Displaying reports 67441-67460 of 86956.Go to page Start 3369 3370 3371 3372 3373 3374 3375 3376 3377 End
Reports until 09:44, Wednesday 29 July 2015
H1 General
jeffrey.bartlett@LIGO.ORG - posted 09:44, Wednesday 29 July 2015 (20033)
08:30 Meeting Minutes 
The Tuesday maintenance day was a bit rough but successful.
CDS will be working on PEM wiring
DtEng commissioning work:
PSL – TTFSS testing and commissioning
           PD power budget
           ISS Outer Loop electronics 

PCAL – End-X clipping investigation

ALS – Diff calibration measurements

PEM – Cabling work on the roof
             Railed sensor at Mid-X


Safety Meeting: 
   John asked the GSA cars be kept available especially during the Tuesday maintenance window for onsite work. All car use must be entered in the log, and the keys returned to the key box when finished with the car. It was stressed NOT to eat or leave food and drinks in the cars, as this attracts rodents to the cars, with rather unpleasant and expensive repairs.
H1 CDS (DAQ)
david.barker@LIGO.ORG - posted 08:16, Wednesday 29 July 2015 (20026)
CDS Maintenance Summary

h1susey BIOS change

Mike Thomas, Dave, Jim:

Mike took detailed photographs of l1susey's BIOS screens. After reviewing them and those of the slower front end computers Jim had some changes to try on h1susey. These were installed and it looks like we have not seen an EY IOP glitch since then.

RCG 2.9.6 upgrade

Rolf, Jeff, Betsy, Jim, Dave:

All front ends were upgraded to RCG 2.9.6. The IPC file was created from scratch. All front end models were restarted. Detailed alog on its way.

PCAL duotone channel to DAQ

Rick, Dave:

the models h1calex and h1caley were modified to write the FPGA duotone channel to the DAQ commissioning frame.

Cosmic Ray Channel to DAQ

Richard, Dave:

h1pemcs was modified to write the TRIG channel from the cosmic ray detector to the science frame.

OBSERVATORY MODE install

Vern, Dave, Stefan:

h1odcmaster was modified to add the H1:ODC-OBSERVATORY_MODE EPICS channel. The associated MEDM screen was added to the SITEMAP under the OPS tag.

ISC IOP model settings

Dave:

The PCAL models at the end stations require the DUOTONE loop back path to allways be engaged. I modified the safe.snap for the models h1iopisce[x,y] to ensure this is so. SDF will altert if they are turned off.

New SUS PI models and DAQ configuration:

Matt, Sheila, Joe B, Dave:

Installed Monday, DAQ configued Tuesday. New h1susetm[x,y]pi models were started in the end station SUS front ends. To avoid the "DAQ too small" error two channels were added at full rate but filled with zeros to minimize impact on commissioning frame size. DEMOD channels were added to DAQ at 4kHz rate.

Other New user models

Hugh, Jeff, Kiwamu, Daniel:

Many user model changes other than those detailed above went in: New ISI models from HAMS and BSC, new ASCIMC model, some SUS models showed a DAQ change (investigation needed), PSL PMC finally applied its 32kHz to 16kHz DAQ channel transition.

DAQ Restart:

Jim, Dave:

The DAQ was restarted to support the above changes. Both frame writers continue to be completely stable.

Restart Log:

The models restart log is attached, due to the RCG upgrade it is lengthy.

Non-image files attached to this report
restart_report_28july2015.txt
H1 CDS
jeffrey.bartlett@LIGO.ORG - posted 08:08, Wednesday 29 July 2015 (20025)
Reset CDS Errors at End Stations 
Reset the following CDS errors:
H1SUSETMY TIM, ADC
H1SUSETMY TIM
H1SUSTMSY IPC

H1IOPSEIEY IPC
H1ISIETMY  IPC

H1ALSEY IPC
H1ISCEY IPC

H1IOPSUSEX ADC
H1IOPSEIEX IPC

H1ALSEX IPC
H1ISCEX IPC
H1 ISC (ISC)
lisa.barsotti@LIGO.ORG - posted 02:43, Wednesday 29 July 2015 - last comment - 08:13, Wednesday 29 July 2015(20020)
Interferometer re-locked to low noise, measurements for noise budget, MICH and WFS centering cut-offs 
Evan, Stefan, Sheila, Matt, Lisa

The official goal of tonight was to make measurements for the ultimate noise budget plot that Evan is about to produce (work still in progress).

