Displaying reports 61061-61080 of 84519.Go to page Start 3050 3051 3052 3053 3054 3055 3056 3057 3058 End
Reports until 18:17, Wednesday 09 December 2015
H1 DetChar
jordan.palamos@LIGO.ORG - posted 18:17, Wednesday 09 December 2015 (24092)
~650Hz peak fixed, ALS COMM VCO TUNEOFS set to 2

Following up yesterday's alog 24062.

We think that the ~650 Hz peak was caused by the ALS COMM VCO beating against the DIFF VCO. At times when the COMM VCO is parked at the lower value (as discussed in the earlier alog) the two VCOs are < 700 Hz apart and this beat shows up in darm.  To get rid of this peak, we added a line in guardian so that H1:ALS-C_COMM_VCO_TUNEOFS is set to 2 in full lock. This way, the COMM VCO gets parked at a high value far from the DIFF VCO. See figure 1 if you want to see the actual values of the two VCOs;  the top plot is from yesterday (peak present; the two VCOs are within 700 Hz of each other) and the bottom plot is from today (the two VCOs are >10 kHz apart, peak is not present).

Also attached (figure 2) is a darm spectrum comparing yesterday, when this noise was present, to the current lock. It is clear that the peak between 600 Hz and 700 Hz (and the higher harmonic) is now gone. No other peaks have been observed to appear due to this change. We think this has solved the issue, but we should keep an eye out to make sure it does not return. Also, it will be good to keep beating VCOs in mind if similar wandering peaks show up again.

Jordan, Robert, Sheila

Images attached to this report
H1 General
nutsinee.kijbunchoo@LIGO.ORG - posted 18:10, Wednesday 09 December 2015 (24093)
Lockloss 01:52 UTC

Possibly due to a wind gust that reached almost 40 mph.

H1 ISC
evan.hall@LIGO.ORG - posted 17:48, Wednesday 09 December 2015 - last comment - 19:32, Wednesday 09 December 2015(24091)
IMC-F offloading suffers because of digital EX UIM offset

When we transition DARM control from EX to EY, we ramp off the DARM input into the EX test/PUM/UIM filter banks.

Since the UIM filter bank has an integrator, this leaves a static offset on the output of this filter bank which is cancelled by the offloading of IMC-F to the UIMs.

However, depending on the size of the offset, this can use up a significant amount of the control range of the offloading (which is set by a digital limiter). Today, the EX offloading was hitting this limiter, causing IMC-F offloading to stop and start (see attachment).

Since the offloading signals were trending even further toward saturation (i.e., greater likelihood of IMC-F saturating and causing lockloss), I dropped the interferometer out of observing and zeroed this offset using two one-minute ramps.

We should modify the ISC_LOCK guardian to do this automatically during lock acquisition.

Non-image files attached to this report
Comments related to this report
evan.hall@LIGO.ORG - 19:32, Wednesday 09 December 2015 (24095)

The offloading completely railed at the end of the most recent lock acquisiton (ca. 03:00:00 Z). I have edited the guardian so that this EX UIM offset is ramped down in the CLOSE_BEAM_DIVERTERS state.

This will result in two SDF diffs on EX.

H1 General
nutsinee.kijbunchoo@LIGO.ORG - posted 17:13, Wednesday 09 December 2015 - last comment - 22:20, Wednesday 09 December 2015(24090)
GRB Alert 01:00:08 UTC

The alert was received at 01:00:08 UTC. GraceDB said the event actually happened at 00:59:16.64 UTC. We were out of Observing mode for a few minutes for a non-invasive change to ETMX UIM offset from 00:53:12 - 00:59:17 UTC. We think it's reasonable to not veto the alert.

Comments related to this report
nutsinee.kijbunchoo@LIGO.ORG - 22:20, Wednesday 09 December 2015 (24097)

Another GRB alert received at 03:15 UTC (LLO received it first and contacted us). We were at NLN clearing SDF at the time. The data should be good for analysis even though it wasn't in Observing intent (we hit "Undisturbed" button right after).

H1 SEI
hugh.radkins@LIGO.ORG - posted 16:36, Wednesday 09 December 2015 (24089)
Monthly HEPI Pump Pressure trends--All look Good

Attached are 45 day trends of the pressure out from the pumps and the control drive to the motor.  After seeing the dips very evident in the End control drives, I replaced the CS pump output for 1 2 & 3, which are as flat as PS4, with the outside air temp.  Very clear, the change in temp drives the pumps' need for speed.

Still much noisier than the others but the EX pressure cleaned itself up for some unknown reason a week ago...

And like clock work, the EndY daily and weekly glitches are still present.  Anybody?

