Evan, Stefan

We fine-tuned the MICH correction todonight.
- Added the SB300vio BS violin stop band filter to MICH_FF to cancel their effect.
- Measured MICHFF_OUT to DARM_IN twice:
    1) drive disconnected at the ITMY. This measures the MICH_OUT to DARM_IN path.
    2) MICH_FF input off, driving MICH_FF. This measures the MICHFF_OUT to DARM_IN path. 
  This data is in plot 1.

- 1)/2) is the desired filter, shown in  plot 2.

- Finally, we used a p:60:z:80 filter to fine-tune the phase a bit. (Plot 3) This significantly improved the achievable subtraction.

Evan, Stefan,

Our late night work was hampered by repeated lock-losses engaging SRC2 loop during the DRMI phase. The few times we made it through that stafe, we lost it in the IFO ASC stage, when the SRCL2 loop gets extra gain.

We tried both a high SRCL offload and low SRCL offload configurations (Gain of 1 and 0.1 respectively in SRM M2 stage.) The high SRCL offload configuration resulted in a 18sec oscillation, growing to a lock-loss.  The low configuration (the default) also broke the loss several times, but we are not sure why.

Sheila, Evan, Stefan

We remeasured the required SRCL FF filter today. The transfer function changed significantly.
The only thing we know we changed was the POP_45 phase (H1:LSC-POP_A_RF45_PHASE_R) from 66deg to 58deg - this minimized a SRCL drive in MICH.

The fit functions are roughly:

May 11: p:0,0  z:2.28571+31.9183i,2.28571-31.9183i,-180    (M1)
May 12: p:0,0  z:2.28571+47i,2.28571-47i,-600              (M2)

The 1st attached plot shows these two measurements, overplayed with the models M1 and M2.
The 2nd plot shows the 4 raw measurements (2 yesterday, 2 today).

We didn't try to engage this SRCL FF yet.

Sheila, Stefan,

We noticed the H1:ALS-X_TR_A_LF_OUT signal (Xarm green transmission) drop to zero with the cavity aligned without good reason. The first time this happened, the signal came back after a few minutes. One lock-loss later the same thing happened, and didn't come back.

We went to ISCT1, and as soon as we touched the BNC cable of the x arm Green transmission photo diode, the signal jumped back.

We replaced the T that was in between the PD and the BNC cable with an L. The T was removed from circulation.

Both the bounce and roll mode were rung up on ITMY.

Roll: freq 13.934Hz damped using AS WFS, a gain of -100dB, bandpass 13.9Hz, and a negative gain around 1.  This was done at a CARM offset of 10 pm since the IFO wasn't stable if we tried to go on resonance.

Designed new filters for compensating the ITM PUM->TST P2P and Y2Y drive path.

- There filters were originally designed starting with Jeff's suspension model. They were then tested and fine-tuned using an optical lever feed-back.
- They include inversions of the two suspension poles - slightly offset in frequency to guarantee stability.
- They also have a notch to kill a rung-up suspension modes a 3.1Hz and 3.3Hz. That will prevent high BW feed-back, but that's currently not planed for the ITMs.
  (I rang up the 3.31Hz mode in ITMX PIT, and thus copied that everywhere. ITMY YAW I actually rung up 3.12Hz, so I moved the notch for that one.)
- They were gain-matched to the old filters at low frequencies.

- The filters were installed in FM10 of the ASC filter banks for DSOFT and CSOFT (see below). They should replace the old lead filters in FM2.

DSOFT_P (ITMX_PIT):
zpk([0.034375+i*0.548925;0.034375-i*0.548925;0.0700002+i*1.39825;0.0700002-i*1.39825],
    [6.52535+i*17.507;6.52535-i*17.507;7.32113+i*15.9155;7.32113-i*15.9155],0.236209,"n")
 notch(3.311,30,20)
gain(12.044,"dB")

DSOFT_Y (ITMX_YAW):
 zpk([0.035625+i*0.568886;0.035625-i*0.568886;0.0650001+i*1.29837;0.0650001-i*1.29837],
    [6.52535+i*17.507;6.52535-i*17.507;7.32113+i*15.9155;7.32113-i*15.9155],0.236209,"n")
 notch(3.311,30,20)
gain(13.06,"dB")

CSOFT_P (ITMY_PIT):
 zpk([0.034375+i*0.548925;0.034375-i*0.548925;0.0700002+i*1.39825;0.0700002-i*1.39825],
    [6.52535+i*17.507;6.52535-i*17.507;7.32113+i*15.9155;7.32113-i*15.9155],0.236209,"n")
notch(3.311,30,20)
gain(12.044,"dB")

CSOFT_Y (ITMY_YAW):
 zpk([0.034375+i*0.548925;0.034375-i*0.548925;0.067+i*1.33832;0.067-i*1.33832],
    [6.52535+i*17.507;6.52535-i*17.507;7.32113+i*15.9155;7.32113-i*15.9155],0.236209,"n")
notch(3.12,20,30)
gain(13.06,"dB")



Attached is a plot of old vs new TF for ITMY YAW.

