Displaying reports 77561-77580 of 83164.Go to page Start 3875 3876 3877 3878 3879 3880 3881 3882 3883 End
Reports until 12:51, Wednesday 13 March 2013
H1 SUS
jeffrey.kissel@LIGO.ORG - posted 12:51, Wednesday 13 March 2013 - last comment - 13:16, Wednesday 13 March 2013(5778)
H1SUSTMSY -- Still Rubbing
J. Kissel, (for K. Kawabe, K. Izumi, and T. Sadecki)

Team TMS + Travis ventured down to the y-end this morning in hopes to discover some obvious source of rubbing, which I'd reported a few days ago (see LHO aLOG 5768). Unfortunately, they didn't find anything. They did adjust the alignment/centering on a few of the BOSEMs (they didn't say which), because only because they looked suspicious. I've taken a new set of transfer functions, and I see little to no change. The best "improvement" is that the three Transverse modes look more like the model -- but the model still comes with many grains of big'ol kosher salt, and the high-frequency noise (for this DOF) looks much worse. I'll continue to push forward on a "new" damping loop design (more likely I'll just model the damping with the measured TFs, asses where things are going unstable, and move around some poles or zeros if need be), in parallel with further investigations of rubbing.

Note: Mark made some improvements to the model this morning -- mostly related to making sure the coordinate system is as expected by the model (it's a whole confusing mess between the SolidWorks XYZ, the Dynamical Model's XYZ, and the Euler Control Basis -- especially since the top mass is the same as a QUAD top mass but rotated 90 [deg] with respect to Dynamical Model expects. Not to mention left-handed vs. right-handed TMTSs). We *think* we've got them correct at the moment, but the only way we can be sure is by opening up SolidWorks and checking (where Mark and I only have the eDrawings).
Non-image files attached to this report
Comments related to this report
kiwamu.izumi@LIGO.ORG - 13:16, Wednesday 13 March 2013 (5779)

Thanks, Jeff. The BOSEMs that Travis adjusted were : two top OSEMs and side OSEM.

LHO VE
john.worden@LIGO.ORG - posted 10:50, Wednesday 13 March 2013 - last comment - 08:09, Saturday 16 March 2013(5777)
Beam Tube Insulation photos

I walked about 300 meters of Y1 this week and took some photos of the beam tube insulation.

Between ports 2 and 3 (a distance of 250m) I counted 35 holes in the insulation. Virtually all of these holes were at taped joints between insulation wraps. These joints occur every 4 feet.

So of 800 taped joints I saw 35 which were violated by rodents. There may have been a few more on the backside of the tube. The photos in this report show some of the holes, some of the "good" taped joints, and some views of the uninsulated bellows regions.

Images attached to this report
Comments related to this report
john.worden@LIGO.ORG - 08:09, Saturday 16 March 2013 (5828)

Thursday I looked into X1 and X2 (but not Y2) specifically to see if the bellows are insulated. It looks like they are so Y1 may be unique in this regard. However, the insulation is pretty ragged and will need to be scrapped.

H1 SUS
arnaud.pele@LIGO.ORG - posted 10:04, Wednesday 13 March 2013 (5776)
PR2 power spectra check after alignment

PR2 (installed in HAM3 chamber) power spectra have been taken after yesterday's gross alignment.

The figures attached show a comparison for PR2 damped and undamped between :

-LLO Phase 3a  (Mai 2012) purge-air off, ham3 door closed

-LHO Phase 3a (October 2012) ham3 doors open and covers on

-LHO Phase 3a (March 2012) ham3 doors open covers off with M2 and M3 OSEM out

Looking at M1 DOFs of the undamped spectra, the resonnances are consistent with LLO and LHO previous measurements.

An other spectra will be taken after the fine alignment.

Non-image files attached to this report
LHO VE
john.worden@LIGO.ORG - posted 09:21, Wednesday 13 March 2013 (5775)
Y1 Accumulation - Leak in GV6 annulus.

After performing another accumulation on Y1 with CP1 isolated from the tube we think we have found our leak. It looks like the annulus of the gate seal has a leak into the system.

This was highlighted when we reopened GV6 after the accumulation.

So in summary the outgassing from Y1 appears to be in line with the 3 other modules, the CP1 outgassing rate is reasonable and we have a leak to follow up on.

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*                            5 e-7                              6.8 e-15                         1.7 e-14                   Mar 12       16/4                             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).

Y1 result is estimated from the sum of two accumulations(tube + CP1) performed on Mar 12.

NOTE: If you subtract the outgassing due to CP1 or CP2 from the Y1 and X1 results you will get numbers much closer to the Y2 and X2 modules. The measured outgassing from CP1 is 2.3 e-7 tl/s.

Images attached to this report
H1 ISC
keita.kawabe@LIGO.ORG - posted 22:31, Tuesday 12 March 2013 - last comment - 14:15, Friday 15 March 2013(5774)
50-50 IR beam splitter is a good AR for green (Corey, Keita)

Seems like the problem we had when using a green beam reflected off of a 50-50 IR beam splitter was because of the fact that 50-50 surface for 1064nm works as a very good AR for 532nm.

The BS in question is this: https://dcc.ligo.org/LIGO-E1000671-v1

Corey used a fiber coupled green laser as the source, placed a PBS cube for 532nm to ensure that the P-pol light is transmitted, and used a HWP for 532nm to change the polarization.

