Displaying reports 55681-55700 of 83068.Go to page Start 2781 2782 2783 2784 2785 2786 2787 2788 2789 End
Reports until 13:17, Tuesday 05 July 2016
H1 CAL (SUS)
jeffrey.kissel@LIGO.ORG - posted 13:17, Tuesday 05 July 2016 (28156)
New (and Old) SUS Oscillator Excitation Signals Added to Frames 
J. Kissel, D. Barker

As Darkhan caught last week (LHO aLOG 28126), when we installed the new individual stage oscillators on the QUADs (LHO aLOG 27733), we neglected to store the excitation channels in the frames. Today, I've added those channels to the ETM QUAD master model, stored inthe science frames at 512 Hz, and restarted the SUS. 

Channels:
H1:SUS-ETMY_LKIN_P_LO_DQ           512
H1:SUS-ETMX_L1_CAL_LINE_OUT_DQ     512
H1:SUS-ETMX_L2_CAL_LINE_OUT_DQ     512
H1:SUS-ETMX_L3_CAL_LINE_OUT_DQ     512
H1:SUS-ETMX_LKIN_P_LO_DQ           512
H1:SUS-ETMY_L1_CAL_LINE_OUT_DQ     512
H1:SUS-ETMY_L2_CAL_LINE_OUT_DQ     512
H1:SUS-ETMY_L3_CAL_LINE_OUT_DQ     512

Model Change to:
/opt/rtcds/userapps/release/sus/common/models/QUAD_MASTER.mdl
LHO VE
kyle.ryan@LIGO.ORG - posted 13:05, Tuesday 05 July 2016 - last comment - 16:15, Tuesday 05 July 2016(28155)
1240 hrs. local -> Connected electronics and energized Y-end RGA filament 
As found, RGA was valved-in to Y-end -> Will take a few scans in an hour or so
Comments related to this report
kyle.ryan@LIGO.ORG - 16:15, Tuesday 05 July 2016 (28172)
Link 

I am short pwr supplies for the electronics so I had to de-energize the filamnet, i.e. leaving the configuration as found.
H1 PSL
jeffrey.bartlett@LIGO.ORG - posted 12:25, Tuesday 05 July 2016 - last comment - 08:04, Thursday 07 July 2016(28154)
Change Diode Chiller Filter (WP #5983) 
Took advantage of laser being down (aLOG #28142 & 28145) to change the water filters in the chiller room. 
Swapped out the Diode Chiller filter. The filter looked fine, but changed it out anyway to see if this had any effect on the rising PSL chiller pressures. 
Did not change the Chrystal Chiller filter. The filter bracket is poorly mounted to the wall and is coming loose. Need to secure the filter bracket to the wall before unscrewing the filter canister.
Comments related to this report
jeffrey.bartlett@LIGO.ORG - 08:04, Thursday 07 July 2016 (28221)
Link 

  48 hours after changing the Diode filter the PSL chiller pressures and flows seem to be flattening out. Will continue to monitor over the next several days. The plan is to swap out the Crystal chiller filter in conjunction with remounting the filter housing.
Images attached to this comment
H1 CAL
kiwamu.izumi@LIGO.ORG - posted 11:36, Tuesday 05 July 2016 - last comment - 14:16, Friday 08 July 2016(28150)
Fit of sensing function completed

With the measured sensing function (28123) in hand, we did an MCMC-based numerical fitting for the sensing function (see E. Hall, T1500553).

The fitting results are

[New sensing function form]

As reported by Evan (27675), it seems that the extra roll off in the DARM response at low frequencies are due to an SRC detuning (or something equivalent). While such detuning should be suppressed by some control loop ideally, we decided to include the detuning-induced functional form in addition to the ordinary single-pole response. We use the following approximated form for the DARM response

S(f) = H / (1 + i f / fc ) * exp( -2 * pi * f * tau) * f^2/(f^2 + fs^2)

where H, fc, tau and fs are the optical gain, DARM cavity pole, time delay and spring frequency. Some details of the derivation will be reported later. Apparently, we now have an additional quantity (i.e., fs) to fit.

