Gerardo, Betsy, Norna

This morning, after consulting Margot (who had just performed this procedure at LLO with the crew on their ITMy), we removed the CP from the ITMy suspension and removed the pyrolux/flexi-curcuit ESD connections from it's 12 o'clock position.  We used the ergo arm to retrieve the optic from the ITMy sus still mounted to the BSC1 ISI on the test stand.  We then moved the CP to a v-block on a small mobile optics table.  Using a CLASS A razor blade we slowly peeled the flexicurcuit off of the pyralux "glue layer" and then worked that layer off in the same fashion.  We then rotated the CP 180deg, while still on the ergo arm, and stuffed it back into the suspension.  By eye, the mass seemed to hang with minimal pitch/yaw/position error after rehanging the mass in the reaction chain.  Back to IAS and testing now...

I am testing a modified version of the code described here to address the problem listed here. The work permit is number 3531.

I recently made a new set of isolation filters level 2 for HAM3-ISI. 

1- I tried them with the new Step_8_Performance_Analysis commissioning script. Spectra are attached*. The blend filters used are the new 250mHz blend filters **. There are some discrepancies between the expected isolation and the measurement. This is especially noticeable along Z. I am not sure why yet.

2 - I also tried the same configuration with the new 100mHz blend** engaged on X and Y. I compared the spectra measured then, with the ones measured earlier this week. Isolation loops show good performance. There is some amplification of motion between 10Hz and 50Hz. This is mainly noticeable along X.

* .pdf created with a new matlab script. I am still perfecting. I should be able to add it to Step_8 soon.
** svn revision 6187

Cheryl, Rodica

Yesterday we measured isolation and transmission of the H1 Faraday isolator with the 4 mm thick DKDP installed. In the first run we measured while ramping up the power to ~140 W and optimizing the HWP and DKDP, the secon set was measured 3 hours later after the system cooled down slightly but without any additional optimization, and the third set was measured immediatelly after the second run, while ramping the power down.

Transmission is ~97%, forward extinction is ~ 25 dB and isolation stays above 25 dB at maximum power. Graphs are attached. The isolation is limited by the amount of stray light from ghost beams from the FI crystals that are dirrected toward the same power meter. 

Two viewports were fully installed on the south door of HAM01,  BF1 (ISC beam) and BF2 (PSL input).  The viewports are currently covered with viewport protectors.

Attached are plots are dust counts > .3 microns and > .5 microns in particles per cubic foot. Also attached are plots of the modes of the dust monitors to show when they were running. The data was taken from approximately 6 AM to 6 PM.

All control room TV displays are now configured to be used with h1.

I encountered some problems yesterday in moving the Beckhoff system at end Y from H2 to H1. The links were lost when I did a global search and replace in the PLC code to change H2 to H1. It is now running with H1 EPICS channel names, but as a temporary hack. The internal variables are still running as H2, I just changed the names to H1 in the EPICS database records. I will try doing a more selective search and replace and see if the links are still lost.

I also had to remove ONAM and ZNAM fields from a long record type. This will have to be fixed in the Beckhoff code, I believe in one of the libraries.

I copied/pasted/renamed the filters files used by the HEPI and the ISI at EY from H2 to H1. ISI currently is damped and HEPI is controlled.

I copied/pasted/renamed the filters files used by the TMS and the QUAD at EY from H2 to H1. The two systems are now damped. Coil driver analog whitening filters are turned ON (State 2) and FM2s of COILOUTF of the TMS are disengaged.

In the modified code I set it to ignore a dust monitor once it encounters an error with it. This was to avoid slowing down the loop waiting to read disconnected dust monitors. It appears that it is encountering these types of errors at random. So dust monitors are being set to invalid and then being ignored after momentary errors. I'm not yet sure the best way to address this. In the mean time, if a dust monitor goes invalid at random, you can bring up the expert screen for it and hit start. This should start it running again.

Cheryl, Rodica

Over the past days we worked on trying to improve thermal lensing in the Faraday isolator by swapping the 3 mm thick DKDP crystal that slightly undercompensated (and also has much poor surface quality) with a 4 mm thick crystal. With the 4 mm crystal we measured the beam profile and estimated a focal length f=-43 m, which determines >98% mode matching. However, the beam quality starts getting altered at powers above ~50 W, and we could assign this to higher oreder modes introduced by phase distortion after a thicker DKDP. The pictures attached show the beam profile and intensity map at ~140 W. For the estimation of the focal length we only used the data from the less distorted axis (y-profile).