Jeff, Evan, Kiwamu,

We changed the delay cycle between the actuation and sensing paths from 4 cycles to 1 cycle in CAL-CS in this evening at around May-12-2015 1:00 UTC. This is going to more correctly reshape the DARM spectrum at around the UGF.

According to the model that Jeff has been working, the expected time delay between the two paths is 40.1 usec which is about 0.657 cycles for a 16 kHz frontend model. This has been consistent with the measured DARM open loop within a phase error of 1 or 2 degrees. Since the CAL-CS accepts only an integer mupltile for the delay cycle, we put 1. Historyically, the previous factor of 4 came from Livingston when we copied their calibration setup (llo 16475).

For more details, see H1DARMmodel_preER7.m in CalSVN/aligocalibration/trunk/Runs/PreER7/H1/Scripts.

Nutsinee, Elli

Both CO2 lasers tripped, about 10 minutes from each other, the H1:TCS-ITMX_CO2_INTRLK_RTD_OR_IR_ALRM had tripped, due to Filberto's working near Ham4 (the temperature sensor which will eventually be attached to the viewport is currently on the electronics rack next to the CO2 laser tables and is sensitive to people working near it.  CO2 X power on the IMTX has been returned to 0.22W. 

HWS X was working.  Then we touched the picomotors on the periscope mirrors and lost the alignment due to hysteresis. Dang.  HWSY SLED is aligned to irisis, green beam still clipping somewhere.

We have decided to leave EY HWS plugged into its separate power supply for the time being.

Geez yes, another update.  See 18354 for past summary.

Something bad for sure for HAM2 (STS2-B) Seismometer but intermittent between very bad and poor.  See screenshot on above reference for when it is running very bad.

I moved the HAM2 instrument back over close (6') to the ITMY sensor.  And I completely swapped the cables.  That is, the HAM2 instrument is entirely on the ITMY sensor chain. and vice versa for the ITMY instrument except that there is a temp cable running from the satellite box to the interface chassis.  See attached.

I've zoomed into the coherence.  Again the Y axis is the worst, X is a little better and Z is actually very good.  Notice how the coherence between ITMY and HAM2 goes up to much higher frequency now indicating no channel wiring errors.  Also notice how the traces associated with ITMY (HAM2, red & blue) don't get to solid 1 coherence like the green trace between ITMY instrument and HAM5.  So while suttle, clearly even when only performing poorly, this sensor could be better.  The problem could be just at the sensor/cable connection but playing with that will be painful for someone, likely me.  I think it should be addressed at the shop.

WP #5195 

Dave Barker, Jim Batch

The 4310B Cesium Frequency Standard has been synchronized to the 1PPS output of the Symmetricom NTP server in the MSR. The 1PPS leading edge from the 4310B is now leading the 1PPS leading edge from the NTP server by 60 to 64nS, within the +/- 100nS specification of the 4310B.

The 4310B was then used to synchronize the Timing Solutions Time Distribution System (TDS).  The 10MHz output of the 4310B is connected to the 10MHz input of the TDS flywheel, the 1PPS output of the 4310B was connected to channel 1 input of an oscilloscope, and the 1PPS out of the TDS was connected to channel 2 of the oscilloscope.  The slew of the TDS was adjusted to provide 0 offset between the 4310B and the TDS 1PPS.

A second (older) 4310 was then synchronized to the 1PPS output of the Symmetricom NTP server in the MSR using the same procedure as the 4310B.  This 4310 is in a short equipment rack with a UPS and has been powered for over 1 month.  This setup is portable, used to synchronize the end stations.  The 1PPS leading edge of the portable 4310 lags the leading edge from the NTP server by 28-32nS, providing a difference of about 90nS between the two standards, where the TDS 1PPS leads the portable 4310.  Both the TDS 1PPS and portable 4310 1PPS were left connected to the timing comparator in the MSR overnight to monitor the stability, which was good.