The unofficial goal was to improve the sensitivity between 50 - 100 Hz, and investigate  the noise that is obsessing Stefan these days . 

More details will follow tomorrow, but after Tuesday maintenance, three earthquakes and some in principle innocuous but effectively disruptive measurements, we finally managed to relock robustly and make a couple of (alleged) improvements (1/1.5 in Valera's scale of awesomeness):

- despite some recent MICH feed-forward tuning, MICH still had some residual coherence (< 0.3) with DARM between 50 and 100 Hz. We saw room for improving the current cut-off, so Matt added another filter to the LSC-MICH filter bank (FM9, EBS50) which only loses a few degrees of phase at 10 Hz, but provides about 10 dB of attenuation between 50 and 100 Hz. The coherence is now reduced < 0.1 above 50 Hz;

- starting by staring at some recent Bruco reports which showed some suspicious (even if small) coherence with the ASC AS DC signals below 100 Hz, we ended up (re)discovering that the current WFS centering loops ASC_AS_A / AS_AS_B --> OM1 / OM2 have a simple cut-off at 100 Hz (CLP100 in H1ASC-DC4/DC3 P/Y). The existing LP8 filter was not stable, so now there is a new cut-off at 20 Hz (ELF20).

Both these filters have been tested a couple of times during the entire locking sequence, so we leave them on.

We leave the interferometer locked undisturbed ~ 2:15 AM (July 29 9:15 UTC). 

P.S.: For the morning crew, as Sheila reported , the locking sequence doesn't currently work automatically to low noise because the ETMX ESDs are not turning off.
Images attached to this report
Comments related to this report
evan.hall@LIGO.ORG - 06:52, Wednesday 29 July 2015 (20023)
Link

Another task is to automate some CARM gain redistribution in the guardian.

Right now in full lock the CMB common gain is −22 dB, the fast gain is +7 dB, and the LSC-MCL gain is 240 ct/ct. We can reduce the input-referred noise of the SNB+CMB by a factor of 2 by changing these values to −15 dB, 0 dB, and 107 ct/ct.

[In fact, from a noise perspective it would probably be even better to do a little more redistribution by removing some gain from the IMC ao path (currently it's −2 dB) and adding it to the CMB common gain.]

keita.kawabe@LIGO.ORG - 08:13, Wednesday 29 July 2015 (20027)
Link

Since the IFO was still locked when I came in, at around 8:06AM local time I started manually reallocating the CM and MC board gain as Evan suggested:

[CM common, CM fast, LSC MCL, MC AO] =

 originally [-22, 7, 240, -2]

 then to [-15, 0, 107, -2]

 then to [-12, 0, 107, -5]

Finished at around 8:11 AM.

[update] After running in this state for ~30min, the IFO lost lock during the morning meeting. I manually reverted the CM board and MC board gains back as I wasn't sure which part of these is NOT touched by the guardian when locking.

H1 ISC
matthew.evans@LIGO.ORG - posted 02:24, Wednesday 29 July 2015 (20019)
OM dithers reduced

The OM dither lines (around 1.7kHz) are not being used, so I turned them down by a factor of 10.

H1:OMC-ASC_P1_CLOCK_GAIN = 0.1

I'll leave them on to make sure that we don't run into DAC bit-noise problems (e.g., no HF signal gathers the DAC noise around DC, which is not fun).

Images attached to this report
H1 SUS
matthew.evans@LIGO.ORG - posted 02:05, Wednesday 29 July 2015 - last comment - 09:08, Wednesday 29 July 2015(20018)
Excited BS modes

Occasionally, we ring up the BS butterfly mode (2.5kHz), the BS violins (300 Hz) and something at 41Hz.  What is that thing at 41Hz (which is always present, though usually not so big), and how are we exciting the other BS modes?

