(Jenne, Fil)

The slow controls interface for the EOM drivers is now up and running. The attached screen shot shows the remote controls screen. RF power can be adjusted between 4dBm and 27dBm in 0.2dB steps. On the unit the remote switch must be set to External, the excitation switch be set Off and the RF power switch to On. 

Fast channels are available under H1:LSC-MOD_RF9/45_AM with filter modules ERR, CTRL (in loop), AC and DC (out of loop).

Cables have been pulled to the PSL, but the unit we have is not connected yet.

Timing monitors for the 1 PPS signals have been added. Each signal channel has a nominal and tolerance field as well as an out-of-range flag. A screen shot is attached.

As per alog 20169 all the ISI models were restarted with the new WD saturation updates.

J. Kissel, B. Weaver

We've restarted all SUS models to install the changes described in LHO aLOG 20177. Betsy is going through the IFO_ALIGN screen cap found in LHO aLOG 20187 and restoring alignment offsets.

Attached are the plots for the temperature and RH data for the Dry Box storage containers #1 & #4 (Box 2 & 3 are empty) from July. Data shows both cabinets functioning as expected.

There was no data from the desiccant cabinet in the LVEA due to a sensor programming error. This problem has been corrected.    

Aug  4 07:54:42 h1conlog1-master conlog: ../conlog.cpp: 301: process_cac_messages: MySQL Exception: Error: Incorrect string value: 'xFBxFFxFF@' for column 'value' at row 1: Error code: 1366: SQLState: HY000: Exiting.

I found the IFO struggling to keep the IMC locked through ALS lock acquisition. It appears as through the ISS and FSS are struggling this morning; attached are screen shots of the FSS and ISS screens before I took the IMC to DOWN, one can see the ISS diffracted power suddenly jump to ~10%. Not sure what's going on there. But good to know that we are having troubles with the ISS *before* we're going into the PSL, so we don't blame the team going in for causing the problems during recovery!

Beginning maintenance day prep at 14:10 UTC (7:09 PDT) by bring ISC_LOCK to DOWN. Because the ISC_LOCK guardian was still transitioning, as opposed to in NOMINAL_LOW_NOISE, (and maybe because DOWN has become a goto again? LHO aLOG 20134 leaves it unclear if LHO aLOG 20125's changing the DOWN state to a goto has been reverted. The current ISC_LOCK graph shows that it *has* been reverted.)

Also, I ran the OFFLOAD WFS script before bringing the IMC to OFFLINE. Strangely, the IMC lost lock during this process and it took ~1.5 minutes of flashing before it recovered. However, the IFO align screen has been captured with the IMC locked and well aligned, and the ISC_LOCK guardian is down,

Jenne, Nergis, Stefan


We hooked up monitoring points for measuring the 9MHz and 45MHz RIN going into the interferometer.

Here is the rig:
9MHz:
 - We inserted a 10dB coupler into the 9MHz cable feeding the EOM. This dropped the drive signal from 4.7Vpkk to 4.5Vpkk - small enough the interferometer didn't care.
 - It's output we directed into a two-way splitter, and fed both signals into a level 1 mixer.
 - The output was low-passed through a 10MHz low pass.
 - This gave us a DC level of 0.195V, and a noise of ~4.9nV/rtHz, resulting into a RIN of 2.5e-8.
 - We hooked it up to an SR560 (Gain=1e4, AC coupled, band-passed with poles at 300Hz and 30kHz), and stuck it into LSC-EXTRA_AI_1 (IOP-LSC0_MADC2_TP_CH8)
 - the ADC gain is 16384cts/10V

45MHz:
 - We used the two remaining spare spigots of the 45MHz distribution rack, and mixed them in a level 3 mixer.
 - Low-passed at 15MHz, we got a DC level of 0.57V, and a noise level of 120nV/rtHz...
 - ... resulting in an outrageous RIN of 2e-7/rtHZ
 - Again into an SR560 (Gain=1e3, AC coupled, band-passed with poles at 300Hz and 30kHz)
 - and into LSC-EXTRA_AI_2 (IOP-LSC0_MADC2_TP_CH9)

Plot 1 shows the RIN measured through the digital system
Calibration: LSC-EXTRA_AI_1 (IOP-LSC0_MADC2_TP_CH8): Gain=9.39e-5; p= 1, 728.178 65532    ; z= 300, 30000, 10062, 4973.6 9356.4, 33157, 426840 (dtt notation)
Calibration: LSC-EXTRA_AI_2 (IOP-LSC0_MADC2_TP_CH9): Gain=3.21e-4; p= 1, 728.178 65532    ; z= 300, 30000, 10062, 4973.6 9356.4, 33157, 426840 (dtt notation)

Note: the AA chasis itself has p= 728.178 65532    ; z= 10062, 4973.6 9356.4, 33157, 426840 (dtt notation)

Next Evan locked the interferometer, and we found a coherence of 0.9 between the 45MHz RIN (IOP-LSC0_MADC2_TP_CH9) and  ASC_AS_C (IOP-ASC0_MADC6_TP_CH11) - this was oue best monitor for mystery noise.... BINGO

We also calibrated OMC_DCPD_A (IOP-LSC0_MADC0_TP_CH12) in Amps (today the whitening filters were off):
Calibration:Gain=7.726e-7; p= 7.689, 7.689, 728.178 65532    ; z= 78.912, 90.642, 13700, 17800, 10062, 4973.6 9356.4, 33157, 426840  (dtt notation)

The noise level in OMC_DCPD_A was 7e-8mA/rtHz. Shot noise would be 5.7e-8mA/rtHz at 10mA.

