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Reports until 16:23, Tuesday 12 March 2013
H1 SUS
jeffrey.kissel@LIGO.ORG - posted 16:23, Tuesday 12 March 2013 (5768)
H1 SUS TMSY Top 2 Top Transfer Functions -- SUS Style
J. Kissel, (S. Steplewski)

After putting in the effort of "cleaning up" the infrastructure for H1SUSTMSY (see LHO aLOG 5754), I've taken M1 to M1 (Top2Top) transfer functions, in hopes that Double Model (including a parameter file built by Szymon and myself) we put together would match the measurement as beautifully as the rest of the SUS and their models. 

Attached are the results; no such luck. (Queue sad trombone).

Szymon took a data set before the makeover (shown in orange), with the damping loops closed, so the data definitely won't match up with any model (especially the rotational degrees of freedom), but I plot it anyway to see if we can pull out any useful information comparing it the current data. The current data (in black) was taken last night, after the makeover, with damping loops open.

Since all three show totally different things, it's difficult to know which to trust. However, I'm 90% confident that the current data shows there's rubbing present in the suspension. My reasoning is as follows:
- Driving as hard as I can without saturating, but still see very noisy, poorly coherent data up to 1 Hz, if not higher
- Resonant modes of independent degrees of freedom are seen in each others TF; e.g. ~3.5 Hz Y mode visible in R, T, and L, or 
- Vertical and Yaw modes -- typically very mechanically stable (read: hard to screw up) show noisey/muted resonances peaks

This rubbing might be the source of Keita's complaints that the damping was unstable to increasing the gain. I'd really like to resolve the rubbing issues before I go any further on redesigning the damping loops -- because they may just not need it.

LHO aLOG 1825 is the best thing I can find regarding previous "accepted" transfer functions, and regardless of that the resolution is low, and the measurement frequency band is less, I think it's still pretty clear that those former transfer functions are much cleaner than what I've measured.

I've spoken with Kiwamu, and they'll begin the time-honored SUS tradition of finding sources of rubbing.

In the mean time, we'll continue to refine the model, such that they converge.

----------

As an aside -- you may recognize the format of the attached plots. This now means that there are functional aLIGO SUS standard analysis scripts that can process and compare data sets. Szymon had started writting them, and I've pushed them through to completion and full functionality. I've also begun building up the svn structure similar to other suspensions. As such, I describe everything:

The data was taken with DTT using the templates:
${SusSVN}/sus/trunk/TMTS/H1/TMSY/SAGM1/Data/
2013-03-11_0800_H1SUS-TMSY_M1_L_WhiteNoise.xml
2013-03-11_0800_H1SUS-TMSY_M1_P_WhiteNoise.xml
2013-03-11_0800_H1SUS-TMSY_M1_R_WhiteNoise.xml
2013-03-11_0800_H1SUS-TMSY_M1_T_WhiteNoise.xml
2013-03-11_0800_H1SUS-TMSY_M1_V_WhiteNoise.xml
2013-03-11_0800_H1SUS-TMSY_M1_Y_WhiteNoise.xml

exported in the format L_EXC to F1, F2, F3, LF, RT, SD, L, T, V, R, P, Y in the files
${SusSVN}/sus/trunk/TMTS/H1/TMSY/SAGM1/Data/
2013-03-11_0800_H1SUSTMSY_M1_L_WhiteNoise_tf.txt
2013-03-11_0800_H1SUSTMSY_M1_P_WhiteNoise_tf.txt
2013-03-11_0800_H1SUSTMSY_M1_R_WhiteNoise_tf.txt
2013-03-11_0800_H1SUSTMSY_M1_T_WhiteNoise_tf.txt
2013-03-11_0800_H1SUSTMSY_M1_V_WhiteNoise_tf.txt
2013-03-11_0800_H1SUSTMSY_M1_Y_WhiteNoise_tf.txt

then individually processed into
${SusSVN}/sus/trunk/TMTS/Common/MatlabTools/plotTMTS_dtttfs.m

which saves a .mat file in a standard format and place,
${SusSVN}sus/trunk/TMTS/H1/TMSY/SAGM1/Results/2013-03-11_0800_H1SUSTMSY_M1.mat
and produces the "individual measurement" plots attached, 2013-03-11_0800_H1SUSTMSY_M1_ALL_TFs.pdf

