Matt H, Jason O, Aidan B, Thomas V

Aidan will write an alog regarding the alignment of the HWS optics in HAM4, this is more about the setup to do it.

We haven't been able to solve why the SR3 is pitched low and so I locked the face EQ stops of all three stages, then with Jason making sure the pointing of the HeNe of the total station was correct and that the beam splitter offsets were engaged and damping on, and Aidan standing at HAM4 directing me using the headsets, I altered the EQ stops on the optic of SR3 so as to steer the beam onto the center of SR2 optic (or as close as we could tell it was to center).

This was enough to allow the alignment of the HWS to begin. Just for curiosity we looked at how the beam was going from SR2 to SRM. Luckily we could see it and so we could steer the HeNe beam onto roughly the centre of SRM with ~1500 offset in pitch and ~1800 offset value in YAW on SR2 upper mass (note Jason seemed to think that the sign of which way the beam went up and down when he provided an offset was flipped. Maybe someone wants to look into that).  So thats a good sign.

Note: The HWS optics were aligned WITHOUT any offsets applied to SR2.

7:00 PRAXIAR Delivery to CP1
9:30-11:14 -Heading into the LVEA to work on HAM2 PSL ISS PD array cables.- Rick S/Peter/Michael
9:32- 10:45 Going into the LVEA to work on several Dust Monitors – Jeff B
10:25-11:59 Visiting End Y (cleaning) – Karen
11:00-11:58 Heading to EndX to replace a bench – Jeff B
11:03- 12:00 Continuing work on HAM5 (More investigation on SR3 pitch situation) –Matt/Jason
11:16- 12:18 Work on HAM4 HWS optics - Thomas/Aidan 
13:13- Heading back to HAM5 – Matt H.
13:00- 15:57 Back to work on HAM4 HWS Optics Alignment - Thomas/Jason/Aidan 

Aidan, Thomas

As we discovered yesterday, two HWS optics (HWSX STEER M1 and HWSX STEER M2) and the HWS scraper baffle are out of position with respect to each other. It turned out that the assembly diagram for the H1 HWSX HAM4 optics is incorrect (when compared to the actual optical coordinates, E1100463, derived from the HWSX optical solution, T1000179). Also, H1 and L1 coordinates are supposed to be the same. The following table summarizes the problem in the documentation:

So ... we have moved the offending HWS-X mirrors (HWSX STEER M1, HWSX STEER M2 and HWSX STEER M3) in HAM4 to the correct positions specified by the L1 assembly diagram. We will update the H1 assembly diagram to reflect this. Photographs will be attached ...

Alignment of the HAM4 HWS optics with the IAS laser is taking place this afternoon ..

Jason O, Matt H

So we decided to see if we could find a simple smoking gun to why the SR3 pitch appears to be so far out.

Using a clean scale and scale stand I measured the height of the HeNe beam behind the SR3 optic. With the BS optic pitch and yaw offsets on (we didnt change the values just used what was already in the fields), we measured the HeNe beam to be  at ~205mm on the scale. The scale stand holder is ~18mm high so the beam is ~223mm high. Jason looked it up and should be 229mm, but I was measuring ~8-10 inches behind the optic (in front of the baffle), and the beam from the BS to SR3 is angled up, so to fist order we are close to the center of the optic. Even so as the SR3 optic is curved, being low should help direct it up.

Also I locked the face stops of the three stages so I could push on the mechanical sliders to see if perhaps one was loose and had moved. They all appear tight, so doesn't appear to be that.

I cant really get a good look at the suspension due to not being able to lock the ISI (and thus not being able to get onto the table to get at the angles I need to look at), so I think I will try to just use the EQ stops to move the optic to direct the beam from SR3 onto SR2, until a more complete investigation can be made. Also will be interesting to see how the beam comes off SR2 and towards SRM.

The pondering as to what is going on continues

And she's not even here today .....

PeterK, MichaelL, JeffB, RickS

Betsy located some aluminum ClassA parts yesterday that we were able to use today to improvise some strain relief for the PSL ISS PD array cables in HAM2.

Jeff and Michael were able to locate some PEEK cable ties (very handy) that we used to dress the cables to the improvised bracket (see attached photos).

Peter is doing one final set of electrical tests now, after which we will consider the ISS PD installation complete (and successful).

model restarts logged for Wed 02/Jul/2014
2014_07_02 10:56 h1iopsusauxey
2014_07_02 10:56 h1susauxey
2014_07_02 11:00 h1iopsusauxey
2014_07_02 11:00 h1susauxey
2014_07_02 11:02 h1iopsusey
2014_07_02 11:02 h1susetmy
2014_07_02 11:02 h1sustmsy

no unexpected restarts. Restarts to recover from DC power loss.

