Mark B. Arnaud P

After Betsy realized the range of the ALIGNMENT OFFSET slider was much greater than the real actuation range (see alog entry 5852), we decided to change the max and min values of the slider for all the suspensions. For now only HSTS and HLTS medm screens have been modified. BSFM and ETM/ITM will be done after verification of the actual range.
The actuation range is limited by the DAC ouptut (2^18/2=131072), which can be transposed in urad for Pitch and Yaw. The chosen numbers can be found in the following documents (HLTS and HSTS), in the spreadsheet page 3.

https://dcc.ligo.org/DocDB/0100/T1300083/001/T1300083-v1.pdf
https://dcc.ligo.org/DocDB/0100/T1300079/001/T1300079-v1.pdf

Now the sliders go from +/- 4195 for HSTS Pitch, +/- 7828 for HSTS Yaw, +/-4409 for HLTS Pitch, and +/- 1708  for HLTS Yaw (see pictures attached)

Technical details

In order to do that :

Created two adl files in /opt/rtcds/userapps/release/sus/common/medm/hxts
SUS_CUST_HSTS_M1_OPTICALIGN.adl
SUS_CUST_HLTS_M1_OPTICALIGN.adl
copied from
SUS_CUST_HXTS_M1_OPTICALIGN.adl

opened
SUS_CUST_${HLTS/HSTS}_OVERVIEW.adl in edit mode with medm
changed the name of the argument calling the adl file from SUS_CUST_HXTS_M1_OPTICALIGN.adl to SUS_CUST_${HLTS/HSTS}_M1_OPTICALIGN.adl

opened
SUS_CUST_${HLTS/HSTS}_M1_OPTICALIGN.adl with medm

changed the range
for HLTS  
from +/-12300 urads to +/-4409 urads for PITCH
from +/-12300 urads to +/-1708 urads for YAW   

for HSTS
from +/-12300 urads to +/-4195 urads for PITCH
from +/-12300 urads to +/-7828 urads for YAW  

Modified the label above the gain from :
[DAC Counts (in EULER Basis)] into [Counts (in EULER Basis)]

svn added and commited the new and modified files in the following folder : /opt/rtcds/userapps/release/sus/common/medm/hxts

Here are the Tfs and Spectra Test results for I1-MC3.

Betsy noticed that the BS screen was in a bad state, with gains and offsets and matrix values not filled in, despite the fact that I'd done setup on it back on 2/18 (alog 5440). It turns out it was because although I'd created 

/opt/rtcds/userapps/release/sus/h1/burtfiles/h1susbs_safe.snap

there was no symbolic link

/opt/rtcds/lho/h1/target/h1susbs/h1susbsepics/burt/safe.snap 

pointing to it. So after the various restarts between now and then it was not getting correctly restored. I created the link and checked that the correct settings were loaded when I restarted the model.

Michael V., Nichole W., Scott S., Gerardo M., Jodi F., Jim W.

Both suspensions for the ITM Elliptical baffles were installed succesfully.  Both baffle "boxes" are not installed, but they are being stored insided the beam tube for now, they can be installed at a later time.  We still need to remove a couple of loose pieces of equipment from inside chamber, such as a "table" and a "lifting" jig, they will be removed some time today.

Big thanks to the Apollo crew for their help (Scott, Chris, and Mark).

Max, Sheila

We went out to the Y end and first tweaked the alignment of the beam from the fiber using a fiber laser (there is such a small amount of light coming from the PSL fiber that it is difficult to see.)  We saw a beat note easily once we had all of the cables connected correctly.  We checked that this signal gets all the way to the timing comparator, (frequency counter?) and we saw that the other input to the timing comparator is at 79.2 MHz.  However, the beckhoff channel for the beat note frequency is always 0.  

We moved on to locking, we were able to lock (using only the PZT, no temperature control) with the laser current at 1.737 and the temperature at 31.45, with a common gain of -22dB and fast gain of -4 (giving a ugf of 3.5kHz).  The OLG measured with these settings is attached, I was able to turn the gain up a bit (ugf around 10 kHz) but the lock was not very stable there.  

The next steps are to turn on the temperature control and get the frequency counter working again.  

