Mark B.

As Travis points out in a comment, this is ITMy not ITMx. Title of post and references below changed.

Preparing to take TFs on main chain of H1:ITMy (which is still wired up as H2:ITMy). I hope to start them imminently (16:40 pm, 10/30) and check progress from home tonight.

Checked at 07:21 am (10/31), damped TFs seemed to have completed successfully. Started undamped TFs.

Today I continued poking at ITMy to address a couple of minor issues on our way to final alignment.  First, I replaced a wonky flag mount for the R0 Side BOSEM (poor pressfit of magnetic disc not allowing flag magnet to seat squarely).  I then adjusted the tablecloth to get it back to a more 'nominal' state where the BOSEM cams still have effective adjustment left.  I then continued with the Test Mass pointing.  I adjusted yaw of M0 by using some slop in the fixing screws for the suspension wire clamp at the Top Stage blades.  I also adjusted some more pitch out using the UIM pitch adjusters.  (Reminder at Betsy's request:  The UIM pitch adjusters have an effect of ~200µRad per full turn of each adjuster.)  The resulting measurement by IAS left ITM at:

Pitch: ~5µRad up

Yaw: ~1.04mRad CW (previously ~185µRad CCW)

Although I overshot, I now know that we have plenty of easy-to-use yaw adjustment at the wire clamp to fix the yaw error.  This work will continue tomorrow.  I then solicited Mark to run some quick TFs to check for rubbing before we get too carried away with fine alignment.

The west door was removed from the chamber this afternoon to allow the installation of the septum viewport.

Both the east and west doors were returned to the chamber to facilitate "dirty" work in the neighborhood.

For the 35W laser. We have not adjusted the mode matching of this path, only the alignment, yet the mode matching improved already from adjusting the lenses for the 200W path.

For the 200W laser. RIck and I adjusted the modematching into the DBB PMC using ML1 and ML2 inside the DBB, reducing the 20-02 peak.

Note that there is a peak in the ISS_rpn plot just under 2kHz which does not appear when using the 35W laser.

After a long, sorted history (see LHO aLOG 4112, and previously LHO aLOGs 2109 and 2022), Travis and I were apparently successful in re-installing the M0 OSEMs on H2 SUS ITMY in such a way that they now obey convention, as per E1000617, and subsequently T120015. 

I've changed the COILOUTF gains accordingly, such that they're now

      F1 F2 F3 LF RT SD
M0 = [ +  -  +  -  +  -]
R0 = [ +  +  -  +  -  -]

I've confirmed that the damping loops are stable on M0 with these new COILOUTF gains (R0 OSEMs are not centered, so I cannot confirm their functionality, but nothing has changed there.)

Also, as per request, with the open light currents as measured by the test stand setup, the H2 SUS ITMY OSEMINF gains an offsets should be / are:

M0_OFFSETS =
F1 -14764
F2 -14379
F3 -14471
LF -13457
RT -12564
SD -14795
M0_GAINS =
F1 1.016
F2 1.043
F3 1.037
LF 1.115
RT 1.194
SD 1.014

R0_OFFSETS =
F1 -12472
F2 -12619
F3 -13171
LF -13894
RT -12380
SD -13062
R0_GAINS =
F1 1.203
F2 1.189
F3 1.139
LF 1.080
RT 1.212
SD 1.148 

NanoScan used to look at the beam about 1m down stream of the EOM. First image is without the EOM, second is with EOM.

Well, the MC3 left primary and secondary prisms sat in another acetone bath all day - the secondary (metal) prism finally fell off, but the primary looks to be well bonded to the barrel of the optic still.  Degradation of the glue joint usually occurs at some vulnerability in the boundary of the bond (like where some glue has chipped away or at an irregular area like a bubble or crack which then lets the liquid seep in more efficiently.  We could see this happen on the secondary, but the primary doesn't show any such areas.  We have even used a razor blade to strip away excess glue and look for soft spots in the joint edge.  No luck today.  More soaking tomorrow.  Of course this debond-rebonding project is time critical so I shouldn't expect it to go well.

Thanks Gerardo for all the prism-sitting.

Attached are plots of dust counts > .3 microns and > .5 microns in particles per cubic foot.

Dave Barker and I checked the status of HAM3-ISI's test points this morning. We noticed they were overloaded. Dave restarted H1-DAQ and they came back to normal. It seems like H1-DAQ was not restarted as it should have been after the model changes of last week.

