Yesterday, filters were installed on ETMY which is now in the same configuration as ETMX. This includes top mass length to angle decoupling, and angular plant inversion at all stages to facilitate loop design for wfs and/or oplev.
When driving in pitch through the drivealign matrix with the "invP2P" filter on, the transfer function from the drive to the test mass should give a single pendulum with a resonance at 0.45Hz, and a Q of 3.
When driving in yaw, the transfer function should be similar, but with a resonance at 0.6Hz.
Note : all the gains are set to 1
The length to angle decoupling for pitch and yaw from the top mass has been roughly tested by sending a longitudinal excitation at 0.5Hz and looking at the oplev signal. I didn't quantify it yet, but it seemed to reduce the angular motion when turning the filters on.
The two filters L2P1 and L2Y1 installed at the top mass should be used with a gain of -1
Left to do for EX and EY is length to angle decoupling on UIM and PUM.
Alexa, Sheila
We were able to lock the x arm again today.
First we lowered the bandwidth of the ALS COMM loop. Alexa and I had looked at her model a few days ago and saw that this will give us an improvement at high frequencies. This looks like factor of 2 decrease in the RMS when we plot the noise with the cavity pole removed. (The plot with the cavity pole still in is more relevant for the CARM handoff, but since this was an easy improvement we tried it anyway). The first plot attached shows the noise with the new and old nominal settings. The low frequency noise is not stationary, the new settings haven't really given us an improvement there although it looks that way from the plot. The improvements from 700Hz up are real and repeatable. After making this plot, we saw that the crossover was unstable, or we were ringing up one of the modes of MC2 possibly. We changed the gain settings to -4dB on In1 and 3dB fast gain to move the crossover back down and keep the ugf the same.
We also replaced the beamsplitter that splits the X arm transmission for DIFF and COMM with a high reflector to get more light on the COMM BBPD. While it seems like this might have improved the 1/f noise, we aren't sure that this will be repeatable since this noise is nonstationary.
In the last plot, we added an ND filter, to bring the light level back to what it would have been with the BS in place. The high frequency noise stayed low, so this isn't related to the power, (we don't know why this changed in the first place). The noise from 60-8Hz is back to the level with the BS, suggesting again that this is related to power.
We have locked the arm on a 01 mode for IR at times, and we see that the high frequency noise is larger when we do that.
The dolphin network stopped working on the test stand, ended up powering off all dolphin front-ends, power cycling the dolphin switch, and restarting x1boot. Front ends still wouldn't start until I ran dxadmin on x1boot to see what the problem was. At that point the dolphin system started working and the front-end computers finished booting.
Would have been done earlier but needed to modify one of the fun Horizontal Angle Mounts (more than usual.) Based on DIs we should be okay for position. Exited LVEA at 1610pdt.
Scott, Mitchell, Today we were able to get the flexure, and locker assemblies completed for unit 3,4, and part of the 5th 3IFO BSC's. A solid amount of house cleaning was accomplished while looking for parts and hardware. At least one part so far is known to be short of needed quantities. MIT is going to look to see if they may have the shorted part. A list of M.I.A parts has been started. So far only the last unit is effected, giving us time to either find or procure parts. The bolting together of the Keel plates on unit 3 was also started today. Preparation for actuator assembly has also begun.
The control-state-definition is now operational for H1ISCEX and H1ECATX1PLC2. New medm screens with convenient edit buttons are available form the site map (SYS-ControlStateDefinition), as well as from the ALS_CUST_MAIN.adl screen. Pictures are attached. Some basic documentation is available at the Wiki: https://awiki.ligo-wa.caltech.edu/aLIGO/Control%20State%20Definition DCC: https://dcc.ligo.org/LIGO-T1300958
Valve will be left closed for a few weeks while the portable RGA is reconfigured and then baked -> PT246A,B gauges will be measuring the "unpumped" space between the closed 10" gate valve and a closed 1 1/2" angle valve-as such ignore them until further notice.
J. Kissel While trying grab a plot of the IMC frequency noise, I noticed that the calibration was different from what Paul had cleaned it up to be in January (see LHO aLOG 9618). I've reverted the calibration, and I attach a spectra of H1:IMC-F_OUT_DQ, compared against the requirements, found in Figure 4 of T050036. I've made no modifications to IMC-F, other than to convert kHz into Hz. The filters engaged are FMs 1,2, 3, and 9; "cts2V," "invGenFilt," "VCO," and "tokHz." Check Giacomo's original entry for details of these filters (LHO aLOG 5945). %% EDIT %% I have corrected the attached plot, increasing the frequency noise by a factor of 10, as instructed by Alexa's comment below. Good catch!
When Jeff's spectrum was taken the IMC-F filter module had a gain of 0.1 ( see alog 11329 ); however the FDD was no longer in place. I have restored this gain to 1. Jeff's noise measurements are therefore off by a factor of 10 (too low).
Travis, Betsy
Last week we installed the new ITMy CP (CP05) in a new reaction chain lower structure assembly and test hung it in a double pendulum. We made a minor coarse pitch correction, finished assembling various bits and pieces of the structure and it's other masses and then mated it to the ITMy monolithic assembly which has been waiting in the fiber welding room for a week. Before bolting the main and reaction chains together, we pulled the FirstContact sheets from the ITMy-AR and the CP05-HR since they would be unaccessable once attached as a single unit.
