Rana, Alexa, Sheila, Peter, Evan

Given last night's strange behavior from REFLAIR_B, we wanted to check the RF powers coming out the BBPD and going into the ISC rack.

With DRMI locked (on 1f, and then on 3f), we used the HP4395A to take an RF spectrum of the "direct" output of the REFLAIR_B diplexer board. This should be the raw RF signal out of REFLAIR_B, with 12 dB of attenuation from a coupler inside the diplexer.

The spectra (adjusted for the 12 dB coupler) are attached.

For 27 MHz, the power into the diplexer is -41 dBm. Using the diplexer schematic (D1300989), this should give -23 dBm at the diplexer's 3x output, which is well below the compression point of the amplifier (ZHL-500HLN+; 1 dB comprsesion occurs at +16 dBm). Similarly, for the 15x output we expect -13 dBm.

The analogous LLO measurement is at LLO#10494.

The second idea that could equalize the magnitude of the positive and negative ion currents in the
ionizer output was to use separately adjustable AC and DC voltages on the field emitting needles. The attempt 
was made with boil off nitrogen gas in the same arrangement that had difficulty achieving equality
of the ion currents in late August 2014 at LHO with AC excitation alone. The experiment showed that
the DC of either polarity and amplitude in combination with AC made no improvement in the equality 
of the ion currents over a range of pressures on the needles between 300 to 900 torr. It was bad 
advice from the "experts" in the electrostatic reduction business. This leaves dry air, tried earlier
this week, as the best method to achieve robust equal magnitude positive and negative ionization. Let's
hope that the optical coating tests being carried out at Caltech show no increase in absorption from the
ionized air.

A report of the ion currents comparing dry air and boil off nitrogen as the carrier gas will be posted later.

A set of scripts was created last week to allow commissioners to switch SEI platforms to SEI’s preferred testing configuration at the end of their shift.

The scripts are very simple for now: 

• They switch the sensor correction on/off using the ezca python library.
• They switch blend filters using the standard SEI Perl script (with smooth ramp)

Those new scripts were put in the svn so they can be remotely adjusted, and improved (made more generic, make classes/methods, etc…):
/ligo/svncommon/SeiSVN/seismic/BSC-ISI/H1/Common/Misc/Test_Configuration_Scripts/

• Switch_To_Test.py 
• Switch_To_Comm.py

To run those scripts:
$ cd /ligo/svncommon/SeiSVN/
$ python Switch_To_Test.py (at the end of the commissioning shift)
$ python Switch_To_Comm.py (when commissioning resumes)

Kiwamu used those scripts at the end of his shift on 10/28/14. JimW and I added the senscor switching capability on 10/29/14, which does not change the way to run the scripts.

model restarts logged for Fri 31/Oct/2014
2014_10_31 08:44 h1fw0
2014_10_31 13:23 h1susauxh34
2014_10_31 13:33 h1broadcast0
2014_10_31 13:33 h1dc0
2014_10_31 13:33 h1fw0
2014_10_31 13:33 h1fw1
2014_10_31 13:33 h1nds0
2014_10_31 13:33 h1nds1
2014_10_31 21:46 h1fw0

one unexpected restart. New h1susauxh34 model (driftmon change) and associated DAQ restart.

Alexa, Rana, Peter, Evan

Tonight we spent some time looking at REFLAIR_B to see if we could improve DRMI 3f locking. This was motivated by the experience at Livingston, where supposedly too much power on the PD causes RF saturation, which in turn screws up the demod phases of the DRMI length signals.

To test this, we drove PR2 with 300 counts at 131.7 Hz, and SR2 with 300 counts at 183.7 Hz. We then looked at the ASDs of RF135I&Q under the following configurations:

1. The first configuration is with no ND filter. Incident power on the PD was 28 mW.
2. Rana and Alexa then added an ND1.0 filter in front of the PD, and made sure to direct the reflection from the filter onto a razor blade dump. Incident power on the PD was then 3 mW.
3. Rana and Alexa then replaced this with an ND0.5 ND filter. Incident power on the PDwas 8 mW.

The results are summarized in the table below. In each cell, the first number is the height of the peak (in cts/rtHz), and the second number is the pedestal that the peak sits on (also in cts/rtHz), and so the difference gives the net power. The bandwidth for all these ASDs is the same (0.1 Hz), so there should be no bandwidth normalizaton issue.

This seems to indicate that the PR2 signal transitions from 135Q to 135I as we lower the power, while the SR2 signal transitions from 135Q to 135I, consistent with the idea that there is some funny business with REFLAIR_B.

