Work by ISCT1/IOT2L (LVEA) – Corey Work in H2 Building - Dave Trip to End X – Corey Work on H2 PSL enclosure – Pablo/Michael R. Start Spectra Test on Beam Splitter – Arnaud P. Work on BS Optical Lever – Thomas Vo Work on IOT2L (LVEA) – Cheryl Going to end Y to work on ALS table – Corey Back to work on H2 PSL enclosure – Pablo/Michael R.
#1) I found the hardware in the attached picture shoved under the foil that was protecting my class-A hardware - unknown cleanliness of this package and contents now puts into question the cleanliness of my parts. #2) my parts are now on both tables in the cleanroom by HAM2. If you need to get into this cleanroom, call me.
[Sheila, Kiwamu]
We found that there was a small mistake in the slow control channel linking. This was fixed in the software and committed to the SVN.
The mistake:
The VCOs had two RF monitor channels cross-wired. "ReferenceMon" was taking the ADC signal which was for "DividerMon" and vice versa.
Correction:
In order to correct them we simply swapped the links in the twinCat system manager file, H1ECATC1.tsm. This modification was applied on three corner VCOs, namely IMC, ALS-DIFF and ALS-COMM. This change was then commited to the SVN. Also Sheila modified the link document [1] accordingly. She will be applying the same mods for the VCO at the end stations.
[1] DCC LIGO-E1201049-v4
Mark B and Thomas V
While showing Thomas how the numbers in the HLTS OSEM2EUL matrix for the optic (M3) were derived, I noticed a nasty bug: the code in
/ligo/svncommon/SusSVN/sus/trunk/HLTS/Common/MatlabTools/make_sushlts_projections.m
had M2 in two places where it should have had M3. I fixed it as follows (and committed the fix):
OSEM2EUL.M3 = [ 0.25 0.25 0.25 0.25 ; ... % L
[ 0.50 -0.50 0.50 -0.50]./M3.PitchArm; ... % P - corrected by Mark B, 5/17/13, had been M2.PitchArm
[-0.50 -0.50 0.50 0.50]./M3.YawArm]; % Y - corrected by Mark B, 5/17/13, had been M2.YawArm
The corrected output is
0.25 0.25 0.25 0.25
2.40963855421687 -2.40963855421687 2.40963855421687 -2.40963855421687
-4.15973377703827 -4.15973377703827 4.15973377703827 4.15973377703827
We typed these numbers into the SUS_CUST_HXTS_M3_OSEM2EUL.adl screen for PR3 and SR3 and updated the safe.snap files. LLO should do likewise.
The equivalent HSTS file had the same bug and has been fixed also: /ligo/svncommon/SusSVN/sus/trunk/HSTS/Common/MatlabTools/make_sushsts_projections.m . However the M2 and M3 levels have the same lever arms, so it doesn't make any difference to the values in MEDM.
Andres took Transfer Function and Power Spectra data on I1-SR2. The results look positive and the plots are posted below. All scripts and data files have been committed to the SVN vault. We are waiting for the testing group to review the results before proceeding.
After looking through the undamped and damped transfer functions provided for SR2, these TFs raise absolutely no concerns, since all measurements are in good agreement with the model and are consistent with other HSTS suspensions. Power spectra plots now include the expected sensor noise (black dashed line), which shows the measurement agrees with the prediction in the majority of cases. Where there's a discrepancy between the expected sensor noise and the measurement (e.g. M2_WIT_P_DQ and M2_WIT_L_DQ) SR2 measurements are consistent with previous HSTSs, implying the issue is most likely with the calculated sensor noise. Thus, I will investigate this sensor noise calculation further... In the interim, please consider SR2 approved for India. Nice work!
Attached are plots of dust counts > .3 microns and > .5 microns in particles per cubic foot requested from 5 PM May 15 to 5 PM May 16. Also attached are plots of the modes to show when they were running/acquiring data.
Attached are plots of dust counts > .3 microns and > .5 microns in particles per cubic foot requested from 5 PM May 14 to 5 PM May 15. Also attached are plots of the modes to show when they were running/acquiring data.
I moved all of the MC TRANS optics about 6 inches toward the MC REFL path, to compensate for the change in the steering mirror pointing. There are some optics and electronics yet to be installed, but the analog camera and PD100 are installed and cabled up. Kiwamu helped with moving the periscope to it's new location, and we both noticed that the MC TRANS beam is going to be near the edge of the viewport as it exits the vacuum system. How close to the edge is unclear until we have a beam.