Kiwamu, Keita, Filiberto, Rich

Finished installation of all RFPD cabling inside ISCT1.  Received LSC diode by Fedex from Caltech.  Ran through same procedure as Lisa and Matt did when they verified the calibration of the MC length diode in log entry 5277.

Data Taken on LSC-REFL-AIR-A RFPD

System Constants:
LSC Detector Serial Number - S1203919
LSC Detector Frequencies - 9 MHz and 45 MHz
LSC Detector RF Transimpedance - 341 ohms at 45 MHz
LSC Detector DC Transimpedance - 100 ohms at BNC Jack on detector body
LSC Detector Photodiode Responsivity at 980nm - 0.67 A/W
Laser Calibrator Head Serial Number - S1300150
Calibrator Output Power - 4mW at 980nm
Calibrator Head Gain - 13 mW/V (From Lisa and Matt)

Measured Parameters:
RF drive amplitude into calibrator head - 0.1Vp-p at 45.497379MHz
DC Output of RFPD Head (at BNC) - 0.165 VDC
Measured Counts of RFPD DC - 538 Counts (consistent with DC output of head and factor of two differential gain).
I and Q beat note counts - 3400 Counts p-p
Measured RF input to demodulator - 180 mV p-p at 45... MHz

Calculated Parameters:

Responsivity = 538 counts/(1638 counts/V * 200 V/A *4e-3 W) = 0.41 A/W (0.37 A/W by Lisa and Matt)

Expected RF to Demodulator = 341 V/A * 0.41 A/W * 0.013 W/V * 0.1 Vp-p = 182 mVp-p (180 mV measured)

Check of Laser Calibrator Head against LSC RFPD measured parameters:

(This calculation must correct for the amount of light that doesn't hit the RFPD diode.  This is seen in the last calculation:)

Calibrator head gain = 0.180 Vp-p / (0.67A/W * 341 V/A * 0.1 Vp-p)  = 7.9 mW/V

The incident power and observed DC photocurrent requires following correction factor:
4mW * 0.67 A/W * 100 V/A = 268 mVDC vs the actual measured 165 mVDC, therefore the correction factor of 268/165 is applied
Calibrator head gain (corrected for light spillage) = 7.9 mW/V * 268/165 = 12.8 mW/V (vs. 13 mW/V from Lisa and Matt)


Conclusion is that the LSC REFL-AIR-A RFPD and calibrator head seem to be functional within reasonable levels and is in agreement with the measurements taken by Matt and Lisa.

The BSC5 dome leak repair effort worked (unaided annulus ion pump in equilibrium @ 8 LEDs with X-end vented) 

John W. started roughing the X-end earlier today -> I closed the safety valve then the 10" valve @1615 -> will resume pumping tomorrow

For the record, this afternoon, Travis aligned the lower stage AOSEMs of the PR2 now that it is aligned.  He also cleaned out tools from the chamber.  I spent some time cleaning with isopropanol and contec wipes some of the horizontal surfaces from the south end of the chamber, namely the ISI table and the floor and bellows near the cat-eye baffle. 

Are all working,I tested with an out of vacuum picomotor plugged into the connectors on the front of the controller, combined with the test done in vacuum with the hardware tester it seems like everything is working.  

One problem was that in the system manager here, we had the 8 bits of PICOIn.MOTOR_X and Y connected as bytes in the system manager, while they need to be individually connected as bits. 

I also added a message that appears for 2 seconds when someone tries to drive a motor but the step size is 0.  

Sheila

Michael V., Nichole W., Scott S., Gerardo M.

Both H1-ITM elliptical baffles were assembled, suspended and balanced under the test stand, tomorrow we will continue with the preparations for their installation.

Attached are plots of dust counts > .3 microns and > .5 microns in particles per cubic foot requested from 5 PM March 19 to 5 PM March 20. Also attached are plots of the modes to show when they were running/acquiring data.

Data was taken from h1nds1.
T0=13-03-20-00-00-00; Length=86400 (s)
1440.0 minutes of trend displayed

Kiwamu, Aaron, Rich. A

Installed and tested RF cabling for LSC and ASC detectors on ISCT1 (LSC-POP-AIR-A, LSC-REFL-AIR-A, ASC-REFL-AIR-A, ASC-REFL-AIR B).   All cables are ~41 feet long LMR-195 type cable from the ISC racks to the outer wall of ISCT1. 

