Arnaud is launching our last* set of time-critical TF's on the ETMy which will tell us if we are clear to put the spool on tomorrow or not. Please don't do anything at EY to disturb any of the watchdogs set on the chamber equipment (HEPI/ISI/SUS/TMS). Normal foot traffic, ISC table work, cleaning, etc OK. Thanks!
After Jim finished up some SEI checkouts and Mitch some ACB hardware swaps at WBSC10, Travis, Jason and I put the final touches on the pitch alignment. (Recall it was out of the pitch tol yesterday after we removed the First Contact sheet on the HR surface. The ISI is unlocked, and so is the ETMy and TMSy.
While in-chamber, we observed more particulate on places that we had previously cleaned. So, I took more PCL samples for Kate near the purge air port (to look for migration) and on a repeat place from a prior sample. For the most part, "we" have been cleaning the floor and large easy to get to surfaces in-chamber every day. I also went upstairs and clened the entire surface of the walking plates which have had little attention, hoping to limit what is getting stirred up and dumped in from above. I left a box of wipes there for SEI to keep up better mainenance there from now on. ;)
I left a witness plate and a 1" optic in the tube under the ACB (between the purge and the chamber optics) for Kate to do further studies on.
We'll keep hunting.
With the new ETMX ISI target positions, the intial alignment for TMSX has changed (this will be updated in guardian)
ITMX Baffle PD1: P = 201, Y = -233.3
ITMX Baffle PD3: P = 270.4, Y = -294.8
TMSX Final aligment: P = 235.7, Y = -264.1
(Alexa posting as Sheila)
Finally got to completing the HEPI Actuator connection, evaluating the position numbers and zeroing the IPS. Attached are 5 pages from my log book, it's all I've got to jog my memory so best to put it in here.
Page1(95)--Calcs & givens for position
Page2(96)--Observation of Horizontal position and calculation of errors
Page3(97)--Observation of starting Elevations & while making adjustments (next page)
Page4(98) --Locked Dial Indicator(DI) readings, HEPI floating & final readings after correcting elevation and positions
Page5(101)--(week later)Prepare for HEPI Actuator connection. Found DI2 off registration and DI3 had a large horizontal shift but vertical was fine. Swung the DI2 back in place and verical was good again, I didn't try to put the horizontal back--see me if you want details there. This leads me to believe the south side DIs were disturbed somehow horizontally as the north side DIs show almost no motion from Page 98 numbers.
After the L4Cs were leveled and the Actuators attached, if the south side DIs are 'reset' on March3, there is possibly 100uradCCW rotation from final observation from Page97. It was already CCW 100urads so we could be at 200+CCW now.
Still, I decided not to hold up progress here, we can revisit this later if requested.
I zero'd the HEPI IPS (<50cts{655cts/0.001"}), inspected the Actuator Plate/Bellows Shield gaps (need to do range of motion tests,) and locked the HEPI (for door install.)
Several of the TMS Cable connectors are missing screws to attach to the vacuum feedthru plugs. Have discussed with Keita and because these connectors are a tight fit into the feedthrus as they are, we will not worry about installing these screws in the connectors.
Mitchell had a reservoir of spare connector screws at one point.
WP4488, new h1asc and h1lsc models, new DAQ channels
I SVN updated the LSC and ISC common/models area, carefully checking only the updates I expected were received. Rebuilt and installed the h1asc and h1lsc models
10:46 PST h1asc restarted
11:12 PST h1lsc restarted
11:40 DAQ restarted
The DAQ restart had problems restarting the DMT broadcaster. I had to kill and restart monit which in turn restarted daqd, which got running at 11:49PST.
Other changes ingested by this DAQ restart:
Note, h1pemmy was not added during this reconfiguration, that will require a separated DAQ restart.
