Shift Summary - Evening Transition

Cavity pole tracker, now available in CAL CS

Related alog: 27349

I have coarsely adjusted the demodulation phases for the 331.9 Hz calibration line in CAL CS. Now the CAL CS model returns a live cavity pole value in unit of Hz. The first attachment shows the current filter settings. The second attachment shows where to look for getting the live cavity pole value. This screen is linked from CAL_CS_OVERVIEW.adl; clicking a pink box in the upper left takes you to the screen shown in the second attachment. I have adjusted the demod phase of the Pcal line to get the cavity pole between 340 and 360 Hz. Also, I set the demod phase of the DARM error demodulation to 180 deg so that the imaginary part of  the calculation is negative. We still need to do a careful measurement of the cavity pole with the usual swept sine to make the live value more accurate, but for now this should be good enough for commissioning purpose. I believe that the current accuracy of the live cavity pole frequency is about 10%.

Additionally, I have bumped up the excitation amplitude of the 331.9 Hz Pcal line by approximately a factor of 10 for obtaining a high SNR. I will leave the excitation amplitude as it is.

.3micron Dust alarm at EY

At 05:04UTC

Manually over-filled CP3 at 23:15 utc

LLCV bypass valve 1/2 turn open, and the exhaust bypass valve fully open.

Flow was noted after 85 seconds, closed LLCV valve, and 3 minutes later the exhaust bypass valve was closed.

Shift Summary - Evening Transition

CO2Y alignment not correct - wrong pico motor mirror used

Summary:

We discovered today that the CO2Y alignment on the table and to the test mass is not correct. It turns out that when we were actuating on the picomotor mirrors on TCSY back in February (aLOG 25353), we ended up moving one of the mirrors before the rotation stage on the table, not the top periscope mirror (despite the labeling in EPICS).

This was determined by reviewing the CO2Y QPD channels and confirming that the position of the beam on the QPDs moved at the same time we actuated on the PICO_G MOTOR 3.

We are working to resolve this alignment issue and further improve the alignment to the test mass (should be feasible with the Hartmann sensor now).

CO2 laser QPD DC offsets

During the laser shutdowns last night, we acquire the background values for the CO2 laser QPDs.

 

	X (counts)	Y (counts)
QPD_A_SEG1	171	-17.7
QPD_A_SEG2	-74.3	22.8
QPD_A_SEG3	-131.3	451.5
QPD_A_SEG4	419.5	-446.9
QPD_B_SEG1	-150.2	-53.95
QPD_B_SEG2	854	-238.1
QPD_B_SEG3	197.1	366.9
QPD_B_SEG4	181.7	68.4

 

The following adjustments were made to CO2 QPD EPICS channels to enter (and activate) the offsets and to add in the correct coefficients in the  PIT/YAW/SUM summing matrices

caput H1:TCS-ITMX_CO2_QPD_A_SEG1_OFFSET -171

caput H1:TCS-ITMY_CO2_QPD_A_SEG1_OFFSET 17.7

caput H1:TCS-ITMX_CO2_QPD_A_SEG2_OFFSET 74.3

caput H1:TCS-ITMY_CO2_QPD_A_SEG2_OFFSET -22.8

caput H1:TCS-ITMX_CO2_QPD_A_SEG3_OFFSET 131.3

caput H1:TCS-ITMY_CO2_QPD_A_SEG3_OFFSET -451.5

caput H1:TCS-ITMX_CO2_QPD_A_SEG4_OFFSET -419.5

caput H1:TCS-ITMY_CO2_QPD_A_SEG4_OFFSET 446.9

caput H1:TCS-ITMX_CO2_QPD_B_SEG1_OFFSET 150.2

caput H1:TCS-ITMY_CO2_QPD_B_SEG1_OFFSET 53.95

caput H1:TCS-ITMX_CO2_QPD_B_SEG2_OFFSET -854

caput H1:TCS-ITMY_CO2_QPD_B_SEG2_OFFSET 238.1

caput H1:TCS-ITMX_CO2_QPD_B_SEG3_OFFSET -197.1

caput H1:TCS-ITMY_CO2_QPD_B_SEG3_OFFSET -366.9

caput H1:TCS-ITMX_CO2_QPD_B_SEG4_OFFSET -181.7

caput H1:TCS-ITMY_CO2_QPD_B_SEG4_OFFSET -68.4

 