Used: /ligo/cds/lho/h0/burt/2014/07/01/00:00/h0fmcs.snap
This sets the alarm levels and H0:FMC-MILLIAMP_MAXVAL.

Particle counts

HAM2

Morning ISS work. In cleanroom:

All counts zero

In chamber start of session:

All counts zero

In chamber end of morning:

05um..20 counts

remainder...zero

HAM4

Afternoon HWS work

In cleanroom:

0.3um....70 counts

0.5um.....20 counts

0.7um...10 counts

remainder...zero counts

In chamber start of work:

0.3um...30 counts

remainder...zero counts

In chamber end of work:

Forgot....was a long day again

HAM5

Afternoon work removing door/HWS work

In cleanroom sart of work:

all...zero counts

In chamber start of work:

0.5um...20 counts

remainder zero counts

In chamber end of work:

Again forgot....was a long day

Matt H, Aidan B, Thomas V, Jason, Apollo

Okay so we jinxed ourselves when we said..okay this should only take a couple hours. We have run into multiple problems.  Here we go...I am going to have some fun with this just to lighten the mood:

SR2

As reported in a previous alog SR2 had its first contact layer on the HR surface. Okay no big deal as it had its peek tab on it so simply locked the optic, and with the top gun ioniser in hand, removed the first contact (left a little of the alignment layer behind :-(..but we can get that when we re-first contact), unlocked the optic and that suspension ready (Note: ISI unlocked).

SR3

As also reported in a previous alog, SR3 also has its first contact layer on it. Okay so slightly bigger deal as the doors on HAM5. So Apollo kindly removed the south door and yep there is first contact on the HR surface...but no peek tab. Also the ISI is unlocked. Betsy asked me to look to see if the magnets that they thnk were knocked off the IM on SR3 are really gone. And I am sorry to say that yes the LL and UR IM magnets are gone...and I couldn't find them. I did notice the EQ stops on the top and IM stage were wwwwwaaaaaaayyyyyyyy back (optic level was at the distance we usually set it), so I am guessing these stops were potentially forgotten about. I have set what I could easily reach/see closer. Anyways so I locked the south side lockers and the front and back face stops of the optic. After gently easing myself into the chamber I then painted on the peek tab and waited.

Whilst waiting for the first contact to dry we turned on the HeNe laser and first bit of good news is we see the two HeNe beams expect to see (see pic two beams). Maybe a little low though (hard to say exactly).  So then pulled the FC again using the top gun (see pic peeling first contact). Looking with a flashlight there is more of the alignment layer left behind. Basically where the alignment layer met the thicker layer in a semi circle from around the 1pm position to the 5pm position. Shouldn't be in the beam path though....and again because first contacting optics again before close out should be able to get it then. I then climbed back out of chamber and unlocked first the optic of SR3 and then the ISI.

Okay so now we thought...great thats all the problems. Lets start aligning. Be done in an hour.

HAM4

Aidan stepped up to HAM4 and it immediately was...umm guys we have a problem. The baffle doesn't line up with the beam path between two mirrors. And he was right (see pic baffle mirror out of place). The red line I have drawn shows where the beam roughly goes and that should be going through the center of the baffle. A quick check of the SYS drawings and yep everything is where it should be as per that...so somewhere along the line must of been a miscommunication.

We found an added suprise of a loose SEI rectangular mass sitting in the tube near the HAM4 ISI. Its wrapped in foil and sitting outside the chamber near the North HAM4 door at the moment

Okay so no big deal. We move a baffle or a mirror (or both) and then the ISI gets rebalanced at some stage....we can still get this done tonight.

SR3 pitch

Okay so the beams bouncing off SR3 but we cant find it. So I climb back into SR2 and eventually find the beams coming back towards SR2. Unfortunately the beam looks like its 4-5 inches to low from going through the center of the baffle (see pic front reflection low). Heintze the others say..you looking at the wrong beam. No I say thats it as the back reflected beam is even lower (see pic front and back reflection). I have tried to take a better picture of just how low it is compared to where it should be (see pic beam and where it should be). It should be going through the centre of the baffle and thats 4 or 5 inches low.

So we tried pitching the optic using the BOSEMs. First off there was some queries as if the calibration is right. Can someone please quickly look at that. Then we seemed to run out of BOSEM range at around 5000 counts I think Jason said....with the beam still 1-2 inches to low on the SR2 optic. We thought maybe the suspension was grounding out on the EQ stops and I had a look and yes some of the optic ones were touching, but even after I backed them off we are still to low.