Today, the portable 4310 was loaded into a van and taken to EY to compare with the 1PPS output of the time code translator (TCT) which is connected via fiber to the TDS in the MSR. The delay adjustment of the TCT was set to have the leading edge of the TCT be 90nS before the leading edge of the portable 4310, the 90nS being the time difference of the portable 4310 to the TDS.  The adjustment is to the nearest 10nS, and ended up at about 85nS.  The procedure was repeated at EX, and the adjustment ended up at 90nS.  This leaves the TCT units at the end station with 1PPS signals synchronized to the corner station TDS.  The 1PPS signals for each unit is connected to input 1 of the timing comparators at EX, EY, and the MSR, allowing the timing differences to be monitored as EPICS channels.

EX - H1:SYS-TIMING_X_FO_A_PORT_9 SLAVE_CFC_TIMEDIFF_1
EY - H1:SYS-TIMING_Y_FO_A_PORT_9 SLAVE_CFC_TIMEDIFF_1
MSR - H1:SYS-TIMING_C_MA_A_PORT_2 SLAVE_CFC_TIMEDIFF_1

Timing Calibration

Jeff, Jim, Dave:

Jim synced up the atomic clock system to the NTP GPS receiver and then used it to sync the MCA unit which in turn drives the end station TCT units. The 1PPS originating from the MCA was connected to the first input of the MSR comparator. Jim also synchronized the original atomic clock to the same source, and we transported this unit (continually powered via UPS) to both end stations. At the end stations the time offset dip switches on the TCT units were changed to compensate for the TOF to the end stations. At the end stations the 1PPS coming from the TCT are being fed into the comparators, first channel.

We also connected the 1PPS from the NTP GPS to the second comparator input in the MSR.

A more detailed alog of these procedures is in the works.

PSL ISS model change:

Sudarshan and Jeff.

A new h1psliss model was created. This is a "stand alone" model, no common PSL parts are being used. Full details in Jeff and Sudarshan's alog.

HWS Beckhoff gain setting

Aidan, Elli, Nutsinee, Patrick

A HWS gain setting was incorrectly set as a read-only channel and therefore could not be changed from zero. Patrick has made this changeable and it is now 1.0

DMT channel list changed

John Z and Dave

John Zweizig requested a new DMT channel list be applied to the DAQ broadcaster, this was done at 15:00 local time.

LDAS Tape Robot Move

Greg, Dan, Jim, Dave

The LDAS tape robot was moved from the computer users room to the warehouse. Fiber optics cabling was added in the MSR between the warehouse patch panel and the Q-Logic switches in the DAQ racks.

LVEA: Laser Hazard
Observation Bit: Commissioning 
  
07:00 Karen & Cris – Cleaning in the LVEA
08:16 Karen – Out of the LVEA
08:17 Karen – Cleaning at End-Y
08:30 Filiberto – Cabling work at BSC1, BSC2, BSC3 & HAM4
08:30 Elli – Hartman work at End-Y
08:35 Jason & Perter – RefCav alignment work H1-PSL
08:40 Kyle – Bake out of RGA and pump work at End-Y
08:48 Hugh – Moving HAM2 seismometer to Beer Garden area
08:54 Jim – Sensor correction work on ETM-X
08:55 Bubba – 3IFO crane work in LVEA North Bay area
09:00 Add 125ml water to Crystal chiller
09:00 Jodi – 3IFO PM work at Mid-X and Mid-Y
09:01 Elli – Back from End-Y 
09:02 Elli – Going to LVEA to work on Hartman sensor
09:16 Nutsinee – Going into the LVEA
09:18 Paradise Water - delivery on site
09:25 Elli & Nutsinee – Out of the LVEA
09:30 Kyle – Going to Mid-X 
09:31 Robert – Staging in PSL for periscope tuning
09:42 Joe – Checking batteries in the LVEA
09:50 Karen – Finished at End-Y
09:53 Cris – Finished in LVEA – Going to End-X
09:56 Mitch – Going to Mid and End Y 
10:05 Nutsinee & Elli – Going to End-Y
10:13 Joe – Out of the LVEA
10:37 Elli & Nutsinee – Back from End-Y
10:40 Mitch – Back from Mid & End stations
10:43 Dave & Jim – Going to End-Y for atomic clock calibration 
10:58 Mike – Tour of LVEA ahead of VIP tour on 05/19
11:12 Elli & Nutsinee – Checking the TCS-X laser
11:23 Kyle – Back from Mid-X
11:30 Jason & Peter – Finished in the PSL
11:30 Robert – Going into the PSL for periscope work
11:32 Elli & Nutsinee – Out of LVEA
11:33 Jim & Dave – Finished at End-Y 
11:40 Jim – Going to End-X for atomic clock calibration
11:41 Elli & Nutsinee – Checking the TCS-Y laser
11:42 Jeff – DAQ restart
11:45 Filiberto & Andres – Finished in LVEA
11:48 Truck on site for tape robot move
12:04 Elli & Nutsinee – In LVEA working on Hartman sensor at TCS-HT4
12:15 Jim – Back from End-X
12:20 Kiwamu & Jason – Finished with OpLev-PR3 alignment
13:15 Jodi & Jim – In LVEA to recover a broken computer
13:29 Nutsinee & Elli – Out of the LVEA
13:31 Jodi & Jim – Out of the LVEA
14:12 6.8 Magnitude EQ in Japan 
14:15 Robert – Finished with PSL periscope alignment