Images attached to this report
H1 SEI
hugh.radkins@LIGO.ORG - posted 16:20, Wednesday 09 December 2015 (24088)
ETM ISIs Blends all on 45mHz X and Y

Jenne, Sheila, EvanH, Hugh

We had a fortuitous rapid drop in the wind speeds around 1400pdt and while not attempting to lock, it was a quick study looking at the GS13 signal while changing the blends to see that the 45 mHz were much quieter.  Of course there still is the worry about the ETMX X 45 blend ringing up MCF but we decided that if it does,maybe we can study it or try something.

The blend switch, and why we though it was a good idea given the reduced winds ad the very elevated microseism is clearly seen on the attached plot.

It still took some time to lock, maybe still a little much wind or something else.  Still we decided to not switch the ETMX X blend back fearing that it woould likely break the lock.  So for over an hour we've only had minor flare ups of MCF but it really hasn't grown and faded after just a couple cycles.

Images attached to this report
H1 General
edmond.merilh@LIGO.ORG - posted 15:59, Wednesday 09 December 2015 (24087)
Shift Summary -Day

TITLE:    Dec 9 DAY Shift 16:00-00:00UTC (08:00-16:00 PDT), all times posted in UTC

STATE Of H1: Observing

SUPPORT: Sheila, Hugh, TJ, Jenne, Robert and Jordan

LOCK DURATION: 36min

INCOMING OPERATOR: Nutsinee

SHIFT SUMMARY:

 

ACTIVITY LOG:

16:15  Fil out to LVEA to do some more cable pulling

16:25 Jeff Bartlett and Mitch out to LVEA to do some more work on dust monitor plumbing

16:30  Peter into LDR

16:40  Peter out of LDR

17:01  Jeff and Mitch out of LVEA

17:03  Jeff and Mitch to EX

17:21 Richard called to let me and Mike know that he has started his work in the CER.

17:40  Gerardo out to Y-2-8 to refuel the generator

17:54  Richard, et al, are finished in the CER and are heading down to EY.

18:19 Bubba heading to MX to work on a fan.

18:39 Gerardo back from Y-2-8

21:22  Kyle to Y-2-8 to take some temp readings

21:55 Kyle back to corner station

23:21  H1 is locked at Nominal Low Noise!

23:50  Intention Bit set to UNDISTURBED

H1 General
edmond.merilh@LIGO.ORG - posted 15:50, Wednesday 09 December 2015 (24086)
H1 Intention Bit set to Undisturbed

23:50UTC

H1 SEI
hugh.radkins@LIGO.ORG - posted 11:14, Wednesday 09 December 2015 - last comment - 11:24, Wednesday 09 December 2015(24082)
GS13 Gain Switching--Alternate sequence attempted--No better

TJ & Hugh

With IFO down from elevated winds, we attempted to have the Guardian switch the gains more like how the old SEI COMMANDS script switch the gains--WP5647.

Original svn update 24 Nov alog 23695--Change tested on HAM5 and worked.

7 Dec, ISI trips with EQ reveal problem of this switching but only for HAMs 2 & 3, aLOG 24028.

In alog 24054 I report how the GS13 gain switch when done by the guardian well after the platform was isolated and quiet would still trip the HAM3 ISI.  This led us to believe it was not the timing of the guardian GS13 switching--at the end of Isolation process after/while finishing the driving to the reference CPS location; but, that it was more related to how the guardian was doing the switching.  The guardian switches both FM4 & 5 at the same time whereas the COMMAND script switches all the FM4 and then all the FM5s with a 1 sec sleep between.--See SEI Log 894 comment for code comparison.

Today,TJ modified the guardian code, see comment below, to try simulating the way the COMMAND script switches the Gain.  Bottom line it still tripped.

We even tried reversing the order of the FM4 & 5, that is first FM5 then FM4 to turn off the analog whitening before we increased the analog gain, still tripped... So we still scratch our heads, it's winter, my skin is dry and it itches anyway.

Comments related to this report
thomas.shaffer@LIGO.ORG - 11:24, Wednesday 09 December 2015 (24083)GRD

Below is the code that we tried. I just added in a sleep for 1 second between the switching of the FM4 and FM5 banks in all dofs. When executed, it looked to have worked the same as the old perl script, but there must be some deeper magic that I need to look into.



def switch_gs13_gain(command, doflist):
    """Swtich GS13 analog gain between HIGH and LOW"""
    lf_gs13 = LIGOFilterManager(['GS13INF_'+dof for dof in doflist], ezca)
    if command == 'HIGH':
        log('Switching GS13s to high gain')
        #lf_gs13.all_do('switch', 'FM4','OFF','FM5','OFF')
        lf_gs13.all_do('switch', 'FM5', 'OFF')
        time.sleep(1)
        lf_gs13.all_do('switch', 'FM4', 'OFF')
    elif command == 'LOW':
        log('Switching GS13s to low gain')
        #lf_gs13.all_do('switch', 'FM4', 'ON', 'FM5', 'ON')
        lf_gs13.all_do('switch', 'FM5', 'ON')
        time.sleep(1)
        lf_gs13.all_do('switch', 'FM4', 'ON')
    # To account for the 2s zero-crossing timeout
    time.sleep(3)
    return

(I switched this back to what it was before and committed it back in the svn).