Using the coherence between OMC_DCPD_A and RF45 RIN we estimated the ransfer function to be about 9e-5 A/RIN per photo diode. (Plot2)

This let's us estimate the RF45 RIN contribution: 9e-5 A/RIN * 2e-7RIN/rtHz = 1.8e-8mA/rtHz. Very close to the 1.4mA/rtHz estimated in alog 19856.

We are a bit puzzled by the fact that this doesn't seem enough the explain the full elevated noise in DCPD_A: sqrt(1.8^2 + 5.7^2) = 6.0 < 7  (everything x1e-8mA/rtHz). (Plot3)

Plot 4 shows the coherence (ignore below 300Hz - the interferometer wasn't completely in low noise mode.

In all the last lock stretches we saw a lot of very loud glitches, clearly visible as large drops in the range. See reports from Sheila and Lisa.

I had a look at the time period pointed out by Lisa (1122456180 - 1122486360). I wrote a MATLAB script (attached) that load the range and select the glitch times looking at the large drops. Since the range is sampled once per minute, I then look at the DARM error point and search for an excess of noise in the 30 to 300 Hz region. In this way, 16 loud glitches were selected.

Most of them are similar, see the first figure. I checked with the MATLAB script the value of all suspension actuation signal, using the MASTER channels. No saturation or unusual behavior is visible.

I also checked that there is no drop or change in the IFO powers. Then, as suggested by Sheila, I checked the DACKILL signals as well as the CPU_METER signals. Nothing there.

Finally, I selected the loudest glitch (1122479776) and looked at all (literally) *_DQ channels. I couldn't find any interesting correlation, except for signals that are known to be related to the DARM loop, like for example ETM* and ITM* control signals. For this glitch and a couple of the loudest ones I could see a similar glitch in H1:LSC-ASAIR_A_RF45_Q_ERR_DQ, H1:ASC-AS_A_RF45_I_YAW_OUT_DQ, H1:ASC-X_TR_A_NSUM_OUT_DQ, H1:ASC-Y_TR_A_NSUM_OUT_DQ. All these are signals somehow sensitive to DARM.

In conclusion, I couldn't find any channel, except DARM ones, that are correlated with those glitches.

This is a summary of the thermal test we did yesterday (alog 20146) in which we changed the power of the CO2 laser for ITMX as a part of noise coupling study.

We were interested in four quantities as listed below together with some observations.

• Frequency noise coupling can be lowered by a factor of 10
• Intensity noise coupling does not dramatically improve. A factor of 2-ish at best if we tune the CO2X power.
• SRCL coupling was not sensitive to the CO2X power. It changed by 30% or so.
• DARM coupled cavity pole frequency was stable throughout the test. It seems insensitive to the CO2X power.

Here are some plots. All of them are pltos of time series data starting at 2015-08-02 22:35:00 UTC for 8 hours. The interferometer was locked at the first 10 minutes of the plots and kept locked for more than 8 hours. Our thermal test start at around t = 2.7 hours. The time stamps for important activities are written in Evan's alog (alog 20146).

[1 st plot]

This plot is meant for showing how the noise couplings evolved during the test. The middle panel shows the measured coupling coefficients using the LSC front end demodulators. The signals are measured as in- and q-phases which are demodulated with cosine and sine local oscillators respectively. Since the excitation were done by independent awgs, the i- and q- phase don't mean anything except that they are 90 deg apart. Meaningful data start several 10 minutes before the CO2 power was changed. The intensity noise coupling shows an abrupt change at around t = 5.2 hours because Stefan closed the 2nd loop to try out a configuration for the maximum intensity suppression (alog 20155). Similarly, the SRCL excitation was disabled at around t = 6.5 hours resulting in a sharp drop in the measured I and Q signals. The bottom panel shows quadratic sum of the I and Q signals for frequency, intensity and SRCL couplings. The definition of the quadratic sum here is sqrt( I^2 + Q^2) in order to show the absolute magnitude of the couplings.

The in- and q-phase signals of the frequency noise coupling experienced a zero crossing -- but at different times as shown in the middle panel. After the frequency noise was found to be overshot, Evan and Stefan tuned the CO2 power to 410 mW in order to bring the frequency noise back to a point where the coupling is minimized. This tuning attempt seems to be successful because the coupling settled to a small number and roughly a factor of 10 smaller than the one when we started.

