J. Kissel, S. Ballmer, C. Wipf

After discussions with both Chris and Stefan, I have re-arranged how the IMC WFS' master switch, gain, and trigger bit are combined such that the implementation is a little less obfuscated and well-annotated in the Simulink model. I attach a new screenshot. In this new arrangement, each of the three variables -- all nominally 0 (zero) or 1 (one) for OFF and ON, respectively -- are simply multiplied together by one block, as opposed to feeding the trigger into a switch block that compares its value against the master switch (nominally 1 [one]) and a ground (equivalent 0 [zero]) [See identically named screenshot in LHO aLOG 7984 for previous implementation]. 

For historical purposes: Stefan had originally implemented the triggering with the comparator switch for philosophical reasons in that (at least with conventional c-code) it is bad practice to assume a trigger could only be 0 or 1 -- typically when programming in c, a flag is either zero or non-zero, where non-zero can be anything and should never be assumed to be one. However, the trigger library part used (from ${userapps}/release/isc/common/models/LSC_TRIGGER.mdl) is written to ONLY spit out a 0 or 1. Therefore this bad-practice failure-mode dos not apply, and we are free to make the output bit generation more clear.

As of this entry, the 
${userapps}/release/asc/h1/models/h1ascimc.mdl
has been re-compiled, re-installed, re-started, and re-stored. Since the mode cleaner is dead for the time being due to venting of the corner volume (light from the PSL has been shuttered), I cannot *confirm* all is still functional, but I'm 99% confident all is well.

Sheila, Alexa, Stefan, Rich

Present Status:
1.  Day started with one DC cable needing to be fixed.  We did this and all the RFPDs are properly powered now.
2.  After getting DC stuff going, found one bad connection in an RF cable due to the 5-way coaxial connector not being properly seated.
3.  When we undid the 5 way coaxial connector, the 4-40 helicoil came out of the RFPD.  Now things went downhill.  We spent many hours going through bag after bag in the LVEA, Staging building, and X-end station looking for a 4-40 helicoil insertion tool and a single class A clean 4-40 helicoil.  Never found any.  Took one from a perfectly good cable which must now be fixed later.
4.  As of now, 100% of the electrical components in HAM1 are functional.
5.  Bolted down and optically aligned REFL A&B, and REFL LSC detector.  Didn't have a beam to align LSC POP detector, so it's bolted down, but not final aligned with light

Next Actions:
1.  Complete and log the RF transfer functions to establish reference levels for each signal at the respective operating frequency (test input to each RF output)
2.  Clean up the cable routing in HAM1
3.  Final table balancing
4.  Log all data taken during checkout
5.  ASC screen checkout

Sheila, Stefan, Rich

Things went so well yesterday that it was a bit suspicious.

Present status:
1.  Finished a crude checkout of the tip/tilts after installing jumpers inside the coil driver chassis to enable the normal signal path.  The HAM1 tip/tilts are showing signs of damping, so the electronics are fine.  The anti-dewhitening is probably not right, so the servo needs attention.  (The HAM6 tip/tilt coil drivers have not yet had the jumper installed, so they won't work yet).
2.  REFL A and B Wavefront Sensors seem to be fully functional as checked out from the rack.
3.  Both the REFL and POP LSC detectors are in HAM1 and are functioning, but after much troubleshooting we found that there was a voltage missing in the DC wiring serving one of the LSC detectors probably inside the chamber.  This is despite testing each and every wire prior to installation beginning.  After finding that (and being so relieved that the detectors were OK) we realized that it's going to involve getting inside the chamber, which we will do in the morning.

Next Actions:
1.  Fix DC cable serving LSC detectors
2.  Do optical alignment of RFPDs
3.  RF AM measurements

J. Kissel

Following up on the initial installation of the Online Detector Characterization channel for Input Mode Cleaner control system (see LHO aLOG 7894), I've cleaned things up further by 
- fixing the bit-bug that was inherent to the CTRLON bit (BIT 1), 
- added a few more EPICs records to make
    - calibration of the sum signals and power ratios possible and 
    - the bit generation a little more clear and useful,
- added negative space, notes, and clarifying colors to the slightly-complex bit-logic chain
- spiffing up the screen to Izumi level. 

All bits, even up to the summary bit level, are now regularly green. This channel (H1:IMC-ODC_CHANNEL_OUT_DQ) should be ready for DetCharian DataAnalystic consumption.

I attach new screen shots of the bits (pun intended) I've changed -- just the ODC block in the front-end model, and the screen.

