The LSC model has been edited to accommodate a normalized REFLAIR9I signal (LSC-TR_REFLAIR9) alongisde normalized REFL9I (LSC-TR_REFL9). A switch determines which of these is signals is fed into LSC-REFLBIAS.

Correspondingly, I have switched back the cabling on the ISC rack so that the demodulated REFL_A_RF9 signals feed into the REFL_A_RF9 whitening chassis, and likewise for REFLAIR_A_RF9.

Wanted to confirm the long runs to the amplified BSC2 Pressure Sensors weren't the main ground noise culprit.  Richard plans to add following resistors to the satellite amplifier before the long runs.

Anyway, it does not look like these are making the Pump Station Pressure signals noisy.

Attached is 30 minutes where we disconnected these channels from the servo inputs: Ch3 goes away as the return and supply pressures from BSC2 (Chs7 & 8) are disconnected. The Main Supply pressure, Ch9, shows that the noise level doesn't change during this period.  The servo is in free running manual mode.

model restarts logged for Sun 01/Feb/2015
2015_02_01 14:40 h1fw0
2015_02_01 20:06 h1fw0

both unexpected restarts. Conlog frequently changing channels report attached.

Evan, Sheila

We did a little bit of cleaning up today.  First edited the IMC guardian to adjust the input gain for different input powers.  We though we had implemented this before, but what we had actually wasn't working.  I added an if statement in the BOOST step that sets the input gain for 1W, 4W, or 10W.  We could have something better which adjusts it for any input power.  

We also changed the ISC_CONFIGs guardian to accoun for the cable swap we did on friday night, PRX locked is not using reflAIR in the input matrix, which is really REFL 9.  

Evan and I then locked DRMI just to make sure everything is OK with the TCS back on, it locked with no problem, now we are checking demod phases.  

Sheila, Evan

We have been changing the PSL power up and down during CARM offset reduction. Among other things, this changes the optical gain of the IMC PDH loop. So far, we've been compensating for this gain using the IMC servo board as follows:

• For 10 W of PSL power, the input gain on the IMC servo board is 0 dB.
• For 4 W of PSL power, we change the input gain to +6 dB.

Just to make sure that the IMC loop is still OK in the latter configuration, we took an OLTF by driving a 20 mV swept sine into EXC A and monitoring the test points before and after. The result is attached.

model restarts logged for Sat 31/Jan/2015
2015_01_31 06:40 h1fw0
2015_01_31 08:08 h1fw0
2015_01_31 18:39 h1fw0
2015_01_31 19:04 h1fw0

all unexpected restarts. Conlog frequently changing channels report attached.

Dan, Elli

Today we did a few non-locking things:

• Turned on the ISS second loop and measured the RIN at the dark port.  The measurement showed RIN@AS less than 10^-7 at 10Hz, I will post data on Monday after the Patriots crush the Seahawks.  The ISS second loop behaved very well, we left it on all day.
• Measured the Michelson contrast and turned on the ITMX CO2 laser.  Data to follow; before the laser was turned on the [Bright, Dark] counts were [38180, 51] on OMC REFL A, for a contrast of 1-(Bright-Dark)/(Bright+Dark) = 2668ppm (is this the right formula?).  After a few hours of heating we observed [38600, 39] or 2018ppm.
• Collected a 'before TCS' mode scan of the OMC with a single bounce beam from ITMX.  Plots showing the peak fitting and frequency fitting are attached.  The mode matching into the OMC was 0.893 (=1-TEM20/TEM00) without TCS.
• Diagonalized the AS WFS DC centering.
• Measured the OMCS --> OMC QPD transfer function and made some filters to smooth out the peaks of the OMC suspension.
• Measured the OMCS, OM3 --> OMC QPDs sensing matrix, inverted, and closed the OMC ASC loops.  The alignment in HAM6 is now nicely decoupled, WFS are centered using OM1 and OM2, the OMC is centered using OM3 and OMCS.  The loop gains are not too high or else the OMCS saturates.  Plots to follow.
• The OMC dither alignment did not work, with the improved intensity stabilization.  Need to investigate this further.
• Now that the fast shutter is installed we centered the beam on the OMC REFL QPDs and checked that it was coming out of the vacuum.

