After bleeding/flushing since Friday should be good to go.  I'll run some static test now to confirm everything is okay.  The valve was replace due to a leak, not from a performance perspective.

- Jason is working on HAM4 and HAM54 OpLev rough alignment.  
- Mike, Gerardo, and Jeff K. continuing the TM Charging Experiments in the corner and end stations. 
- Jodi is recording H1 PEM tilt meter and seismometers serial numbers.
- Betsy & Travis working on the 3IFO Quads in the West Bay.
- Filiberto general cleanup in the LVEA and pulling wires for cameras & OpLevs.
- The commissioning crew is working on OMC alignment.
- Jamie doing a core upgrade to the Guardian code. This will require a DAQ restart.
- Hugh is working on HEPI End-X restart after a Parker valve replacement. There are new Alarm Handlers for HEPI which will be added to the alarm system startup.
- Peter is working on the PMC alignment of the H1 laser. ISS work has been deferred until next week.
- Jonathan will be doing a reboot of the GC systems and the aLOG.   

No ISS noise report will be generated this week as the ISS is still acting up - I didn't have the opportunity to look at it last week.  The alignment into the PMC should also be looked when the time opportunity arises.

The relative power noise measurement is consistent with the last measurement taken and is similar to the reference measurement on file.  Both are well within the requirements for the laser.

For frequency noise measurement the control signal looks nominal.  The error signal is noticeably different from the reference measurement for some reason.  It might be alignment related but will require checking.  It is known that the alignment into the reference cavity, and perhaps onto the RF photodetector, is slowly deteriorating.  This in turn is suspected due to a problem with the frequency shifting acousto-optic modulator.  That will also be looked at when time is granted by the integration crew.

The beam pointing measurement does not make sense compared to the one previously performed.  The numbers report as zero and the plots are significantly off.  The calibration age and control signals look comparable to the previous scan.  The error slopes in the current measurement are significantly off, which would explain the problem seen with the plots.
A second measurement (dbb_pnt-002) was done.  This measurement looks more like the others on file.  Not sure what was wrong with the first measurement other than perhaps the calibration age (~20 minutes) was too old?  The second measurement has calibration ages of less than 10 minutes.

The mode scan measurement is practically identical to the previous one.  Higher order mode content and power the same at 58 and 4.6% respectively.

The aLOG will be restarted at 10am pacific today for regular maintenance.

Please save your entries prior to that point in time.

model restarts logged for Mon 01/Sep/2014
2014_09_01 23:44 h1fw0

unexpected restart of h1fw0

no restarts reported

Thursday, no restarts reported

model restarts logged for Fri 29/Aug/2014
2014_08_29 16:17 h1omc
2014_08_29 16:19 h1broadcast0
2014_08_29 16:19 h1dc0
2014_08_29 16:19 h1fw0
2014_08_29 16:19 h1fw1
2014_08_29 16:19 h1nds0
2014_08_29 16:19 h1nds1
2014_08_29 16:52 h1fw0

no unexpected restarts. OMC model change and associated DAQ restart.

Sadly, the RF phase in ASAIR_A_RF45 changed again (see the previous report).

This time, an optimum demodulation phase for the simple Michelson was found to be 30 deg in ASAIR_RF45 while it was 14 deg last night. If we blame today's table repositioning (see alog 13683) for this phase shift, the ASAIR path would have shifted by (3 x 10⁸ m/s) / (45 MHz) x (16 deg) / (360 deg) = 30 cm. This seemed too big as we did not so much modify the setup. Also, I quickly checked the REFL_A_RF45 by locking PRX on the carrier. The optimum demodulation phase was 6.9 deg and this is slightly off from the last night which was 4.6 deg. No idea what is going on.

Nic, Kiwamu

We made a brief measurement for the ITMX spot position to study the alignment situation.

According to the result, the beam is off from the center roughly by 2.3 cm in yaw toward the Y arm. But, we are not confident with this number as we had some concerns in this measurement. We did not measure the off-centering in pitch yet.

(Method)

We shook the ITMX L2 stage at 2 Hz and monitored the oplev output and ASAIR_A_RF45_Q signal with the Michelson locked on a dark fringe. This is a type of the standard angle-to-length coupling measurement. By taking a transfer function at this excitation frequency from the oplev output to the length signal, we estimated the amout of the off-centering.

(Results)

According to the measurement, the angle motion in yaw was about 0.17 urad at the bottom stage and length coupling was about 0.21 nm both in rms. I used the MICH optical gain calibration that was obtained yesterday (see alog 13664), 5.8 x 10⁹ counts / meters. Also, at 2 Hz, the MICH open loop has a gain of about 20, so the actual longitudinal motion would be 4.14 nm in rms. Dividing the two numbers, we obtained a off-centering of 2.4 cm. The orientation of the off-centering was then indendently checked by introducing some inbalance in the yaw actuation just like the usual spot position measurement (for example, see LLO alog 5010). Note that we assumed that the bottom stage moves at 180 deg off-phase compared with that of the exciation at the L2 stage.