Images attached to this report
Comments related to this report
matthew.evans@LIGO.ORG - 02:29, Wednesday 29 July 2015 (20021)
Link

Is the line at 75Hz from the ring heater fans, as in LLO?

jeffrey.kissel@LIGO.ORG - 08:19, Wednesday 29 July 2015 (20028)
Link 

The highest Roll mode of the HSTS is modeled to be at 40.3 [Hz] -- I suspect SR2 or SRM as you drive it for lock acquisition, or they could have been rung up during the low-frequency sawtooth waves from the earth we saw last night.
gabriele.vajente@LIGO.ORG - 09:08, Wednesday 29 July 2015 (20031)
Link

At 75 Hz there is coherence with magnetometers and microphones at the Y end. So I guess it's the ring heater.

H1 CDS
sheila.dwyer@LIGO.ORG - posted 01:53, Wednesday 29 July 2015 - last comment - 08:24, Wednesday 29 July 2015(20016)
ETMX ESD not turning off

We noticed that we can't really turn off the ETMX ESD.  We aren't sure why.  

This causes the guardian to hang, in the state LOWNOISE_ESD_ETMY because it checks that the ESD is off. This can be worked around using manual, but the operator has to be carefull not to skip steps if we force the gaurdian to move on.

Comments related to this report
richard.mccarthy@LIGO.ORG - 06:19, Wednesday 29 July 2015 (20022)
Link 

Not sure why this is.  I was able to cycle the power to the High Voltage ESD Amp multiple times from the Binary MEDM screen.  I was also able to turn each channel On and Off individually from this screen as verified at the output of the unit not just the read-back.
richard.mccarthy@LIGO.ORG - 07:42, Wednesday 29 July 2015 (20024)
Link 

We need to update the channel that is used to turn the ESD on  and off.  I verified again this morning that the Binary switch does in fact work.
jeffrey.kissel@LIGO.ORG - 08:24, Wednesday 29 July 2015 (20029)ISC, SUS
Link 

I second what Richard says -- the Beckhoff binary signal that *was* used to control the HV driver on ETMX has now been replaced by similar "fast front-end" binary I/O that's at ETMY. So, for each quadrant, to turn off the high voltage, set the EPICs records 
H1:SUS-ETMX_BIO_L3_${QUADRANT}_VOLTAGE_SW to 0 and
H1:SUS-ETMX_BIO_L3_${QUADRANT}_HVDISCONNECT_SW to 0.

This has been true since Richard cabled up the LVLN driver yesterday afternoon (see LHO aLOG 19994).
H1 ISC (ISC)
stefan.ballmer@LIGO.ORG - posted 01:25, Wednesday 29 July 2015 (20015)
test point reurning zeros instead of data 
Sheila, Stefan

We lost the interferometer a couple of times in TR_CARM, but where able to track it down to a test point data access error (through hcdu.avg). (We used this to zero the offsets for the arms.) 

For some unexplained reason the test point for LSC-TR_X_QPD_B_SUM_IN1 was returning zero instead of the actual arm power numbers. We verified this with data viewer - but just after we convinced ourself that this problem was real, the data started to flow again.

Sure enough the script worked again...
H1 ISC
jenne.driggers@LIGO.ORG - posted 19:55, Tuesday 28 July 2015 - last comment - 09:18, Wednesday 29 July 2015(20008)
Global burt restore guardian option

[Jenne, StefanB, Cheryl]

We were having some trouble getting the IMC WFS to converge (WFS came on, looked okay for a while, then started dragging the MC transmitted power down), so we implemented and tested the new global burt restore state, accessible from the ISC_LOCK guardian. 

In the end, the specific problem with the IMC WFS was that the ISC input filters on the M3 stage of the MC mirrors (definitely MC1, maybe others) had gain of zero, so the WFS signals weren't getting through to the optics' outputs. 

The solution we created, which should solve all kinds of problems, is a guardian state that does a global burt restore to a recent set of autoburt snapshots. This state has a date and time hard-coded in the guardian script, although it is easily change-able if we find a more preferable time.  Currently, it is restoring to the autoburts of 28 July 2015, 07:10.  To select this state, you need to go to "manual", since there are no edges to get there from any other state.  When it has finished the restores, it will immediately go to and run the Down state. 

The list of snapshots that are restored is:

Perhaps though, we should just restore *every* snapshot that is captured by autoburt?