There are two beams in reflection, one from 50-50 IR BS surface and one from the back surface. There is one beam spot in transmission, because the 50-50 IR BS surface is very small. Anyway:

  P-pol S-pol
50-50 IR surface reflection 0.92% 0.044%
AR surface reflection 6.3% 20.7%
Transmission 92% 79%

On TMS ISC table (and in the arms) the green light has S-polarization, and according to Corey's measurement we're totally screwed.

Now that we know about this, we could either align the red QPD path assuming that there is an invisible beam next to a visible beam at a known distance, or we could place a HWP on the ALS table and inject a wrong polarized beam to see if we get anything.

Corey will write a one-page document and add it to E1000671.

Comments related to this report
corey.gray@LIGO.ORG - 14:15, Friday 15 March 2013 (5819)

Note added to E1000671v1 is here.

LHO General
patrick.thomas@LIGO.ORG - posted 21:11, Tuesday 12 March 2013 (5773)
plots of dust counts
Attached are plots of dust counts > .3 microns and > .5 microns in particles per cubic foot requested from March 12 00:00 UTC to March 13 00:00 UTC. Also attached are plots of the modes to show when they were running/acquiring data.

Data was taken from h1nds1.
T0=13-03-12-00-00-00; Length=86400 (s)
4020 seconds worth of data was unavailable on this server
1440.0 minutes of trend displayed
Non-image files attached to this report
LHO General
patrick.thomas@LIGO.ORG - posted 20:57, Tuesday 12 March 2013 (5759)
Ops Summary
Richard to end Y to look at seismometer
John to mid Y to close GV 10
Rebuild of h1susmc2 against unmodified 2.6.2 RCG code, restarted
LN2 CP7 fill
restarts of corner station PEM, DAQ restart
alignment work in HAM3
restart of mid X PEM, end Y PEM
Richard re-zeroed STS2 seismometer, removed tilt-meter from PEM at end Y
h1slow-cds gateway restarted
H1 IOO
chris.mueller@LIGO.ORG - posted 20:21, Tuesday 12 March 2013 - last comment - 20:34, Tuesday 12 March 2013(5771)
Input Optics Work
[Rodica M., Deepak K., Chris M.]

Today we resolved the issue with IM3 which turned out to be an earthquake stop rubbing.  It isn't clear how this became an issue after pumping down, perhaps it slipped in over time.  See the attached transfer functions for an idea of the badness and subsequent goodness.  

After we were allowed to turn on the laser we double checked the centering on the IMC mirrors which seems very good to us.  We added an iris at MC2 to double check the 'by eye' centering which was done at the end of last week, and the beam looked very good.  We also installed the MC2 scraper baffle.  

Tomorrow we will check the alignment of the components downstream of the IMC.  Afterwards we will align the MC refl beam onto the trans beam path and use it to align the auxiliary paths and measure mirror transmissivities.
Non-image files attached to this report
Comments related to this report
deepakmanoj.nandakumar@LIGO.ORG - 20:34, Tuesday 12 March 2013 (5772)

The Dog clamps installed on the MC2 Scraper Baffle are 

  • D1100640-V2 Type 03 - S.N. 009.
  • D1100640-V2 Type 03 - S.N. 010.
  • D1100640-V2 Type 03 - S.N. 011.
  • D1100640-V2 Type 03 - S.N. 012.
H1 SUS
arnaud.pele@LIGO.ORG - posted 17:14, Tuesday 12 March 2013 (5770)
OMC cart2eul and eul2cart matrices

Jeff K., Arnaud P.

Filled up the CART2EUL and EUL2CART matrices for OMC. 

CART2EUL=

                    0.8572                     0.515                   -0.1402                         0                    -0.538                    0.8954
                    -0.515                    0.8572                    0.0094                         0                   -0.8954                    -0.538
                         0                         0                         0                         1                     0.125                    0.0642
                         0                         0                         0                         0                    0.8572                     0.515
                         0                         0                         0                         0                    -0.515                    0.8572
                         0                         0                         1                         0                         0                         0

EUL2CART=

                    0.8572                    -0.515                         0                   -0.5379                   -0.8954                     0.125
                     0.515                    0.8572                         0                    0.8954                   -0.5379                    0.0641
                         0                         0                         0                         0                         0                         1
                         0                         0                         1                   -0.1402                    0.0093                         0
                         0                         0                         0                    0.8572                    -0.515                         0
                         0                         0                         0                     0.515                    0.8572                         0

The values are saved in the /opt/rtcds/userapps/release/isc/common/projections folder under ISI2SUS_projection_file.mat.

In order to get those matrices we updated the script SEI2SUScoordinates.m with relative coordinates between OMC and the center of the ISI table (from the attached bgchbiai.png and HAM6[...].pdf for x, y, yaw and the solidwork screenshot for z from dcc document D0900295).

x=-64.197mm

y=125.01mm

z=637.08mm

yaw=31 degrees

A new snapshot with safe values has been commited on the svn as well as the ISI2SUSprojection_file.mat file.

Images attached to this report
Non-image files attached to this report
LHO VE
kyle.ryan@LIGO.ORG - posted 16:45, Tuesday 12 March 2013 (5769)
GV10, GV6 stroked
John -> Hard-closed GV10 
Kyle -> Soft-closed GV6 
Kyle -> Opened GV10 
Kyle -> Opened GV6 

Y1 accumulation study -> looks like gas load is GV6 gate annulus air leak -> John will post data soon
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.

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 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    
Images attached to this comment
Non-image files attached to this comment
Displaying reports 77561-77580 of 83164.Go to page Start 3875 3876 3877 3878 3879 3880 3881 3882 3883 End