caput H1:TCS-ITMY_CO2_QPD_A_SEG1_SW1 8

caput H1:TCS-ITMY_CO2_QPD_A_SEG2_SW1 8

caput H1:TCS-ITMY_CO2_QPD_A_SEG3_SW1 8

caput H1:TCS-ITMY_CO2_QPD_A_SEG4_SW1 8

caput H1:TCS-ITMY_CO2_QPD_B_SEG1_SW1 8

caput H1:TCS-ITMY_CO2_QPD_B_SEG2_SW1 8

caput H1:TCS-ITMY_CO2_QPD_B_SEG3_SW1 8

caput H1:TCS-ITMY_CO2_QPD_B_SEG4_SW1 8

 

caput H1:TCS-ITMX_CO2_QPD_A_SEG1_SW1 8

caput H1:TCS-ITMX_CO2_QPD_A_SEG2_SW1 8

caput H1:TCS-ITMX_CO2_QPD_A_SEG3_SW1 8

caput H1:TCS-ITMX_CO2_QPD_A_SEG4_SW1 8

caput H1:TCS-ITMX_CO2_QPD_B_SEG1_SW1 8

caput H1:TCS-ITMX_CO2_QPD_B_SEG2_SW1 8

caput H1:TCS-ITMX_CO2_QPD_B_SEG3_SW1 8

caput H1:TCS-ITMX_CO2_QPD_B_SEG4_SW1 8

 

caput H1:TCS-ITMY_CO2_QPD_A_MTRX_3_1 1

caput H1:TCS-ITMY_CO2_QPD_A_MTRX_3_2 1

caput H1:TCS-ITMY_CO2_QPD_A_MTRX_3_3 1

caput H1:TCS-ITMY_CO2_QPD_A_MTRX_3_4 1

caput H1:TCS-ITMY_CO2_QPD_A_MTRX_1_1 1

caput H1:TCS-ITMY_CO2_QPD_A_MTRX_1_2 1

caput H1:TCS-ITMY_CO2_QPD_A_MTRX_1_3 -1

caput H1:TCS-ITMY_CO2_QPD_A_MTRX_1_4 -1

caput H1:TCS-ITMY_CO2_QPD_A_MTRX_2_1 1

caput H1:TCS-ITMY_CO2_QPD_A_MTRX_2_2 -1

caput H1:TCS-ITMY_CO2_QPD_A_MTRX_2_3 -1

caput H1:TCS-ITMY_CO2_QPD_A_MTRX_2_4 1

 

caput H1:TCS-ITMY_CO2_QPD_B_MTRX_3_1 1

caput H1:TCS-ITMY_CO2_QPD_B_MTRX_3_2 1

caput H1:TCS-ITMY_CO2_QPD_B_MTRX_3_3 1

caput H1:TCS-ITMY_CO2_QPD_B_MTRX_3_4 1

caput H1:TCS-ITMY_CO2_QPD_B_MTRX_1_1 1

caput H1:TCS-ITMY_CO2_QPD_B_MTRX_1_2 1

caput H1:TCS-ITMY_CO2_QPD_B_MTRX_1_3 -1

caput H1:TCS-ITMY_CO2_QPD_B_MTRX_1_4 -1

caput H1:TCS-ITMY_CO2_QPD_B_MTRX_2_1 1

caput H1:TCS-ITMY_CO2_QPD_B_MTRX_2_2 -1

caput H1:TCS-ITMY_CO2_QPD_B_MTRX_2_3 -1

caput H1:TCS-ITMY_CO2_QPD_B_MTRX_2_4 1

 