ASC and LSC DAQ changes summarized below
| model | num fast chans [before,after] | num slow chans [before,after] | DAQ data rate kB/s [before, after] |
| h1asc | 76,78 | 17444,17650 | 1739,1768 |
| h1lsc | 120,124 | 3048,3048 | 2733,2995 |
Took photos of the table today. Turned on fan before opening doors. I was not able to turn on the interior lights (I tapped on "switch"at front-center of table to no avail).
Mitchell, Jim, This morning the pushers were removed and the final dog clamps installed. The only work that remains for the ETM-Y ACB is to route and plug in the cable. This work will be done with SEI cable clean up. All tools and hardware removed from the building.
Brett and Mark The matlab parameter file quadopt_fiber.m has been updated on the svn with the values found from the H1ETMY fitting results. The corresponding temporary file quadopt_fiber_H1ETMY.m has been removed. The parameters have been moved by the following amounts: --------------------------------------- mn: 0 g Inx: -1.1168 % Iny: 3.0445 % Inz: -0.87769 % Inxy: 0 kgm^2 Inyz: 0 kgm^2 Inzx: 0 kgm^2 hn: 0 mm m1: 473 g I1x: 4.0141 % I1y: 12.3876 % I1z: -0.087956 % I1xy: 0 kgm^2 I1yz: 0 kgm^2 I1zx: 0 kgm^2 h1: 0 mm m2: 43 g I2x: -2.9363 % I2y: 8.4274 % I2z: -0.034308 % I2xy: 0 kgm^2 I2yz: 0 kgm^2 I2zx: 0 kgm^2 h2: 0 mm m3: 10 g I3x: 2.1949 % I3y: -8.9273 % I3z: 0.70939 % I3xy: 0 kgm^2 I3yz: 0 kgm^2 I3zx: 0 kgm^2 h3: 0 mm ln: -0.183 mm l1: -0.212 mm l2: 9.121 mm l3: 0 mm rn: 0 mm r1: 0 mm r2: 0 mm Yn: 0 % Y1: 0 % Y2: 0 % su: 0 mm si: 0 mm sl: 0 mm nn0: 0 mm nn1: 0 mm n0: 0 mm n1: 0 mm n2: 0 mm n3: 0 mm n4: 0 mm n5: 0 mm kcn: 1.0376 % kc1: 1.091 % kc2: 2.2895 % kw3: 9.4232 % kxn: 0 % kx1: 0 % kx2: 0 % dm: 0 mm dn: -0.22438 mm d0: 0 mm d1: 1.8536 mm d2: 0 mm d3: 0 mm d4: -4.8596 mm --------------------------------------- Note, the mass values were changed to the as-built values from H1 ETMY. The wire lengths changes are updated values found from the mathematica model, which is the origin of the matlab. Note that the pum wire length (l2) is within about 0.1 mm of that found from the model fitting code. All other values are from the model fitting. Ref https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=10089. The d4 change is probably not so large in reality because it can be distributed between d3 and a little bit of d2. The change in kw3 (fiber bounce stiffness) is likely due to the fact the the original value was from the LASTI fibers, which may not be exactly the same. The pitch inertias also changed a lot, which I cannot readily explain, but it could be there is some degeneracy with the updates in the d values. There is still a mystery on the wire lengths, where the lengths the model requires as determined by the master mathematica model are different by a few mm from those we cut them to. The context for this can be found in these previous log entries: ETMY model fitting results - https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=10089 PUM wire length calculation - https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=10476
Jeff B., Andres, Kate
Yesterday, we took counts with a handheld particle counter outside the HAM4 chamber before removing the soft cover, and again in chamber. The counts were low, especially compared to the counts taken in February (see aLOG 9974). The battery on the counter was very low, and it may not have been working properly.
| Size (um) | Cleanroom Count | Chamber Count |
| 0.3 | 0 | 1 |
| 0.5 | 0 | 1 |
| 0.7 | 0 | 1 |
| 1.0 | 0 | 0 |
| 2.0 | 0 | 0 |
| 5.0 | 0 | 0 |
The vertical wafer in front of SR2 (T1400195) was replaced with a new one. This will give us an idea of the contamination generated by door activity only. The table and suspension are not locked down, so the horizontal wafer in the center was not replaced.