This file can then be picked up and compared with other measurements by
${SusSVN}/sus/trunk/TMTS/Common/MatlabTools/plotalltmts_tfs.m

which produces the "measurement collection" plots attached, alltmtss_2013-03-11_H1SUSTMSY_ALL_ZOOMED_TFs.pdf 

All of the above are committed to the SusSVN for your future use!
Non-image files attached to this report
H1 INS
jodi.fauver@LIGO.ORG - posted 14:23, Tuesday 12 March 2013 (5765)
X End status
Assembly of Buffer cleanroom completed and cleanroom moved into place.

Randy and I checked to see what preparations were needed to facilitate ETMX install and discussed a possible sequence of events. Below is a first attempt at a checklist.Please email me any additions/corrections and I will post this checklist periodically.

1. Find BSC5 dome leak (Apollo)-In progress
2. Install Work Platforms at BSC9/Walking Plates setting on Work Platforms? (Apollo/Jodi)
3. Move BSC cleanroom over BSC9 (Apollo)
4. Assemble and place E-module including upper garbing/staging cleanroom (Apollo/Jodi)
5. Determine test stand location (IAS/Michael L./Jodi)
6. Get BSC ISI and Quad into VEA (SEI/SUS/Apollo)
7. Assemble Test Stand cleanroom (Apollo)
8. Move Work Space cleanroom into VEA/Nest cleanrooms (Apollo)
9. Get engine hoist into VEA? (Apollo)
10. Assemble Test Stand (Apollo)
11. Level Test Stand (IAS?)
12. Gross clean Test Stand (Tech Cleaners)
13. Place lower level support cleanrooms-Test Stand, Work Space, Garbing/Staging (Apollo)
14. Clean all cleanrooms (Tech Cleaners)
15. Move ISI to Test Stand (SEI/Apollo)
16. Level, balance and test ISI (SEI)
17. Marry SUS to ISI (SUS/Apollo)
18. SUS check-out (SUS)
19. Remove dome and doors (Apollo)
20. Install cartridge (SEI/Apollo)
H1 INS
jodi.fauver@LIGO.ORG - posted 13:56, Tuesday 12 March 2013 (5764)
BSC5 Leak Hunt
Soft roof was installed in the morning. First and second cleanings were accomplished by early afternoon. 
H1 CDS
david.barker@LIGO.ORG - posted 13:11, Tuesday 12 March 2013 (5763)
CDS Maintenance Summary

WP3758. All three PEM systems were restarted with new code today (h1peml0,mx,ey). After the filter modules were removed some weeks ago, the RCG generated MEDM screens for ADC became white-screened. Today's change installed EPICS OUTPUTparts in place of the missing filter modules to fix the MEDM screens (see attachments). I noticed that I had two difference BLRMS parts, one with a fllter in the input arm (h1pemmx and h1pemey) and one without the filter (h1peml0). I added a filter to the h1peml0 part so I did not need to add EPICS parts for the SIES signals.

h1susmc2 was rebuilt against  stable RCG2.6.2 (it was built last Tues against a modified RCG). The model was restarted at 09:52

The epics gateway between CDS and H1SLOW networks was restarted to support Beckhoff work.

The DAQ was restarted many times. On one restart 9 of the 26 FE went into 0xbad DAQ status. The affected front ends appear to be random and not related to the mx-stream end point distribution.

EDCU channel list had the EX DUST channels removed while those channels are unavailable.

