40m QIL Cryo_Lab CTN SUS_Lab TCS_Lab OMC_Lab CRIME_Lab FEA ENG_Labs OptContFac Mariner WBEEShop
  40m Log, Page 291 of 341  Not logged in ELOG logo
ID Date Author Type Categoryup Subject
  5222   Sat Aug 13 15:40:38 2011 NicoleSummarySUSTT Shaking Today and Hopefully More?

As reported in my  previous entry of TT supsension bode plots, I found that my experimental data had what appears to be very noise peaks above 20 Hz (as mentioned earlier, the peak at 22 Hz is likely due to vertical coupling, as 22 Hz is the resonant frequency of the cantilever blades). This is very unusual and needs to be explored further. I would like to vertically-shake the TTs to obtain more data on possible coupling. However, I am leaving on Monday and will not return until Thursday (day of SURF talks). I am leaving campus Friday afternoon or so. I would may need some help coming up with an assembly plan/assembling set-up for vertical shaking (if it is possible to do so in such a limited time frame).

 

Today I wanted to see if the "noisy peaks" above 30 Hz were due to EM noise coupling. I tested this hypothesis today, seeing if EM fields generated by the coil at higher frequencies were injecting noise into my transfer function measurements. I found that the "noisy peaks" above 30 Hz are NOT DUE TO EM NOISE COUPLING. I am very curious as to what is causing the high peaks (possibly coupling from other degrees of freedom)?

 

 emnoise_and_flex.jpg

  5223   Sat Aug 13 15:47:47 2011 NicoleSummarySUSTT Optimization Curves

Using my Matlab model of the flexibly-supported eddy current damping system, I have changed parameters to see if/how the TTs can be optimized in isolation. As I found earlier, posted in my bode plot entry, there is only a limited region where the flexibly-supported system provides better isolation than the rigidly-supported system.

 

Here is what I have found, where \gamma is the scale factor of the magnetic strength (proportional to magnetic strength), \beta is the scale factor of the current damper mass (estimated by attempting to fit my model to the experimental data), and \alpha is the scale factor of the current resonant frequency of the dampers.

magstrength1.jpgdampermass.jpg resfreq.jpg

 

Here are my commentaries on these plots. If you have any commentaries, it would be very helpful, as I would like to incorporate this information in my powerpoint presentation.

It seems as if the TT suspensions are already optimized?

It may be difficult to lower the resonant frequency of the dampers because that would mean changing the lengths of the EDC suspensions). Also, it appears that a rather drastic reduction (at most 0.6*current EDC resonant frequency --> reduction from about 10 Hz to 6 Hz or less) is required . Using the calculation that the resonant frequency is sqrt(g/length), for my single-suspended EDC model, this means increasing the wire length to nearly 3 x its current value. I'm not sure how this would translate to four EDCs...

The amplification at resonance caused by increasing the magnet strength almost offsets the isolation benefits of increasing magnet strength. From my modeling, it appears that the magnet strength may be very close (if not already at) isolation optimization.

 

Lowering the mass to 0.2 the current mass may be impractical. It seems as if the benefits of lowering the mass only occur when the mass is reduced by a factor of 0.2 (maybe 0.4)

 

  5224   Sat Aug 13 19:08:01 2011 KojiSummarySUSTT Optimization Curves

What are the parameters you are using? As you have the drawings of the components, you can calculate the masses of the objects.

 

Reducing the ECD resonance from 10Hz->6Hz looks nice.

The resonant freq of the ECDs are not (fully) determined by the gravitational energy but have the contribution of the elastic energy of the wire.

Q1: How much is the res freq of the ECDs if the freq is completely determined by the grav energy? (i.e. the case of using much thinner wires)

Q2: How thin should the wires be?

  5225   Sat Aug 13 21:15:47 2011 NicoleSummarySUSTT Optimization Curves

Quote:

What are the parameters you are using? As you have the drawings of the components, you can calculate the masses of the objects.

 

Reducing the ECD resonance from 10Hz->6Hz looks nice.

The resonant freq of the ECDs are not (fully) determined by the gravitational energy but have the contribution of the elastic energy of the wire.

Q1: How much is the res freq of the ECDs if the freq is completely determined by the grav energy? (i.e. the case of using much thinner wires)

Q2: How thin should the wires be?

 The drawings do not have the masses of the objects.

 

For the resonant frequency:

Instead of sqrt (g/l) would the numerator in the square root be[ g + (energy stored in wire)/(mass of damper)] ?

 

  5226   Sat Aug 13 21:48:17 2011 KojiSummarySUSTT Optimization Curves

1) Drawing has the dimensions => You can calculate the volume => You can calculate the mass
Complicated structure can be ignored. We need a rough estimation.

2) Your restoring force can have two terms:
- one comes from the spring constant k
- the other from the gravity

 

  5227   Sun Aug 14 00:26:51 2011 NicoleSummarySUSTT Optimization Curves

Quote:

1) Drawing has the dimensions => You can calculate the volume => You can calculate the mass
Complicated structure can be ignored. We need a rough estimation.

2) Your restoring force can have two terms:
- one comes from the spring constant k
- the other from the gravity

 

 Thank you.

 

The wire used to suspend the EDCs is tungsten?

To verify, for my model, the EDC will be the mass of all four dampers or a single damper? The length of the wire used to suspend the EDC will be the combined length of 4 wires or length of  a single wire?

 

Taking into account the densities for each material (specific material of each component was listed, so I looked up the densities), and trying my best to approximate the volumes of each component, I have determined

the mass of the mirror + mirror holder to be ~100 g and the mass of a single EDC to be ~19 g

  5229   Sun Aug 14 13:57:52 2011 NicoleSummarySUSTT Optimization Curves

Quote:

Quote:

1) Drawing has the dimensions => You can calculate the volume => You can calculate the mass
Complicated structure can be ignored. We need a rough estimation.