Still to-do, but not imperative for the functionality of the channel:
- Get calibration factors for 
    - All ASC error signals, H1:IMC-DOF[1,2,3,4]_[P/Y]_IN1, in [ct/urad]
    - H1:IMC-PWR_IN, the broad-band PD on PSL periscope in [ct/W]
    - H1:IMC-ODC_MC2_TRANS_SUM, the DC sum signal for MC2 transmitted light QPD in [ct/W]
    - H1:IMC-ODC_IM4_TRANS_SUM, the DC sum signal for MC2 transmitted light QPD in [ct/W]
    - Expected power ratio between PWR_IN and each transmitted sum in [W/W].
  and install them in the available ODC EPICs records.
- Fill out all the EPICs string records explaining each of the bits (though I tried to make the corresponding, EPICs channels {that are redundant with the ODC bitword itself BTW...} have names which are clear-ish).
    
As of this log, new versions of
/opt/rtcds/userapps/release/asc/h1/models/h1ascimc.mdl
/opt/rtcds/userapps/release/ioo/common/medm/IMC_CUST_ODC.adl
/opt/rtcds/userapps/release/asc/h1/burtfiles/h1ascimc_safe.snap
have been committed to the userapps repo.

(Kiwamu, Sheila, Arnaud, Stefan)

We moved TT2 (RM2) back 1.6 in and M5 back 1 in. This gives us the telescope that Sheila calculated to be optimal for Paul's beam parameters.
We swapped the beam diverter cables for REFL and POP at the CB-2 bracket - this brings it in agreement with document D1300075.
We switched one in-vacuum RF cable (the one plugged in to D6-2D, for WFS A) against a spare. All in-vacuum cables now checked out o.k.
We took some ModeMaster measurements - but before RM1 and RM2 were damped, so the beam was still moving a lot. This should be repeated.
We adjusted the RM1 and RM2 OSEM positions - for details see Arnaud's elog. However the drive is not yet working.
We placed the beam dumps behind RM1 and RM2, as well as the dump for the POP PD.

We left the BS for the REFL LSC diode moved back by 1in to send the beam to the ModeMaster.

Open light values have been measured on RM1 and RM2

damping gains have been set to

-30 in long

-0.02 in Pitch

-0.02 in Yaw

the safe snapshot has been commited to the svn

A rare day indeed...

Alexa, Stefan, Sheila, Kiwamu, Rich

HAM1 Status:
1.  All RF connections from air to vacuum have been fixed.  After much head scratching, we found an idiosyncrasy (=design flaw) with the air-side 2-row 5-way coaxial connector.  Each coaxial element in the 5-way connector is supposed to free float somewhat in order to mate properly when inserted into the flange.  Moreover, each coaxial element is spring loaded such that there is a restoring force to maintain proper insertion.  The air side connector has large coaxial cables to minimize the RF loss on the trip back to the racks, and it is here that the trouble begins.  This large coaxial cable - being quite stiff - has enough friction inside the connector body that when you try and plug the 5-way connector into the flange, some of the individual coaxial elements simply compress the spring, and don't insert into the socket.  With the strain relief screws loosened, it is actually possible to push an individual cable and feel it snap into the flange.  Of course, there's a down side to this.  If you pull an individual cable, it is possible to pop it out of its socket causing a loss of connection.  We secured the cable bundles to the conflat protector ring cross bolt such that all the cables are reasonably immobile.  This will likely be quite sufficient.

A small consolation prize is that the in-vacuum version of this connector doesn't seem to be anywhere near as susceptible to this phenomenon.  Still, any plugging and unplugging (which is highly discouraged) should be done by watching with a time domain reflectometer (TDR) to ensure no harm has been done before and after the evolution.

2.  Beam diverters have been tested and are all OK
3.  Tip/tilt electronics chain is showing good signs of life in that the sensors are sensing and the pushers are pushing. 

Next Steps:
1.  Remaining parts for the RFPDs are to be delivered in town tomorrow.  Assembly will be completed and the detectors will be installed in HAM1
2.  Finish checkout of tip/tilt chain
3.  Take transfer functions for all RFPDs in HAM1
4.  Clean up in-vacuum cable installation

We've removed temporarily restraint and put the real one in.  TMSX is floating but cannot crash into ETMX.

We left two big wipes on the ISC table to protect the mirrors, which is probably like 0.2 lbs or something total. If this is a problem for you, please feel free to remove them, but take care not to touch or bump any of the mirrors/lenses/detectors on the table.

There are some minor things that should not affect the task of other people, but these should be fixed later before we pump the volume down:

1. We need one class A 3/8 nut (either aluminum or Nickel Copper alloy) and two washers for a bolt that is necessary when pulling the TMS back away from ETM. We have the bolt but that is not in place for now due to this.
2. We need two class A pear shaped link parts. For now we're using class B parts, but they should be replaced with class A parts. We'll ask C/B to get two from Thomas and class A them.
3. Tuned mass damper pins are still in place.