And so thats where we called it quits...without having even really officially starting the HWS alignment but having spent 6 hours on it (I do still have the south side of HAM5 ISI still locked). Jason had a look at his IAS numbers and will add a comment to this alog. So I guess we have a meeting of the minds to decide how to proceed from here.

SO much for "this will only take an hour or two"....lol. You just have to laugh in these situations............

I made some needed cable moves on one of the switches in the MSR, which had the unfortunate side effect of killing some of the processes on some of the machines...

So the following processes/services were restarted:

- The EPICS alarm e-mail/text alerter.
- The MEDM web screenshots on script0.
- The weather station, video mux control and FMCS readout on h0epics2.

Hopefully that's everything.

The temporary RGA setup used for the accumulation testing of the Y2 BT module was decoupled from the Y2-1 gauge pair port -> The nominal 1.5" O-ring valve which had been removed was reinstalled and the "dead space" between the two 1.5" valves was pumped out -> The Y2-1 gauge pairs and associated hardware are in their normal configuration and pressures/alarms indicated by PT246A and PT246B legitimate -> The RGA setup will now be move to the X-mid in preparation for X2 accumulation testing

The O-ring pairs which seal the septum plate to HAM5 and to HAM6 have passed leak testing -> Leak testing was done with HAM5 and HAM6 vented and their North and South doors removed (effectively) -> The annulus pump ports to these removed doors were plugged with No. 0? 1? rubber bungs (stoppers) which allowed the annulus volume comprised of the HAM6 East door, Septum plate and HAM5-Spool flange and connecting piping to be pumped out with the LD -> Helium was sprayed around the outer septum O-rings with no response -> The ultimate test was the demonstration that the HAM5 annulus ion pump (unassisted) was able to overcome the total gas load of this configuration -> ion current starting out at ~10mA continually decreased to 3mA over the course of two weeks 

9:00 MattH, PeterK, RickS to HAM2 for ISS work 
9:00 Fil to EY
10:00 JimB to EY to ts SUS computer and install HWS computer, back at 11:00
10:00 Aidan and TVo to EY, transitioning to laser hazard
12:45 Karen to My back 14:15
13:00 Betsy, MattH, JasonO, TVo to beer garden to remove laser dams
13:15 Aidan, JasonO to HAM4 for HWS
13:30 Justin to EX, EY
13:30 Fred R & Guest to LVEA
13:45 JeffB Andres to LVEA, EX for clean room survey
14:30 Kyle to MY working on gate valve
15:00 Apollo pulling door on HAM5

Matt H, Rick S, Peter K

This will be a quick summary alog which hopefully Rick or Peter may expand upon (correct my mistakes)

The ISS array work is mostly done now (I know I said that yesterday as well). Yesterday we had the array aligned so that there was readouts on all 8 photodiodes (couldn't see a QPD signal though). Unfortunately because the steering mirrors are either side of the lenses, this meant that the beam was not going through the center of the lenses anymore...and in fact was probably half way between the center and the edge of the lens. After some discussion we decided to see today if we could get it better. So we put the beam back going through the center of the lenses (by adjusting back the beamsplitter before the lenses), and then by a combination of adjusting the last mirror before the ISS array to center the beam on an aperture we put in the input aperture of the ISS array (confusing I know) , and twisting the ISS array itself to get the beam onto the photodiodes, we were able to get as good DC readouts on the photodiodes as yesterday (around 50mV each photodiode for 200mW PSL power),

How do we get DC readouts for the photodiodes you may ask. Well (hopefully I get this explanation right)  we took the lid off one of the in-air amplifiers and using clip leads to pick off the signal before the whitening etc..which is also done on the board (thus enabling us to have a higher gain) we were able to see a signal. We simply altered the ISS array until we got a maximum signal.

One thing of note is that either the top bank or the bottom bank set of photodiodes reads slightly different to the other bank (I cant remember which way around it is). One bank has max DC levels of 45-50mV the other bank of diodes 50-55mV. Should simply be a case of ever so slight misalignment that should correct with picomotors once all hooked up.

Rick also had an idea on seeing something on the QPD's. He proposed the following to Rich A:

I wonder if we can increase the QPD gain from 1e3 to 1e5.

Here is my logic:

We get about 250 mW on the ISS array for 200 W into the mode cleaner, let’s call it 200 mW for 200 W for simplicity.

Yesterday we were running with 200 mW (rather than 200 W) and for the near future the most power we plan to use is 20 W.

200 mW into the MC -> 200 microW onto the PD array

200 microW /2 (for the upper and lower bank) /100 for the 1% transmission of the upper HR mirror -> 1 microW onto the QPD

250 nW onto each quadrant of the QPD, with 1 k ohm transimpedance -> 250 microW, which explains why we didn’t see anything on the QPD signals.