I re-measured BS and PRM actuation transfer functions in PRY configuration after plant inversion done on Mar 5 (see alog #10559).
It seems like we succeeded in BS and PRM balancing within ~8 % and MICH to PRCL coupling is expected to be supressed by factor of ~4, compared with using only BS as an actuator.
For the sensing matrix measurment, the effect of residual MICH to PRCL coupling gives ~6 % error for MICH to REFL45Q element and ~16000 % error for MICH to REFL45I element.
[Motivation]
Before measuring the PRMI sensing matrix, we wanted to estimate how good output matrix diagonalization is.
[Method]
1. Lock PRY and measure open loop transfer function. Compare it with the model to derive optical gain.
2. Measure actuator transfer function of BS and PRM from ISCINF to REFLAIR_RF45_I_ERR in PRY (using the same template used in alog #10450). Calibrate these TFs into m/counts with the optical gain derived in step 1.
3. Closed loop correct TFs measured in step 2. TFs should look like 1/f^2 at 1-300 Hz (see comments on alog #10450). Since output matrix for MICH in PRMI are set to (BS,PRM)=(1,-0.5), these TFs should be equal (see alog #10559 and table below).
-table of actuation efficiency (optic motion to interferometer length change in m/m)-
PRY PRCL MICH
BS sqrt(2) 1/sqrt(2) sqrt(2)
PRM 1 1 0
4. Calculate expected actuator TFs for MICH to PRCL coupling using the measured TFs. BS ISCINF to PRC length change will be half as that of PRY. BS-0.5*PRM gives the residual MICH to PRCL coupling.
[Result]
1. OLTF_PRCL_1078572000.png: Openloop transfer function of PRY lock. By comparing with the model, this gives PRY optical gain of 1.8 W/m. So, the calibration factor for REFLAIR_RF45_I_ERR in PRY is 4.7e11 counts/m. Note that this calibration factor includes losses in the PD signal chain (e.g. loss from long cable). Also, note that PRM suspension model was 30 % off from the measurement (see #10482; measurement = 0.77 * SUS model). This correction factor is included in the model to derive the optical gain.
2. BSandPRMact_PRY.png: Measured actuator transfer functions for BS and PRM in PRY. x marks show raw measured TFs and dots show closed loop corrected ones. After closed loop correction, actuator TFs look like they follow 1/f^2. From the fit, BS actuator TF is 1.79e12 Hz^2/f^2 m/counts and PRM actuator TF is 1.93e12 Hz^2/f^2 m/counts for PRY. Considering the error bar from coherence and cavity build up fluctuation during the measurement, this 8% difference between BS and PRM is significant (error bars in TF magnitude are derived using the formula in alog #10506). We have done the balancing with the precision of ~10%, so this difference is reasonable.
3. BSandPRMact_MICH2PRCL.png: Estimated MICH to PRCL coupling from actuator diagonalization. Blue dots show BS ISCINF to PRC length change and red dots show BS and PRM combined actuator to PRC length change. Fitted lines show that MICH to PRCL coupling is expected to be supressed by factor of ~4 by actuator balancing. We can improve this supression ratio a little bit by changing the gain balancing between BS and PRM by 8%, but it's not easy to improve more and prove we did more.
[Is this enough?]
This means that our MICH actuator (BS - 0.5*PRM) changes MICH length by 1.79e12 Hz^2/f^2 m/counts and PRC length by 2.06e11 Hz^2/f^2 m/counts. According to Optickle simulation in LIGO-T1300328, sensing matrix for PRMI sideband is
PRCL MICH
REFL 45I 3.4e6 2.5e3
REFL 45Q 6.4e4 1.3e5 W/m
So, the estimated effect of residual MICH to PRCL coupling to the sensing matrix measurement is;
MICH to REFL45Q element: 6 % error (= 6.4e4/1.3e5/(1.79e12/2.06e11) )
MICH to REFL45I element: 16000 % error (= 3.4e6/2.5e3/(1.79e12/2.06e11) )
If we ignore MICH to REFL45I element, which is hard to measure anyway, I think this is acceptable.