The RF loss from the RF patch panels in ISC-R2, to the outer wall of ISCT1 is 0.6 dB at 9MHz, and 1.2dB at 45MHz.  All cables tested are +/-0.1dB of these numbers.

In preparation for installation of the in-air and in-vacuum RFPDs on ISCT1 and HAM1, we tested every signal chain (ASC and LSC, air and vacuum) by injecting a 0dBm RF signal offset 0.5 Hz from each respective modulation frequency and viewing the beat note in Data Viewer and on a scope locally at the front panel monitors of the I/Q demodulator chassis.  The goal of this was not to accurately calibrate each signal chain (this happens once the respective detectors are in place), but to verify proper plumbing and get a sense of the overall consistency in signal detection.  The results are remarkably good, in that all RF gains from demodulator inputs to Data Viewer output were within our measurement certainty of ~+/-5% or so.

Here's a sense for what you can expect for an RF injection directly at the input of the I/Q demodulator at 0.5 Hz offset from the modulation frequency:

Input RF Test Signal Amplitude = 0dBm +0dB, -0.5dB
Beat Note Frequency = ~0.5 Hz
I/Q Demodulator Front Panel Monitor Amplitude = ~3.45 V pk-pk
Data Viewer Amplitude = +/- 5500 counts pk-pk

The data taken on the LSC-REFL-AIR-B-135MHz signal showed more like +/-5000 counts pk-pk, and a Front Panel I/Q Demodulator Monitor amplitude of 3.5 V pk-pk, but because we didn't have a function generator that went up that high in frequency on hand, we used the RF network analyzer as the signal input.  The signal amplitude uncertainty could easily account for some of the difference in demodulating the 135 MHz signal.

Tomorrow we are expecting a 9 and 45 MHz LSC style detector to be delivered.  This will be placed on ISCT1 as the LSC-REFL-AIR-A detector and the light to counts transfer function will be measured.  The plan is to create a simple written guide to this type of measurement such that calibration and recalibration is easy for anyone to do.  We will use the dedicated ISC RFPD calibration light source to inject a signal.

While we were at it, I measured how much slider range it took to move the beams on various optics.

Using the PR3 pitch bias slider, we moved the IAS beam 81mm at the PR2 optic.  The PR2 and PR3 are separated by 16.16m (so says T0900043, optical layout numbers for aLIGO).  Since this is an optical lever type measurement, 2*theta = 81mm/16.16m = 5mRad, theta = 2.5mRad.  The slider amount used to move the beam the 81mm was 2000uRad (units as advertized on the medm) = 2.0mRad.  So, comparable numbers.

PR3 yaw:  2*theta = 54mm/16.16m = 3.3mRad, theta = 1.65mRad, while the slider says that we had moved 1500uRad = 1.5mRad.

Similarly for PR2, looking at the beam down on PRM:

PITCH

2*theta = 60mm/16.61m = 3.61mRad, theta = 1.8mRad

Slider says we moved 1550uRad = 1.550mRad

YAW

2*theta = 150mm/16.61m = 9mRad, theta = 4.5mRad

Slider says we moved 4000uRad = 4.0mRad

Again, the slider was roughly in agreement with what we saw.  However, we did encounter 2 other oddities:

1) It seems strange that the IAS direct alignment of PR3 advertised that we had aligned the PR3 in pitch to within +/- 50 uRad.  We had achieved this, yet as recorded above, we used 1.5mRad of slider bias to center on PR2.  Why??

2) We found the bias sliders quit actuating on the PR3 optic in PITCH at ~4500 uRad, and in YAW at ~2000 uRad.  The slider full range is +/-12,300uRad, so I'm not sure what is physically stopping the slew of the optic at ~4000.  We'll investigate tomorrow, via repeating with others.  Mark B. and Arnaud are also chewing on the original uRad calibration.  The MC optics have alignment biases in some cases near 3000 and 4000 uRad, so I wonder if they have seen this...