We tried locking DRMI on 3f with the ND0.5 filter in place, but found that we could not do it, even after increasing all loop gains by 3 to compensate for the decreased optical power.

The attached spectra perhaps show why. These were taken with DRMI locked on 1f. The dashed spectra are with the ND0.5 filter present, and the solid spectra are with no ND filter. With the ND0.5 filter, RF135I&Q seem to be noise-dominated above 10 Hz or so. Additionally, we note removing the ND0.5 filter does not boost the low-frequency portions of the spectra by 3.4 (=27/8), as we would expect. RF27I appears to be increased by a factor of 5 or so, while RF135Q appears to be increased by a factor of 10 below 1 Hz, and by a factor of 30 at 10 Hz. So there seems to be something strange going on.

Alexa, Kiwamu,

We spent most of the daytime today for

• Measuring the spot position on various optics
• Moving the spot on PR2 by 12 mm to minimize the risk of clipping on the PR2 scraper baffle

There were a few noticable effects after the PR2 spot was moved:

• the right side of the BS elliptic baffle as seen by the analog camera became brighter.
• POPAIR_RF18 increased to 260 uW from 220 uW in the PRMI sb lock.
• However, the optical gain did not change either in PRCL of MICH, indicating that the recycling gain did not change.

Summary of the spot measurements before and after the unclipping.

(Some more notes)

We aimed for a displacement of 16 mm on PR2 in order to bring the beam to the ideal point according to Keita's measurement (see alog 14640).  However, later, I realized that I had picked a wrong number from his entry -- I must have chosen eitehr 14 or 10 mm. Anyway, the resultant dither measurement suggested that we moved it by 11.5 mm to the right direction on PR2. So it happened to fall into a OK displacement. I think that we anyhow improved the clipping situation on the PR2 baffle.

The POP extraction path was then corrected by using the pico-motorized mirror in HAM3. This was not a difficult task as the beam was hitting the swiss cheese baffle and therore it was visible. We then went out and did fine tunings. The pico motor was adjusted to recover the highest green TRX. We steered a steering mirror for each POP diode.

In order to compute the off-centering on HLTS, I used the mirror sizes described in D1101381.

• R = 132.5 mm
• L = 101.4 mm
• D = 206 mm for vertical 
• D = 120 mm for horizontal
• conversion factor for vertical = 52.5 mm per alpha
• conversion factor for horizontal = 94.9 mm per alpha

For computing the HSTS spot position, I used 42.2 mm per alpha (see alog 13765).

This is not blocking our progress right now, but M3 LL FAST IMON is not working, and M3 UR NOISEMON is lower than others by 6 db.

I know that this not the problem of actuation as giving DC offset for each coil moves the optic by roughly the same amount in a correct direction, and VMON works for all coils. There's no reason to believe that there is a big difference in the current/counts between coils.

Doug, Sheila Evan

We used the stage controller to align the PR3 oplev to <0.1 urad in yaw and pitch.

The dip switch board for PR3 now has the serial number H202. There are already H201, H203, and H204 in the oplev cabinet by the PSL. Other unlabeled boards should probably be assigned serial numbers accordingly.

J. Kissel

I've collected all the information necessary to reproduce the corner-station optical lever status report (see LHO aLOG 14749) for the end-station levers. I attach pictures, and tabulate info as before below.

Rack          Board      Optical Lever    Config Board  |------------------ Switch Status ----------------|    Centered?    Raw Segment Counts
              Number                       Installed?    Board    Switch                                        
                                                        CH Name   CH Name    Function    HI   LO    ON/OFF       

SUS H1-R2       1          ETMX               Yes          B0       1       +24 [dB]     X            OFF          No*      *SUS is Misaligned, 
  (pg 1)                 (pgs 2-3)                         B1       2       +12 [dB]     X            OFF                   so can't get info
                                                           B2       3       +6  [dB]          X       ON                
                                                           B3       4       +3  [dB]          X       ON
                                                           B4       5       (1:10)       X            OFF
                                                           B5       6       (1:10)            X       ON
                                                           B6       7       (1:10)       X            OFF
                                                           B7       8       Latch        X            OFF
                                                              Total ETMX TF = (1:10), G = +9 [dB]
 
                2          none               Yes          N/A                                                     N/A

SUS H1-R2       1          ETMY               Yes          B0       1       +24 [dB]     X            OFF          No*      *SUS is Misaligned
  (pg 4)                 (pgs 5-6)                         B1       2       +12 [dB]     X            OFF                   so can't get info
                                                           B2       3       +6  [dB]     X            OFF               
                                                           B3       4       +3  [dB]     X            OFF
                                                           B4       5       (1:10)            X       ON
                                                           B5       6       (1:10)            X       ON
                                                           B6       7       (1:10)       X            OFF
                                                           B7       8       Latch        X            OFF
                                                              Total ETMY TF = (1,1:10,10), G = 0 [dB]
 
                2          none               Yes          N/A                                                     N/A

I can confirm that any whitening stages have been correctly compensated for digitally. In addition, recall that ETMX is compensating for the gains shown above, but it's not necessary. Will fix all the levers and compensation on some (glorious) day (hopefully soon) when the IFO isn't needed.