The PLL at the Y end has been locked for about 30 minutes. I've changed the slow servo back to the old code, which has a simple 1/f response if Pf is set to zero. The settings are: In 1 Gain = -15 dB fast gain 4dB Slow servo "ugf" -0.055 Pf=0 With these settings the UGF is 14.3kHz, the phase at the ugf is -100 deg. From the transfer function it looks as though higher gains would be possible, but if you add more than 3 dB of gain an oscillation starts. As far as I know there are no diagnostics in the slow control system to detect the oscillation.
Craning Forklift over Xarm in the morning
Ski visitors: Snow Valley & other contractor
PCal Alignment & laser hazard in H2 LAE (Pablo/Rodruck)
H1 PSL Shutter closed at 10am (Kiwamu)
Praxair on site at 11:05
ISC (Sheila) & HEPI (Hugh) work at EY
HAM4 Doors Off
BS Oplev work (Thomas)
IO MC Trans periscope move (Cheryl)
Now that BSC3 is on the test, we are working on gettting it checked out and connected for testing prior to integration. Today, Fil helped me re-route the in-air cables (because this ISI is sitting 180 from the previous 3 ISI's, so the cables no longer reached the right corners), then Greg helped me ring them out with the emulator, to verify the routing. After that, I powered off the electronics, wired everything up I could (some of the CPS in-air cabling is improperly gendered, requiring adapters I didn't have on hand) and powered everything up. Tomorrow, balancing and lockers, and if we are lucky, TF's over the weekend.
Thomas V. & Szymon S.
Over the last couple weeks we have noticed that the ETMY optical lever power monitored on the channel H1:SUS-ETMY_L3_OPLEV_SUM_OUTPUT has been periodically fluctuating. The monitored power level has been dropping from a nominal 10,000 counts to 0 counts on a regular interval. Exchanging the power supply on May 3 seemed to have slightly improved the situation with the power level dropping to 6,000 counts from 10,000, but still on a very regular schedule. I tried another spare power supply as well as using a different cable connecting the laser with the power supply. Attached is a plot of how the power level read from the quad photodiode varies after the last change on May 15, still fluctuating.
Testing the power supply pins with a voltmeter I saw the voltage at a steady 5 volts, and no regular power glitch as seen on the oplev sum. Additionally, the laser module for ETMY optical lever is loudly buzzing most likely due to the cooling fan interfering with something inside the chassis.
The ITMY optical lever was installed and aligned a week ago, but has drifted significantly since initial alignment. One theory is that the cables for the electric micrometer stage are forcing the stage holding the QPD to move around. ITMY optical lever plots show that the laser power is wandering in a sawtooth pattern, probably due to drift of the stage.
The Apollo crew flew the forklift from the West Bay to the near side of the LVEA so that it would be available to remove doors. Christina and crew took care of second cleaning by ~9:00 am. Then, the Apollo guys started the assembly of the A-frames used in ISI install. There was also some Apollo help on HEPI actuators.