With the longitudinal, vertical and horizontal alignments of the PRM and PR3 completed (although no alogs to support this since Jason has 180'ed to LLO again), the PLX was removed from the alignment.  The theodolite was set up on the IFO beam path (BS to PR3) and we retroreflected the beam through the PR optics.  We needed to use some alignment bias:

PR3 bias to center beam on PR2

PITCH = -225

YAW = -85

PR2 bias to center beam on PRM

PITCH = +450

YAW = +350

Finding the Theodolite HeNe beam reflection from PRM back up to PR2 proved extremely difficult however.  After spending a few hours walking the MC beam tube and sorting the who's-who of beams, we finally found it, but it was very faint and blowing up in size.  By the time it reached the IO baffle in the beam tube just a few feet away, it was ~3 inches in size.  I could not trace the beam back down the tube, even while walking it down with a laminated target.  We will need a different means of optical alignment to complete the PRM alignment.

Note, it would have been helpful for IAS to have a set of beam height targets, like we did for iLIGO.  I have not been fond of holding rulers up near the fronts of suspensions with naked optics inches (or less) away!  Please pursue this for the SR alignment.  I believe IO has some iris targets for specific suspensions in their chain - let's copy those...

The issue of the 9 MHz amplifier box [1] was solved. The box is now back in the R2 rack and working fine.
I tested the box at the EE shop and it was very healthy. Then it turned out that the exterior signal cable was flaky even though Rich had replaced its N-connector by a new one yesterday because we had suspected it at the beginning. We swapped the cable with a temporary one and everything worked fine. The temporary cable will be replaced by an LMR cable at some point but we will go with it for now to carry out the demodulation chain and photo-diode calibration tests.

[1] LHO alog 5846 "9 MHz amplifier box pulled out for testing"
 

I, Arnaud and Dave came across a problem which was somewhat confusing at first.

The problem I encountered was that the EPICS channel names for user model DAC output of TMSY, e.g. H1:FEC-99_DAC_OUTPUT_2_4 and such, were not working (in this channel name, 99 is the front end code number which you can find in the model, 2 is meant to show the DAC number and 4 shows the channel number) which made watchdog-related part of some medm screens white.

In this specific case TMSY uses two DAC cards, DAC2 and DAC3.

Dave pointed out that in the user model the DAC cards are logically addressed starting from 0 no matter what, so in our case H1:FEC-99_DAC_OUTPUT_2_4 and such should be addressed as H1:FEC-99_DAC_OUTPUT_0_4 and such. Simple once Dave explained this to me.

In IO model (which has all physical DAC) the corresponding channel is addressed as  H1:FEC-97_DAC_OUTPUT_2_4, here the logical and physical card number are the same. Simple again.

Complication was that the TMSY medm screen used to only accept one addressing that is used common for both the user model and the IO model channel names for the macro substitution, i.e.

chan="$(IFO):FEC-$(FEC)_DAC_OUTPUT_$(TF1)"

chan="$(IFO):FEC-$(IOPFEC)_DAC_OUTPUT_$(TF1)"

were used for the user model and io model channel names, and $(TF1) carries something like "2_4", so either the io model channel name was correct but the user model was not, or vice versa. And there were also $(TF2), $(TF3), $(LF), $(RT), $(SD) or something like that.

AS a dirty solution, I made another set of DAC card_channel macro for user model, i.e. $(UTF1), $(UTF2) etc. such that

chan="$(IFO):FEC-$(FEC)_DAC_OUTPUT_$(UTF1)"

etc. are used for user model outputs and

chan="$(IFO):FEC-$(IOPFEC)_DAC_OUTPUT_$(TF1)"

etc. are used for the io model outputs. This is ugly, maybe it makes more sense to use $(TF1) and such for the channel number, $(UDAC0) etc. for the DAC card number in the user model, and $(IDAC0) etc. for the DAC card number in the io model, such that you use

chan="$(IFO):FEC-$(FEC)_DAC_OUTPUT_$(UDAC0)_$(TF1)"

chan="$(IFO):FEC-$(IOPFEC)_DAC_OUTPUT_$(IDAC0)_$(TF1)".

Anyway, I did the ugly and quick change, made the necessary change to the site map and the OAT medm screen and committed them to the svn.

Thing is, there are other instances where the first DAC in the user model is not the first physical DAC card (e.g. BS), and I didn't do anything, I expect that SUS people will decide what is the better way of doing things, modify the MEDM for everything (including TMSY if necessary), and propagate it back to LLO.

   We took TFs and Power Spectra data for HSTS I1-MC1. All files have been committed to the SVN repository.  The data files are attached below for review by Stuart A. and Jeff K.