LVEA: Laser Hazard
Observation Bit: Commissioning

08:00 Alarm on Mid-X Instrument Air; informed the vacuum group
08:18 Aidan – In LVEA to check TCS laser
08:40 Travis – Going to both end stations to work on PCal cameras
08:55 Robert & Sudarshan - End-X to work on PEM
09:00 King Water – On site for water sampling
09:25 Bubba – Repaired Instrument Air compressor at Mid-X
09:30 Filiberto – End-X to work on PEM cabling 
10:05 Jodi & Gary – At Y-End
10:45 Betsy & Sheila – In LVEA for quick survey
13:05 Alistar – Working on TCS in LVEA
13:30 Dave – DAQ restart
14:38 Jeff K. – Going to X & Y end stations to take pictures of OpLevs
15:18 Robert – In the beam tube enclosure between Mid and End-Y

Hanford transportation will operate during swing shift tonight, 10/31.  There's no indication that site crews will work over the weekend.  Over the last two weeks there's been some day-to-day variation in the number of containers moving in and out of ERDF because of high winds.  Transportation and rubble pit operations apparently aren't affected much by rain.

In preparation to correcting the Matrices on HEPI for HAM2, I generated new Plants to see if they'll be too different for the generic controllers.  Here are the Symmeterized L2L & C2C,the latter equivalent to the plant with a HEPI Position loop blend (1,0.)  The L2Ls are the same as the previous (data from 4 Sept 2013) since I did not collect new data.  But the C2C are different.  Attached are two pdf with all the plots to compare.

Bottom line--asside from the VP dof at DC, they all look pretty much the same and I think the generic loops will be fine.

This is related to Hugh's log 14774. To elaborate a bit on Hugh's log, I made a measurement with Stage 1 Damped only and HPI isolated. The first plot shows the GND_T240_X ,  ST1_T240_X  and HPI L4C (out of loop witness). There was no coherence with ground below 0.1 Hz but there was significant coherence with HPI L4C. This meant that HPI was somehow introducing excess low-frequency motion.

We then did the same measurement on ETMY and saw no such excess motion. The second pdf shows the corresponding measurement. Stage 1_Y was very coherent with ground_Y. Jim mentioned he had modified the HPI controllers on ETMY as described in Hugh's log, so we decided to try the same on ETMX in X and Y.

This has made a significant difference to the low frequency performance of Stage 1 as shown in the third file. Performance below 0.1 Hz is much closer to ground motion now.

Dave, Jeff [WP 4927]

the h1susauxh34 model  was modified to add EPICS channels to support the SUS Drift Mon program. The model was restarted at 13:22 and the DAQ was restarted to resync at 13:32. It was not a clean DAQ restart, mx-streams had to be restarted on h1pemmx, h1pemmy, h1susex and h1susauxex.

I reverted out my local changes to the driftmon files (changes needed when we didn't have the supporting epics channels) and svn updated this code to the latest version.

The Driftmon MEDM is linked to the SITEMAP via the SUS button on the left-hand block (see attached)

The python script to update the alarm levels is in the general search path. To run it to update all suspension the command is

driftmon_update.py H1 -H nds2.ligo-wa.caltech.edu -P 31200 -l 3600 -d 600 --minor-stdev=4 --major-stdev=5 --all

This gets data starrting one hour ten minutes ago up to one hour ago.

This closes out WP 4927.

The ever eagle-eyed Peter Fritschel found some duplicate PEM channels in my list of science-frame channels (see earlier aLOG entry 14718).  I had failed to remove an old channel list (H1PEML0.ini) from the compilation.  I redid all the files and tables after that change (see attached rate, channel list files). The commissioning-only counts did not change, as all PEM are in both frames)

I have posted the updated FrameRates spreadsheet and PDF of science, commissioning frame counts.

The science-frame H1 PEM rate drops from 6.79 to 4.19 MB/s (uncompressed). This is still equal to all the ISC channels (LSC,ASC,OMC,OAF,ISC).