With 100 k ohm transimpedance we would have had 25 mW per quadrant yesterday.  This would give 2.5 V/quadrant with 20 W.

The decision was made to change the resistors (Rick/Rich will have to say from what to what and on what board), but after this was done we actually saw counts on each segment. Something that I don't understand was making there seem to be some gain somewhere adjusting the levels from a couple hundred counts to 1x10^9 so we didn't see anything on the QPD screen until we put in a gain of 1x10-9 and then we see a signal mostly centered on the QPD (its jumping around a but due to the purge air buffeting the optics slightly). So some troubleshooting still needs to be done, but we see something.

Lid was placed on, but when I was putting the baffles back in place, I ever so slightly brushed the cables, and four of the connectors fell off. Luckily we could get them back on correctly and we checked that they photodiodes were all still reading out, but I think we really need some kind of strain relief on these cables, as there is nothing to stop them potentially popping off at anytime...maybe even under vacuum.

Also it appears that the photodiodes sense the halogen lights when we have them turned on or off. This is actually a blessing as I strongly suggest that after done all the cleaning, etc in chamber, before put on the doors, you put the halogen lights on and see if still get a readout from all 8 photodiodes.

(Sorry no pics)

To support the OutputFaraday Isolator Suspension (OFIS), I created a new Mathematica single pendulum model with two blades but four wires (as opposed to two for HAUX/HTTS). It lives in the SUS SVN at

^/trunk/Common/MathematicaModels/FourWireSimpleBlades

I exported Matlab matrix elements symbexport1blades4wiresfull.m from the Mathematica, copied them to the Matlab single model at

^/trunk/MatlabTools/SingleModel_Production

and adjusted the ssmake1MB.m file to use them when the new parameters pend.dx1 and pend.dx2 are defined. These represent the double-sided wire attachment point separations in the Mathematica x direction (normal to the line between the blade tips).

Because the OFIS is TMTS-style with the optic axis of the payload at right angles to the superstructure compared to most other suspensions, I created a new define_ofisModel_insandouts.m file which mapped MEDM-style L/T/V/R/P/Y to Mathematica y/x/z/pitch/roll/yaw. Note that because of the limitations of the data structure (swaps but no sign changes), I wasn't able to do x->-T, y->L, z->V but had to settle for x->T, y->L, z->V, which is left-handed.

I created a case 20140625OFIS of the Mathematica model using mostly data from D0900623-v8 and D0900136-v5. I chose the blade stiffness to match the measured V mode frequency of 1.509 Hz from LHO alog 11530 and added damping to match the measured L, T and V Q's. I also added a token amount of damping in each angular DOF. The parameters and mode frequencies are summarized at 

https://awiki.ligo-wa.caltech.edu/aLIGO/Suspensions/OpsManual/OFIS/Models/20140625OFIS

The model L and T modes (0.6374 and 0.6306 Hz) are in good agreement with the measured L and T modes (0.6211 and 0.6248 Hz) without any additional tweaks. Unfortunately I didn't do measurements of the angular modes because the damping spec was only about the linear modes. Note the obnoxious R mode at 25.4 Hz.

I exported a Matlab parameter set and copied it to the Matlab directory as ofisopt_damp.m. 

I added a new clause to the switch statement in generate_Single_Model_Production.m to associate the new parameter set with the tag ofisopt_damp. I also added lines to use the new define_ofisModel_insandouts.m when the parameter file name starts with 'ofis', but left them disabled initially.

I adapted plottest.m to do a comparison plot between TFs generated in Matlab (using the standard define_singleModel_insandouts.m), and TF data in FourWireSimpleBlades_20140625OFIS_TF.m exported from Mathematica. After some debugging I got perfect agreement.

In the process of debugging I realized that the damping parameter names being exported from Mathematica (e.g., pend.bx0) didn't match what the Matlab was expecting (e.g., pend.B0xx), so I changed the Matlab to match the Mathematica. I also adjusted the handcrafted (not exported) hauxopt_damp.m and httsopt_damp.m that I'd created previously.

Finally I enabled the code in generate_Single_Model_Production.m to select define_ofisModel_insandouts.m. The rewiring was copied from TMTS and is probably right but I can't think of a good additional test because the OFIS has no sensors or actuators so we can't do measured TFs to compare.

Everything has been committed to the SVN.

While HWS was starting their work in HAM4, they discovered that they needed the FirstContact removed from the SR2 and SR3 optics.  After bantering about possible other work arounds or schedule rearrangements, we decide we needed the access to HAM5 immediately.  (The major schedule contributor being that many people, Apollo included, are not here the rest of the week and HWS crew leaves at the end of the week.)  So, Bubba is pulling the crew together to get the door off and we're collecting FC removal tools.