As part of this work we changed a few whitening gains.  The gain for IM4 TRANS had been turned down to zero because it was saturating from the aux laser for the Schnupp and PRCL measurements.  We turned this gain back to 36dB.

Also we increased the whitening gain on the OMC QPDs, they are now 30dB (were 18dB).

Turned on at 1Feb 2:55:22 UTC.  .3W requested power, 0.21W registered at the power meter. 

I requested central heating, although the H1:TCS-ITMX_CO2_FLIP2MON and H1:TCS-ITMX_CO2_FLIP1MON mon channels are jumping all over the place, we need to fix this.  ITMx HWS was runningand shows an increase in the spherical power, which is consistent with central heating.  

model restarts logged for Fri 30/Jan/2015
2015_01_30 04:45 h1fw0
2015_01_30 08:03 h1fw0
2015_01_30 11:02 h1fw0
2015_01_30 17:27 h1fw1

C1PLC1 7:54 1/30 2015

C1PLC2 7:54 1/30 2015

C1PLC3 7:54 1/30 2015

unexpected daq restarts. Beckhoff corner station restart for fast shutter install. Conlog frequently changing channels report attached.

Alexa, Elli, Sheila, Kiwamu, Rana, Evan

Summary

With CARM controlled by a combination of sqrt(TRX+TRY) and TR_REFL9 (i.e., REFL9I normalized by TRY), we've achieved a power buildup in each arm that is 800× the single-arm buildup. We believe this corresponds to a CARM detuning of 5 pm.

At this point, REFL_A_LF is at about 2.3 mW, compared to 40 mW when the arms are anti-resonant. If this is truly an indication of the power reflected back from the PRM, this means that the visibility of the interferometer is in excess of 90 %.  We do not have TCS on today.

One major roadblock to further progress seems to be angular instability that is seen at the AS port. We have ASC feedback from AS_B_45_Q to ETMX and ETMY, but the bandwidth is too low to suppress the 1 Hz motions that we see. We may need to spend some time increasing the WFS bandwidth, or resort to more aggressive oplev damping.

Details

A laundry list of things we've done today to troubleshoot the transition:

• Locking at 4 W input power. This appears to reduce the amount of angular instability during CARM offset reduction.
• Engaged oplev damping on ITMs.
• Increased the DHARD WFS BW. The gains are now 0.1, FM2 (+20dB) is no longer on compared to Elli's old alog (LHO#16345)
• Changed the DARM loop shape (LHO#16387) to achieve higher bandwidth.
• Switched from REFL_A to REFLAIR_A to avoid saturation while locking (LHO#16381).
• Because TCS was accidentally turned off (LHO#16385), we decided to retune the demod phases of the 3f signals. With CARM controlled by sqrt(TRX+TRY), we've adjusted the phases as follows:
  • 27 MHz: 91.3°→111.8°
  • 135 MHz: 65°→25°
• We took a TF from TR_REFL9 to sqrt(TR) at -25 ct of offset on sqrt(TR). Above 10 Hz, the TF was about 50 dB with -180° of phase. Below 10 Hz, the TF began to rise. Therefore, we installed a 1.6 Hz pole, 40 Hz zero in the TR_REFL9, and +50 dB. This behavior does not seem to correspond with simulated TFs given, e.g., in T1400298.

Based on the measured losses in the arms (an average of 110 ppm), we expect an interferometer recycling gain of 32 W/W and a coupled cavity pole of 0.6 Hz (i.e., 9 pm) [using eqs. 6 and 8 from Fritschel et al. 2001]. Therefore, we believe that the arm buildup should be about 1000× the single-arm power with CARM at 0 pm. This is consistent with earlier estimates made by others (LHO#15390, T1000294).

A list of transition steps not yet implemented in the guardian:

• Increase the gain of IN1 on the IMC board by 6 dB.
• Starting at a sqrt(TR) offset of −20 ct, ramp the offset to −30 ct while reducing the DARM gain in the input matrix from 40 ct/ct to 20 ct/ct.
• Turn off the WFS (they appear to flip sign around here).
• Ramp the offset to −36 ct, and ramp the DARM input matrix coefficient to 8 ct/ct. Turn on the WFS with the opposite sign, and 10 dB less gain.
• Turn on TR_REFL9I→CARM feedback with an input matrix gain of 3 ct/ct, and no TR_REFL9I offset.
• Adjust the CARM offset to -41 cts, and hold the TR_X/Y_NORM outputs

Our last three attempts are 11:24:48 UTC, 11:00:27 and 10:37:35 Jan 31.