 

caput H1:TCS-ITMX_CO2_QPD_A_MTRX_3_1 1

caput H1:TCS-ITMX_CO2_QPD_A_MTRX_3_2 1

caput H1:TCS-ITMX_CO2_QPD_A_MTRX_3_3 1

caput H1:TCS-ITMX_CO2_QPD_A_MTRX_3_4 1

caput H1:TCS-ITMX_CO2_QPD_A_MTRX_1_1 1

caput H1:TCS-ITMX_CO2_QPD_A_MTRX_1_2 1

caput H1:TCS-ITMX_CO2_QPD_A_MTRX_1_3 -1

caput H1:TCS-ITMX_CO2_QPD_A_MTRX_1_4 -1

caput H1:TCS-ITMX_CO2_QPD_A_MTRX_2_1 1

caput H1:TCS-ITMX_CO2_QPD_A_MTRX_2_2 -1

caput H1:TCS-ITMX_CO2_QPD_A_MTRX_2_3 -1

caput H1:TCS-ITMX_CO2_QPD_A_MTRX_2_4 1

 

caput H1:TCS-ITMX_CO2_QPD_B_MTRX_3_1 1

caput H1:TCS-ITMX_CO2_QPD_B_MTRX_3_2 1

caput H1:TCS-ITMX_CO2_QPD_B_MTRX_3_3 1

caput H1:TCS-ITMX_CO2_QPD_B_MTRX_3_4 1

caput H1:TCS-ITMX_CO2_QPD_B_MTRX_1_1 1

caput H1:TCS-ITMX_CO2_QPD_B_MTRX_1_2 1

caput H1:TCS-ITMX_CO2_QPD_B_MTRX_1_3 -1

caput H1:TCS-ITMX_CO2_QPD_B_MTRX_1_4 -1

caput H1:TCS-ITMX_CO2_QPD_B_MTRX_2_1 1

caput H1:TCS-ITMX_CO2_QPD_B_MTRX_2_2 -1

caput H1:TCS-ITMX_CO2_QPD_B_MTRX_2_3 -1

caput H1:TCS-ITMX_CO2_QPD_B_MTRX_2_4 1

New CW hardware injection actuation under test

Evan G. and I have restarted CW hardware injections, using the
old iLIGO actuation scheme, where the correction for the actuation
function is done directly, frequency by frequency, for each of
the 15 injected pulsars individually, without using a time-domain
inverse actuation filter. That filter is now no longer in the
path between H1:CAL-PINJX_CW and H1:CAL-PINJX_HARDWARE. We have
verified that the new envelope of the H1:CAL-PINJX_HARDWARE channel
is close to what it was before and that the spectral heights of
the injected signals look about the same (we don't expect perfect 
agreement). 

The injections will be left running for at least 24 hours, to verify
that the sidereal-day envelope agrees with what it was before,
within expectation, and that same-sidereal-time spectral snapshots 
agree reasonably well.

For reference, a new subdirectory O2test has been created in
the hinj Details/pulsar/ directory for this test and the
symlink RELEASE redefined to point to it. The only differences
between the files in O2test and O1test are the addition of
Evan's actuation function posted here and new in.N (N=0-14)
command files with the makefakedata actuation argument turned on.

Once we are satisfied the new injection actuation is working
as intended, the svn directories will be updated. One other
change I'd like to make is to use an actuation function file
that takes into account the extra time delay for the excitation
channel itself. Evan will consult with Jeff on approval for
that swap.

BSC5 annulus IP going bad(?)

BSC5 annulus IP is flickering between red and green state. 

BSC8 aIP was in the red a few days ago, but seems to have recovered. 

Someone told me BSC5 was not connected.

I just added BSC5 and BSC6 to the overview this morning (alog 27377).