Comments related to this report
jeffrey.kissel@LIGO.ORG - 08:28, Wednesday 29 July 2015 (20030)CDS, GRD
Link 

J. Kissel, J. Driggers

Use this feature with caution, as we found yesterday evening during the rest of recovery (LHO aLOG 20011), BURT restoring to a single time with the IFO was at low-noise isn't necessarily the right time to BURT restore to, especially until we've caught all of the settings that have fallen between the guardian and SDF cracks.
jameson.rollins@LIGO.ORG - 09:18, Wednesday 29 July 2015 (20032)
Link

I really don't like this as a solution to whatever problem you're trying to solve.  Is there something wrong with the SDF system that is causing you to resort to such a sledgehammer approach?

H1 GRD
cheryl.vorvick@LIGO.ORG - posted 18:18, Tuesday 28 July 2015 - last comment - 11:07, Wednesday 29 July 2015(20009)
Breaking the IFO Lock for Maintenance:

For Maintenance this morning I needed to break the IFO lock, so recorded the steps used today.

- Besty, Jeff, TJ, Cheryl

Comments related to this report
sheila.dwyer@LIGO.ORG - 02:02, Wednesday 29 July 2015 (20017)
Link

The reason that requesting ISC_LOCK to down doesn't work anyore is because I made down not a goto state.  This means that there is no path from NOMINAL LOW NOISE to DOWN.  (We were having problems with unintentially going to DOWN.)  So when you request DOWN, the guardian doesn't actually go there.  To force it to do that, you can go to manual mode and select DOWN. 

cheryl.vorvick@LIGO.ORG - 11:07, Wednesday 29 July 2015 (20035)
Link

I understand more now, and was not aware that you had changed that on purpose.

No suggestion for a change, just reporting what I was asked to try and the results I got.

H1 ISC (ISC)
stefan.ballmer@LIGO.ORG - posted 02:41, Thursday 23 July 2015 - last comment - 14:53, Monday 24 August 2015(19856)
Coherent broadband noise in OMC_DC_SUM 
We observed broadband coherence of OMC_DC_SUM with ASC_AS_C_LF_SUM and ASC_A_RF36_PIT. We made some numbers and plots, using the 64kHz version of the channels.

First the measurements we made on OCXO oscillator:
- ASC_AS_C sees a RIN of about 5e-7/rtHz above 100Hz (either from H1:ASC-AS_C_SUM_OUT_DQ or from H1:IOP-ASC0_MADC6_TP_CH11). The same is true for its segment 1.
- The calculated shot noise RIN at 20mA (quantum efficiency 0.87) detected is 4.0e-9/rtHz.
- The 4.0e-9/rtHz agrees with DCPD_NULL_OUT_DQ's prediction (8.0e-8 mA/rtHz/20mA).
- DCPD_SUM_OUT_DQ sees a slightly elevated RIN of 4.6e-9/rtHz (9.2e-8 mA/rtHz/20mA).

- The RIN in DCPDA (H1:IOP-LSC0_MADC0_TP_CH12, corrected for the whitening) is about 5.9e-8 mA/rtHz, or RIN = 5.9e-9/rtHz at 20mA/2diodes (~15pm DARM offset)...
- ...or about 3.3e-8 mA/rtHz or 1.2e-8/rtHz at 5.7mA/2diodes (~8pm DARM offset).

- ASC-AS_C_SEG1 (H1:IOP-ASC0_MADC6_TP_CH11) and OMC-DCPD_A (H1:IOP-LSC0_MADC0_TP_CH12) shows a coherence of 0.053 at 20mA, suggesting a white noise floor a factor of 0.23 below shot noise.
- At 5.7mA the same coherence is about 0.13, i.e. the white noise floor is a factor of 0.39 below shot noise.
- These two measurements are in plot 1.

- Taking the last two statements together, we predict a coherent noise of
  - 5.9e-8 mA/rtHz *0.23 = 1.4e-8 mA/rtHz at 20mA/2diodes (~15pm DARM offset)  (RIN of coherent noise = 1.4e-9/rtHz) - The pure shot noise part is thus 5.7e-8 mA/rtHz
  - 3.3e-8 mA/rtHz *0.39 = 1.3e-8 mA/rtHz at 5.7mA/2diodes (~8pm DARM offset)  (RIN of coherent noise = 4.5e-9/rtHz) - The pure shot noise part is thus 3.0e-8 mA/rtHz.