Images attached to this report
H1 CDS
cyrus.reed@LIGO.ORG - posted 11:22, Tuesday 12 March 2013 (5761)
CDS-GC Routing Changes Finished
Finished making the changes to the CDS edge router, as specified under WP3759.  Could not complete the fiber patch swap as planned, since the new fiber run had some unforeseen issues.  That change will have to take place at a later date, once the run is repaired.  Access to and from CDS systems should be back to normal.
H1 SUS
betsy.weaver@LIGO.ORG - posted 09:27, Tuesday 12 March 2013 - last comment - 10:05, Tuesday 12 March 2013(5757)
PR2 IAS alignment is well underway

Betsy, Travis, Doug, Jason, Arnaud

Yesterday we started the alignment of the PR2 on the HAM3 table.  We made a position adjustment based on the corner cube mdistance measurements by IAS.  We are now working on pitch and yaw.  We also took the opportunity to swap in the shorter top mass blade tip EQ stops.  Arnaud also checked resonance peaks to make sure we were fully suspended after these mechanics were performed.

Comments related to this report
arnaud.pele@LIGO.ORG - 10:05, Tuesday 12 March 2013 (5760)

Something looks to be touching on M3 from the spectra taken.

H1 PSL
justin.bergman@LIGO.ORG - posted 07:03, Tuesday 12 March 2013 (5736)
Refilled Diode Chiller
I have refilled the crystal chiller in the diode anteroom---used about half a liter. Logbook seems to have gone missing since the unit was replaced last week.

Edited: Earlier I had said the diode chiller.
H1 SUS
jeffrey.kissel@LIGO.ORG - posted 21:51, Monday 11 March 2013 (5754)
TMSY Makeover
Kieta and Kiwamu sat down next to me this evening and suggested "The TMS damping loops suck. Make them better."

 Upon accepting the task, I wanted to make sure I started from a good place, so I gave the infrastructure a good looking-over. I found a whole bunch that was just totally dissimilar to how the rest of the suspensions were done, so I gave 'er a SUS makeover. Perhaps most importantly for the current work at the end station -- I've made sure, above all else, that the optical bench is being offset to the same place as before the below upgrades. I've also captured and committed a new safe.snap.

Also post-changes, I've measured all six DOFs of Top to Top transfer functions. I'll process the results first thing tomorrow morning, but it kinda looks like there's some rubbing going on... 

---------

Here's what I've changed:
- Only the offsets for OSEM Open Light Current compensation (in the OSEMINF banks) were in place. 
Assuming the offsets are accurate (I couldn't find any aLOG where they'd been documented), I've taken them as cannon, multiplied by -2, and taken those for the open light current (in [ct]):

>> offsets = [-11250    % M1_OSEMINF_F1_OFFSET
              -11550    % M1_OSEMINF_F2_OFFSET
              -14150    % M1_OSEMINF_F3_OFFSET
              -15200    % M1_OSEMINF_LF_OFFSET
              -9215     % M1_OSEMINF_RT_OFFSET   <--- why so low?!
              -15300];  % M1_OSEMINF_SD_OFFSET
>> olc = -2*offsets;
   olc = 22500    
         23100
         28300
         30400
         18430
         30600
>> gains = 30000./olc;
   gains = 1.333   % M1_OSEMINF_F1_GAIN
           1.299   % M1_OSEMINF_F1_GAIN
           1.060   % M1_OSEMINF_F1_GAIN
           0.987   % M1_OSEMINF_F1_GAIN
           1.628   % M1_OSEMINF_F1_GAIN
           0.980   % M1_OSEMINF_F1_GAIN

- Once the OSEMs were properly normalized, I can safely correct the sensor calibration filter (which had been set to the really old, incorrect 40.6 [nm/ct]). It's now like every other OSEM we've normalized to 30000 [ct] open light current: 0.023 [um/ct].

- Once the OSEM singals are in meters, I've upgraded the OSEM2EUL and EUL2OSEM matrices to preserve units across the transformations (they were just signs before). So now the EUL2OSEM drive matrix is
          
          % L            T            V            R            P            Y
            0            0            0      -12.821            0            0   % F1
            0         -0.5            0       6.4103            0       4.1667   % F2
            0         -0.5            0       6.4103            0      -4.1667   % F3
            0            0         -0.5            0      -2.7778            0   % LF
            0            0         -0.5            0       2.7778            0   % RT
            1            0            0            0            0            0   % SD

where the lever arms for R, P, and Y are 0.078, 0.36, 0.24 [m] respectively (copied from a QUAD Top Mass, since they're the same), and using E1200045 to confirm that the basis transformation was as expected (and it was). The OSEM2EUL matrix is the transpose (*winces, bracing himself for another round of "why the transpose -- it should be the inverse, right?"*). I've also updated the function
${SusSVN}/sus/trunk/TMTS/Common/MatlabTools/make_sustmts_projections.m 
which calculates the values. Note, the function is only capable of doing RIGHT-handed TMTSs. It will need added functionality once we get further down the road.