Oh! So these channels are now available. We just need to run cables from the pump to rack.

CDS workstations mini-freeze up

many CDS workstations experienced a mini-freeze at roughly 14:10 this afternoon. The freeze up lasted only 10 seconds or so. Unlike the one reported several weeks ago, no "/ligo unavailble" errors were logged, in fact no errors of any type were logged at the time.

Updated PINJ_TRANSIENT / PINJ_HARDWARE filters

Transitioning over to the new, improved inverse actuation filters (see LHO aLOG 27176), I removed the old filters from PINJ_HARDWARE and installed the new inverse actuation filters into the PINJ_TRANSIENT bank. Since the CW injections will apply the inverse actuation function to condition their signals before sending it to the PINJ path, we don't want the filters in PINJ_HARDWARE any longer.

CW injections are running right now using this new actuation function. Keith R. and I made a test of this earlier to verify the output was roughly correct (Keith will post an aLOG about our work). He wants to see this running over the next few days to gain confidence that the injections are operating normally.

Reference to Keith's aLOG regarding today's CW injection test.

Attached is a comparison of the old and new inverse actuation filters. Note the discrepancy at low frequencies because the old version assumed only a free-mass response instead of the real force-to-length suspension model. Also, different approximations were made at high frequencies leading to different magnitude and phase effects. Recall the new filter is valid within 5% in magnitude and 5 degrees in phase up to 2 kHz, when taking into account that waveforms must have an assumed 200 us advance.

Keith R. noticed that the CW injections appeared to be ~10% smaller in amplitude now that they are no longer passing through the old inverse actuation filter. To see if the new design is the cause, I plotted the inverse actuation transfer function in Foton and plotted the results of the old/new. Note that there is also an old AI2 filter module that didn't appear to be in-use lately. In any case, I plot all three curves in the attached plot.

Importantly, the inverse actuation transfer function is larger in magitude for the Old version compared to the New version by about 10% at 2 kHz. Meanwhile the Old w AI2 is smaller than the New version. This difference is the likely explanation to Keith's observation.

TCS chillers troubleshooting

Peter, Jeff B, Dave, Kiwamu, Nutsinee

 

Quick conclusion: They work now.

 

Details: This morning we troubleshoot the cause of TCS chillers failure last night. All the channels in the chiller servo was requesting the right number (20C, no crazy gains). We went to the chillers and realized that the set point was 5 degree C for both TCSX and Y chillers instead of its nominal (20C). We tried to reset the set point at the chiller and it would come right back to 5C. This suggested that the front end was sending out some bad number to the chillers. This was confirmed further by measuring the voltage between pin 6 (ground) and pin 7 (temperature control) at the connector pinout and we were able to change the temperature setpoint when we unplugged this connector. Later we found out that H1OAF DAC went bad yesterday 19:18 PT. This forced the IOP to send out 0 values and caused the chiller setpoint to change to the lowest temperature possible. 10 minutes after DAC failed the chiller interlocks tripped because the chiller temperature was to low. Accordning to Sheila this happened when the temperature reached about 15 deg C. Below I included the plot of CO2 laser temperature, which is slightly higher than the actual chiller temperature but it's a good indicator of what happened to the chiller temperature (I couldn't find a channel that would report the actual chiller temperature).

 

We don't know what caused this DAC error. Dave also mentioned that this is quite rare.

 

Totally unrelated note to what happened, TCSY chiller is really nasty. I've attached a picture of inside the chiller Peter took earlier today.

Updated medm screens on Beckhoff vacuum controls computers

I did an svn update of C:/SlowControls/TwinCAT3/Vacuum/LHO/MEDM on each computer and ran C:/SlowControls/TwinCAT3/Vacuum/LHO/MEDM/Source/create_medms.py to regenerate the screens.

Completes WP 5900.