 

Note to me: Had to restart the node in order for it to take any bits of new code. I've seen this before but I'm not sure what warrents a restart vs just a reload. I'm writing this here so I can look back and find the trend.

H1 General (DetChar, PSL)
edmond.merilh@LIGO.ORG - posted 09:45, Wednesday 09 December 2015 (24081)
PSL Status and Past 10 Day Trends
Laser Status:
SysStat is good
Front End power is 30.97W (should be around 30 W)
Frontend Watch is GREEN
HPO Watch is RED
 
PMC:
It has been locked 14.0 days, 23.0 hr 44.0 minutes (should be days/weeks)
Reflected power is 1.843Watts and PowerSum = 24.85Watts.
 
FSS:
It has been locked for 0.0 days 0.0 h and 6.0 min (should be days/weeks)
TPD[V] = 1.341V (min 0.9V)
 
ISS:
The diffracted power is around 7.185% (should be 5-9%)
Last saturation event was 0.0 days 0.0 hours and 5.0 minutes ago (should be days/weeks)
Laser Status:
SysStat is good
Front End power is 30.97W (should be around 30 W)
Frontend Watch is GREEN
HPO Watch is RED
 
PMC:
It has been locked 14.0 days, 23.0 hr 44.0 minutes (should be days/weeks)
Reflected power is 1.843Watts and PowerSum = 24.85Watts.
 
FSS:
It has been locked for 0.0 days 0.0 h and 6.0 min (should be days/weeks)
TPD[V] = 1.341V (min 0.9V)
 
ISS:
The diffracted power is around 7.185% (should be 5-9%)
Last saturation event was 0.0 days 0.0 hours and 5.0 minutes ago (should be days/weeks)
Laser Status:
SysStat is good
Front End power is 30.97W (should be around 30 W)
Frontend Watch is GREEN
HPO Watch is RED
 
PMC:
It has been locked 14.0 days, 23.0 hr 44.0 minutes (should be days/weeks)
Reflected power is 1.843Watts and PowerSum = 24.85Watts.
 
FSS:
It has been locked for 0.0 days 0.0 h and 6.0 min (should be days/weeks)
TPD[V] = 1.341V (min 0.9V)
 
ISS:
The diffracted power is around 7.185% (should be 5-9%)
Last saturation event was 0.0 days 0.0 hours and 5.0 minutes ago (should be days/weeks)
 
Images attached to this report
H1 General
edmond.merilh@LIGO.ORG - posted 08:46, Wednesday 09 December 2015 - last comment - 13:31, Wednesday 09 December 2015(24078)
Taking advantage of Environmental Down time

Mike Landry has given the final "OK" to proceed with maintenance tasks this morning due to the IFO being down due to high winds. Livingston has been contacted regarding our plan. They are currently back "UP".

Comments related to this report
edmond.merilh@LIGO.ORG - 13:31, Wednesday 09 December 2015 (24085)

This period ended at ≈ 19:00UTC

H1 CDS (DAQ)
david.barker@LIGO.ORG - posted 08:23, Wednesday 09 December 2015 (24077)
CDS model and DAQ restart report, Monday, Tuesday 7th,8th December 2015

O1 days 81,82

model restarts logged for Tue 08/Dec/2015
2015_12_08 11:51 h1broadcast0

Maintenance day, DMT channel added to broadcaster

model restarts logged for Mon 07/Dec/2015

No restarts reported

H1 General
edmond.merilh@LIGO.ORG - posted 08:08, Wednesday 09 December 2015 (24076)
Shift Summary -Day Transition

TITLE: Dec 9 DAY Shift 08:00-1t6:00UTC (00:00-08:00 PDT), all times posted in UTC

STATE Of H1: Environment

OUTGOING OPERATOR: Patrick

QUICK SUMMARY: Doesn’t look like a good day for locking unless the wind dies back significantly.