- The alignment offsets were -72000 (P) and -53000 (Y). The EUL2OSEM matrix elements for P to LF & RT used to be [-1 1], and Y to F2 & F3 used to be [1 -1]. I've *divided* these by the lever arm in [m], so in order recover the original offset values heading out to the DAC, I should multiply them by the lever arms in [m].

-72000 * 0.36 = -25920
-53000 * 0.24 = -12720

These values have been entered in.

- I've used the SolidWorks model D0900419 to fill out the oddball, H1 BSC6 TMSY suspension point location with respect to the ISI optical table center. The vector from the optical table's surface center is (X,Y,Z) = (0.2,0.4889,-0.0998) [m], with a yaw (angle between +L and +X) of 270 [deg]. I've added and committed this info to ${SusSVN}/sus/trunk/Common/MatlabTools/SEI2SUScoordinates.m and committed the updated projection file ${userapps}/isc/common/projections/ISI2SUS_projection_file.m (which is generated by the wrapper ${SusSVN}/sus/trunk/Common/MatlabTools/make_ISI2SUS_projections.m)

- Installed the usual ISI sensor input filters -- except that both the ISI and the TMTS are running at 4096, so there's no need for the 4kto16kAA filter. 
H1 ISC
kiwamu.izumi@LIGO.ORG - posted 19:19, Monday 11 March 2013 (5753)
EY in-vac work not completed

[Keita, Sheila, Kiwamu]
We spent hours trying to align the infrared path on the transmon suspension in BSC6. This mission hasn't been completed yet.

Mysterious off-centering at a QPD
There was a mystery which we are not sure at the moment and this currently prevents us from finishing the mission --- one of the two infrared QPDs always had a horizontally off-centered beam on it (by about 5 mm from the center) when every optics else have a well-centered beam. This is quite strange since all the optics in the QPD sled had been well-adjusted in the lab before it was installed in the chamber. Therefore in principle the beam on this QPD must be well-centered too when everyone else is well-centered.
One possible scenario can be due to the fact that we've been using the green light instead of the actual infrared light. There is a 50/50 beam splitter before this QPD and the reflection of the beam splitter is supposed to go to the QPD. But the beam splitter is meant for 1064 nm and thus the HR surface may not be high reflective for 532 nm and the AR surface may be high reflective for 532 nm. In this case the beam splitter can provide such an offset for the beam at the QPD because the beam is reflected off of the AR surface rather than the HR.

A test will be performed in the lab
 In order to test this hypothesis, we are planning to do a simple test in the lab where we measure the reflectivity of the same beam splitter with green light. During this test we don't need to jump in to BSC6 and therefore somebody can work on some vacuum/suspension businesses while we are at the lab.

TMSY damping was not great
The damping of TMSY was not really useful in the sense that it took a fairly long time (~ 20 sec or more) to quiet down the motion every time when the suspension rung up due to our alignment work. Because of this we spent large portion of our time just standing by the suspension and doing nothing. We increased the gain of the servo loops, but it didn't help at all. We suspect that the DOFs are coupling to each other too much. Jeff K. will be taking a look at it when he gets a chance.
 

H1 CDS
david.barker@LIGO.ORG - posted 17:29, Monday 11 March 2013 (5752)
IOP sus watchdog, overview screens, hepi pump controller

WP3757. I added the top OSEMS for PRM and PR3 to h1iopsush2a sw watchdog and disabled the wd on h1iopsush56. All models on these front ends were restarted. The s/w watchdog MEDM screens were modified accordingly, a new screen for the seih16 was added.

