• HAM5:  SR3--small adjustments to make this morning
• TCSy Table work (need hazard probably by 2pm)
• TCSx 2-day run with laser
• Hartman Table work
• Richard:  Beckhoff modules, fiber work, EY ESD cont.,
• Travis ACB:  box & bagged,  blade pull down
• Staging Pull Down:  Unit2:  electronics issue for testing, Unit 3 pulled springs Fri & actuator/trillium measurement,
• Apollo:  scotty staging, machining TCS camera mount
• Commissioning:  discussions of installation work/noise impact (issues regarding yaw change with ITMx)
• Jamie here for HEPI integration into Guardian

model restarts logged for Sat 10/May/2014
2014_05_10 05:02 h1fw1
2014_05_10 18:42 h1fw0

both unexpected restarts, not simultaneous so no data lost.

No restarts reported.

(Daniel, Alexa)

Over the past few days we have been working on ISCT1 in order to measure the noise produced by the difference in path lengths between the POP beam and the PSL reference beam. See alog 11748 and alog 11737.

To complete the installtion, we aligned the BBPD and borrowed 15V power supply used for REFLAIR B BBPD on the table. We measured the power of the PSL reference beam to be 95mW before the SHG, 90mW after the SHG and dichrioc, and 12mW after the ND06A and 50/50BS. With the BBPD responsivity of 0.1A/W and 2kOhm trans at DC and RF, this amounts to 2.4V at DC. We measured about 2.5V at DC. Meanwhile for the POP beam with PRMI locked, we measured about 50uV (consistent with the 172nW --> 35uV we measured with PRX locked previously). With these values we expected a beatnote signal of about 10uV or -30dBm. Looking at an RF spectrum analyzer at both 9.1Mhz, and 45MHz, we found the beatnote maximum to be about -45dBm; this was consistent enough with our estimate since our alignment on the PD was not very good. 

We borrowed POP_A_RF9 to look at the signal and added an RF amplifier of +30dB, and +30dB whitening gain. It was unclear to us whether we were seeing turn-arounds or fringes. We tried splitting the signal between RF9 and RF45; however, these appeared to be in phase, so this did not help us.  Since we had PRMI locked during this measurement; its likely we lose some of the macroscopic length difference that arises when the cavity is moving freely during ALS. We repeated the above measurement with PRM misaligned and only using the straight shot. I have attached the time series and power spectrum displaying the result. Using the rms of the time series, we calibrated the power spectrum into rad/sqrtz for red. The ALS beam to ISCT1 is green. Since the fringe speed will be twice as fast, we must also shift the frequency to 2f (not shown in DTT image).

In the second plot I have attached, the green trace is the out of loop infrared noise for ALS COMM we have been using ( in particular from alog 11106). Meanwhile, the blue trace is the power spectrum calibrated back into red. From 1 to 10Hz we see that the noise produced from this path difference is very consistent with the 1/f noise we have been hunting. The measurement probably does not hold above ~20Hz.

Switched all Guardian medm calls on the main Guardian screen, the IFO align screen and the ALS screen to a standard medm display call. This fixes the long-standing issue of Guardian not popping up.

For this I made modified copies of two guardian screens:
sys/common/medm/SYS_CUST_GUARD.adl  (a copy of the GUARD.adl screen in the guardian distribution"
sys/common/medm/SYS_CUST_GUARD_OVERVIEW.adl  (a copy of the GUARD_OVERVIEW.adl)

These screens now point directly to the medm screen, instead of calling guardmedm.

I also updated the IFO_ALIGN.adl screen and the ALS_CUST_MAIN.adl screen.

ETMX tripped @ 1083716829 because the IOP dackill tripped because of a suspension measurement.

Today I updated by as-built drawing for the RFM networks down the X and Y arms (DCC D1200562). I found that the order of nodes in the X and Y arm loops are not the same (see figure below). This may explain why the LSC receiving error rate of data from h1iscey is greater than that from h1iscex. In the Y arm loop, there is the maximum number of nodes between the iscey and the lsc, while on the X arm loop the two other nodes at the end station and not "in the way".

We will work next tuesday to make the two loops the same.

• X axis (lateral): -2.2 mm (south)
  • Tolerance: ±3.0 mm
• Y axis (longitudinal): +4.7 mm (west)
  • Tolerance: ±3.0 mm
• Z axis (vertical): +0.9 mm (high)
  • Tolerance: ±3.0 mm

SR3 needs to be pushed to the east to correct the longitudinal error, and if we correct some of the lateral error in the process I won't complain.  We will commence with the pushing of the suspension on Monday.