2) Your restoring force can have two terms:
- one comes from the spring constant k
- the other from the gravity

 

 Thank you.

 

The wire used to suspend the EDCs is tungsten?

To verify, for my model, the EDC will be the mass of all four dampers or a single damper? The length of the wire used to suspend the EDC will be the combined length of 4 wires or length of  a single wire?

 

Taking into account the densities for each material (specific material of each component was listed, so I looked up the densities), and trying my best to approximate the volumes of each component, I have determined

the mass of the mirror + mirror holder to be ~100 g and the mass of a single EDC to be ~19 g

 I am thinking that perhaps my mass estimations were off? The model that I have used fits the data better than the model that I have made (changing the masses to fit my estimations of the values)

FLEX_exp_mod_comp.jpg

  5231   Sun Aug 14 17:47:39 2011 NicoleSummarySUSTT Shaking Today and Hopefully More?

Quote:

As reported in my  previous entry of TT supsension bode plots, I found that my experimental data had what appears to be very noise peaks above 20 Hz (as mentioned earlier, the peak at 22 Hz is likely due to vertical coupling, as 22 Hz is the resonant frequency of the cantilever blades). This is very unusual and needs to be explored further. I would like to vertically-shake the TTs to obtain more data on possible coupling. However, I am leaving on Monday and will not return until Thursday (day of SURF talks). I am leaving campus Friday afternoon or so. I would may need some help coming up with an assembly plan/assembling set-up for vertical shaking (if it is possible to do so in such a limited time frame).

 

Today I wanted to see if the "noisy peaks" above 30 Hz were due to EM noise coupling. I tested this hypothesis today, seeing if EM fields generated by the coil at higher frequencies were injecting noise into my transfer function measurements. I found that the "noisy peaks" above 30 Hz are NOT DUE TO EM NOISE COUPLING. I am very curious as to what is causing the high peaks (possibly coupling from other degrees of freedom)?

 

 emnoise_and_flex.jpg

 I have been redoing the noise test multiple times today. Here is the best plot that I got

noisetest.jpg

  5234   Sun Aug 14 22:48:37 2011 kiwamuUpdateSUSfree swinging again

Excited all optics
Sun Aug 14 20:22:33 PDT 2011
997413768

  5235   Mon Aug 15 10:02:27 2011 kiwamuUpdateSUSBS OSEM adjustment done

[Suresh / Kiwamu]

 Adjustment of the OSEMs on BS has been done.

All the bad suspensions (#5176) has been adjusted. They are waiting for the matrix inversion test.

  5237   Mon Aug 15 13:16:50 2011 JenneUpdateSUSRe: ETMY hopefully good again

Quote:

I guess the ETMY suspension is still fine. Their OSEM DC voltage and the free swinging spectra look healthy.

It could be a failure in the initial guess for fitting.

Quote from #5216

I'm no longer convinced that ETMY is healthy. I can't fit the peaks to get the input matrix.

 Turns out I was missing a critical step in the process...running makeSUSspectra.m  After I do that, everything is back under control, and ETMY looks fine. 

I'm almost done doing the peak-fitting and matrix inversion for all optics.

  5239   Mon Aug 15 14:10:56 2011 JenneUpdateSUSMonday SUS update

The moral of the story here is that none of the suspensions are overwhelmingly awesome, but most of them will be fine if we leave them as-is.

SUS DoF Plot Input Matrix "BADness" (1==good)
ITMX inMatDiag.png       pit     yaw     pos     side    butt
UL    0.438   1.019   1.050  -0.059   0.717 
UR    0.828  -0.981   1.128  -0.215  -0.956 
LR   -1.172  -1.201   0.950  -0.275   1.241 
LL   -1.562   0.799   0.872  -0.120  -1.087 
SD   -0.579  -0.847   2.539   1.000  -0.170 

 
4.68597
 
 ITMY  inMatDiag.png        pit     yaw     pos     side    butt
UL    1.157   0.185   1.188  -0.109   0.922 
UR    0.020  -1.815   0.745  -0.051  -0.970 
LR   -1.980  -0.090   0.812  -0.024   1.158 
LL   -0.843   1.910   1.255  -0.082  -0.949 
SD   -0.958   1.080   1.859   1.000   0.325  
4.82756
ETMX  inMatDiag.png        pit     yaw     pos     side    butt
UL    0.338   0.476   1.609   0.316   1.046  
UR    0.274  -1.524   1.796  -0.069  -1.180  
LR   -1.726  -1.565   0.391  -0.100   0.938  
LL   -1.662   0.435   0.204   0.286  -0.836  
SD    0.996  -2.629  -0.999   1.000  -0.111
 
 
 4.32072
 ETMY  inMatDiag.png        pit     yaw     pos     side    butt
UL    1.123   0.456   1.812   0.231   0.936 
UR   -0.198  -1.489   0.492  -0.096  -1.098 
LR   -2.000   0.055   0.188  -0.052   0.764 
LL   -0.679   2.000   1.508   0.275  -1.201 
SD    0.180  -0.591   3.355   1.000   0.200  
 10.643
 BS  inMatDiag.png        pit     yaw     pos     side    butt
UL    1.575   0.697   0.230   0.294   1.045 
UR    0.163  -1.303   1.829  -0.133  -0.958 
LR   -1.837  -0.308   1.770  -0.171   0.944 
LL   -0.425   1.692   0.171   0.257  -1.053 
SD    0.769   0.345  -3.380   1.000   0.058 
6.111
 