Note that since H1 seems to be in (unintentionally) an anti-spring detuning, fs should be a real number whereas it should be an imaginary number for a pro-spring case. Obviously, Q is set to infinity for simplicity.

[MCMC-based numerical fitting]

Following the work by Evan (T1500553), we adapted his code to include the spring frequency as well. In short, it is a Bayesian analysis to obtain posteriors for the parameters that we want to estimate. We gave a simple set of priors as follows for this particular analysis.

The quad plot below shows the fitting result. The estimated parameters are obtained by taking the mean values of the resutling probability distribution. As usual, the two plots on the left hand side show a bode plot of the measured and fitted data. The two plots on the right hand side show the residual of the fit. As shown in the residuals, there are several points which are as big as 20% in magnitude and 6 deg in phase below 10 Hz. Otherwise, the residual data points seem to be within 10-ish % and 4 deg. The code is attached in pdf format.

EDIT: I am attaching the actual code as well.

Images attached to this report
Non-image files attached to this report
SensingFunction.pdf
SensingFunctionipynb.zip
Comments related to this report
kiwamu.izumi@LIGO.ORG - 15:15, Tuesday 05 July 2016 (28170)
Link

A detailed derivation of the new functional form can be found at https://dcc.ligo.org/LIGO-T1600278

kiwamu.izumi@LIGO.ORG - 16:03, Tuesday 05 July 2016 (28171)
Link

EvanG noticed that we have unintentionally included high frequency poles in the previous analysis (28157). So we made the same fitting for the data with all the high frequency poles removed.

Here are the fitting results for the latest data:

  • Optical gain = 9.070764e+05 +/- 8.071988e+02 [cnts/m]
  • Cavity pole = 3.287361e+02 +/- 5.692504e-01 [Hz]
  • Time delay = 5.554816e+00 +/- 3.424867e-01 [usec]
  • Spring frequency = 9.831483e+00 +/- 5.434934e-02 [Hz]

Since the bode plot looks very similar to the one posted above, I skip showing it here. Observe that the time delay is now smaller than it was because we now don't have the high frequency poles.

craig.cahillane@LIGO.ORG - 14:16, Friday 08 July 2016 (28274)CAL
Link 

C. Cahillane, K. Izumi

I have added in a new term to our sensing function fit, an optical spring Q factor to gain back phase information.

From the functional form f^2/(f^2 + f_s^2) we only get a magnitude correction from detuning, but we also expect detuning to slightly affect phase in the sensing function response.

This can be clearly seen in lower right subplot Figure 1 of this comment, where Kiwamu originally plotted the full RSE sensing function.  Here we see that when we have 1 degree of detuning we also have +1.5 degree phase difference at 10 Hz when compared to the sensing function without detuning. 

In the phase residual plot in the original post you can see this phase loss in the actual ER9 sensing measurement.  

In order to try and gain back some of this phase information, we have added in an additional term to the detuning function:

    f^2                        f^2
-----------    ===>  -----------------------
f^2 + f_s^2          f^2 + f_s^2 - i*f*f_s/Q

This adds another parameter to our fit, but lets us get back phase information lost to detuning.

**********

Figure 2 shows Kiwamu's original fit parameters posted above in red alongside my new results in green.
I argue that including the optical spring Q factor has improved the phase fit significantly.  
Quantitatively, here are the phase Χ-Square values:

With Optical Spring Q Χ-Square    = 85.104
Without Optical Spring Q Χ-Square = 819.28

**********

I have modified Kiwamu's SensingFunction.ipynb into a SensingFunctionSimulation.ipynb which fits to both phase and magnitude of the sensing function.  SensingFunctionSimulation.ipynb is attached as a zipped file in this aLOG and is also in a Git repo called RadiationPressureDARM owned by Kiwamu.