Intensity noise coupling appeared to be sensitive to the thermal tuning as well. However it did not show a zero crossing. As far as the tested CO2 power range is concerned, the best reduction in the coupling was only a factor of 2, and the minimum point does not coincide with the one for frequency noise.

SRCL coupling initially appeared to be responsible to the thermal tuning, however it then behaved as if it was not as sensitive as before any more for some reason. In any case, the variation was only 30% or throughout the test.

[2nd plot]

This plot shows cavity pole frequency and arms' transmitted light in time series. As shown the cavity did not show a obvious change and in fact, it seems insensitive to the CO2X. A meaningul measurement starts at around t = 2.5 hours since we were setting up a demodulator for it right before the measurement started. 

As for the transmitted light, there was a slowly varying component which raised the power level as a function of time. Since the slow variation was present from the beginning, this might be some other component independently of our test. There was a jump in both TRX and TRY which coincided with the time when the 2nd loop ISS was closed. So this must be something induced by a slightly different diffraction power in the AOM of the ISS. So, I don't see any obvious sign of improvement or degradation in the power recycling gain.

[3rd plot]

Since there was a suspicion that the frequency noise coupling may have been modulated by some misalignment, I plotted the optical lever signals which did not show a significant correction with the thermal steps that we made.

J. Kissel
WP 5405

I've prepped, compiled, and committed changes to the QUAD_MASTER (and FOUROSEM_DAMPED_STAGE_MASTER_WITH_DAMP_MODE) library parts to incorporate the following changes:
1) Added ${IFO}:SUS-${OPTIC}_L3_CAL_LINE oscillator infrastructure for future tracking of the L2-PUM / L3-TST actuation strength ratio.
    ECR E1500329
    Integration Issue 1088

2) Added ${IFO}:SUS-${OPTIC}_L3_ISCINF_L_IN1 to the science frames at 16384 [Hz], as option 2 in 
    ECR E1500323
    Integration Issue 1085

3) Adding low-pass filter banks and log10 processing after the True RMS violin mode monitors as a final implementation.
    ECR E1500271
    Integration Issue 1066

4) Removing all residual, redundant EPICs records storing IPC error rates. I mention them here, but these changes were prepped last Friday (see LHO aLOG 20124).
    ECR E1500230
    Integration Issue 1054

Attached are the relevant screenshots of the changes. 

To absorb the first three of these changes at LLO, one needs only to update the following library parts:
/opt/rtcds/userapps/trunk/sus/common/models/
QUAD_MASTER.mdl
FOUROSEM_DAMPED_STAGE_MASTER_WITH_DAMP_MODE.mdl
Unfortunately, the 4th change requires pruning on every top level model, as described in LHO aLOG 20124.

I'll construct MEDM screens to go with these model changes once they're installed and running.

Attached is the whiteboard list of tomorrow's scheduled tuesday maintenance activites.  We'll start withnumerous model restarts and move into some hardware work.

Here are the list of tomorrow's maintenance day tasks organized as we intend to execute them chronologically, and prioritized such that the tasks with the most global impact on the IFO are done first (such that we have the most time to recover from them). As with previous Tuesday, all tasks, associated estimated times for completion, and responsible persons will be added to the reservation system when they are *actually happening*, and removed after the task manager has checked in with the operator and confirmed completion. PLEASE PAY ATTENTION TO THE RESERVATION SYSTEM. 

As always, please keep the operators informed of your activities as accurately as possible / reasonable throughout the maintenance day so the reservation list can be adjusted accordingly and remain accurate. We appreciate your cooperation!

1st Round:

Cabling of EOM Driver - will involve climbing on HAM1 and HAM2 chamber areas

Restart all ISI Models

Restart all SUS Models

Restart ASC and LSC modelsInstall TCSy CO2y temperature sensor on viewport

Revert Ey fast FE to slower machine to reduce glitching

Revert Ey BIOS

VE EX NEG Regeneration

PEM injection hardware setup

2nd Round:

DAQ Restart

TCS Ring Heater Filter Install

PSL PMC/ISS checkout

IO (in PSL) Documentation

Guardian Upgrade/restart

3rd Round:

ETMy UIM rocker switch fix

EX/EY PCAL Tune up and Calibration

Jamie, Sheila, everyone,

Over the past several days, TJ's verbal alarams have been warning us about ETMX software watchdog trips which aren't really happeneing.  This is interseting though, since we've noticed that sometimes this seems coincident with a huge glitch in DARM that can be seen in the spectrum.  The verbal alarm script is checking the channel H1:IOP-SEI_ETMX_DACKILL_STATE.  It sometimes jumps to a value of 3 for about a second and comes back to 0. 

Three incidents from Friday night happened in the 10 to 20 seconds proceeding these times (UTC):

8/1/2015 7:37:40, 5:32:10, 4:00:00

One of these incidents a huge glitch is visible in the DARM time series before the DACKILL state changed. 

Two questions probably need further investigation, is DACKILL behaving the way we want it to, and are the glitches in DARM cauing the DACKILL state to change or is something else causing both DARM glitches and the change in DACKILL state?