 PRM  inMatDiag.png        pit     yaw     pos     side    butt
UL    0.597   1.553   2.000  -0.469   1.229  
UR    1.304  -0.447   0.383  -0.043  -0.734  
LR   -0.696  -1.048  -0.277   0.109   0.687  
LL   -1.403   0.952   1.340  -0.317  -1.350  
SD    0.518  -1.125  -1.161   1.000   0.394  

 
 8.43363
SRM inMatDiag.png       pit     yaw     pos     side    butt
UL    0.831   1.039   1.153  -0.140   1.065 
UR    1.071  -0.961   1.104  -0.057  -1.061 
LR   -0.929  -0.946   0.847  -0.035   0.837 
LL   -1.169   1.054   0.896  -0.118  -1.037 
SD    0.193  -0.033   1.797   1.000   0.045 
 4.17396

 

  5240   Mon Aug 15 17:23:55 2011 jamieUpdateSUSfreeswing script updated

I have updated the freeswing scripts, combining all of them into a single script that takes arguments to specify the optic to kick:

pianosa:SUS 0> ./freeswing
usage: freeswing SET
usage: freeswing OPTIC [OPTIC ...]

Kick and free-swing suspended optics.
Specify optics (i.e. 'MC1', 'ITMY') or a set:
'all' = (MC1 MC2 MC3 ETMX ETMY ITMX ITMY PRM SRM BS)
'ifo' = (ETMX ETMY ITMX ITMY PRM SRM BS)
'mc'  = (MC1 MC2 MC3)
pianosa:SUS 0>

I have removed all of the old scripts, and committed the new one to the SVN.

  5241   Mon Aug 15 17:36:10 2011 jamieUpdateSUSStrangeness with ETMY (was: Monday SUS update)

For some reason ETMY has changed a lot.  Not only does it now have the worst "badness" (B matrix condition number) at ~10, but the frequency of all the modes have shifted, some considerably.  I did accidentally bump the optic when Jenne and I were adjusting the OSEMs last week, but I didn't think it was that much.  The only thing I can think of that would cause the modes to move so much is that the optic has been somehow reseated in it's suspension.  I really don't know how that would have happened, though.

Jenne and I went in to investigate ETMY, to see if we could see anything obviously wrong.  Everything looks to be ok.  The magnets are all well centered in the OSEMs, and the PDMon levels look ok.

We rechecked the balance of the table, and tweaked it a bit to make it more level.  We then tweaked the OSEMs again to put them back in the center of their range.  We also checked the response by using the lockin method to check the response to POS and SIDE drive in each of the OSEMs (we want large POS response and minimal SIDE response).  Everything looked ok.

We're going to take another freeswing measurement and see how things look now.  If there are any suggestions what should be done (if anything), about the shifted modes, please let us know.

  5244   Tue Aug 16 04:25:34 2011 Suresh, KiwamuUpdateSUSalignment of MC output to Y-arm using PZTs

We did several things today+night.  The final goal was to lock the PRC so that we could obtain the POX, POY and POP beams.  However there were large number of steps to get there.

1) We moved the ITMY into its place and balanced the table

2) We then aligned the Y-arm cavity to the green beam which was set up as a reference before we moved the ETMY and ITMY to adjust the OSEMS.  We had the green flashing in Y-arm

3) We checked the beam position on PR2. It was okay. This confirmed that we were ready to send the beam onto the Y arm.

4) We then roughly aligned the IR beam on ETMY where Jamie had placed an Al foil with a hole.  We got the arm flashing in both IR and green. 

5) We used the PZTs to make the green and IR beams co-incident and flashing in the Y arm.  This completed the alignment of the IR beam into the Y-arm.

6) The IPPO (pick-off) window had to be repositioned to avoid clipping.  The IPANG beam was aligned such that it exits the ETMY chamber onto the ETMY table.  It can now be easily sent to the IPANG QPD.

7) Then BS was aligned to direct the IR beam into the X-arm and had the X-arm flashing.  It had already been aligned to its green.

8) It was now the turn of the SRC.  The beam spots on all the SRC related optics were off centered.  We aligned all the optics in the AS path to get the AS beam on to the AP table.

9) The AS beam was very faint so we repositioned the AS camera to the place intended for AS11 PD, since there was a brighter beam available there. 

10) We could then obtain reflections from ITMY, ITMX and PRM at the AS camera. 

11) Problems:

      a) ITMY osems need to be readjusted to make sure that they are in mid-range.  Several are out of range and so the damping is not effective.

      b) When we tried to align SRC the yaw OSEM had to be pushed to its full range.  We therefore have to turn the SRM tower to get it back into range.

 12)  We stopped here since moving the SRM is not something to be attempted at the end of a rather long day. Kiwamu is posting a plan for the rest of the day.

  5246   Tue Aug 16 04:50:17 2011 kiwamuUpdateSUSfree swinging again

 Since Suresh and I changed the DC biases on most of the suspension, the free swingning spectra will be different from the past.

- -

EXcited ETMX ETMY ITMX ITMY PRM SRM BS

Tue Aug 16 04:48:02 PDT 2011
997530498

  5247   Tue Aug 16 10:59:06 2011 jamieUpdateSUSSUS update

Data taken from: 997530498+120

Things are actually looking ok at the moment.  "Badness" (cond(B)) is below 6 for all optics.

  • We don't have results from PRM since its spectra looked bad, as if it's being clamped by the earthquake stops.
  • The SRM matrix definitely looks the nicest, followed by ITMX.  All the other matrices have some abnormally high or low elements.
  • cond(B) for ETMY is better than that for SRM, even though the ETMY matrix doesn't look as nice.  Does this mean that cond(B) is not necessarily the best figure of merit, or is there something else that our naive expectation for the matrix doesn't catch?

We still need to go through and adjust all the OSEM ranges once the IFO is aligned and we know what our DC biases are.  We'll repeat this one last time after that.