See D1400363 for overall scheme and cable details.

The 71 MHz sine is ported to D1400155 in TCS-X1-R2-27 SE of BSC1.  From there sync signals go to the three BSCs corners 1 & 3 satellite racks.  At each BSC, the corner 1 signal is passed on to corner 2 with a local cable.

Attached are three plots with the three BSCs showing reference traces from early this morning before the big EQ.  Current traces are from later today.  There are no combs popping up suggesting there are no cross talking sync signals.  There is variablilty between the reference and current noise floors.  Some are lower a few are slightly higher but nothing standing out affecting an entire corner (see ITMX ST2 H2.)  I suspect when the middle of the night comparison is done with similar conditions, they will look even better and that cables are okay.

Low temp baking RGA on BSC6 during maintenance periods -> Also, temporarily shut off instrument air to X-mid VEA while re-routing copper line

J. Oberling, P. King

Summary

We tweaked the beam alignment into the PMC in the horizontal direction using both mirrors M06 and M07.  Final PMC transmitted power was 22.3 W with a visibility of 91.5%.  This did not recover the FSS RevCav TPD voltage, so we transitioned to realigning the FSS RefCav.  We found the beam clipped between mirror M26 and the 21.5MHz EOM.  We corrected this using mirror M25 and the used mirror M26 and the top input periscope mirror to tweak the alignment into the FSS RefCav.  Final RefCav TPD was 1.37V.  Still unclear where the drift in the RefCav TPD is coming from.

Details

We measured the power before the FSS AOM, after the AOM (single pass), and at the base of the RefCav input periscope.  Peter also measured the power between M34 and L05 (after the 35W pickoff for the DBB)

• Before AOM: 63 mW
• After AOM (single pass): 45 mW
• Base of RefCav input periscope: 30 mW
• Between M34 and L05: 297 mW

According to Peter this is all reasonable, so we moved on to the PMC.  Motive here is to make the reflected beam shape more concentric, thereby improving the beam alignment into the PMC, and increasing the transmitted power (and hopefully the FSS RefCav TPD in the process).  We tweaked the horizontal alignment using mirrors M06 and M07, and ended with a final transmitted power of 22.3 W, an improvement of about 0.3 W.  We then had to adjust the alignment into the PMC Refl PD, PD03, by adjusting mirror M20 and thin film polarizer TFP03 (to keep the unlocked voltage reading of the PD at ~-1.5V).

• PMC Refl PD before
  • locked: -0.305 V
  • unlocked: -2.85 V
• PMC Refl PD after
  • locked: -0.132 V
  • unlocked: -1.55 V

This gives a PMC visibility of 91.5%.  Unfortunately this did not significantly increase the FSS RefCav TPD, so it seems we really do have an alignment issue.

This first thing we did was to check the beam position on various irises in the beam path.  We found the beam clipping on the iris high and to the west between M26 and the 21.5 MHz EOM.  We corrected this with M25, and then used M26 and the top periscope mirror to tweak the RefCav TPD.  While a small bit of lateral adjustment was needed, the majority of the adjustment was to pitch.  The final TPD voltage was 1.37 V, and the RefCav Refl PD read 0.060 V while the RefCav was locked.  Unfortunately we are still unclear where the RefCav drift is coming from...

SudarshanK, DarkhanT

We introduced two Pcal lines at 240 Hz and 310 Hz on photon calibrator at Y end.  The Pcal lines are about a factor of 10 above the DARM sensitivity at those frequencies. We will look into any changes in the amplitude and phase of these lines to determine the the position of cavity pole frequency. The cavity-pole has been observed at frequencies listed in  alog LHO #18360.