The SUS models for h1sush56 were added to the state-word overview medm screen. The detailed medm overview screen was redesigned to show the new state word and remove data duplication. Also GPS time and CPU usage was added, while unused features were removed. The h1sush56 SUS models were also added to this screen.

The DAQ was restarted with the addition of the LVEA HEPI pump controller slow channels. The pump controller MEDM screen was added to the SITEMAP medm screen.

H1 TCS
greg.grabeel@LIGO.ORG - posted 16:18, Monday 11 March 2013 (5749)
SM2 mirror cleaning
Thomas Vo, Greg Grabeel

Steering mirror serial #3 is cleaned and baked. The holes that the alignment rods fit through were mis-aligned from the manufacturer. They had drilled through half way, then rotated and drilled the other half. The holes had to be opened up from 0.25" to 0.262" to allow for the mis-alignment.

After reaming the holes cleaning started with liquinox on the back surface, an isopropyl bath including ultrasonic wand, and a freon wipe down. FTIR samples were taken before a 48 hr 200°C bake. The bake discolored the copper backing but not the reflective gold surface. The copper backing didn't change in any other ways and the oxidation didn't wipe off or shed.

A small stain survived the high purity rinse, as seen in the picture.

Steering mirror #4 underwent a similar cleaning process and is awaiting FTIR results.
Images attached to this report
LHO General
justin.bergman@LIGO.ORG - posted 16:03, Monday 11 March 2013 (5745)
Ops activities
All PSL environmental monitoring channels offline all day. 
LVEA laser safe all day

8-945 HFD onsite testing alarms in OSB
915 Hugh, Jim and Mitch craning payload masses up to BSC2 work platform and loading the ISI
0900 Diode chiller low level alarm; refilled by Justin
1030 Kyle briefly soft-closed GV19 while Jodi and Apollo crew flying cleanroom over BSC5
1230 Travis and Batsy working in HAM3
1240 Students from Stevens Middle School touring the control room
1350 Hertz rental onsite to retrieve scissor lift
1420 Patrick power-cycling Beckoff systems while working to bring PSL monitoring channels back up
H1 SUS
jeffrey.kissel@LIGO.ORG - posted 15:30, Monday 11 March 2013 - last comment - 16:48, Monday 11 March 2013(5747)
sus corner of the userapps repo updated
I've updated the sus corner of the cds_user_apps repository, in order to get up-to-date guardian stuff from LLO. 

In doing so, though there were many updates unrelated to H1 (mostly stuff unique to L1, M1, or C1, etc), there were several bits common to all IFOs, including updated TMTS and HAUX medm screens, and the HAUX front-end-model library part. Though the screen updates require no action, the update to the HAUX library part requires recompiling the model (that it's unknown what the changes are). I'll inquire as to what they might be, and then decide on going forward with re-compilation tomorrow during maintenance.
Comments related to this report
jeffrey.kissel@LIGO.ORG - 16:48, Monday 11 March 2013 (5751)
The last attempt to get Guardian running at LHO was Matt's attempt during the H2OAT (see Guardian aWiki Page for a log of his activity). This was back when the userapps repository lived in the /opt/rtcds/lho/h1/userapps/release/ folder, as opposed to the current, common location /opt/rtcds/userapps/release/. As such, the soft link to the GuardTools.pm perl module library was broken, as it pointed to the lho/h2/ location. I've now fixed the pointer:


controls@opsws0:perlmodules 0$ pwd
/ligo/apps/linux-x86_64/perlmodules
controls@opsws0:perlmodules 0$ ls -l GuardTools.pm
lrwxrwxrwx 1 controls controls 50 2013-03-11 16:06 GuardTools.pm -> /opt/rtcds/userapps/release/guardian/GuardTools.pm
LHO VE
john.worden@LIGO.ORG - posted 14:31, Monday 11 March 2013 - last comment - 15:58, Tuesday 12 March 2013(5742)
Beam Tube Module Accumulation Summary

 