TM   M cond(B)
BS  BS.png       pit     yaw     pos     side    butt
UL    1.456   0.770   0.296   0.303   1.035 
UR    0.285  -1.230   1.773  -0.077  -0.945 
LR   -1.715  -0.340   1.704  -0.115   0.951 
LL   -0.544   1.660   0.227   0.265  -1.070 
SD    0.612   0.275  -3.459   1.000   0.046
5.61948
SRM  SRM.png       pit     yaw     pos     side    butt
UL    0.891   1.125   0.950  -0.077   0.984 
UR    0.934  -0.875   0.987  -0.011  -0.933 
LR   -1.066  -1.020   1.050   0.010   1.084 
LL   -1.109   0.980   1.013  -0.056  -0.999 
SD    0.257  -0.021   0.304   1.000   0.006 
4.0291
ITMX  ITMX.png       pit     yaw     pos     side    butt
UL    0.436   1.035   1.042  -0.068   0.728 
UR    0.855  -0.965   1.137  -0.211  -0.969 
LR   -1.145  -1.228   0.958  -0.263   1.224 
LL   -1.564   0.772   0.863  -0.120  -1.079 
SD   -0.522  -0.763   2.495   1.000  -0.156
4.55925
ITMY  ITMY.png       pit     yaw     pos     side    butt
UL    1.375   0.095   1.245  -0.058   0.989 
UR   -0.411   1.778   0.975  -0.022  -1.065 
LR   -2.000  -0.222   0.755   0.006   1.001 
LL   -0.214  -1.905   1.025  -0.030  -0.945 
SD    0.011  -0.686   0.804   1.000   0.240 
4.14139
ETMX  ETMX.png       pit     yaw     pos     side    butt
UL    0.714   0.191   1.640   0.404   1.052 
UR    0.197  -1.809   1.758  -0.120  -1.133 
LR   -1.803  -1.889   0.360  -0.109   0.913 
LL   -1.286   0.111   0.242   0.415  -0.902 
SD    1.823  -3.738  -0.714   1.000  -0.130 
5.19482
ETMY  ETMY.png       pit     yaw     pos     side    butt
UL    1.104   0.384   1.417   0.351   1.013 
UR   -0.287  -1.501   1.310  -0.074  -1.032 
LR   -2.000   0.115   0.583  -0.045   0.777 
LL   -0.609   2.000   0.690   0.380  -1.179 
SD    0.043  -0.742  -0.941   1.000   0.338 
3.57032

 

  5255   Wed Aug 17 15:47:18 2011 AnamariaUpdateSUSETMX Side Sensor slow channel down for a long time

Jenne, Anamaria

We aligned the ETMX OSEMs and ran into this issue. Looking at the SENSOR_SIDE channel, we pulled out the OSEM and determined that the open light voltage is 874 counts, so we centered it around 440 as well as we could. This is same channel as its slow counterpart SDSEN_OUTPUT (grey number immediately to the right on SUS medms).

 

 

Quote:

The slow signal from the side sensor on ETMX was last seen in action sometime in May 2010!  And then the frame builder has no data for a while on this channel.  After that the channel shows some bistability starting Sept 2010 but has not been working.  The fast channel of this sensor  (C1:SUS-ETMX_SDSEN_OUTPUT) does work so the sensor is working.  Probably is a loose contact... needs to be fixed.

 

 

  5260   Thu Aug 18 00:58:40 2011 jamieUpdateSUSoptics kicked and left free swinging

ALL optics (including MC) were kicked and left free swinging at:

997689421

The "opticshutdown" script was also run, which should turn the watchdogs back on in 5 hours (at 6am).

 

  5261   Thu Aug 18 10:17:04 2011 kiwamu, steveUpdateSUSoplevs reestablished at Vertex

Kiwamu and Steve, from yesterday

PRM and BS oplev paths were relaid after setting 1/2 OSEM voltages. The incident beam on suspended optics are centered  within  ~ +- 2 mm

I noticed many unvected ss screws are used on the big Al table tops. The SS 1/4-20 screws

 used on the optical tables in vacuum MUST be VENTED!

Also, please use  SS clamps. Replace aluminum ones when you can. We have plenty baked ones.

 

 

  5263   Thu Aug 18 12:22:37 2011 jamieUpdateSUSsuspension update

Most of the suspension look ok, with "badness" levels between 4 and 5.  I'm just posting the ones that look slightly less ideal below.

  • PRM, SRM, and BS in particular show a lot of little peaks that look like some sort of intermodulations.
  • ITMY has a lot of elements with imaginary components
  • The ETMY POS and SIDE modes are *very* close together, which is severely adversely affecting the diagonalization
 PRM  PRM.png        pit     yaw     pos     side    butt
UL    0.466   1.420   1.795  -0.322   0.866  
UR    1.383  -0.580   0.516  -0.046  -0.861  
LR   -0.617  -0.978   0.205   0.011   0.867  
LL   -1.534   1.022   1.484  -0.265  -1.407  
SD    0.846  -0.632  -0.651   1.000   0.555