We brought the transport restraint and some in-vac parts that I thought are ours back to the EX lab. I and Pablo didn't label these, they are just layed out on the work table there. For later labeling purpose for our own sake, these are:

1. Transport restraint turnbuckles and chains. Chains are inside one of stainless steel tubs.
2. ISC table covers and support rods. Rods are wrapped separately from covers but are put on the covers.
3. Class B in-air restraint rod assembly for fake Genie. Do never ever confuse this with the class A restraint rods.
4. Spare parts for in-vac restraint and one 3/8 bolt that are to be installed in EX are in stailess steel tubs.
5. Some smaller stainless steel bins containing kapton tubing and screws and 1/4-20 nuts (both Nickel-Copper alloy and alluminum).

Jim and Dave.

We noticed that the TCS rack layout was slightly differerent between EX and EY. The EY layout was more optimal, so we made EX the same as EY. This involved moving the PEM BNC patch below all the timing systems, and moving the End Link chassis down 1U. So from the top of the rack we have: timing fanout, comparator, space, serial concentrator, space, End Link Chassis, space, PEM patch.

Daniel provided the serial cables to hook up the fanout. The large 37pin cable was ran from the End Link to the serial concentrator. A 9pin serial was ran from the RS422 output on the back of the fanout to port 5 (lower left) on the concentrator (Daniel says this is the first RS422 port, lower numbered ports are RS232).

I dont see the timing diagnostics data on my MEDM, perhaps something on ex beckhoff needs to be restarted?

LVEA Laser Hazard
Alarms: FMCS/RO and CDS

08:00 Dave B. - DTM Broadcaster down and front-end DAQ errors, 
           Jim B reset h1broadcast0 and restarted MX-Streams on affected DAQs. 

Apollo working at End-X removing tooling back to the LVEA
Rich A. Testing cables in the HAM1/HAM/2 area

09:00 Paul F. taking MC measurements
09:55 Cheryl and Pablo in LVEA taking measurements
10:09 Gerardo M.Jr doing assembly work in LVEA mechanical test stand cleanroom
11:16 Justin B. at end-x checking laser barriers 
11:48 Stefan B. working in the HAM1/HAM2 area
16:00 several dust alarms in the DR. Justin B and Jeff B checked dust monitor in diode room.   

   I assembled the TS cartridges for the 3IFO TMS using a modified procedure from that documented in D060370. I removed the big jacking screw that is used to pull flattening roller across the blade. Instead, I pulled the flattening roller out by hand. 

   This seemed to work better than using the screw jack because: 

      (1). It was much faster. Instead of several minutes to run the screw in and out, pulling by hand took just a couple of seconds to flatten the blade. 
      (2). There is little or no contamination generated by the hand pulling process. When using the screw jack one must continually lubricate the jacking screw with alcohol. As the jacking screw turns, it generates a large amount of aluminum shavings. These shavings mix with the alcohol to make a nasty paste, which drips on the optics table the puller is clamped to and the floor. The Teflon bearing the end of the jacking screw rides on also sheds during the pulling process. Both these contamination sources are eliminated when pulling by hand. 
      (3). The jacking screw is a source of binding. The turning of the jacking screw causes the two guide rods on the sides of the puller to twist. This twisting causes the guide rods to bind, which puts excess stress on the guide rods and the jacking screw. The hand pull greatly reduced this problem, but it did not eliminate it. 

   It did take some strength to pull the blade flat, but it was not excessive. There is a possibility the roller could snap back across the blade, without the screw jack holding it in place. However, there are notches cut into the sides of the puller, which the roller bearings drop into when the puller is fully engaged. The force of the blade pushing upwards holds the roller bearings into the notches very securely. In addition, there are holes on either side of the puller just inside the notches the roller bearings fit in. I put a pin through these two holes to act as a safety stop, should the bearings come out of the notches. 

   This process worked as well for disassembly as it did for assembly. The hardest part of the disassembly process was getting the roller bearings out of the notches.  

Joe, Pablo, Cheryl, Sheila

We measured the beams coming out of the HAM2 viewport, with the nanoscan head 2 feet 6 inches from the viewport.  (in the first version of this alog I wrote the wrong distance)

For the brighter beam we measured beam diameters: 2549 um horizontal, 2632 um vertical.  after rorating the scan head 90 degrees we measured 2650um vertical, 2561 um horizontal.  