(Some caveat and concerns)

• Oplev has not been accurately calibrated yet. This introduces some uncertainty in the measurement.
• We saw a weird phase discrepancy between the oplev signal and the longitudinal signal. The signals are off by 90 degrees from each other, which seemed very strange.
• We tried to move the beam spot on ITMX by introducing beam translation/angle by moving PR2 and/or PR3, but this did not seem to change the position. We need to think about the ABCD ray trace to understand what we are doing.

Nic, Kiwamu

We locked the PRMI on the carrier light for the first time.

(Variable finesse technique turned out to be good to start)

Since I have been unsuccessful in locking the PRMI in the past two or three days, I wanted to try some other locking technique. We tried LLO's variable finesse technique (see LLO alog 11340) which seemed more reliable than randomly adjusting the gains and triggers. It turned out that it almost repeatably locks the initial low finesse PRMI. Very nice. We then fiddled with the MICH gain which needed some gain correction as we got rid of the offset in the MICH locking point.

POPAIR_B_LF fluctuated a lot presumably due to some misalignment in some optics. POPAIR_B_LF was about 20000 counts in average and ASAIR_B_LF stayed approximately 3000 counts in average. After 15 minutes or so, we lost the lock for some reason, we did not have a close look.

The attached is a video of ASAIR when the PRMI was in lock.

Nicolas, Keita, Dave

The h1omc model was modied. In the ASC block, 8 filtermodules were removed and 4 were added downstream. In the DAQ list, 8 OUT channels were removed and 4 OUT were added (all at 2048Hz). Four CLOCK channels were connected to the CLK outputs of the oscillators (previously they were tee'ed to the SIN outputs).

After the model was restarted, we restarted the DAQ to sync with the new INI file. The safe.snap restore was not good, so I manually burt restored to 16:10 (h1omc safe.snap needs updating).

[Dan, Nic, Koji]

Summary

The OMC alignment servo was commissioned today.

• The sensing matrix (between OM1/2/3 P/Y to OMC QPD A/B P/Y) was measured.
• From OM3 to OMC QPD A/B measurement, the ratio of the spot sizes on the QPDs were inffered.
• From the geometry of the OMC and the spot size ratio, the alignment input matrix was set
  such that the beam angle and position with regard to the beam waist becomes the servo basis.
• From the sensing matrix measurement and the input matrix, the output matrix was set such that the actuation is diagnalized in terms of the servo basis.
   
• The servo loops were engaged and the spot on the QPDs were successfully controlled.

To Do

• Open loop TF measurements
• Noise measurement (inloop & free running)
• Servo shape tuning
• Confirmation of the servo diagonalization
• Dither alignment implementation

1. Sensing matrix

The ISC alignment input of OM1/2/3 was excited at 3.9Hz and 2.9Hz for Pitch and Yaw, respectively.
The spot motion was read out by QPDA and QPDB.

Measured sensing matrix was

| H1:OMC-ASC_QPD_A_PIT_OUT |   | -2.21e-3 +3.05e-3 -1.35e-3 || H1:SUS-OM1_M1_LOCK_P_IN1 |
|                          | = |                            || H1:SUS-OM2_M1_LOCK_P_IN1 |
| H1:OMC-ASC_QPD_B_PIT_OUT |   | -1.05e-3 -1.64e-3 -6.24e-4 || H1:SUS-OM3_M1_LOCK_P_IN1 |
 
| H1:OMC-ASC_QPD_A_YAW_OUT |   | +1.11e-3 -3.13e-3 +1.84e-3 || H1:SUS-OM1_M1_LOCK_Y_IN1 |
|                          | = |                            || H1:SUS-OM2_M1_LOCK_Y_IN1 |
| H1:OMC-ASC_QPD_B_YAW_OUT |   | -6.38e-4 -1.86e-3 -9.55e-4 || H1:SUS-OM3_M1_LOCK_Y_IN1 |

2. Spot size ratio

Since OM3 is a flat mirror it is straight forward to use it as a scanner to infer the beam size on the QPDs.
Unfortunately, I don't have the absolute calibration of the OMs, only the ratio of the beam size was obtained.

The geometrical arrangement of the QPDs and OM3 are found in the attachement.

(H1:OMC-ASC_QPD_A_PIT_OUT) = Sqrt(2/Pi)/omega_A * [(2 L_QPDA) * A_OM3_PIT(f) * (H1:SUS-OM3_M1_LOCK_P_IN1)]
(H1:OMC-ASC_QPD_B_PIT_OUT) = Sqrt(2/Pi)/omega_B * [(2 L_QPDB) * A_OM3_PIT(f) * (H1:SUS-OM3_M1_LOCK_Y_IN1)]

3. Input matrix

(TO BE FILLED)

4. Output matrix

(TO BE FILLED)

5. Servo control

The servo filter did not have the slow integrator which surpresses the DC component. An integrator below 0.1Hz was added to FM6.