We have available 3.5 mm thickness for DKDP which we are planing to measure this afternoon. Meantime, we are finishing the isolation measurements for the FI with the 4 mm thick DKDP crystal. We needed to redo the alignment for the isolation beam and redump ghost beams, which changed after modifying the alignment on the IO path, now with the EOM out of the beam.

Today is day 2 of the EY conversion from H2 to H1. We are pretty much done, just a few mopping up tasks remain.

I redesigned the IOP SUS watchdog screens now that H1 has more of them, making the default screen an overview and creating a separate detailed screen per Seismic system which can be disabled by its attached SUS systems. So for example SEIH23 gets a screen, as does ETMY.

I tested the IOP watchdog at EY, and then Vern and Jim went out to EY just after lunch time and energized the EY coil drivers and removed their tags.

Jim booted the Hartmann Wavefront Sensor slow controls computer and renamed it h1hwsey giving it its new IP address. We are working with Aidan on getting the HWS EPICS channels renamed. Jim also relabeled the EY computers with their H1 names.

Jim converted most of the control room workstations to H1, including the main operator station. We are keeping two workstations as H2 machines for LVEA Test Stand work.

The Beckhoff slow controls computer h2ecatey was transitioned to h1ecatey by Patrick (name and IP change). He converted all the Beckhoff EPICS records' names from H2 to H1.

I redesigned the H1 MEDM sitemap to add the EY systems. Some linked screens still need to be converted to H1.

We did not get around to damping the EY optics, so for tonight I have manually tripped the IOP watchdogs to disable the DAC outputs.

At 14:31 local, we powered up the h1lscl0 front end and it mysteriously Dolphin glitched the H1 corner station front ends. All HAM SUS and HEPI systems crashed, but the ISI systems did not. The only systems which were being used at the time were SUS MC2 and PR2. We could not reproduce this error by repeating the power up the lsc front end, so we restarted all the crashed models.

Still to be done:

• Activate the ETMY HEPI, ISI and SUS systems, get the ETMY and TMSY optics damped.
• complete the list of slow channels to be added to H1 DAQ.
• complete the H1 sitemap and remaining medm screens which need to be converted to H1.
• Complete the removal of EY from H2, e.g. sitemap.
• Alarm handlers reconfiguration.

• Axial Position Error: +2.8 mm (North on the test stand)
  • Spec: ±3 mm
• Lateral Position Error: -0.06 mm (East on the test stand)
  • Spec: ±1 mm
• Vertical Position Error: -0.2 mm (low)
  • Spec: ±1 mm
• Pitch: ~78 µrad down (this is with the first contact still on)
  • Target Pitch: Without knowing the mass of the First Contact, we currently have no target pitch (see E1200791 for more info).  Pitch will be adjusted to within the No-First-Contact target of 12.5 µrad up (±160 µrad) when the current layer of First Contact is removed.
• Yaw: ~45 µrad CCW
  • Target Yaw: 0.0 ±160 µrad

Over the past few days, we've been checking the cabling between the IMC electronics on ISC R1 and the EtherCAT CM Chassis.

Note: When I refer to slot numbers, I am using the convention used in D1001460. The racks on the floor are numbered using the opposite convention. After discussing with Filiberto, I have decided to relabel these racks later this week.

The relevant changes are between the VCOs and on the Mode Cleaner Servo.

Cable ISC_28 was attached to 79.4 MHz PSL VCO in slots 23-24, and was moved to its correct location at the 79.4 MHz ALS VCO in slots 32-33. The 79.4 MHz PSL VCO is intended to be attached to cable ISC_2. This cable is the wrong gender and will be changed in the near future. 

The mode cleaner servo had Cable ISC_6 in Controls 1, and Cable ISC_5 in Controls 2. The cable pull table did not make a distinction between Controls 1 and Controls 2 for this cabling. After checking the pinouts and cabling, I determined that cable ISC_5 needed to be in Controls 1, and cable ISC_6 needed to be in Controls 2. I made the change today.

After brewing the Left sliver of the MC3 optic (IMCF06) in acetone for a total of ~22 hours, the problematic prism finally came off.  Today, I followed the coordinates in the gluing doc E1200211 and reglued it back on.

Because it looks (from my remote connection) like data from the H1 SUS PR2 (and H1 SUS MC2, probably more) has frozen, and anticipating a bootfest, I've taken (and svn committed) a new 
${userapps}/sus/h1/burtfiles/pr2/h1suspr2_safe.snap
to absorb all the new features and EPICs values I've been entering in. I've checked, and there is an approriate softlink in 
/opt/rtcds/lho/h1/target/h1suspr2/h1suspr2epics/burt/safe.snap
and checked that it works by changing a few things, and restoring to it.

