splitter in my setup. I plugged the PD output to the oscilloscope to measure the voltage output and positioned the PD such that the voltage output was maximized. At best I was able to achieve a 300 mV DC output voltage from the PD, (which seems a bit low, as the PD is specified to go from 0 to 5 V and the specifications say that the response becomes nonlinear after 10 mW/cm^2 and my beam has an intensity of approximately 5 mw/cm^2. I would therefore expect to get more beam power but after over an hour of maneuvering, 300 mV was the highest voltage output I could get).

I am planning, tomorrow afternoon, to take a measurement of the amplitude response of the PZT driving the NPRO laser. I moved the 4395 spectrum/network analyzer to near the PSL table and connected the RF output to an RF splitter. I fed one output of that into the PZT and the other output into the R port on the network analyzer. I fed the PD output into the A port. I plan to measure A/R as a function of driving frequency, sweeping from 10 Hz to 30 mHz.

I also worked to improve the mode matching of the NPRO beam coming from the AP table to the reference cavity. I drove the temperature of the NPRO at 0.100 Hz with an amplitude of 0.300 V, which Koji told me corresponds to a 1GHz change in the laser frequency. The transmission from the cavity is being monitored by a camera connected to a TV monitor, and also by a PD connected to an oscilloscope. I then repositioned the second lens in my mode matching setup in an attempt to increase the transmission peaks from the zeroth order spacial mode and decrease the transmission peaks from higher order modes. I may have improved the mode matching slightly but I was unable to improve it significantly.

The ABSL beam had been blocked so that it wouldn't enter the interferometer. I moved the block so that the beam I've been using is unblocked by the beam going to the interferometer is still blocked.

I positioned a fast lens (f=28.7mm) a little over an inch in front of the PDA255 in order to decrease the spot size incident on the PD. I adjusted the rotation angle of the half wave plate to maximize the transmitted power through the PBS to the cavity and minimize the power reflected to my PD. I then adjusted the lens potion to fix the beam on the PD. The voltage output of the PD is now 150mW, but I have the ability to increase the incident power by rotating the wave plate slightly.

Now all I need is to set up the network analyzer again to record the amplitude response to modulating the PZT from 10 Hz to 30 MHz, reduce the input voltage into the analyzer using a DC block.

  5133   Sun Aug 7 14:01:58 2011 kiwamuUpdateGreen LockingX green beam re-aligned

[Jenne / Kiwamu]

 The X green beam has been realigned to compensate the effect of the ETMX repositioning.

After the alignment we became able to lock the 00 mode with the X green beam.

 

For the alignment:

  spot position on the ETMX mirror = within ~ 1 cm. This number is strictly constrained by a homemade aluminum iris that Jamie put last Friday.

  spot position on the ITMX mirror = unknown, but looks pretty good on the CCD camera.

  spot position on the PSL table = ~ 1 mm downward from what it used to be. The horizontal alignment is perfect.

Conclusions :

  The X green beam again became a reference of the beam axis.

  The ETMX suspension tower is in a good place.

Quote from #5127

Kiwamu will work on the green alignment over the weekend.  Assuming everything works out, we'll try the same procedure on ETMY on Monday.

 

  5134   Sun Aug 7 14:11:53 2011 JenneUpdatePEMParticle counts through the roof

[Jenne, Kiwamu]

While Kiwamu was finalizing the X green alignment, I started to prepare to remove the ETMY door, and begin checking out its OSEMs, etc, so we could start moving it to it's new place, and figure out why it's been wonky for a while.  I ran the particle counter, and we have a factor of ~5 more particles than normal.  Kiwamu and I agreed not to open ETMY.  Since we had briefly opened the IOO and Output Optics chambers to check the X green's position on the PSL table, we immediately shut those doors.  They were probably open for ~15 minutes or so.  (Yes Steve, we should have checked before opening any doors, but at least we remembered to check at all, and the doors were only open for a few minutes rather than for a few hours.)

I attach a 24hrs trend of the particle counts, for reference.  It looks like it's been a little high for a while, but today it's really dirty in the air.

Attachment 1: ParticleCount_High_7Aug2011.png
ParticleCount_High_7Aug2011.png
ELOG V3.1.3-