TCS chillers tripped

Evan, Sheila, Ed, Nutsinee on the phone

Both TCS lasers tripped off within 20 minutes tonight, apparently because of a low temperature alarm on the chillers.  We called Nutsinee and used the wiki to reset the chillers and lasers, but the lasers didn't come on although the lights on the controller were lit. The chillers tripped again within 15 minutes of being reset.  

We tried setting the TCSX guardian to Down and resetting the chiller again, but the temperature dropped quickly and the chiller started beeping and had a low temperature warning message, so we shut it off using the power button.  

In the attached screenshot the bottom screen is a time machine image of the laser screen from yesterday, the top screen is right now.  We tried enabling the output of LZR_HD, but that didn't work.  

Nutsinee wondered on the phone if this could be related to some bad settings after todays model restart.  I laoded the burt that was created by the model restart, but there are no diffs so that seems OK. 

90MHz and 36MHz at AS Port

Sheila, Haocun

We are trying to compare the amplitudes of 90MHz and 36MHz modulations at the AS port.

1. Using gpib connected to Agilent 4395A to measure the spectra of photo-current signals. The measurements are 1E-7 V/rtHz for 36MHz, 6E-8 V/rtHz for 45MHz, and 7E-8 V/rtHz for 90MHz. 
   All three signals are at the similar level.
2. Using RF detectors to check the input signal of demodulator, which are -18dBm for 36MHz, -12dBm for 45MHz, and -28dBm for 90MHz. 
   The 90MHz is lower, about 1/4 of 36MHz.
3. From measurements coming out from the demodulator are: 2943 counts for 36MHz, 2557cnts for 45MHz, and 17cnts for 90MHz (after being divided by gains).
   The factor drops to < 1/100.

These results are not consistent with each other, and we will check by changing the whitening gains and the demodulator.

Updated measurement with the analyzer: -47dBm for 36MHz and -72dBm for 90MHz. There is a factor of 17 between them.

ETMX Pcal actuation function and new inverse actuation filter

Summary:
A new, better inverse actuation filter has been made for the x-arm Pcal, but it has not yet replaced the old filter. This was constructed using knowledge of the Pcal OFS-AOM gain coefficient (see LHO alog 27155), the suspension model, and models of the digital/analog AI components. The AI components had to be approximated since the injection model runs at 16k. Also, the actuation function delays couldn't be included in the filter, so all waveforms using the attached actuation function or using the inverse actuation filter should assume a timing advance of 225 us. Another aLOG will be posted once the new filter is in place.

When including this timing shift, the new actuation function/inverse actuation filter match the real values to within 5% in magnitude and 5 degrees in phase up to 2 kHz. Above 2 kHz, the deviations from the true actuation function are significant due to the approximations chosen for the analog/digital AI filters and a rolloff filter being applied.


Details:
The continuous wave hardware injections would like to use the Pcal actuation function instead of an inverse actuation filter for O2. Meanwhile, the transient injections will continue to use an inverse actuation filter. The actuation function is nominally modeled as follows:
PCALX_EXC --> IOP-15 --> 16k-64k AI(D) --> DAC (V/ct) --> ZOH 7.5 --> AI(A) --> OFS --> AOM --> N/W --> Norm. SUS --> 1/f^2 --> DC SUS (m/N) --> 1/L (h/m) --> strain
Legend:
IOP-15 = 15 us delay from the IOP
16k-64k AI(D) = digital anti-imaging filter (using the new RCGv3.0.2 filter, see LHO alog 27173)
DAC = digital-to-analog converter
ZOH 7.5 = zero-order-hold, 7.5 us delay
AI(A) = analog anti-imaging filter
OFS = optical follower servo
AOM = acousto-optic modulator
N/W = power-to-force coefficient = 2*cos(theta)/c (Note that this does not include rotation-induced errors, with 1-sigma uncertainty of 0.4%, see LIGO-L1600018)
Norm. SUS = normalized suspension transfer function model which has been multiplied by zpk filter with 2 zeros at 1 Hz
1/f^2 = zpk filter with 2 poles at 1 Hz
DC SUS (m/N) = suspension force-to-length "DC" coefficient
1/L (h/m) = inverse of the mean arm length