Jim Krishna Hugh

The gain was too close to the UGF and there was very little margin.  The zero in the boost where it meets the main controller was lowered from 1.75 to 0.75 hz.  This lowered the boosted gain but it is only a position loop anyway.

Lisa, Rana, Evan, Sheila, Chris, Kiwamu,

The DRMI was stable tonight. So we did several attempts for reducing the CARM offset and the smallest we got tonight was 125 Hz in IR. We will performe careful analysis of lock losses tomorrow.

Lock loss events to lock at are: 7:59:30, 8:11:09 and 8:56 UTC. The second one reached 200 Hz in IR and the last reached 125 Hz. We decreased the MICH gain from 7.9 to 3.0 because its UGF was found to be too high when the arm cavities were held at a off resonant point. According to the lockin demodulators, all the loops stayed without a significant gain change or anything. ALS COMM seemed to tend to lose its lock when it is "IR FINE TUNE". We need to investigate what causes lock losses.

Rana, Kiwamu, Lisa, Alexa, Sheila, Evan

We took some time to measure the 1f and 3f DRMI sensing matrices.

To do this, we used the digital lock-in oscillators on the LSC screen to feed back onto some of the DRMI optics (PR2, SRM, BS, and a combination of 1×BS + 0.02×PR2 that we refer to below as BS+PR2).

The procedure was as follows:

1. In the first digital oscillator lock-in matrix, we wired REFLAIR9I→DEMOD 5, REFLAIR9Q→DEMOD 6, REFLAIR45I→DEMOD 7, and REFLAIR45Q→DEMOD 8. Each demod had an 0.1 Hz Butterworth filter.
2. For each demod, we made all the power appear in I by running, e.g, cdsutils servo -r LSC-LOCKIN_1_DEMOD_5_Q_OUTPUT -g -10 -s 0 -t 100 LSC-LOCKIN_1_DEMOD_5_PHASE.
3. For each optic in turn, we enabled the oscillator in the output matrix. We then turned on a 131.7 Hz oscillator excitation whose amplitude was 15, 3333, 1999, and 1999 counts for PR2, SRM, BS, and BS+PR2, respectively.
4. We monitored the four demod I channels in StripTool. Then we used z avg -s 8 to average them.

Results for the 1f sensing matrix are as follows. The drive amplitudes have been divided out (and the entire matrix normalized).

The matrix elements for SRM (in red) are probably bogus, because we were saturating the SRM actuator while driving.

Then we repeated this for the 3f signals, with REFLAIR27I→DEMOD 11, REFLAIR27Q→DEMOD 12, REFLAIR135I→DEMOD 13, and REFLAIR135Q→DEMOD 14. The drive amplitudes were 15, 9333, and 1999 counts for PR2, SRM, and BS. The results are as follows. Again the drive amplitudes have been divided out (and the entire matrix normalized).

DRMI lost lock before we were able to get the BS+PR2 measurement for 3f.

The current cdsutils installation (r361) has a new and improved NDS avg() function.  The previous version was buggy, was calculating the standard deviation incorrectly,  and had a clunky interface.  This new version fixes those issues:

fixes to standard deviation calculation

The standard deviation was previously being calculated incorrectly and the returned values were wrong (off by some unknown but kind of large factor).  The new version uses the python numpy.var() function to calculate the variance, from which the standard deviation is calculated.  It has been verified to be correct.

channel IFO prefixes no longer need to be specified

Previously, the avg() function required full channel names, with IFO prefixes.  This new version works like the ezca interface whereby the IFO prefix can be left off of the channel name.  This makes things much cleaner, and allows scripts to be portable.  E.g., instead of:

cdsutils.avg(2, IFO+':LSC-DARM_OUT')

just do:

cdsutils.avg(2, 'LSC-DARM_OUT')

new format for returned values

Probably the thing that's going to cause the most trouble is that the interface to the function has been fixed up.  Previously, the function was returning a dictionary of channel:avg key pairs.  This was very clunky to use.

The return value of the function now mirrors the input argument.  So for instance, if a single channel is requested, a single avg value is returned.  If a list of channels is requested, a list of average values is returned, in the same order as the input channel list.  So calls like:

avg = cdsutils.avg(2, 'LSC-DARM_OUT').values()[0]

can now just be:

avg = cdsutils.avg(2, 'LSC-DARM_OUT')

If the stddev option is provided, the output will be an (avg, stddev) tuple, or if multiple channels is requested, a list of such tuples, e.g.:

avg, stddev = cdsutils.avg(2, 'LSC-DARM_OUT', True)

I have fixed all calls to cdsutil.avg() that I could find in the USERAPPS/release.  I likely didn't catch everything, though, so be aware of the new interface and update your code appropriately.