- AS_C calibration:
 - 200V/W (see alog 15431)
 - quantum efficiency 0.8 (see alog 15431)
 - 0.25% of the HAM 6 light (see alog 15431)
 - We have 39200cts in the AS_C_SUM. Thus we have
   - 39200cts / (1638.4cts/V) * 10^(-36/40) (whitening) / (200V/W) = 1.89mW and AS_C. (shot noi
   - 1.89mW/0.025 = 76mW entering HAM6. I.e. we have slightly more sideband power than carrier power (Carrier: 27mW in OMC transmission).
   - Shot noise level on AS_C_SUM is at 2.0e-8 mA/rtHz, corresponding to a RIN of 1.6e-8/rtHz. I.e. the coherent noise seen at 5e-7/rtHz is high above the shot noise. Dark noise TBD.
   - The light entering HAM 6 has a white noise of 5e-7/rtHz*76mW = 3.8e-5 mW/rtHz 
    

Bottom line:
 -We have ~1.4e-8mA/rtHz, or 1.9e-8mW/rtHz of coherent white noise on each DCPD.
 -It corresponds to 3.8e-5mW/rtHz before the OMC, i.e. the the OMC seems to attenuate this component by 2000.
 -This noise stays at the same level (in mW/rtHz) for different DCPD offsets.


Next, we switched back to the IFR for testing. plot 2 shows the same coherences (all at 5.7mA / 8pm DARM offset), but on the IFR. Interestingly now AS_C and AS_A_RF36 start seeing different noise below 2kHz. We convinced our selfs that the higher excess noise seen in AS_A_RF36 is indeed oscillator phase noise from the IFR - so that is clearly out of the picture once of the OCXO. (Evan will shortly log the oscillator phase noise predictions.)


64k Channel list:
H1:IOP-LSC0_MADC0_TP_CH12:     OMC-DCPD_A  (used in plot)
H1:IOP-LSC0_MADC0_TP_CH13:     OMC-DCPD_B
H1:IOP-LSC0_MADC1_TP_CH20:     REFLAIR_A_RF9_Q
H1:IOP-LSC0_MADC1_TP_CH21:     REFLAIR_A_RF9_I
H1:IOP-LSC0_MADC1_TP_CH22:     REFLAIR_A_RF45_Q
H1:IOP-LSC0_MADC1_TP_CH23:     REFLAIR_A_RF45_I
H1:IOP-LSC0_MADC1_TP_CH28:     REFL_A_RF9_Q
H1:IOP-LSC0_MADC1_TP_CH29:     REFL_A_RF9_I
H1:IOP-LSC0_MADC1_TP_CH30:     REFL_A_RF45_Q
H1:IOP-LSC0_MADC1_TP_CH31:     REFL_A_RF45_I


H1:IOP-ASC0_MADC4_TP_CH8:      ASC-AS_A_RF36_I1
H1:IOP-ASC0_MADC4_TP_CH9:      ASC-AS_A_RF36_Q1
H1:IOP-ASC0_MADC4_TP_CH10:     ASC-AS_A_RF36_I2
H1:IOP-ASC0_MADC4_TP_CH11:     ASC-AS_A_RF36_Q2
H1:IOP-ASC0_MADC4_TP_CH12:     ASC-AS_A_RF36_I3
H1:IOP-ASC0_MADC4_TP_CH13:     ASC-AS_A_RF36_Q3   (used in plot)
H1:IOP-ASC0_MADC4_TP_CH14:     ASC-AS_A_RF36_I4
H1:IOP-ASC0_MADC4_TP_CH15:     ASC-AS_A_RF36_Q4

H1:IOP-ASC0_MADC6_TP_CH11:     ASC-AS_C_SEG1  (used in plot)
H1:IOP-ASC0_MADC6_TP_CH10:     ASC-AS_C_SEG2
H1:IOP-ASC0_MADC6_TP_CH9:      ASC-AS_C_SEG3
H1:IOP-ASC0_MADC6_TP_CH8:      ASC-AS_C_SEG4
Images attached to this report
Comments related to this report
stefan.ballmer@LIGO.ORG - 17:01, Thursday 23 July 2015 (19882)
Link 

Some more estimation - this time for frequency noise:

- Shot noise on the refl diodes is given by Pshot=sqrt(2*h*nu*Pr_lock)
- The cavity sensing function is P_9_pk = 4*Gam9*P0 * dNu(f)/(f_p + i*f), where P0 would be the carrier power incident on the PD without the IFO.
- from this we can estimate a frequency (phase) noise of about 8e-11 rad/rtHz.