We added final shielding, removed the sus structure from the LSAT tooling and stowed it in a re-cleaned storage box. The unit will wait in the sealed box for another few weeks until it is time to move it to the beer garden.
LVEA Laser Safe Hugo – Updating all BSC/ISI models Thomas & Richard – Working on End-Y Op-Lev 08:45 Thomas – Going to End-X to work on Op-Lev 09:30 Hugo – Restarting all BSC/ISI Models 09:35 Betsy, Travis, & Margo – Working in SUS cleanrooms in the LVEA 09:35 Bubba & Apollo – Working on cleanroom curtains in beer garden area 09:38 Andres – Kitting 3IFO parts in HAM2 area 09:45 Praxair – Going to Mid-X to check valve repair 09:50 Justin – Working in Optics Labs 09:50 Dave – Working on TCS-X 09:56 Hugh – HAM5 HEIP work 10:48 Cyrus – Going to End-X to work on weather station 11:05 Dave – Doing DAQ restart 12:25 Dave – Powering recycling Solaris box and restarting Frame writer #1 13:04 Justin – Working in the Optics Lab 13:30 Cyrus - Going to End-X to work on workstation 14:12 Dave & Greg – Working on TCS 14:16 Hugh – Working on HAM5 HEIP 15:04 Aaron – Installing AA chassis at End-X
I have changed the workstations at EX to run Linux instead of Mac OS. This will allow running guardian directly (among other things), but is also very much a test. I do not know what demons are lurking in the wireless setup, but suspect there are some, as nothing ever just works as expected on Linux, especially in this department.
The ITMY watchdogs tripped. After resetting the watchdogs, Guardian restored the remaining parts of the ISI.
Sheila switched the blends when the trilliums were still rung up.
was this using the new ramp code? that is less glitchy?
Yes, this was using the new ramp code but the trip has nothing to do with the ramping itself. The blends were just switched from Start (no T240) to TCrappy (with T240) while the Trilliums were still saturated, causing the ISI to trip on the actuators as soon as the T240s got into the blend.
Switching the blends after waiting for the Trilliums to quiet down, as recomended, worked perfectly fine.
The watchdogs on ETMX had tripped twice. Jim W. brought ETMX up via pre-Guardian scripts at the same time ops tried to recover ITMX using Guardian. This resulted in the ISI tripping a second time. Ops then started to recover the ISI using Guardian and the ISI tripped again. Ops reset the watchdogs and Guardian completed the recovery. Plots of both trips are attached below.
at 11:09 I restarted the DAQ to suport new INI files from the ISI model changes. All came back OK except h1fw1, which now could not write any frames.
12:27 I stopped h1fw1 daqd process and unmounted the NFS export from h1ldasgw1. I then power cycled h1ldasgw1
12:46 had problems getting the file system viewable again, did a reboot of h1ldasgw1.
12:55 Finally got h1fw1 writing again, had the to the following on h1ldasgw1
# mount /cds-h1-frames
# shareall
Lets see if the reboot of the Solaris QFS server restored h1fw1 to stability.
during this DAQ restart I added back the weather stations for EX and MY (H0EDCU_WEATHER.ini). Note the EX weather station is not working, the EPICS channels exist but have bogus values. This reconfiguration is in anticipation of getting this going again.
It recently turned out that switching blends was causing glitches in the blend output to the servo loops, which were tripping the ISIs. The script handling the transition between blend filters was modified to provide a smoother ramp and prevent WD trips.
After testing at MIT, HAM and BSC master models were updated here. Every ISI on site was recompiled and restarted. The new blend switching was tested by using the blend switchall buttons* on BSC-EX. It works as expected. I was able to do the following blend switchall without tripping the ISI:
Work was performed under WP 4568, which is now closed.
*:one button to switch every blend filter of a stage a once
Note: ITMY foton file turned out to be corrupted. We only found out after restarting the model because the corrupted foton file never got loaded in the first place. Please make sure that anytime you update a Foton file, you push the Coeff load button in the GDS-TP screen. Please note that pushing the Coeff Load button from individual filter banks does not create a backup foton file, which pushing the same button from the GDS-TP sceen does.
(Alexa, Daniel)
We added an FDD in the IMC VCO path (currently borrowed the ALS DIFF FDD). In doing so, we have reduced the signal by a factor of 10. We adjusted the MC common mode board fast gain to 14dB from the original -6dB. The MCL-MCF Crossover is still the same (UGF: 14.7Hz w/ 39 deg phase margin). I have attached a DTT plot with the current crossover and a reference taken on 03-17-2014. We have also adjusted the gain in the IMC_F filter to be 0.1 to account for the reduced VCO DC gain. We remeasured the IMC_F noise as done in alog 5311; the results are suffeciently consistent (see second DTT image; DTT is saved uner my public directory). Finally, we measured the IMC OLTF; the UGF is 31kHz with a phase margin of 38deg (close enough to the nominal UGF: 53kHz, 45 deg phase margin). The data and plot are attached.
I have placed an IFR below the 79Mhz RF source on the ISC C4 Rack. The IFR is set to 78.95MHz with an RF level of 10dBm and is now used instead of the RF source.
We are waiting for the x-arm to test if the 1/f noise has actually decreased with these changes...TBD.
(Alexa, Sheila)
This alog is refering to work done yesterday...
We have reverted to the nominal configuration, i.e. no FDD for the IMC VCO and we are using the RF source at 79.2MHz again.