I'm covering for Jeff B from 8:00am-2:15pm

Day's Activities

• Had Reverse Osmosis (RO) FMCS Alarm since yesterday afternoon (John investigating)
• MY Pressure Sensor which is valved out is alarming high again...But Kyle may be restoring it soon.  Once he does this, we'll change Alarm HIHI value from 1e-05 to 5.11e-08
• Hartman table work Thomas & Dave
• HAM5 SR3 work beginning (Jeff, Andres, Jason, Betsy)
• Quick incursions into LVEA:  Mitch (9am), Daniel (9am), Scotty (9:25)
• Alexa working at ISCT1 (kiwamu/stefan call at -224)
• Y Arm Cavity Baffle assy work begins (942am)
• SR2 measurements (Arnaud)
• Had trouble with projector0 FOM (needs more memory & have trouble bringing up DMT)
• Guadrian computer was discovered to be near death, but it appeared to have stabilized (Dave/Cyrus investigating)
• ISS was causing issues & was not locked, Rick turned on autolocker and then raised the Ref Signal (from -1.67 to -1.63) to get it locked
• Dave B heading to both end stations at 1:50pm(not in VEAs)
• Tour at 2:05pm

Last night we saw that there is some angular motion of the optics coupling to DIFF.  The first attached screen shot shows our diff noise (calibrated in volts, with a foctor of 10 for the FDD which is not currently in) showing coherence with the OpLevs below 3 Hz.  Most of the RMS comes from frequencies where there is coherence with the OpLevs.  Above about 0.4 Hz, there is coherence with ETM oplevs, but not ITMs, suggesting that our drive to the suspension is causing the coherence. The second screenshot confirms that the ETM opLevs have higher noise when DIFF is locked and we are driving the suspension (solid lines) than when we are not (dashed lines). In both plots ETMY seems to have higher noise than ETMX. 

While we were measuring the ETMY UIM transfer function last night we also measured the transfer function to the OpLevs, screen shots of this and our older (not quite complete) measurement for ETMX are attached.  There are resonances at 0.5Hz, 1 Hz, and 1.3-1.5 Hz that correspond to our noise in DIFF, and the coupling to for ETMX seems to be about a factor of 10 less than the coupling for ETMY. 

Kiwamu found that MICH feedback signal suddenly becomes quiet about a second before the lock loss of PRMI.

Attached shows that this is due to the output of the M3 ISCINF filter (observed by the input of M3 lock filter, top right) creeping up and hitting the 5e5 count output limit.

Stefan remembers that this limit was necessary for lock acquisition to prevent one of OSEMs from going out of range and causing a bad alignment disturbance. Once the lock is acquired, then, the logical thing is to increase the limit or disable it.

Also, though the LSC feedback goes to the top stage, it seems like no optimization was done, M1 Lock filter only has 0.01 Hz pole. It should be possible to make a better blending to relieve M2 stage.

Sheila, Kiwamu,

The goal tonight was to add TOP and UIM of ETMY to the DARM actuator in order to increase the control bandwidth. This worked fine and the UGF was pushed a bit higher and it is now 4 Hz.

As Sheila reported on alog 11787, we prepared ETMY. So we started using ETMY in addition to ETMX. Since ETMY's ESD is not ready yet, we used only TOP and UIM of ETMY. This helped the DAC range of the UIM stage and therefore we could push the UGF a bit higher. At the end, we ended up a UGF of about 4 Hz. The infrared RMS is now about 90 Hz. We didn't redesign the low-frequency boost this time as our target was to have a higher UGF. The attached is the ALS diff spectrum (shown in red), with the spectra from yesterday for comparison. You can see that the noise is suppressed below 4 Hz. Currently the UGF is limited by UIM and TST which saturate at high frequencies.

Yesterday night, I tried to run SR2 M2-M2 and M3-M3 (lower stages) in chamber transfer functions after the osems were centered on wednesday. Although both M2 and M3 watchdogs tripped during the measurement, so I am running it again tonight. (This time, I decreased the drive and increased the watchdog threshold).

(David H, Thomas V, Greg G, Alasitair H, Matt H)

Well if yesterday was "The Empire strikes back", today was "Return of the Jedi" and the good guys had a win.

You may remember from this mornings alog that we had been having a few troubles with the alignment of TCSx.

After a brainstorming meeting with Aidan the decision was made to ignore the path defined by the flipper mirrors having problems with (what is supposed to be the central heating path) and align what is the annular heating path (which only uses mirrors) to the output beam splitter and through the irises defining the beam path up the periscope, into the chamber and onto the CP. We will then use the central heating mask instead of the annular heating mask (in the location the annular heating mask would be ), and thus temporarily turn the annular heating beam path into the central heating beam path.