J. Kissel In preparation for the HIFO-Y and DRMI integration phases, I've redesigned the H1SUSBS (a BSFM) damping loops in a similar vein as those for the QUAD (see LLO aLOG 6949 and G1300537). I've tried my best to make the figures of merit identical to that of the QUAD, so if you understand those figures of merit, you'll understand these. Unlike the QUAD, however, one can in-almost-all-cases beat the aLIGO requirements with the same, only-slightly-more-complicated, level/style of filters. Vertical turns out to be the trickiest DOF, if you can believe it; it's the only one that I couldn't get below that DOF's requirements at all frequencies. However, as can be seen on pg 1 of dampingfilters_BSFM_2013-05-15.pdf, the vertical noise projected onto DARM is still a factor of ~10 below even the best aLIGO sensitivity (if all coupling factors are correct). Details below! Note, I've captured a new safe.snap, copied, and committed both the snap and the newly modified filter file to the userapps repo: ${userapps}/sus/h1/burtfiles/h1susbs_safe.snap and ${userapps}/sus/h1/filterfiles/H1SUSBS.txt Details: -------- Since most of the figures of merit are either self-explanatory or the exact same as what's described in detail in the QUAD design (again, see (see LLO aLOG 6949 and G1300537)), I won't go through them in detail, but instead highlight the interesting points where the BSFM differed from the QUAD. Design Philosophy / Comments: (These notes are entirely focused on the dampingfilters_BSFM_2013-05-15.pdf attachment) - Initially, the focus was on reducing the sensor noise for the L degree of freedom. However, because the BSFM is a very long Triple suspension, the L/P modes are relatively low in frequency. This meant that there's plenty of room between the last L/P mode and the goal frequency of 10 [Hz]. - Because the BSFM's blades are not diagonally oriented like they are in the QUAD, there is no fundamental cross-coupling between (T/R) motion and (L/P) motion. (L/P), (R/T), V, and Y are entirely independent of each other. - These two features of the plant (the highest resonances are at lower frequency, and DOFs are much better decoupled) makes rolling of the sensor noise by 10 Hz relatively easy for these degrees of freedom. - Even in the fundamentally cross-coupled degrees of freedom, (L/P) and (R/T), the MIMO interaction between them makes it easy to isolate certain modes, and damp them in DOFs where the noise requirement is less stringent. For example, the highest (R/T) modes at 2.1 and 3.2 [Hz], which are the only substantial modes that show up in the R2R plant, can be almost entirely taken care of in R where there is no requirement. This offloads damping authority from the what-would-be-difficult T design. (That being said, the T requirements are so loose, that even the Level 1 controllers beat the requirement by several orders of magnitude). - The point at which I stopped tuning the L, P, and Y loops was when the sensor noise was reduced to a factor of a few below the M2 actuator noise (as shown on pgs 2/10, 34, and 40). They probably could be made more aggressive, but until the M2 actuator noise is reduced, there's no point. (Remember, there are no actuators on the M3 / optic stage of the BSFM). - An interesting diversion from the QUAD design for these DOFs was that for R and Y (see pgs 23 and 35), I've moved the boost to reasonably high frequencies, "skipping" the first few modes. They're Qs are reduced enough by the "velocity damping" portion of the controller, and in the case of R, by the T loop as well. Because the boost was so close to the elliptic filter, the phase is evolving a little faster than ideal, but I think I've still managed to squeak out a good looking loop that is fairly insensitive to small changes in gain. - Vertical, it turns out was the most difficult to design (see pgs 17-22 of dampingfilters_BSFM_2013-05-15.pdf). The last V mode visible from the top/M1 stage is at 3.8 [Hz], very close to the 10 [Hz] requirements. As such, there's very little phase left for the elliptic filter. - On top of this, the last vertical mode at 17.5 [Hz] is invisible at the top stage. This meant that, regardless of whether I could see it in the M1 V2V plant, I needed to get rid of the sensor noise in that region between the two modes, since it shows up in the M1 to M3 V2V transfer function. - As such, I used a 4th order elliptic instead of the 3rd order I'd used for all of the QUAD DOFs and other BSFM DOFs. In doing so, I tried to get the second notch of the filter as close to 17.5 [Hz] as possible, while still having enough gain to evenly damp the 1st and 2nd V modes, and have enough phase to be stable. - In summary, what you see here in this Level 2 V filter is a comprimise between 4 things: - The resulting Q of the 1st and 2nd V modes, both in the M1-to-M1 TF (pg 17) and in the GND-to-M3 TF (pg 22) - The phase and gain margins (i.e. the stability of the loop) - The sensor noise level between 10 Hz and the 3rd V resonance at 17.5 [Hz] as