Fit parameters:

Optical gain = 9.124805e+05 +/- 8.152381e+02 [cnts/m]
Cavity pole = 3.234361e+02 +/- 5.545748e-01 [Hz]
Time delay = 5.460838e+00 +/- 3.475198e-01 [usec]
Spring frequency = 9.975837e+00 +/- 5.477828e-02 [Hz]
Spring Inverse Q = 1.369124e-01 +/- 3.522990e-03

(I choose to parametrize using inverse Q = Q^{-1} because Q^{-1} can be zero.)
Images attached to this comment
Non-image files attached to this comment
H1 SEI (GRD)
hugh.radkins@LIGO.ORG - posted 11:18, Tuesday 05 July 2016 - last comment - 13:32, Tuesday 05 July 2016(28151)
LHO HEPI Guardians Restarted w/corrected code

WP 5984--Addressing a couple month old bug, see SEI log 989 for details.  Summary: We had added a condition to turn off Damping if a platform trips but this code is common for HEPI and the ISI and the HEPI does not have a damping state so there was an error.  This was reverted and Friday Arnaud added a conditional to the code that excluded the HEPI from this action; it was tested at LLO.  I've updated the python code and restarted all the HPI nodes--no impact to the platforms.  See attached for keystrokes.  WP closed.

Images attached to this report
Comments related to this report
hugh.radkins@LIGO.ORG - 13:32, Tuesday 05 July 2016 (28159)
Link

Duh, of course since the code is common, I actually need to restart all the SEI and ISI guardians as well.  This has been done and the platforms were not affected--thanks guardian programmers!  And thanks to Arnaud for pointing this out to me.  The txt file attached has the restart record.

Non-image files attached to this comment
H1 General (OpsInfo)
cheryl.vorvick@LIGO.ORG - posted 10:02, Tuesday 05 July 2016 - last comment - 11:26, Tuesday 05 July 2016(28149)
Maintenance as of 9:24PT, 16:24UTC - laser is down
microphones Vincent calibration
LVEA Joe batteries
CR Dale tours at noon
all buildings Christina-Karen cleaning
all buildings Fil electorinics inventory
all buildings Joe-Sprague spraying
LVEA Kyle energizing turbo pumps
all buildings Huge checking HEPI pumps
EX and EY JeffK charge measurements
EX and EY Kyle energise RGA filaments
laser Peter-Jason take PSL offline
LVEA DavidM physical measurements
LVEA Nutsinee

swap TCS sled and drain AOM
Comments related to this report
cheryl.vorvick@LIGO.ORG - 11:26, Tuesday 05 July 2016 (28153)
Link

Since last alog:

  • EX-EY - Vincent - microphone-calibration
  • LVEA - Fil - electronicsInv
  • all platforms - Huge - modify HEPI guardians
  • LVEA - Christina/Karen - cleaning
  • Ex-EY - JeffK - EX/EY model restart
  • all buildings - pest control is complete, they checked in as they left

Current:

in LVEA:

  • Nutsinee, TCS
  • Christna, cleaning
  • Fil, inventory
  • David McManus, physical measurements

In end stations:

  • Vincent, microphone calibrations

coming up:

  • DAQ restart
  • small tour to LVEA around 11:30
  • large tour of children at noon
  • restarting laser, H1 recovery
H1 General
cheryl.vorvick@LIGO.ORG - posted 09:18, Tuesday 05 July 2016 (28146)
Morning update: Maintenance is underway - light pipe from LVEA being closed for work on TCS table
H1 PSL
peter.king@LIGO.ORG - posted 09:15, Tuesday 05 July 2016 - last comment - 09:55, Tuesday 05 July 2016(28145)
Front end laser is hobbled 
Diodes 3/4 are seemingly kaput.
Comments related to this report
jason.oberling@LIGO.ORG - 09:55, Tuesday 05 July 2016 (28147)
Link

Filed FRS 5822.