LHO Module      Total Outgassing     Outgas rate/unit area          Hydrogen              Date         Outdoor Temps      Post Bake(1998) H2 at 23C             at 0C

                                 torr- l/sec                    torr-l/s/cm^2                     torr-l/s/cm^2                              high/low  C              torr-l/s/cm^2

Y1                            1.3 e-6                          1.77 e-14                         4.4 e-14                   Mar 5         7.2/0                        6.3 e-14                                     9.0 e-15

Y2                             2.4 e-7                          3.3 e-15                          8.25 e-15                Mar 6          5/1.1                        4.7 e-14                                    6.8 e-15

X1                             5.4 e-7                          7.3 e-15                          1.83 e-14                Mar 7          12.2/3.3                        5.2 e-14                                    7.4 e-15

X2                             3.4 e-7                          4.6 e-15                          1.2 e-14                   Mar 8          12.2/1.1                        4.6 e-14                                   6.6 e-15

 

Volume of each module ~ 2.35 e6 liters

Area of each module  ~ 7.35 e7 cm^2   (excludes baffles and port hardware)

Gauge factor for cold cathode and H2 = 2.5

Note that each module accumulation includes the 80k pumps at either end - a significant surface area of untreated SS with H2 outgassing of perhaps 100x that of the beam tube steel(per unit area).

A quick estimate of the SS surface in the long pump is 285,000 cm^2.  If you assume 100 times the H2 outgassing this yields an equivalent 2.8 e7cm^2 or 1/3 of the beam tube. The internals of the pump are largely aluminum and likely do not contribute to the H2 outgassing.

Comments related to this report
rainer.weiss@LIGO.ORG - 20:26, Monday 11 March 2013 (5755)
Current temperatures are in F not C
john.worden@LIGO.ORG - 20:36, Monday 11 March 2013 (5756)

80K pump contribution added, fixed degrees C.

 

john.worden@LIGO.ORG - 15:58, Tuesday 12 March 2013 (5767)

Second accumulation on Y1 March 12 with 80K pump CP1 isolated:

We have two accumulations - one for the 80K pump and one for the Y1 module.

CP1 outgassing:

Estimated volume of CP1 including one gate valve interior = 22,800 liters

Estimated surface area of SS of CP1 plus valve = 285000 cm2

Pressure rise in 8700 seconds = 8.9 e-8 torr = 2.3 e-7 t-l/sec    x gauge factor of 2.5 = H2 outgassing of 2.1 e-12 tl/s/cm^

Y1 Module:

Outgas rate without CP1 is now 2.63e-7 e-7 t l/s or 1/5 of what it was before. On the other hand summing the two yields ~5 e-7 tl/s rather than the 1.3 e-6 obtained a few days ago.

Perhaps this is an indication of our measurement error. Arithmetic error?

Images attached to this comment
H1 SEI
hugh.radkins@LIGO.ORG - posted 12:23, Monday 11 March 2013 - last comment - 16:33, Monday 11 March 2013(5739)
WBSC2 BS ISI Keel Payload Proceeding

The base layer of the Keel Payload is positioned per D1001514-v2 each atop 2 square inches (1.41x1.41) of 0.25" thick viton in each corner (see image).  The second layer is stacked on and the third layer is near by.  All the heavy lifting got Jim a bit sweaty and me a bit winded so we decided to call it there.  And Betsy reminded to feed Jim and that the HAM3 table which was ready to be locked.  We'll complete the bolt down and stacking after lunch.

Images attached to this report
Comments related to this report
hugh.radkins@LIGO.ORG - 16:33, Monday 11 March 2013 (5750)

Finished Stacking the payload.  See the image as you wish.