Spectra measured on HAM3-ISI make sense again. I tried most combinations of ISO/blend filters on HAM3-ISI today. I attached a sum-up plot of HAM3-ISI isolation performance in the following configurations:
1- No control
2- Damping only
3- Damping + "old" blend* 250mHz     + "old" ISO level 2
4- Damping + "newer" blend** 250mHz  + "old" ISO level 2       
5- Damping + "newer" blend** 250mHz  + LLO HAM5 ISO level 2

ISO=Isolation filters
*: old blend filters - SVN revision 6036
**: newer blend filters - SVN revision 6187

• Pitch: ~750 µrad up
  • Target pitch: 12.5 µrad up
• Yaw: ~185 µrad CCW
  • Target yaw: 0.0 µrad

Temporary air compressor intended to be used today needed to be fixed first

F. Clara, J. Kissel. T. Sadecki

We reconnected and reinstalled the BOSEMs to the TOP stages of what-is-now H1 SUS ITMY (but is still being run on H2 SUS ITMY electronics), gathered and installed new open light current values (as the resistance of the long temporary cables significantly reduced the voltage at the ADC, see table below), and aligned them by-eye laterally, and by and axially by speed dials.

After resurrecting the sensor diagonalization templates 
${SusSVN}/sus/trunk/QUAD/H2/ITMY/SAGM0/Data/
20110803_ITMY_Diagonalize_1p3_Yaw.xml
20110803_ITMY_Diagonalize_2p2_Vert.xml
and finding that the isolation between expected and unexpected degrees of freedom was not-so-hot, we took a few averages of M0 P to P and V to V TFs using
${SusSVN}/sus/trunk/QUAD/H2/ITMY/SAGM0/Data/
2012-02-15_1802_H2SUSITMY_M0_Mono_V_WhiteNoise.xml
2012-02-01_H2SUSITMY_M0_Mono_P_WhiteNoise.xml
(which are sorely out of date) and found both to be crap (really noisy, low amplitude, little-to-no visible resonances). After a few tweaks here and there, we found that the bump stops on the reaction chain were rubbing against the main chain. What's worse, is that we saw the top bump stop rubbing first ("sweet! we'll just tweak up the pitch"), but then noticed the -Y bump stop was also rubbing ("that requires adjusting yaw, that's hard, let's go home instead").

So, indeed, we will leave further alleviation of rubbing for Monday.

Welcome back to QUADs everybody!


%%%%%%%%%%%%%%%%% Open Light Current Values %%%%%%%%%%%%%%%%%
BOSEM      Production      Test Stand     % Drop
Name       OLC [cts]       OLC [cts]      [%]
M0 F1      30805           29529          4.14
M0 F2      30164           28758          4.66
M0 F3      30160           28942          4.04
M0 LF      28050           26914          4.05
M0 RT      26205           25128          4.11
M0 SD      31046           29590          4.69

R0 F1      25530           24943          2.3
R0 F2      26272           25238          3.93
R0 F3      27538           26342          4.34
R0 LF      29513           27787          5.85
R0 RT      25210           24760          1.79
R0 SD      27113           26124          3.65


(Note, I gathered the previous OLC values from what was installed in the offset/gain fields; I couldn't find a report of them in the log [though I didn't try that hard]. For M0, I gathered to offsets and gains before I started entering in the new values, hence I trust their accuracy. For R0, I entered in the new offsets before remembering to get the old values, so I had to use the gains [which are entered in with less precision], so that's probably why the % drop varies by ~1% from 4%.)

-- Huh! A ~4% drop. Since V=IR, and nothing else has changed, I guess we know that there's therefore a 4% increase in resistance between the production sensor readout chain and the test stand. No show stopper, just good to know, and annoying to have to redo the normalization.

From approximately 9am until 3pm four vertical HEPI actuators were installed in the BSC2 pier housings.  Four matching horizontal actuators were also installed on the Piers.  This was with the use of a crane.  Thanks to Ed and Mick.               

Other than getting the wiring out of the way which wasn't too big a deal, and moving the CPS racks-now not so solidly attached, installation was pretty straight forward.  The bolts tying the upper section of the handrails didn't lineup easily; these holes should be a little more oversized.  A mod to lower the overall height a couple inches would make install safer for the ISI as well as working around the ISI--reduces contact of shoes and ISI.  Additionally, a couple inches lower might allow big Jim to stand upright!

Thanks Apollo-MarkD, Mark2 & Slim.

Couple photos

At 8:03AM today, the IOP watchdog tripped, and I saw connection error messages in the alarm handler.  I talked to JeffK and we cleared all alarms, and at 9:03AM, I got another round of alarms, but nothing tripped.

At 10:03AM, I got connection alarms for the ITM.  Now it's in a funny state for work, however, the alarm was exactly at 10:03AM, so suspicious.

Alarms again at 1:03PM, 2:03PM, 3:03PM.

Emailed DaveB and RichardM, and Operators (to give them a heads up).  

   Ran transfer functions and power spectra on H1-SR3. In general, the results look good. There are a couple of peaks in the undamped plots, which are suppressed in the damped plots.