5.62863

SRM SRM.png       pit     yaw     pos     side    butt
UL    0.783   1.046   1.115  -0.149   1.029 
UR    1.042  -0.954   1.109  -0.060  -1.051 
LR   -0.958  -0.926   0.885  -0.035   0.856 
LL   -1.217   1.074   0.891  -0.125  -1.063 
SD    0.242   0.052   1.544   1.000   0.029 
4.0198
 BS BS.png        pit     yaw     pos     side    butt
UL    1.536   0.714   0.371   0.283   1.042  
UR    0.225  -1.286   1.715  -0.084  -0.927  
LR   -1.775  -0.286   1.629  -0.117   0.960  
LL   -0.464   1.714   0.285   0.250  -1.070  
SD    0.705   0.299  -3.239   1.000   0.023 
 5.5501
 ITMY  ITMY.png        pit     yaw     pos     side    butt
UL    1.335   0.209   1.232  -0.071   0.976  
UR   -0.537   1.732   0.940  -0.025  -1.068  
LR   -2.000  -0.268   0.768   0.004   1.046  
LL   -0.129  -1.791   1.060  -0.043  -0.911  
SD   -0.069  -0.885   1.196   1.000   0.239 
 4.28384
ETMY ETMY.png       pit     yaw     pos     side    butt
UL    1.103   0.286   1.194  -0.039   0.994 
UR   -0.196  -1.643  -0.806  -0.466  -1.113 
LR   -2.000   0.071  -0.373  -0.209   0.744 
LL   -0.701   2.000   1.627   0.217  -1.149 
SD    0.105  -1.007   3.893   1.000   0.290 
9.25346

 

Attachment 2: SRM.png
SRM.png
  5264   Thu Aug 18 15:54:35 2011 steveUpdateSUSdamped and undamped OSEMs

damped sus at atm1 and freeswingging sus at atm2

 

Attachment 1: 5susLL.jpg
5susLL.jpg
Attachment 2: 8freeSUSLL.jpg
8freeSUSLL.jpg
  5266   Fri Aug 19 01:15:22 2011 SureshUpdateSUSFreeSwing all optics

I ran "freeswing all" at Fri Aug 19 01:09:28 PDT 2011 (997776583)  and "opticshutdown"  as well.

 

  5269   Fri Aug 19 10:26:53 2011 steveUpdateSUSOSEM sensor spectra

Free swingging OSEM sensors LL at atm

Attachment 1: 8freeSUSosemSensors.jpg
8freeSUSosemSensors.jpg
  5282   Tue Aug 23 01:09:44 2011 kiwamuUpdateSUSfree swinging test

excited all the optics ---

Tue Aug 23 01:08:00 PDT 2011
998122096

  5286   Tue Aug 23 10:38:27 2011 jamieUpdateSUSSUS update

SUS update before closing up:

  • MC1, MC2, ITMX look good
  • MC3, PRM look ok
  • SRM pos and side peaks are too close together to distinguish, so the matrix is not diagnalizable.  I think with more data it should be ok, though.
  • all ITMY elements have imaginary components
  • ITMY, ETMX, ETMY appear to have modest that swapped position:
    • ITMY: pit/yaw
    • ETMX: yaw/side
    • ETMY: pos/side
  • MC3, ETMX, ETMY have some very large/small elements

Not particularly good.  We're going to work on ETMY at least, since that one is clearly bad.

OPTIC   M cond(B)
MC1 MC1.png       pit     yaw     pos     side    butt
UL    0.733   1.198   1.168   0.050   1.057 
UR    1.165  -0.802   0.896   0.015  -0.925 
LR   -0.835  -1.278   0.832  -0.002   0.954 
LL   -1.267   0.722   1.104   0.032  -1.064 
SD    0.115   0.153  -0.436   1.000  -0.044
4.02107
MC2 MC2.png        pit     yaw     pos     side    butt
UL    1.051   0.765   1.027   0.128   0.952  
UR    0.641  -1.235   1.089  -0.089  -0.942  
LR   -1.359  -0.677   0.973  -0.097   1.011  
LL   -0.949   1.323   0.911   0.121  -1.096  
SD   -0.091  -0.147  -0.792   1.000  -0.066 
4.02254
MC3  MC3.png        pit     yaw     pos     side    butt
UL    1.589   0.353   1.148   0.170   1.099  
UR    0.039  -1.647   1.145   0.207  -1.010  
LR   -1.961  -0.000   0.852   0.113   0.896  
LL   -0.411   2.000   0.855   0.076  -0.994  
SD   -0.418   0.396  -1.624   1.000   0.019
3.60876
PRM  PRM.png        pit     yaw     pos     side    butt
UL    0.532   1.424   1.808  -0.334   0.839  
UR    1.355  -0.576   0.546  -0.052  -0.890  
LR   -0.645  -0.979   0.192   0.015   0.881  
LL   -1.468   1.021   1.454  -0.267  -1.391  
SD    0.679  -0.546  -0.674   1.000   0.590 
 5.54281
BS  BS.png        pit     yaw     pos     side    butt
UL    1.596   0.666   0.416   0.277   1.037  
UR    0.201  -1.334   1.679  -0.047  -0.934  
LR   -1.799  -0.203   1.584  -0.077   0.952  
LL   -0.404   1.797   0.321   0.247  -1.077  
SD    0.711   0.301  -3.397   1.000   0.034 
 5.46234
SRM  NA  NA  NA
ITMX  ITMX.png        pit     yaw     pos     side    butt
UL    0.458   1.025   1.060  -0.065   0.753  
UR    0.849  -0.975   1.152  -0.199  -0.978  
LR   -1.151  -1.245   0.940  -0.243   1.217  
LL   -1.542   0.755   0.848  -0.109  -1.052  
SD   -0.501  -0.719   2.278   1.000  -0.153
 4.4212
ITMY  ITMY.png        pit     yaw     pos     side    butt
UL    0.164   1.320   1.218  -0.086   0.963  
UR    1.748  -0.497   0.889  -0.034  -1.043  
LR   -0.252  -2.000   0.782  -0.005   1.066  
LL   -1.836  -0.183   1.111  -0.058  -0.929  
SD   -0.961  -0.194   1.385   1.000   0.239 
 4.33051
ETMX ETMX.png        pit     yaw     pos     side    butt
UL    0.623   1.552   1.596  -0.033   1.027  
UR    0.194  -0.448   1.841   0.491  -1.170  
LR   -1.806  -0.478   0.404   0.520   0.943  
LL   -1.377   1.522   0.159  -0.005  -0.860  
SD    1.425   3.638  -0.762   1.000  -0.132 
 4.89418
ETMY ETMY.png        pit     yaw     pos     side    butt
UL    0.856   0.007   1.799   0.241   1.005  
UR   -0.082  -1.914  -0.201  -0.352  -1.128  
LR   -2.000   0.079  -0.104  -0.162   0.748  
LL   -1.063   2.000   1.896   0.432  -1.119  
SD   -0.491  -1.546   2.926   1.000   0.169 
 9.11516