Gam9=0.219; %alog15874
PSL_low=2; %W
Pr_nolock_low=13.7e-3; %W
PSL_lock=24;
Pr_lock=3.5e-3; %W
IMCt=0.88; 
att=Pr_nolock_low/(PSL_low*IMCt);
P0=PSL_lock*IMCt*att;
inlockdrop=Pr_lock/(P0);

Pshot=sqrt(2*h*nu*Pr_lock);
dphi=Pshot/P0/4/pi/Gam9;
stefan.ballmer@LIGO.ORG - 12:28, Monday 27 July 2015 (19963)
Link 

For reference, I ran the numbers on where we would expect the sidebands to show a resonance feature.

I used the following values:
RITM=1939.3m
RETM=2241.54m
L=3994.485m

Checking accidental sideband resonances in the arm cavities:
Resonance condition: fres = FSR * (q  + (l+m+1)*fTM/FSR)
Free Spectral Range (FSR)    : 37.5258 kHz
Transverse Mode Spacing (fTM): 32.4297 kHz
Checking f1 sideband:
q=242	l+m=0	 Freq. diff. = 18.2284 kHz
q=242	l+m=0				 Freq. from antiresonant = 0.534516 kHz
q=242	l+m=1	 Freq. diff. = 14.2013 kHz
q=241	l+m=1				 Freq. from antiresonant = 4.56162 kHz
q=241	l+m=2	 Freq. diff. = 9.10514 kHz
q=-242	l+m=0	 Freq. diff. = 18.2284 kHz
q=-243	l+m=0				 Freq. from antiresonant = 0.534516 kHz
q=-243	l+m=1	 Freq. diff. = 13.1322 kHz
q=-244	l+m=1				 Freq. from antiresonant = 5.63065 kHz
q=-244	l+m=2	 Freq. diff. = 8.0361 kHz
Checking f2 sideband:
q=1212	l+m=0	 Freq. diff. = 16.0903 kHz
q=1212	l+m=0				 Freq. from antiresonant = 2.67258 kHz
q=1212	l+m=1	 Freq. diff. = 16.3393 kHz
q=1211	l+m=1				 Freq. from antiresonant = 2.42356 kHz
q=1211	l+m=2	 Freq. diff. = 11.2432 kHz
q=-1212	l+m=0	 Freq. diff. = 16.0903 kHz
q=-1213	l+m=0				 Freq. from antiresonant = 2.67258 kHz
q=-1213	l+m=1	 Freq. diff. = 10.9942 kHz
q=-1214	l+m=1				 Freq. from antiresonant = 7.76872 kHz
q=-1214	l+m=2	 Freq. diff. = 5.89804 kHz
stefan.ballmer@LIGO.ORG - 00:19, Wednesday 29 July 2015 (20014)ISC
Link 

Evan, Matt, Lisa

We did one more test for the broadband coherence noise: Common mode gain +3dB vs -3dB

We see no chnge in the broadband level of the noise below 10000Hz.
However, we do see an FSS gain oscillation at 7320Hz showing up in the OMC_DCPD_SUM - but not in AS_C_LF or AS_A_RF36 - in fact that coherence has adip where we get the frequency noise oscillation.
This strongly suggests that our broadband noise is NOT frequency noise.

Evan also took the frequency noise transfer function - a preliminary analysis here also confirms: the frequency noise should be significantly below the O(1e-8mA/rtHz) noise level we see.
Images attached to this comment
stefan.ballmer@LIGO.ORG - 18:53, Sunday 02 August 2015 (20150)
Link 

Note that the higher order mode estimates above were made using a slightly wrong modulation frequency. Updated estimates for the correct modulation frequency are attached to alog 20147
stefan.ballmer@LIGO.ORG - 14:20, Monday 24 August 2015 (20826)
Link 

 - ASC-AS_C GETS 2.5% of the HAM 6 light (see alog 15431) (NOT 0.25%)
daniel.hoak@LIGO.ORG - 14:53, Monday 24 August 2015 (20828)
Link

Actually AS_C gets 400ppm of the light entering HAM6 -- the OM1 mirror was swapped from 5% transmission to 800ppm transmission in early April.  See alog:17738.

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