The file was captured "by hand" using the command

pr2 0$ burtrb -f /opt/rtcds/lho/h1/target/h1suspr2/h1suspr2epics/autoBurt.req > /opt/rtcds/userapps/release/sus/h1/burtfiles/pr2/h1suspr2_safe.snap 

... but if LLO has a script for this, that'd be great to have ...


(and as I was writing this entry, I saw that someone had rebooted H1 SUS PR2. *phew*).

Following a similar prescription as what Keiko's done at LLO (see e.g. LLO aLOG 4030), but now using the new infrastructure, I've installed a few gains,

H1:SUS-PR2_M1_OPTICALIGN_P_GAIN 2.636 [drive cts/urad]
H1:SUS-PR2_M1_OPTICALIGN_Y_GAIN 1.859 [drive cts/urad]

into the new OPTICALIGN bank, which should now be responsible for aligning the optic. With this gain, the offsets

H1:SUS-PR2_M1_OPTICALIGN_P_OFFSET (for Pitch)
H1:SUS-PR2_M1_OPTICALIGN_Y_OFFSET (for Yaw)

are then calibrated into [urad] of optic motion. This gain should be [applicable to / the same for] every HSTS.

I attach some shots of the new screens demonstrating where these gains live (and showing off the new screens).

-----------------------------
How the gain was calculated:
It's along signal chain, but here goes (I use Yaw on an HSTS as an example):
                                            
                                                                 LF  +--------+  +------+  +-----------+  +-----------+  +---------+  
                                                                  +->|COILOUTF|->| DAC  |->|Coil Driver|->|Coil/Magnet|->|Lever Arm|->+
+-----------------+  +---------------+  +----------+  +--------+  |  +[cts/ct]+  +[V/ct]+  +---[A/V]---+  +---[N/A]---+  +---[m]---+  |  +-------------+   +------------------+           
|OPTICALIGN OFFSET|->|OPTICALIGN GAIN|->|DRIVEALIGN|->|EUL2OSEM|->+                                                                   +->|HSTS M1 to M3|-->|Optic Displacement|
+-----[urad]------+  +---[cts/urad]--+  +-[cts/ct]-+  +[cts/ct]+  |  +--------+  +------+  +-----------+  +-----------+  +---------+  |  +--[rad/N.m]--+   +------[urad]------+
                                                                  +->|COILOUTF|->| DAC  |->|Coil Driver|->|Coil/Magnet|->|Lever Arm|->+
                                                                 RT  +[cts/ct]+  +[V/ct]+  +---[A/V]---+  +---[N/A]---+  +---[m]---+

(see fullsignalchain.png if you browser sucks at ASCII art)
Thankfully, because 
- we're only looking for the DC gain of this path, 
- the DRIVEALIGN matrix is an identity at this point
- the EUL2OSEM matrix accounts for (divides out) the number of actuators (two in this case) and the lever arm between the OSEM and the center of rotation
- the COILOUTFs are unity at DC
then our calculation only involves this simplified chain:

+-----------------+  +---------------+  +------+  +-----------+  +-----------+  +-------------+   +------------------+
|OPTICALIGN OFFSET|->|OPTICALIGN GAIN|->| DAC  |--|Coil Driver|--|Coil/Magnet|->|HSTS M1 to M3|-->|Optic Displacement|
+-----[urad]------+  +---[cts/urad]--+  +[V/ct]+  +---[A/V]---+  +-["N.m"/A]-+  +--[rad/N.m]--+   +------[urad]------+

(see reducedsignalchain.png if you browser sucks at ASCII art)
which means the OPTICALIGN GAIN is:

OPTICALIGN GAIN [cts/urad] = ( DAC [V/ct] * Coil Driver [A/V] * Coil/Magnet [N/A] * HSTS M1 to M3 [rad/N.m] * 1e6 [urad/rad] )^-1
                           = ( (20/2^18)  * 0.011919          * 0.963             * 0.4332 (for Yaw)        * 1e6            )^-1
                           = 1.850 [cts/urad]

The only difference for pitch is that HSTS M1 to M3 [rad/N.m] = 0.6172 (for Pitch). The electronics gains of the signal chain were taken from T1000061 (the contents of which have been experimentally confirmed elsewhere), and the HSTS M1 to M3 coefficients were taken from the production model (e.g. see T1200404).