 

  5287   Tue Aug 23 11:57:22 2011 kiwamuUpdateSUSfree swinging test during lunch time

excited all the optics. (with ITMY WTF OFF)

Tue Aug 23 11:52:52 PDT 2011
998160788

  5288   Tue Aug 23 14:49:14 2011 jamie, jenne, kiwamu, suresh, keikoUpdateSUSAdjustment of ETMY, issue with ITMY whitening

Before lunch we took a closer look at two of the suspensions that were most problematic: ITMY and ETMY.  Over lunch we took new free swinging data.  Results below:

  • For ITMY we discovered that the whitening on the UL sensor was not switching.  This was causing the UL sensor to have a different response, with a steeper roll of, which was causing all of the transfer function estimates to the other sensors to have large imaginary components.   We took new free swing data with all of the whitening turned OFF.  The result is a much improved matrix and diagnalization.  The input matrix elements are mostly the same, but the coupling is basically gone.  We'll fix the whitening after the pump down.
ITMY ITMY.png       pit     yaw     pos     side    butt
UL    0.157   1.311   1.213  -0.090   0.956 
UR    1.749  -0.490   0.886  -0.038  -1.042 
LR   -0.251  -2.000   0.787  -0.007   1.066 
LL   -1.843  -0.199   1.114  -0.059  -0.936 
SD   -0.973  -0.205   1.428   1.000   0.239 
4.34779
  • ETMY has a very problematic SIDE OSEM.  The magnet does not line up with the OSEM axis, and since there is no lateral adjustment in the side OSEMs, there's not much we can do about this.  We're using aluminum foil to wedge the OSEM over as far as possible, but it's not quite enough.  With the OSEM plates horizontal there is a lot of POS->SIDE coupling.  With the OSEM plates vertical, the magnetic sits a little too close to the rear face, which can cause the magnet to get stuck to the LED plate.  We're trying to decide where to leave it now, but the new diagnalization with the OSEM plates vertical is definitely better: 
ETMX ETMY.png        pit     yaw     pos     side    butt
UL   -0.138   1.224   1.463  -0.086   0.944  
UR    0.867  -0.776   1.501  -0.072  -1.051  
LR   -0.995  -0.896   0.537  -0.045   0.754  
LL   -2.000   1.104   0.499  -0.059  -1.251  
SD    0.011   0.220   1.917   1.000   0.224 
 4.42482
  5290   Tue Aug 23 17:21:45 2011 kiwamuUpdateSUSfree swinging test for ETMY

 

Excited ETMY

Tue Aug 23 17:20:45 PDT 2011
998180460

 

  5291   Tue Aug 23 17:45:22 2011 jamieUpdateSUSITMX, ITMY, ETMX clamped and moved to edge of tables

In preparation for tomorrow's drag wiping and door closing, I have clamped ITMX, ITMY, and ETMX with their earthquake stops and moved the suspension cages to the door-edge of their respective tables.  They will remain clamped through drag wiping.

ETMY was left free-swinging, so we will clamp and move it directly prior to drag wiping tomorrow morning.

  5293   Tue Aug 23 18:25:56 2011 jamieUpdateSUSSRM diagnalization OK

By looking at a longer data stretch for the SRM (6 hours instead of just one), we were able to get enough extra resolution to make fits to the very close POS and SIDE peaks.  This allowed us to do the matrix inversion.  The result is that SRM looks pretty good, and agrees with what was measured previously:

SRM SRM.png        pit     yaw     pos     side    butt
UL    0.869   0.975   1.140  -0.253   1.085  
UR    1.028  -1.025   1.083  -0.128  -1.063  
LR   -0.972  -0.993   0.860  -0.080   0.834  
LL   -1.131   1.007   0.917  -0.205  -1.018  
SD    0.106   0.064   3.188   1.000  -0.011 
4.24889

 

  5294   Wed Aug 24 09:11:19 2011 jamieUpdateSUSETMY SUS update: looks good. WE'RE READY TO CLOSE

We ran one more free swing test on ETMY last night, after the last bit of tweaking on the SIDE OSEM.  It now looks pretty good:

ETMY ETMY.png       pit     yaw     pos     side    butt
UL   -0.323   1.274   1.459  -0.019   0.932 
UR    1.013  -0.726   1.410  -0.050  -1.099 
LR   -0.664  -1.353   0.541  -0.036   0.750 
LL   -2.000   0.647   0.590  -0.004  -1.219 
SD    0.021  -0.035   1.174   1.000   0.137 
4.23371

 So I declare: WE'RE NOW READY TO CLOSE UP.

  5295   Wed Aug 24 11:30:27 2011 jamie, jenne, kiwamu, suresh, steveUpdateSUSETMX wiped, replaced, door on

We've closed up ETMX:

  • the optic was drag wiped
  • the suspension tower was put back in place
  • earthquake stops were backed off the appropriate number of turns, and de-ionized
  • chamber door was put on
  5296   Wed Aug 24 11:40:21 2011 jamie, jenne, kiwamu, suresh, steveUpdateSUSproblem with ITMX

ITMX was drag wiped, and the suspension was put back into place.  However, after removing all of the earthquake stops we found that the suspension was hanging in a very strange way.