shown on (pg 22) with respect to the specifically-defined, beam splitter vertical requirements (from T010007-v5) - The assumed 0.001 V2L cross coupling into DARM as shown on (pg 1) with respect to the BS L requirements (again in T010007) and the current predictions of interferometer sensitivity - While this compromise does not meet the requirements for the T010007-defined, BSFM vertical, the noise is still a factor of 10-20 away from even the best expected DARM curve, assuming the BS2DARM = pi / (sqrt(2) * F) factor from T080192 is correct (Note, I've used F = 450 for the arm cavity finesse, found in T010075, and T070303). The configuration: ------ For all degrees of freedom, FMs 1 ("rolloff_*"),2 ("boost_*"),5 ("norm*"), and 10 (ellip_*) should be engaged. After discussing it with Arnuad, we've decided to fold the overall gains of the loop into the boost_* filter, so that all the EPICs gains are an easy-to-remember -1. Note that this deviates from traditional SUS gains, but it's time for a new era of not-just-velocity-damping-anymore. <gullable, annoying pre-teen voice> Seismic is doing it </gullable, annoying pre-teen voice>. Hence, the new EPICs gains are: L = T = V = R = P = Y = -1. In the fullness of time, we intended to go back to QUAD filters and do the same. As mentioned above, I've already captured a new safe.snap. The files: ------ The 2013-05-15 loops were designed using ${SusSVN}/sus/trunk/BSFM/Common/FilterDesign/design_damping_BSFM_20130515.m which saves the .mat file of the filters, ${SusSVN}/sus/trunk/BSFM/Common/FilterDesign/dampingfilters_BSFM_2013-05-15.mat and produces the dampingfilters_BSFM_2013-05-15 set of plots, as well as saving the model itself in an additional .mat file, ${SusSVN}/sus/trunk/BSFM/Common/FilterDesign/dampingfilters_BSFM_2013-05-15_model.mat These were compared with the previous filters, (whose figures of merits were plotted with the similar ${SusSVN}/sus/trunk/BSFM/Common/FilterDesign/design_damping_BSFM_20130130.m and saved to ${SusSVN}/sus/trunk/BSFM/Common/FilterDesign/dampingfilters_BSFM_20130130.mat) using the script, ${SusSVN}/sus/trunk/BSFM/Common/FilterDesign/compare_bsfm_dampfilter_design.m The performance measurement was taken using the DTT template ${SusSVN}/sus/trunk/BSFM/H1/BS/SAGM1/Data/2013-05-15_H1SUSBS_M1_DAMPOUT_Spectra.xml Note, because of the experience taking the open loop gain transfer functions of the QUAD (low SNR, confusing results at low frequency, but otherwise confirming the MIMO nature of the plant, and the ability for my models to predict it), I did *not* take open loop gain transfer functions. ------- As of this edit, all of the above mentioned files are committed to their respective repository, whether it be the userapps, or SUS repos. ------- Edit: Replaced the dampingfilters_BSFM_2013*.pdf plot sets because there was a bug in the Title and Legend of the DARM coupling plots -- I'd writting BS2DARM as 2*F instead of sqrt(2)*F. Note, the code that processed the data did/does not have this bug, it was just the plot labels.
Annuli continue to be pumped with a few more transferred to ion pumps this week.
The attached plot shows a step up in pressure and a possible slope reduction. This is currently unexplained but could indicate a leak or a gauge artifact .
We currently have only one operating gauge on the volume so nothing to compare to.
The STS-2 at the corner station is currently installed by BSC4 (under the stairs). Since the STS-2 is relatively "far appart" from the BSC1 and BSC2 chambers, I checked the coherence from the STS-2 and the T240s installed in stage 1 of the ISIs. Plots of coherence are presented in attachment. Coherence is really good (in the 100mHz to 3Hz frequency band) but not as good as the end station where the STS-2 is closer from the chamber. Coherence between the stage 1 of the 2 ISIs is also presented.
The isolation filters are ramped up with no DC offsets on the super sensor. Once the platform is isolated, it will be translated and rotated as desired. Tests were performed on ISI-BSC6 to evaluate the risk of saturation on the T240s when tilting the platform. Tests were performed with damping loops on every DOFs. Isolation filter (with BOOST to lock the platform to the ground at DC) was engaged in the RX direction with a blend at 750mHz. Then, the platform was tilted by 100nrad in the RX direction. Time series of all T240s signals were recorded during 600s and presented in attachment.
A 100nrad rotation in RX creates a 5000 count peak on the local inputs and a 22000nm/s velocity peak in the Y direction.
The macro substitution text files of the HAM-ISIs were moved from:
/opt/rtcds/userapps/release/isi/common/medm/hamisi/ (now at revision 4499)
into:
/opt/rtcds/userapps/release/isi/h1/medm/hamisi/ (now at revision 4498)
The $(IFO) part of the name of those text files was removed to avoid redundancy: i.e. H1_isiham2_overview_macro.txt became: isiham2_overview_macro.txt
The sitemap was updated to reflect those changes. (now at revision 4500)
