Sudarshan, Gabriele

Since yesterday we were not able to move the beam on the ISS QPD or PDs using the picomotors, today we tried to use IM3 to change the beam position. In brief, we are able to see a change in the QPD signal when we move IM3, so it seems there is a beam on the QPD. We read a sum of about 830 count on the QPD, which corresponds to 0.5 V. The transimpedance should be 100kOhm, so the power on the QPS should be of the order of few microwatts, while we expect 1% of the total power going into the ISS box, which should be more like 0.1 mW.

We couldn't see any change in the mean value of the PD signals, however the RMS could be changed a lot, see the striptool trace. The initial position of IM3 was: PIT 55500, YAW 2600. The one corresponding to the largest RMS in the PDs was PIT 59500, YAW 1600.

The second plot shows a comparison of the PD spectrum (dewhitened) in the original position (red) and in the new position (blue). There is significantly more signal in the new position.

In summary

1. If we move the beam into the ISS box we can change the level of signals on the PDs
2. There still seems to be too low power, even on the QPD
3. We were not able to move the beam using the (old) picomotor, so this is likely not working

Aidan. Greg.

We removed the yellow viewport covers on HAM4 by the Hartmann sensor table (the acrylic covers are still in place). As expected, there was a leakage of the green ALS-X beam coming out of the HWSX and HWSY viewports (the HWSY green beam comes from the reflection of the ALS-X beam from the 50/50 surface of the beamsplitter, the HWSX green beam from the reflection of the ALS-X beam from the AR surface of the BS). The beams are incident on the apertures in the HWS table.

The beams are not centered on the apertures. However, due to the proximity of the HWS table to the H1-TCS-R1 rack (there's about 3"  and a lot of cables between them), and due to adequate clearance of the green beams (~2") from the edge of the apertures, I elected not to move the table any closer to the rack to center the beams more than they already are.

HWSX:

HWSY:

The I/O chassis of h1seib2 died Tuesday evening, requiring a power cycle of the I/O chassis and h1seib2 computer.

The MC2 suspension have been misaligned by the guardian since 8:00 pm last night probably for the green light activity. I restored it at 9 am this morning.

We  opened to both arms yesterday. The attached shows the result of exposing the chambers to the 80K pumps and the arms.

model restarts logged for Tue 23/Sep/2014
2014_09_23 02:28 h1fw1
2014_09_23 11:49 h1ascimc
2014_09_23 12:46 h1ascimc
2014_09_23 12:59 h1ascimc
2014_09_23 16:06 h1broadcast0
2014_09_23 16:06 h1dc0
2014_09_23 16:06 h1fw1
2014_09_23 16:06 h1nds0
2014_09_23 16:06 h1nds1
2014_09_23 16:07 h1fw0

unexpected restart of h1fw1. ASC-IMC model work with associated DAQ restart.

all the models on h1seib2 (Seismic Beam Splitter) stopped running around 7pm Tuesday night PDT. Looks like the IO Chassis is having problems.

Alexa, Keita, Gabrielle, Dan, Sheila

The bottom line: X arm is locked on green, we are having trouble finding the beam on ITMY and it might be helpfull to have a camera on ITMY tomorow. 

Both PLLs are now working.  Both beatnotes needed to be realinged.  I reduced the power on the end Y BBPD, and realinged the laser green power monitor diode which was totally off. 

We spent some time searching for the green beam on the ITMY baffle PDs, but didn't find the real beam, I think. 

There is a beam which doesn't seem to have enough power, which can be found on PD1 at 2.2PIT, 7.3 YAW (20dB gain setting we get 3.6 Volts)  PD4 at -97.8 PIT 74 YAW (3.6 Volts, 20dB setting) When aligned to the center of these points, there is no beam arriving on ISCT1, and we could not find any return beam on the ETM baffle PDs even after a long search.  The ETM baffle PDs are working, since they clearly see the IR when PRMI flashes.  I have left  slow excitations on TMSY pitch and YAW hopping that at some point we will see light on the ITMY baffle PDs. 

Other things today:

Keita and I briefly tried to move the bem spot on PR2, using the output matrix he described here :  alog 13939

To do this we coped the gains from the opticalign filter banks into cal filters for pitch and yaw of iM4, PRM, PR2, and PR3.  However, when I briefly tried moving the spot around I misaligned the cavity. 

Gabrielle and I also tried locking DRMI using the configuration Kiwamu described from last night.  We were able to see any lock longer than a few seconds. 

PRMI however seems to be locking consistenly within a minute. 

Thanks-H

Sudarshan, Peter, Keita, Gabriele

Checking the power on the diodes

According to the electornic schematics, the ISS second loop transimpedance board has two parts:

• the transimpedance has large bandwitdh and a conversion factor of 1600 V/A
• the following part is a "whitening" filter with a DC gain of -20 dB, inceasing after a corner at aout 10 mHz, flattenig at about +66 dB at 10 Hz, and then low passed above 200 Hz. See the first attachment for a Bode plot

With the present input power of 10 W, we should have something like 10 mW into the array, which means 1.25 mW per photodiodes, corresponding to about 1.0 mA of photocurrent. After the transimpedance we should get 1.6 V  and 160 mV at the output of the board. This should corresponds to about 260 counts. However, we see that the RMS of the photodiode signals is about 17 counts and dominated by high frequency, while the mean value is ver close to zero, about 1 count (see second attachment, one minutes of data). It seems that we're not getting all the power we should.

We also checked in the electronics lab, with one spare board, that sending 1 mA at the input gives the expected signal levels both after the transimpedance stage and at the output. We also checked that adding a long cable at the input doesn't have any effect on the result.