The OFS-AOM system has a wide-bandwidth (UGF ~50 kHz) and a gain of 0.0923 W/V for H1 ETMX Pcal (this is watts impinging on the ETM per volt of drive sent to the OFS, LHO alog 27155). The SUS file used is in the SUS repository:
/ligo/svncommon/SusSVN/sus/trunk/Common/SusModelTags/Matlab/quadmodelproduction-rev7652_ssmake4pv2eMB5f_fiber-rev3601_h1etmx-rev7641_released-2015-08-07.mat
However, in order to construct an *inverse* actuation filter, some of these components cannot be included because a delay would turn into an advance (breaking causality). In addition, the model runs at 16k, so the inverse AI digital filter must be approximated. The high frequency components of the inverse actuation filter need to be rolled off using additional filtering. Thus, the *inverse* actuation filter model is constructed as follows:
strain --> L (m/h) --> 1/DC SUS (N/m) --> f^2 --> 1/Norm. SUS --> W/N --> 1/[OFS * AOM] --> 1/AI(A) approx --> DAC (ct/V) --> 1/AI(D) approx --> Ellip. rolloff --> 3 7kHz poles --> PCALX_EXC
Here, there are two approximations made: the analog/digital AI filters are modeled to roughly match the magnitude (see comparisons in figures 1 and 2), as well as removing the IOP and ZOH delays. Note that two rolloff filters are used to suppress high-frequency content, a 3rd-order elliptic filter and 3 7kHz poles. The phase error in the approximations is accounted for with the expectation that waveforms using this inverse actuation filter will need a timing advance of 225 us.

The analog AI approximation is one zero at 5160 Hz and 2 poles at 7100 Hz (e.g., [5160:7100,7100])--see figure 1. The digital AI approximation is 4 zeros at 7000 Hz, and 2 complex pole pairs (e.g., [7k,7k,7k,7k:pair(4300,30),pair(7000,50)])--see figure 2. The elliptic rolloff filter is given by the Matlab function myellip_z2(6900,3,.4,10,10)--6900 Hz knee frequency, 3rd-order, 0.4 dB ripple, 10 dB stopband, and zQ of 10.

The final Pcal actuation function and comparison to the real value is shown in figure 3 with the delay included, and figure 4 is the inverse actuation function with the advance included. Figure 5 shows the impulse response of the inverse actuation filter (no delay included).

The attached H1PCALXactuation.dat file is the actuation function sampled every 0.125 Hz.

Code that produced these results is located in
/ligo/svncommon/CalSVN/aligocalibration/trunk/Runs/O2/DARMmodel/Scripts/pcal_actuation_function_quack.m

Next steps: replace the old inverse actuation filter, move the inverse actuation filters from the PINJ_HARDWARE bank into the PINJ_TRANSIENT bank so that the CW injections (which will use the Pcal actuation function manually) will not pass through the inverse actuation filter.

Putting the Matlab-designed filters into Foton reveals that a few changes are needed so that Foton stays happy. This means the above actuation function attached above (created before these modifications) should be replaced with the version attached to this comment. Here are the modifications:

1. The analog AI filter is now approximated as two zeros at 8000 Hz and two poles at 7150 Hz (e.g., [8000,8000:7150,7150])

2. The f^2 filter was originally designed as two zeros at 1 Hz, but is now designed as two zeros at 1 Hz and 2 poles at 6500 Hz (e.g., [1,1:6500,6500])

3. Due to these changes, the waveforms using the updated actuation function (attached below) or inverse actuation filter should assume a timing advance of 200 us.

The actuation function and inverse actuation filter remain within 5% in magnitude and 5 degrees in phase with the real versions up to 2 kHz. The version attached with this comment was produced using Foton.