The optic appears to heavily pitched forward in the suspension.  All of the rear face magnets are high in their OSEMs, while the SIDE OSEM appears fine.  When first inspected, some of the magnets appeared to be stuck to their top OSEM plates, which was definitely causing it to pitch forward severely.  After gently touching the top of the optic I could get the magnets to sit in a more reasonable position in the OSEMs.  However, they still seem to be sitting a little high.  All of the PDMon values are also too low:

  nominal now
UL 1.045 0.767
UR 0.855 0.718
LR

0.745

0.420

LL

0.780

0.415
SD

0.840

0.752

Taking a free swing measurement now.

  5297   Wed Aug 24 12:08:56 2011 jamieUpdateSUSITMX, ETMX, ETMY free swinging

ITMX: 998245556

ETMX, ETMY: 998248032

  5298   Wed Aug 24 16:13:36 2011 kiwamuUpdateSUSbroke UL magnet on ITMX

I broke the UL magnet on ITMX

The ITMX tower was shipped into the Bob's clean room to put the magnet back on.

 

 Since we found that all the magnets were relatively high (#5296) in the shadow sensors, we decided to slide the OSEM holder bar upward.

During the work, I haven't made the OSEMs far enough from the magnets.

So the magnets and OSEMs touched as I moved the holder.

Then the UL magnets were broken off and fell into the UL coil.

 

  5299   Wed Aug 24 17:05:11 2011 JenneUpdateSUSBroken UL magnet on ITMX

Quote:

The ITMX tower was shipped into the Bob's clean room to put the magnet back on. 

 Repair work is delayed.  I need the "pickle pickers" that hold the magnet+dumbbell in the gluing fixture, for gluing them to the optic.  Here at the 40m we have a full set of SOS gluing supplies, except for pickle pickers.  We had borrowed Betsy's from Hanford for about a year, but a few months ago I returned all of the supplies we had borrowed.  Betsy said she would find them in her lab, and overnight them to us.  Since the problem occurred so late in the day, they won't get shipped until tomorrow (Thursday), and won't arrive until Friday.

I also can't find our magnet-to-dumbbell gluing fixture, so I asked her to send us her one of those, as well. 

I have 2 options for fixing ITMX.  I'll write down the pros and cons for each, and we can make a decision over the next ~36 hours.

OPTIONS:

(#1) Remove dumbbell from optic.  Reglue magnet to dumbbell. Reglue magnet+dumbbell to optic.

(#2) Carefully clean dumbbell and magnet, without breaking dumbbell off of optic.  Glue magnet to dumbbell.

PROS:

(#1) Guarantee that magnet and dumbbell are axially aligned.

(#2) Takes only 1 day of glue curing time.

CONS:

(#1) Takes 2 days of glue curing time. (one for magnet to dumbbell, one for set to optic.)

(#2) Could have slight mismatch in axis of dumbbell and magnet.  Could accidentally drop a bit of acetone onto dumbbell-to-optic glue, which forces us into option 1, since this might destroy the integrity of the glue joint (this would take only the 2 days already required for option 1, it wouldn't force us to take 2+1=3 days).

  5300   Thu Aug 25 08:12:09 2011 steveUpdateSUSETMY & ITMY wiped, replaced, vac door on

Quote:

We've closed up ETMX:

  • the optic was drag wiped
  • the suspension tower was put back in place
  • earthquake stops were backed off the appropriate number of turns, and de-ionized
  • chamber door was put on

 jamie, jenne, kiwamu, suresh, steve

 

ETMY and ITMY were treated the same way as ETMX. The BS chamber was closed with heavy vac door yesterday also. The IOO access connector's inner jamnuts are torqued to 45 ft/lbs as all vac door bolts.

The vac envelope is ready for pumpdown condition, except ITMX chamber with light atm door cover.

Jenne will summeries the condition of dust on the  TMs before and after the drag wipes.

  5301   Thu Aug 25 13:10:42 2011 JenneUpdateSUSDrag wiping

As we have seen in the past, both of the ITMs were more dusty than the ETMs, presumably because we have the vertex open much more often than the ends.  Kiwamu and I wiped all of the optics until we could no longer see any dust particles within a ~1.5 inch diameter area around the center. 

Since we have ITMX out for magnet gluing, I'll probably drag wipe both front and back surfaces before putting it back in the suspension cage.  All of the optics have clear dust on the AR surfaces, but we can't get to that surface while the optics are suspended.  For the ETMs this isn't too big of a deal, but it does concern me a bit for the ITMs and other transmissive optics we have.  I don't think it's bad enough yet though to warrant removing optics from suspensions just to wipe them.

  5302   Thu Aug 25 15:20:03 2011 JenneUpdateSUSBroken UL magnet on ITMX

Dmass just reminded me that the usual procedure is to bake the optics after the last gluing, before putting them into the chambers.  Does anyone have opinions on this? 

On the one hand, it's probably safer to do a vacuum bake, just to be sure.  On the other hand, even if we could use one of the ovens immediately, it's a 48 hour bake, plus cool down time.  But they're working on aLIGO cables, and might not have an oven for us for a while.  Thoughts?

  5305   Thu Aug 25 17:57:35 2011 SureshUpdateSUSBroken UL magnet on ITMX

Quote:

Dmass just reminded me that the usual procedure is to bake the optics after the last gluing, before putting them into the chambers.  Does anyone have opinions on this? 

On the one hand, it's probably safer to do a vacuum bake, just to be sure.  On the other hand, even if we could use one of the ovens immediately, it's a 48 hour bake, plus cool down time.  But they're working on aLIGO cables, and might not have an oven for us for a while.  Thoughts?

I think we should follow the established procedure in full, even though it will cost us a few more days.  I dont think we should consider the vacuum bake as something "optional".  If the glue has any volatile components they could be deposited on the optic resulting in a change in the coating and consequently optical loss in the arm cavity.