[Next]
- Update gain balancing factor between PRM and BS from 1/16 to 1/14.7 (FM5 in H1:SUS-BS_M3_LOCK_L)
- Update IQ demod phase in H1:LSC-REFLAIR_A_RF45_PHASE_R to minimize PRCL to MICH coupling
- Measure sensing matrix in PRMI
After talking with Yuta, I took a look at our PRM M3 to M3 transfer functions, measured with the osems as actuators and sensors, and compared it with the model. We see a factor difference of ~20% (model=1.18*measurement). This would mean the calibration error comes from the actuation chain (both of us are using T1000061 as a reference for calibrating actuation).
I did the calibration of the error signal wrong. The calibration factor 4.7e11 counts/m was correct, but I multiplied this number to the measured data in the script, instead of dividing.
Correct figures are attached. Actuator calibration from the fitting is as follows
BS to PRY: 8.13e-12 Hz^2/f^2 m/counts (half of this is BS to PRCL in PRMI)
PRM to PRY: 8.79e-12 Hz^2/f^2 m/counts (same as PRM to PRCL)
BS-0.5*PRM to MICH: 8.13e-12 Hz^2/f^2 m/counts (same as BS to PRY)
BS-0.5*PRM to PRCL: 9.28e-13 Hz^2/f^2 m/counts
Discussion about MICH to PRCL supression ratio and sensing matrix measurement error from actuation off diagonal element remain unchanged.
Also, note that my definition of MICH is one-way length difference between BS to ITMX and BS to ITMY. PRCL is PRC one-way length.
[Data and script]
Data and script used lives in ~/yutamich/BSPRMact/ folder.
./PRMdrive_complete.xml (dtt of PRM actuation TF measurement)
./BSdrive_complete.xml (dtt of BS actuation TF measurement)
./PRYoltf_complete1.xml (dtt of PRY OLTF measurement)
./BSPRMact.py (script for plotting and calibrating data)
LASER IS ON
- Output Power = 28.6 W
- Watchdog is active
- System status is good
PMC
- Locked for 4 days, 7 hours
- Refl Power = 1.2 W, Trans Power = 10.2 W
FSS
- Ref Cav locked for 11 hours
- Alignment is OK, PD threshold = .96 Volts
ISS
- 12% diffracted power
- Saturated 14 hours ago.
PRY is locked (POPAIR_B_RF_18_I is around -0.14) and Yuta's measurement started. I'll leave it going overnight.
Measurement done at Mar 11, 13:50 UTC (6:50 local). Thank you Sheila!
Alexa, Sheila
Tonight we decided to try to charachterize the coupling of alingment fluctuations to the error between the arm resonance and the ALS COMM lock point. We did this using the normalized PDH error signal. The frequency dependence of this spectrum is unclear- if we were staying on resonance we would just have the cavity pole, but the transfer function of the transmitted light will change as we move over the resonance. So to make a good calibration we need to lock well enough to stay on resonance. (This is why we have been trying the AO the last few nights). For tonight we concentrated on low frequency noise that is dominating our RMS, where the frqeuency dependence won't matter anyway.
We put a 1 Hz excitation onto ETMX pitch, making it large enough to see the second harmonic. We measured the spectrum of our REFL_DC_BIAS error signal when COMM was locked, and the op lev spectrum with and without the excitations. The attached screenshot shows the spectrum with and without the excitation.