For the dim beam we measured 7160um vertical, 5972 um horizontal after rotating  by 90 degrees we got 6077um horizontal 5865um vertical. 

We also measured the beam in HAM1, in the same location as wensday (we move the BS for the RF PD to 16 inches after M2, we put the nanoscan 40 inches after the BS, there we got 4025 um vertical, 4126 horizontal.  After rotating the head 90 degrees we got 4045 um vertical 4020um horizontal.  

Stefan, Alexa, Rich

HAM1:
1.  All in-air and in-vacuum cabling associated with the ASC detectors,  LSC detectors, and Pico motors have been run.  The in-air cables still require termination in TNC at the rack.
2.  All in-vacuum cabling has been run for the tip-tilts, and the cables have been mated to the tip-tilt stages.
3.  Cables for the beam diverter are attached at the flange, but not run to the diverters yet as one connector set was missing the helicoil inserts.
4.  Operational check was performed on all 4 pico motors, and all axes are correct

HAM6:
1.  All in-vacuum RF detector coaxial cabling is attached at the flange, but not yet run to the racks.

What's Next:
1.  Fix cables requiring helicoils
2.  Hook up and test beam diverters
3.  Mount all in-vacuum detectors and verify proper operation
4.  Clean up in-vacuum cable routing and ensure all is well constrained
5.  Terminate all in-air RF cables at their respective racks
6.  Install tip/tilt coil driver in the ISC R4 rack and test operation in HAM1 through installed air and vacuum cabling

We placed Mode Master downstream of three-mirror Gouy phase matching telescope comprising two tip-tilts and one fixed mirror that is used for REFL WFS. (See the last picture for layout and distances.)

Note that the measured TT1-TT2 distance is about 1cm shorter than nominal described in Sam Waldman's document (http://dcc.ligo.org/T1000247), TT2-M5 distance is about 14mm longer than nominal, both of which should have been quite acceptable.

Anyway, we made this measurement and the beam was much smaller than what was expected. The first plot as well as the table below show the measured VS  the expected mode profile coming out of HAM1 propagated through the telescope with the measured mirror distances.

The total mode overlap between the actual beam and what is expected is somewhere between 0.75 and 0.87 (sort of tedious to do the real calculation so I leave it).

The 2nd plot shows that IF the incoming beam from HAM1 is as expected, in order to explain the measured mode the TT1-TT2 distance labeled as delta1 should be shorter by 4.5cm than was measured for X, or by 5.7cm for Y. This is a huge number, there's no way my distance measurement was that much off.

The 3rd plot  shows the Gouy shift between TTs (i.e. actuation orthogonality) and WFSs for the WFS sled (i.e. sensing), and it seems like both are quite poor for the measured mode, 26deg for actuation and 35 for sensing are sad though not a complete disaster.

Anyway, since it's hard to imagine that the ROC of TT1 (+1.7m), TT2 (-0.6m) and M5 (+1.7m) are grossly wrong, and since it's hard to imagine that the distance measurement has a 5 to 6cm error, this should mean either (or some) of the followings:

1. T1000247 is wrong about the mode coming out of HAM1.
2. IMC mode is not mode matched to the IFO well.
3. Astigmatism of curved optics at an angle (there are 3 such optics on HAM1, more on HAM2), each has small effect but maybe they add up. Neither Sam nor I have included this.

The third one doesn't sound likely, but neither Sam nor I have thought about this.

This is a list of the ISC diagnostic optics in HAM1. Some of these are yet to be installed,  but all will be installed in this installation window.

The only differences between this and D1000313 are:

1. M14, the first BS for the REFL, is a 90% S-pol splitter (E040512-B4), not a 95% P-pol (E1000871-V1-02) as in D1000313, as the reflectivity of the latter was measured to be too much for our purpose.
   • However, 90% is a bit too small, and we might want to insert another 50% splitter later.
2. For M6 (50% P-pol splitter), we used iLIGO REO splitter (E040512-B1, marked "IO824-01" on the barrel) instead of newer ATF optic (E1000671-02) because I couldn't find the latter.
3. We put a black glass behind M5, as all high reflectors upstream of M5 are with some kind of beam dump.

Note:

• The optics with ? in the S/N column just means that I don't know them for now.
• REO optics have markings e.g. IO824-01 on the barrel, but they don't seem to be consistent over the coating type. For example we have IO822-08, IO823-07, IO823-01, IO826-08, IO826-05 and IO824-07, and these are all 50% P splitter.
  • These might be the production run number ("IO824") and the serial number ("-01") for the substrates, but not for the coating. If that's the case we cannot automatically look up the coating type from these numbers, but I'm hoping that each of these numbers is at least unique so I can use these as ID.