H1 PSL (PSL)
peter.king@LIGO.ORG - posted 07:09, Tuesday 05 July 2016 - last comment - 09:11, Tuesday 05 July 2016(28142)
Laser down 
Came in to find the laser was off due to the power watchdog being tripped.
Both chillers were still running.

I have turned the laser back on but it hasn't returned to where it normally
returns to.  Looking into what happened.
Comments related to this report
peter.king@LIGO.ORG - 07:12, Tuesday 05 July 2016 (28143)
Link 

The laser tripped around 4:15 this morning.
peter.king@LIGO.ORG - 09:11, Tuesday 05 July 2016 (28144)
Link 

Looks like the NPRO tripped out.  Maybe due to a minor power surge due to the start of the
week?

    Pre-modecleaner had some problems locking irrespective of the reference level.  Found
that a small tweak to the horizontal alignment brought things back right away.

    Note in passing: with no light the output of the locking photodiode was ~ +29 mV.
Unlocked (ie with light incident on the pre-modecleaner) the output was ~ -230 mV.
Which is sort of low, which might be consistent with a small mis-alignment.  The
locking photodiode is a 1 mm InGaAs photodiode after all.
H1 ISC
marie.kasprzack@LIGO.ORG - posted 15:06, Monday 04 July 2016 (28139)
Beam position on the test masses

The beam position on the test masses is estimated from the a2l gains from the last minimization (method explained in alog 22426)

The gains values before and after the mimization are attached in a2l_gains_1151366417.mat.
The corresponding beam positions are reported in each suspension base in the Fig.1 attached. We can see that the beam is not more off-centered than previously.

However, we can observe that the beam hits the ITM and ETM in differents vertical places now in each cavity, suggesting an increase of the beam tilts in PIT with respect to the optical axes (HARD PIT).
That is what I tried to represent with the projection in Fig. 2, where you can imagine the cavities facing you: the figure axis orientation is the ETMs coordinates orientation.
The YAW tilts are reduced in both cavities. But their directions were opposite before the a2l minimization whereas now both cavity axes have a negative YAW tilt (in the ETM coordinates).

I don't know when the script was run for the last time before that, but it could give an indication that the beam is now more tilted in HARD PIT at 40W, and it enters the cavities from the lower area of the ITMs. 

 

Arm Before a2l After a2l
X

 D pit  = 1.3 mm

D yaw = 9.4 mm

D pit  = 7.8 mm

D yaw = 2.4 mm
Y

D pit  = 2.3 mm

D yaw = 6.5 mm

D pit = 8.0 mm

D yaw = 6.3 mm
Images attached to this report
Non-image files attached to this report
a2l_gains_1151366417.mat
H1 ISC (ISC)
haocun.yu@LIGO.ORG - posted 14:30, Monday 04 July 2016 (28140)
HARD Yaw Loop Low Noise Measurements

Sheila, Jenne, Haocun

We took measurements on the C/DHARD yaw Loops with low bandwidth last Friday.

We firstly turned on the new filter to move compensation peaks for C/DHARD Yaw, then turn off the boost to win more phase. The gain was then lowered to ~half (CHARD_Y: -0.7 ---> -0.3, DHARD_Y: 40 ---> 19), and the new cutoff filters can be turned on.

These steps has been added in the Guardian, and we took measurements with the low noise loop, as attached below.

Both of the UGF are about 3.5Hz at 40 W now, which were ~5Hz before.

Images attached to this report
Non-image files attached to this report
cy04.fig
dy17.fig
H1 General
vernon.sandberg@LIGO.ORG - posted 14:06, Monday 04 July 2016 (28141)
Details on ER9

Engineering Run 9 (ER9) will begin next Wednesday. Here are some important details for operations:

Please see https://wiki.ligo.org/LSC/JRPComm/ER9 for more details.