LHO General
patrick.thomas@LIGO.ORG - posted 08:04, Wednesday 09 December 2015 (24072)
Ops Owl End Shift Summary
TITLE: 12/09 [OWL Shift]: 08:00-16:00 UTC (00:00-08:00 PDT), all times posted in UTC

STATE Of H1: Unlocked
SHIFT SUMMARY: Lock loss likely from earthquake. High winds and microseism have hindered relocking ALS. Tried different combinations of ISI blends to no avail. The Y arm has been the least stable.
There is a timing error on H1SUSETMX.
INCOMING OPERATOR: Ed
ACTIVITY LOG:

10:41 UTC Lock loss. Arms not staying locked on green. Put ISC_LOCK guardian to DOWN to wait out earthquake. Adjusted REF_SIGNAL to increase ISS diffracted power.
13:38 UTC Started attempting to relock
15:33 UTC Bubba driving down arms to assess tumbleweed buildup
H1 PSL (PSL)
peter.king@LIGO.ORG - posted 07:30, Wednesday 09 December 2015 - last comment - 09:24, Wednesday 09 December 2015(24073)
reference cavity transmission
In checking on the reference cavity transmission this morning, I noted that it took a
dive over the last day in particular, and over the last three days in general.  Also
attached is a plot of the IMC locked status.

Looking over the trend data, it appears to me that the reference cavity transmission
suffers when there are long periods of time when the IMC is trying to acquire lock.
My hypothesis is that the IMC trying to acquire lock means that the VCO frequency of
the double-passed AOM swings from one extreme to the other.  This might result in
heating of the AOM, which in turn changes the alignment of the AOM with respect to
the input beam.  We don't observe an alignment change on the nearby EOM because the
EOM is too close for a small alignment change to be noticed.  Of course we observe
the alignment change on the iris located in front of the reference cavity, since that's
some distance away from the AOM (~2 m).

Also attached is a plot of the reference cavity transmission and VCO frequency.

One might ask, why didn't you just fix it by re-aligning the AOM previously.  And the
convenient answer is that the AOM alignment is quite sensitive.  This doesn't necessarily
fix the problem if overheating of the AOM is the culprit.
Images attached to this report
Comments related to this report
peter.king@LIGO.ORG - 09:24, Wednesday 09 December 2015 (24080)
Predominantly changes to pitch with a slight change in yaw.
Images attached to this comment
LHO General
patrick.thomas@LIGO.ORG - posted 07:28, Wednesday 09 December 2015 - last comment - 13:16, Wednesday 09 December 2015(24074)
SNEWS alert test in GraceDB
Mike L. called and notified me that there was a SNEWS test alert entered into GraceDB (E206974, see attached screenshot). I did not get a verbal alarm.
Images attached to this report
Comments related to this report
thomas.shaffer@LIGO.ORG - 13:16, Wednesday 09 December 2015 (24084)

There was no alarm for this in the control room because the script that queries GraceDB (ext_alert.py) will only look back 36000 seconds and the delay for this alarm was 73681.000000sec.

We have been using the default 'lookback' time, but can set to be any value we choose from the command line at the start of ext_alert.py. This delay was a special case, but it might be worth looking back a bit more than 10 hours...

Lookback time code is below if anyone is curious.



actions['run'].add_argument('-l', '--lookback-time', type=float, default=36000,
                            dest='lookback',
                            help='how far back in time to query, '
                                 'default: %(default)s')

...(later, in the loop)

            # query gracedb
            now = gps_time_now(ifo=args.ifo)
            start = now - args.lookback
            client, events = list(
                 query_gracedb(start, now, ifo=args.ifo, connection=client,
                               far=args.far, test=args.test))

H1 SEI (ISC, Lockloss, OpsInfo, SEI, SUS)
cheryl.vorvick@LIGO.ORG - posted 22:45, Tuesday 08 December 2015 - last comment - 09:17, Wednesday 09 December 2015(24064)
ETMY ISI blend filters changed - big improvement in motion in Y and RX

Evan Hall suggested changing ETMY ISI blend filters after a couple lock losses between DRMI and ENGAGE_ASC.

The change from all Quiet_90s to Quiet_90 in X direction, and 45mHz in Y direction was easilly seen on ST1_ISO_RX and ST2_ISO_Y, and the ASC control signal in pitch being sent to the optic, ASC-ETMY_PIT_OUTPUT.

Plot attached shows those channels before and after the blend filter change, and ETMX ASC control signal, to compare.

Current blend filter config. medm is also attached.

Images attached to this report
Comments related to this report
richard.mittleman@LIGO.ORG - 07:48, Wednesday 09 December 2015 (24075)

Why are the y blends set different from the X blends?

evan.hall@LIGO.ORG - 09:17, Wednesday 09 December 2015 (24079)

Over the past month or so, having the 45 mHz blends on EX causes the ISI to ring up in full lock (for example: alog 23674 and comments).

Displaying reports 61061-61080 of 84519.Go to page Start 3050 3051 3052 3053 3054 3055 3056 3057 3058 End