Images attached to this comment
H1 SEI
jim.warner@LIGO.ORG - posted 09:37, Friday 08 March 2013 - last comment - 09:46, Tuesday 12 March 2013(5724)
BSC2 didn't completely survive the flight

This morning I turned on the CPSes at BSC2 to see if they all survived, and it looks like one didn't make it. The horizontal St1 sensor on corner 1 is reading 32k counts, which probably means a broken in-vacuum cable. I went out to the chamber and checked all of the in air connections,  which looked good. I then swapped the horizontal and vertical cables at the box to rule out the board, but the problem followed the probe. At this point it could be the in-air cable (they rarely fail), the feed-thru (seems unlikely), the in-vacuum connection (which can't be accessed right now, there's a hard cover on the chamber) and the probe. I'll try to swap the in-air cable later today, but the rest will have to wait until we can get back into the lower part of BSC2. We can still float the ISI and HEPI, but no post-flight transfer functions until this is resolved. I am a little surprised that this particular sensor broke, because the horizontal sensors are better protected than the verticals, and this corner had a better routing scheme than the other two.

Comments related to this report
jim.warner@LIGO.ORG - 15:27, Monday 11 March 2013 (5746)

After more investigating today, Hugh, Mitch and I discovered that the allegedly bad CPS seems to be innocent. When we swapped in-vac cables, the channel in MEDM didn't change, as it would have if the probe were broken. This leaves the feed-thru and the in-air cable. IAS and SUS are currently working in HAM3, so we will wait until tomorrow to try swapping more parts on the in-air side.

jim.warner@LIGO.ORG - 09:46, Tuesday 12 March 2013 (5758)

More investigating this morning, turns out the in-air cable was bad. Replaced it, and all the sensors are now working.

H1 ISC
sheila.dwyer@LIGO.ORG - posted 17:28, Thursday 21 February 2013 - last comment - 13:29, Tuesday 12 March 2013(5555)
ALS SHG Temperature controller
The ALS SHG oven is assembled without the crystal and the temperature controlled.  

I added washers between the 5 axis stage and the aluminum base for the ALS SHG, now with the vertical adjustment screws all the way in the crystal is just at four inches.  I think if Bram adds 3 mm to the aluminum base plate for the rest of the units they should have the crystal at 4 inches when the screws are in the center of the adjustment, without any extra washers.  

The temperature controller is working.  The TEC is mounted for this unit in a way that seems upside down when you look at it, the larger face is on top, this requires crossing the wires that drive the TEC.  I did that because the data sheet says that the less wide face of the TEC should be the cool face.  

One last warning about assembling it, I thought I was using a very small amount of thermal paste, but I wish I had used even less.  The thermal paste in the hole for the thermistor was not a problem, but when I lightly tightened the bolt that holds the copper holder in place, the small amount of paste I had on the TEC came oozing out.  I was glad that I did this without the crystal installed.  

The TwinCAT library is called TECController.  Daniel Set up the corner 5 chassis for the third interferometer in end X (really the MSR for now) and there is a PLC called TEST on it.  We configured this system manager to control the TEC, and it is in the SVN at C:SlowControlsTwinCATTargetH1ECATX1H1ECATX1.tsm revision 684

So far none of the variables are in EPICS, but I had a look at the step response using a trend in the TwinCAT visualization.  1 Volt sent towards the TEC raises the temperature by about 18.3 C, and the time constant is roughly 50 seconds.  

The library has a servo, the filter has a pole at zero, a zero at 0.02Hz, and you can adjust the UGF with the user interface.  It seems to work for ugf settings up to 9 Hz, you can push the UGF up to 15 Hz if it is already locked and you aren't changing the temperature, but I don't think that's necessary.  

I will try to post some step responses once we have the channels in EPICS.  

Sheila
Comments related to this report
sheila.dwyer@LIGO.ORG - 13:29, Tuesday 12 March 2013 (5762)
Here are some pictures of the SHG temperature controller, with the TEC mounted with the wider side up.  The fig file has some step responses recorded using strip tool, zoomed in on one that is a 1 degree step with the UGF at 5Hz.  The overshoot is around 20% when the ugf is at 5 Hz, and as you can see once things have partially settleded the in loop sensor see fluctuations of less than 0.05 C peak.  
  
The step resposes settings were:
Set Temp   UGF
27         5Hz  (tuning servo on)
29         5Hz
26         5 Hz
28         10 Hz
27         10 Hz
28         7 Hz
27         3Hz
28         3Hz
27         5Hz
28         5Hz    
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