LHO VE
john.worden@LIGO.ORG - posted 19:04, Sunday 03 July 2016 - last comment - 10:21, Monday 04 July 2016(28137)
CP3 Fill

Filled CP3 at ~ 1:50 UTC , 6:50 PM LOCAL Time Sunday.

Opened valve 1/2 turn and observed liquid after 5 minutes, 15 seconds. Windy on site.

Comments related to this report
chandra.romel@LIGO.ORG - 10:21, Monday 04 July 2016 (28138)
Link 

Thanks, John!
H1 SUS
betsy.weaver@LIGO.ORG - posted 15:59, Thursday 30 June 2016 - last comment - 14:46, Wednesday 04 April 2018(28090)
ETM15 Ears bonded

Between yesterday and today, Gerardo and I successfully bonded the ears to core optic mass ETM15, destined for LLO for post-O1 eventual replacement. 

Ear s/n 195 bonded to S3 flat of mass June 29, 2016

Ear s/n 196 bonded to S4 flat of mass June 30, 2016

The first ear (s/n 195) has a series of bubbles along it's edge, but the surface area of these do not add up to more than the allowed amount as per E1000277, so it passes, see pix attached.

The second ear (s/n 196) has no bubbles and is nice full bond. 

Images attached to this report
Comments related to this report
betsy.weaver@LIGO.ORG - 11:54, Friday 01 July 2016 (28118)
Link

Inspection of the bonds this morning showed no change to the nice S4/Ear surface bond.

The small edge bubbles along the S3 Ear have migrated a bit (not worse, just moved a bit).  Therefore, we decided to rewet the edge with solution to see if it would wick in and close some of the bubbles.  This worked to close one of the larger bubbles, but one bubble continued to morph so we'll reinspect Monday.  Note, none of the sizes of the bubbles got bigger, so the surface area of the bubble total remains the same and below spec.

Images attached to this comment
betsy.weaver@LIGO.ORG - 10:02, Tuesday 05 July 2016 (28148)
Link

Attached is a picture of what the bubbles in the ETM15 S3 Ear bond look like today (recall, it was bonded last Wed so it has now been over 5 days since initial bond).  Apparently over the weekend, the bubbles ran inbound a bit further.  I estimate the surface are of the bubbles to be near 20mm sq., still under the 50mm sq. spec. E1000278, although it isn't pretty.  I measured the longest streaks to be almost 3mm long, with a width of 0.4mm.  There are no bubbles inward from the edge near the center - anything shown in the picture is a camera reflection.

 

The S4 Ear bond looks unchanged from inspection last week, very good bond, very little bubbles.

Images attached to this comment
betsy.weaver@LIGO.ORG - 14:46, Wednesday 04 April 2018 (41291)
Link

Pictures of this ear bond taken by Danny at LLO just before use at LLO, indicate that the bubbles have not changed shape or size since the picture attached July 2016.  Phew, said both Gerardo and I.

Images attached to this comment
H1 SUS (DetChar)
betsy.weaver@LIGO.ORG - posted 15:15, Tuesday 21 June 2016 - last comment - 23:54, Saturday 02 July 2016(27893)
TUESDAY Maintenance SUS OSEM noise hunt - SAT AMP Power Cycles

Richard, Filiberto, Ed, Betsy

Following on from Andy's probing alog 27841 regarding funny looking OSEM spectra, today we looked into a few fishy signals.  Based on spectra he took from before and after the early June power outage which show signal changes, he and Jenne identified the following set of problematic OSEM signals.  I've annotated the list with status as to what we found or fixed today:

 

ITMY L2 LR - Fixed after power cycling the Satallite Amp box (see alog below)

ITMY R0 RT - Signal looks funny before power outage, old problem, TBC...

MC1 M3 UL - Signal looks funny before power outage, old problem, TBC...

PRM M2 UR - Fixed after power cycling the Satallite Amp box (see alog below)

PR2 M1 T2 - TBC...