 

 

  5306   Fri Aug 26 07:53:59 2011 steveUpdateSUSBroken UL magnet on ITMX

Quote:

Dmass just reminded me that the usual procedure is to bake the optics after the last gluing, before putting them into the chambers.  Does anyone have opinions on this? 

On the one hand, it's probably safer to do a vacuum bake, just to be sure.  On the other hand, even if we could use one of the ovens immediately, it's a 48 hour bake, plus cool down time.  But they're working on aLIGO cables, and might not have an oven for us for a while.  Thoughts?

 Follow full procedure for full strength, minimum risk

  5308   Fri Aug 26 15:30:36 2011 JenneUpdateSUSITMX magnet reglued
The ITMX UL magnet has been reglued.

I *very carefully* using the corner of a cleaned razor blade dropped single drops of acetone onto the top of the dumbbell, and scratched off the residual glue. I didn't want to get even a sprinkle of acetone on the dumbbell-glass junction, and I managed to avoid it. Also, the dumbbell never broke off of the glass (something I've never been able to achieve before), so all I had to do was glue the magnet back onto the dumbbell.

I also scratched the glue from the magnet, after soaking in acetone. I made sure to keep track of which way the magnet had been glued by putting it in the pickle picker that I received from Betsy before getting rid of the glue. I specifically did not compare the polarity of this magnet to the others still glued, because I have seen that in the past break magnets from dumbbells. They can't really handle sideways forces. But since it's glued the same way that it was, it should be fine.

I then aligned the optic in the gluing fixture. I test-fit the pickle picker with magnet, to ensure that the axes of the dumbbell and magnet were aligned as closely as possible. I adjusted the optic to make this axial alignment as perfect as I could see with my eye. Unfortunately the fixture doesn't allow a whole lot of viewing angles of the magnet-dumbbell joint, so we'll see how well I did after I remove it from the fixture.

I put a little dab of epoxy on the end of the magnet, spread it around so it coated the whole surface, and glued it on.

I'll come in tomorrow (Saturday) to check on it, and take it out of the fixture. If it's going to break coming out of the fixture, which I hope won't happen, but has happened before, then I want to be able to fix it again asap.
  5311   Sat Aug 27 14:33:04 2011 JenneUpdateSUSITMX magnet status

As I feared, since I couldn't see the magnet-to-dumbbell joint from all angles, they ended up being off by ~1/3 of a magnet diameter. 

Because I don't want to deal with finding another failed glue joint tomorrow, I removed the magnet and dumbbell from the optic, and broke the manget off of the dumbbell.  As with yesterday, I kept track of which end of the magnet had been glued to the dumbbell. 

I got a new dumbbell, removed all the glue from the magnet, and reglued them together, in the fixture that ensures they are well aligned. 

Tomorrow I will come in and glue the magnet dumbbell assembly to the ITM.

  5314   Sun Aug 28 20:15:11 2011 JenneUpdateSUSITMX magnet status

Quote:

Tomorrow I will come in and glue the magnet dumbbell assembly to the ITM.

 Glued.

Tomorrow afternoon I'll remove the optic from the fixture, and put it in the oven.

  5318   Mon Aug 29 16:27:34 2011 ManuelConfigurationSUSSUS Summary Screen

I edited the C1SUS_SUMMARY.adl file and set the channels in alarm mode to show the values in green, yellow and red according to the values of the thresholds (LOLO, LOW, HIGH, HIHI)

I wrote a script in python, which call the command ezcawrite and ezcaread, to change the thresholds one by one.

You can call this program with a button named "Change Thresholds one by one" in the menu come down when you click the  button.

I'm going to write another program to change the thresholds all together.

  5320   Mon Aug 29 18:24:11 2011 jamieUpdateSUSITMY stuck to OSEMs?

ITMY, which is supposed to be fully free-swinging at the moment, is displaying the tell-tale signs of  being stuck to one of it's OSEMs.  This is indicated by the PDMon values, one of which is zero while the others are max:

UL: 0.000
UR: 1.529
LR: 1.675
LL: 1.949
SD: 0.137

Do we have a procedure for remotely getting it unstuck?  If not, we need to open up ITMYC and unstick it before we pump.

 

  5322   Tue Aug 30 10:49:29 2011 steveUpdateSUSBS & PRM damping restored

I have restored the damping of BS and PRM. Today is janitor day. He is shaking things around the lab.

  5326   Tue Aug 30 14:44:06 2011 kiwamuUpdateSUSITMY released without opening chambers

The ITMY mirror was released. The OSEM readouts became healthy.

 

To see what is going on, I changed the PIT DC bias slider on ITMY from 0.8 to -1 or so, and then the optic started showing a free swinging behavior.

If there were no responses to the DC bias, I was going to let people to open the chamber to look at it closer, but fortunately it released the optic.

Then I brought the slider back to 0.8, and it looked still free swinging. Possibly the optic had been stacked on some of the OSEMS as Jamie expected.

Quote from #5320

ITMY, which is supposed to be fully free-swinging at the moment, is displaying the tell-tale signs of  being stuck to one of it's OSEMs. 

Do we have a procedure for remotely getting it unstuck?  If not, we need to open up ITMYC and unstick it before we pump.

 

  5332   Thu Sep 1 15:07:45 2011 steveUpdateSUSwhy ITMY is moving more ?

Atm1, ITMY and the SRM are on the same isolation stack.  So why does  the SRM move twice as much?

Atm2, We should check the ITMY  SIDE_OSEM before pump down. Anatomically correct, beautiful picture taken by Kiwamu on August 22

Attachment 1: itmy_srm_etmx.jpg
itmy_srm_etmx.jpg
Attachment 2: P8220152.JPG
P8220152.JPG
ELOG V3.1.3-