New models have been prepared for the splitting the end station isc model:

• New model directories were created in als/h1/models and als/common/models
• als/h1/models contains h1alsex.mdl (DCU 85) and h1alsey.mdl  (DCU 95), as well as the updated IPC file H1.ipc_alsnew.
• isc/h1/models contains h1iscex_new.mdl (DCU 126) and h1iscey_new.mdl (DCU 127).
• als/common/models contains ALS_END.mdl
• isc/common/models contains ASC_END amd LSC_END (no change).
• The integrator has been moved to cds/commmon/models/integrator.mdl and cds/common/src/integrator.c.
• Ramping functions are located in cds/common/models/ramp.mdl and cds/common/src/ramp.c.

The old h1iscex and h1iscey are still the default. To activate the new split models, h1iscex_new  and h1iscey_new need to be renamed, the IPC file copied over chans/H1.ipc, and then everything recompiled. All in svn.

J. Kissel, R. Adhikari, S. Dwyer,

By happenstance calling for another reason (see LHO aLOG 16390), Rana and Sheila informed me of woes at ETMX: a sudden trip, some further trip, followed by more trips of the watchdog. Unsure of what was going on, they had mashed a bunch of buttons in attempt to fix the problem. 

After some remote MEDM'ing, I could tell that the BRS-rotation-corrected, GND X STS signal had gone bonkers, which was being used as the X -direction Sensor Correction signal since Krishna had resurrected the BRS earlier this afternoon (see LHO aLOG 16380). 

I've since switched the STS2CART input matrix to use the normal X-direction STS signal for sensor correction (changed the STS2CART matrix to use STS B for X input to sensor correction instead of STS C). I'm not sure what's gone wrong with the BRS (too difficult to diagnose remotely), we'll figure that out later.

Further, Sheila and I used the SDF system to restore all of the button mashing they'd done. Now only the expected differences from "nominal" remain -- my switch of the STS2CART input matrix, and Krishna's turning on the outputs of the Rotation and Torque correction paths for the STS. Again, the latter no longer has any impact because this GND super sensor output is no longer being used. I second Hugh's love of the new SDF system!

Kiwamu, Sheila, Rich, Daniel, Rana

Summary

We are close to saturating REFL_A_RF9 during our hand-off attempts from sqrt(TRX+TRY) to REFL9I.

For the time being, we are switching to REFLAIR_A_RF9 for the handoff. Sheila and Rana have done some rewiring on the ISC rack so that the I&Q demodulated outputs of REFL_A_RF9 are replaced by REFLAIR_A_RF9.

Details

The attachment shows the 9 MHz rms monitors for REFL_A and REFLAIR_A during a lock acquisition attempt. After some discussion, Rich and Daniel have concluded that the RF monitor channels are calibrated into dBm, as measured at the output of each PD with a 50 Ω load. REFLAIR_A is sitting comfortably below −10 dBm. REFL_A, however, peaks as high as +15 dBm. The amplifier in the RFPD is an LMH6624, for which the minimum output swing is reported as ±4.4 V into 100 Ω. Since the amplifier has a 50 Ω series resistor on its output, that's 20 dBm of power delivered into a 50 Ω load. If we want to keep distortion to a minimum, we should stay well below this limit.

I updated the GUARD_OVERVIEW and the IM/TT medm screens to contain micro/mini Guardians for IM1, IM2, IM3, IM4, RM1, RM2, OM1, OM2, OM3. The scripts were already made available by Stuart Aston and Jameson Rollins at LLO see https://alog.ligo-la.caltech.edu/aLOG/index.php?callRep=15772 and also https://alog.ligo-la.caltech.edu/aLOG/index.php?callRep=15585. The Guardian Nodes were not yet created though so I had to create those and figure out that they also had to be started.

Currently RM1, RM2, OM1, OM2, OM3 do not have any offset.snap files saved to them in userapps/sus/h1/burtfiles/ (hence the red border on the Guardian Minis in the overview screen shot).

Attached are the before and after of the GUARD_OVERVIEW.adl screens along with the new HAUX and one of the new HSSS IM screens.