PR2 M3 UL - Giant nominal YAW Bias which has been on this SUS for over a year - very little signal on OSEM - mechanical fix when vent

PR2 M3 LL - Giant nominal YAW Bias which has been on this SUS for over a year - very little signal on OSEM - mechanical fix when vent

SR2 M1 LF - Funny comb feature, TBC...

SR2 M1 T1 - Funny comb feature, TBC...

SR2 M1 T3 - Funny comb feature, TBC... 

ETMX L2 LL - 50Hz turn up noise, TBC... Turn up is due to LOCK ACQ PUSHING, turn up not present during nominal SUS damping, no LOCK ACQ, see below plot

ETMX L2 LR - 50Hz turn up noise, TBC... Turn up is due to LOCK ACQ PUSHING, turn up not present during nominal SUS damping, no LOCK ACQ, see below plot

ETMX L2 UR - 50Hz turn up noise, TBC... Turn up is due to LOCK ACQ PUSHING, turn up not present during nominal SUS damping, no LOCK ACQ, see below plot

 

ETMY L2 UR - 50Hz turn up noise, TBC... Turn up is due to LOCK ACQ PUSHING, turn up not present during nominal SUS damping, no LOCK ACQ, see below plot

IM3 M1 LL - TBC...

 

We plan to pursue ITMy R0 and SR2 this week at next opportunity.

Comments related to this report
betsy.weaver@LIGO.ORG - 15:43, Tuesday 21 June 2016 (27894)
Link

Before doing the sat amp power cycle, we first tried a coil driver power cycle on a few of our funny OSEM sets.  This did not appear to clear the errant noise in any of the 4 cases.  We then embarked on the sat amp power cycle which cured the 2 shown in the above list.  Tomorrow we hope to revisit ITMY R0 RT and SR2 M1 which we have left off troubleshooting today with only coil driver OFF spectra.  (Betsy, tomorrow you should use the attached spectra as a jump off point.) 

TBC...  Note the wildly different looking symptoms both of which were seen by Lundgren in 20675 AUG 2015.

Images attached to this comment
betsy.weaver@LIGO.ORG - 15:45, Tuesday 21 June 2016 (27896)
Link

Attached is the ITMY L2 OSEM signal spectra shown from before and after today's fix.  The PRM M2 OSEM before and after-fix spectra are very similar to this.

Images attached to this comment
betsy.weaver@LIGO.ORG - 09:58, Wednesday 22 June 2016 (27911)
Link

ETMX High freq turn up during LOCK ACQ, not a stand alone OSEM signal feature.

Images attached to this comment
betsy.weaver@LIGO.ORG - 10:03, Wednesday 22 June 2016 (27912)
Link

ITMy R0 RT investigation - this morning Richard and Fil performed another round of tests on the ITMy R0 RT (shared cable and electronics with R0 LF, M0 RT, M0 LF).  After power cycling the SAT box, other SAT box cable reseating, and reseating of the main cable to the chamber, the noise on this channel still exists.

SR2 M1 bouncy noise on 3 of 4 TOP investigation - Richard and Fil powert cycled the Sat AMp box for this set of 4 OSEMs, but the noise is still there.

TBC...

andrew.lundgren@LIGO.ORG - 23:54, Saturday 02 July 2016 (28136)DetChar, ISC, SUS
Link 

As requested by Betsy, I've made another set of spectra of the OSEMs. The green line is July 1 10:18 UTC. The reference time (black) is a time near the Boxing Day event (Dec 26 2015 4:30 UTC). This is because the OSEMINF channels are only stored in the commissioning frames, and those aren't stored for very long. But we did store them around events in O1.

If we need to do these checks often, then we will need to 1) Store the OSEMINF channels in raw frames. 2) Occasionally save commissioning frames for some time in known-good states 3) Write some code to dump spectra to a file occasionally.
Non-image files attached to this comment
Displaying reports 55681-55700 of 83068.Go to page Start 2781 2782 2783 2784 2785 2786 2787 2788 2789 End