Measuring the peaks due to the excitation we estimated the coupling coefficient with excitations of 2 different amplitudes, 1.7kHz/urad and 1.5kHz/urad. We also can esitmate the quadratic coupling from this data, we got 159Hz/(urad)^2 and 170 Hz/(urad)^2
Attached is a plot of linear and quadratic projections based on the Oplev data (up to 4Hz) into the REFL_DC_BIAS path. It can explain all the noise around the pitch resonance (which is most of the RMS), but not elsewhere. We had wondered if the coupling was nonlinear and some of our unexplained noise from 1 Hz-50Hz (or below 0.3Hz) was upconverted angular fluctuations. Our measurement suggests that this is not the case.
We were planning to repeat this measurement for ITMX, but so far we have been prevented by and earthquake.
At 1 Hz we have 748Hz/0.49urad OpLev motion for ITMX. (saved as references 26-29 in sheila.dwyer/ALS/HIFOX/COMM/NormalizedPDHSpectrumMarch10.xml)
The ITM oplev is much noisier than ETMX, and I was not able to get a good measurement of the quadratic coupling. In the attached plot I assuemd that the pitch coupling to frequency is the same as Yaw, and plot projections for ETM+ITM pitch and YAW, and the total. The total is high above 1 Hz because of the extra noise on the ITMX oplev, but alignment fluctuations do seem to explain all of this noise at low frequencies (not really a suprise).
We don't really need any nonlinear couplings to explain most of the noise we have, a linear coupling explains most of it.
After SUS team was gone, we went in the BSC10 to check a potential rubbing issue that has been bothering SEI.
After backing off all EQ stops and making sure that the top mass is free, we've found that the top mass had ROLL tilt, and somewhat smaller PIT. We don't know where this came from, but in my experience TMS angle changes after transporting to the chamber.
We corrected the roll and PIT by moving top balance masses, roughly centered all BOSEMs (the only one that was left untouched is RT) and left it damped.
Note: While working with TMS yesterday, noticed that the TMS cartoon at the bottom left of the TMS screen (SUS_CUST_TMTS_OVERVIEW.adl) is backwards. The Side, F2, and Left BOSEMs are on the "front" end of the TMS. (Once I get better with medm-editing I can fix this.)
Mitchell and I got the last corner of HEPI Actuaots attached. IAS was at the ready and noted a need to Yaw CW ~140urads. The SEI Dial Indicators suggested ~70 shift CCW from last IAS position. I thought they be better than that but at least they're in the same direction. I turned the HEPI DSCW Springs to compensate (1/4 Turn on every spring.) This put us about 20urads to go. We left it there and checked again after lunch and it looked maybe slightly better, a few urads, and this jived with some slight changes on the DIs.
The last time SEI did an elevation survey combined with the changes on the DIs since then suggest Elevation & Level of the optical table are 0.2mm high of nominal with just 0.2mm of level runout--at spec of 100urads.
With that I zero'd the HEPI Actuator IPS (Inductive Position Sensors) to less that 50 cts, most much less but it is mainly luck at that point. At the raw IPS there are 655cts/0.001" so comfortably under 0.0001". I also checked the gaps between the Actuator Plate and the Bellows Shields which form a range of motion limit and sensor protection mechanism, and these seemed mostly centered well enough. Range of motion and linearity tests will confirm if we are good there.
I'm sure Jason will put in an IAS log, otherwise, SEI/HEPI is good.
Attached are my leveling, DI readings, LoadCell numbers, Springs adjusting notes. Contact me anytime, if you want to talk about the vudoo
While Hugh and Mitchell were working on HEPI during this morning, Margot, Kate, and I did more cleaning inside of WBSC10. We wiped the ACB, viewports, and flooring again. We also wiped the barrel of the ERM more. We removed the ACB target and the ETMy-HR First Contact in order for IAS to continue alignment of the TMS through both the ACB and ETMy.
The floor in the tube nearest the purge port seems to have the most amount of particulate accumulation, although it hasn't had any cleaning attention like the BSC chamber has. We intend to take some samples and then clean it up.
Note, the 1" optic serial number from the bag was: 1.0-FS-PL-1113