Calibration of PD signals

Using the nominal whitening transfer function and transimpedance, we computed the calibration filters t be implemented in the PD filter banks. We don't want to have any 10 mHz pole, so we actaully fitted the whitening ransfer function between 1 Hz and few kHz, see third attachment (blue nominal TF, green implemented TF). Therefore, the PD_OUT signals are calibrated in mA only between about 1 Hz and 5 kHz. Below and above the signals are uncalibrated. This is expecially true for the DC level, which is not correct. Later on, once we'll have solved the missing power problem, we'll implement a calibration in units of RIN.

The result are shown in the forth attachment. The high frequency content of the 1-4 diodes (one board) is clearly different from the 5-8 diodes (the other board). We still don't know if this is due toa really different signal or to a different response of the board. Again, once we'll have solved the missing power problem, we'll see if this difference is still there.

Picomotor game

Right now we are quite sure that the beam is not properly hitting the PDs:

1. the power level is very low
2. the signal level on the eight diodes is quite different
3. there is a large coupling of angular motions to power

So we wanted to move the beam using the two mirrors with picomotors. Of them, we were sure of the cabling of only the older one, which is the one closer to the ISS box and after the telescope. To make the story brief, we moved the picomotor by few 10000 steps in horizontal, bua saw no difference either in the QPD or PD signals. We could however see some "shaking" of the signals. Instead, moving in the vertical direction produced no result. So we're not sure if the picomotor is actually working. As for the second picomotor, we could not understand if it's cabled or not.

More investigations on the pico story tomorrow...

The water level is near the max line and does not appear to need to be filled.

07:56 Hugh running transfer functions on HAM6
08:33 Aidan to HAM4 to connect electronics for Hartmann sensor
08:37 Portable toilet service
08:41 Alexa to end Y to check layout of ISCT table
08:45 Filiberto and Manny pulling cables for TCS near HAM4
08:46 Bubba craning 3IFO equipment at mid X (WP 4862)
09:03 Danny S. to LVEA test stand
09:29 Hugh to HAM6
09:45 Unifirst delivery
09:54 Alexa back from end Y
09:59 Hugh back from HAM6
10:17 Kyle starting work to open beam tube arms (WP 4863)
10:18 Alarm on LT150 cyropump (delivery?)
10:43 Kiwamu compiling and restarting the H1ASCIMC model (WP 4864)
11:46 Kiwamu restarting H1ASCIMC model
12:06 Chris to clean at mid X after lunch
12:44 Kiwamu restarting H1ASCIMC model
12:55 Danny S. to LVEA test stand
12:57 Kiwamu restarting H1ASCIMC model
13:17 Sheila to end Y to lock ALS laser to PSL
13:24 Aidan back to HAM4
~15:20 Fire department on site to check trouble alarm
15:40 Betsy to LVEA test stand
15:44 Peter, Keita to look at electronics racks near HAM2
16:05 Jim B. restarted the DAQ for the H1ASCIMC model change

High dust counts in the Vacuum Prep Lab

Aidan. Greg.

Filiberto helped dress the cables in the H1-TCS-R1 rack. All the connections to the HWS table are now secure. I was able to turn on the HWS cameras and RCX C-Link converters remotely with the Beckhoff system. And I was able to log into H1HWSMSR and successfully connect to the HWS cameras.

HWSY

> serial_cmd -c 0

>> gcp

returns camera information

HWSX

> serial_cmd -c 1

>> gcp

also returns camera information

It appears that around noon each day, including on weekends, both the dust monitor in the beer garden and near HAM 6 are registering high dust counts. A plot of minute trends for the last 30 days is attached. Location 15 is in the beer garden. Location 6 is near HAM 6.

It started near HAM 6 on Sept. 4 and in the beer garden around Aug. 30.

Restarted data concentrator (and frame writers, nds, and broadcaster) to clear the bad DAQ status on the h1ascimc model.

J. Kissel, J. Warner, K. Izumi.

Jim and I were working on ETMX; wiamu rolled over asking us what's up with HAM2 ISI. It had single-saturation tripped on actuators. We've got no idea. Our best guess is Kyle jumping around opening up the ARMs, but it's a terrible guess and probably not right. Sensor correction on HAM2 has been turned off since this morning.

#fortherecord

QUAD 06 (Q6) Phase 1B transfer function plots are attached.   We had a hard time obtaining good coherence in the Transverse TF, so it is a bit hashy.  Will try again.  

Most notably is that, like Q8, the second pitch mode frequency is unexpectedly pushed upward on the main chain.  Recall, we never found the mechanism to fix it on Q8.  Interestingly, both the Q8 and Q6 assemblies are of the same batch of wires and are fresh builds, but by 2 different assembly teams, and on 2 different solid stack/test stand units.  Q8 is an ETM type of QUAD while Q6 is an ITM QUAD, but both main chains have the same pendulum parameters - both are detailed in the 'wireloop' model.

The Q6 data is plotted as QUADTST.

Alexa, Gabrielle, Kiwamu, Sheila

This morning we moved PRMI to the 3F sensors, we used a gain of 3 in the input matrix to move PRCL from REFL 9 I to REFL 27 I, and a gain of 15 to move MICH from REFL 45 Q to REFL 135 Q.  This was locked from about 22:26:55 UTC (september 22) to 22:33:20. 

We then tried to move on to DRMI but have struggled most of the day to get it locked.  We locked it a few times this morning, (21:00 UTC) but haven't been able to recently. 

Also, as is typical recently, the anthropogenic noise is higer durring the evenings than durring the day, there must be an evening shift of hanford work.  Screen shot of the last week is attached. This pattern started in mid august and has been true since then.