The first step we did was to use a HeNe beam to adjust the output beam splitter and the beamsplitter just before the on table power meter so that the front and back reflections were in the same plane (they werent installed that way). We then went all the way back to the first large gold mirror after the polarisers (which are after the beckhoff controlled HWP) and mirror by mirror in the annular (now temporary central heating) beam path made sure that they were set so that the beam was in a plane with the table at a height of 4 inches.

Once the beam got to the output beamsplittler, the beamsplitter and the last gold mirror before the periscope was used to align the beam to the irises that we had defined to put the beam correctly into the chamber. I roughly made sure that the beam transmitted through the output beam splitter was going to the on table power meter, and the beam path that would go to the FLIR camera was beam blocked as I no longer no that the beam path is correct (I removed the lens there so that needs to be reinstalled).

A HeNe beam was setup to trace through the irises (heading in direction of going towards the periscope). Once the optic beam path had been re-established I swapped out the 1" irises we had (which had clipping on the beam occuring) for 2" irises. We then inserted a 2 inch gold mirror into the path between the 2 irises and sent the HeNe beam down towards HAM5 and the target that we had set up at a distance that mimicks where the CP would be. An "X" was marked on the card and the HeNe aligned to this "X' and the FLIR camera setup so that this spot was centered on the camera.

HeNe beam removed and the CO2 beam projected onto the target. Good to see that the CO2 beam appears to hit exaclty where the HeNe indicated it should (lets out sigh of relief)....so this should mean that the CO2 beam should go into the chamber and onto the CP correctly. Whilst doing the projection we also placed in the central heating mask (it has been rotated 90 degrees so that the rejected beam is directed towards the edge of the table not the center of the table as indicated in the drawing because the beam dump would not fit) and used the projection to help center the mask. Worked well...and success was declared. I dont have the pics of the projection, but pics were taken.

All beams have beam blocked so that if wanted to run the laser around the clock we can (we wont be until given the go ahead by the local LSO). A bugzilla list (Bug 868...https://services.ligo-wa.caltech.edu/integrationissues/show_bug.cgi?id=868) has been made of the tasks that can think of that are still outstanding/need to be done for this table.

One concern: A couple times today we had further issues with the HWP. We would dial up an angle for it to go to, the MEDM screens would indicae that the HWP was at the angle we had requested yet it physically was at a different angle. I have asked Thomas to look into tomorrow as this is a concern.

Pic:

TCScurrentalignmentstanding shows a quick summary of whats aligned and what still needs to be done

Re-did measurements from yesterday.  Daniel brought up point about green light leaking into IR measurements and vice versa.  So addressed this.

IR Laser Light:  Look At filters to attenuate IR

Here we wanted to see which filter was best for viewing the GREEN light, so we wanted the filter which passed green & cut out IR.  With the Prometheus laser we used its IR light.  To make sure there was no Green light, we dropped in a Hoya R72 filter (to remove any Green light from laser).  Then we looked at the filters I bought .  So this is what we had:

• IR light from laser ONLY = 420mW
• Hoya R72 in path = 414mW
• BP550 (+ Hoya) = 3.11mW---best filter for viewing GREEN light
• lp550 (+ Hoya) = 423mW
• lp920 (+ Hoya) = 431mW
• bn532 (+ Hoya) = 167mW

The BP550 is OK, but Daniel says the OD of this filter may be low and we should look for a Schott glass filter (order of 4mm thick, similar to our old iLIGO glasses).  Either that or we can see what a couple of the BP 550s filters look like in series.

GREEN Laser Light:  Look At filters to attenuate Green

Here we want to see which filter is best for viewing IR light, so we want a filter which passes IR & attenuates Green.  With the Prometheus laser we had green light.  To make sure there is no IR light leaking in, we dropped an iLIGO goggle in the beam path as a filter.

• Only Green light = 20.2 mW
• iLIGO Glasses in path = 13.18 mW
• iLIGO + Hoya R72 = less than 5nW
• LP550 (+iLIGO glass) = 39.3 uW
• LP920 (+iLIGO glass) = less than 5nW
• BN532 (+iLIGO glass) = 7.45 mW
• BP550(+iLIGO glass) =8.03 mW

LP 920 may be good...maybe have two in series?

(Corey, Gerardo)

- Transition of LVEA to laser safe, Justin.
- Chris W, ASC/LSC front end code, per WP4335.
- TCS clean up, Thomas.
- Sheila and Alexa, X-End station, ALS table work.
- Travis, Alastair, Angus, and Gerardo, to Y-End TM removal from monolithic.
- Filiberto, to LVEA, camera work, ITMY installation.
- Transition of LVEA to laser hazard, Justin.
- Restart of epics gateway.
- Mindy and Thomas, Y-End, TCS ring heater installation.
- Travis, Alastair, Angus, and Gerardo, to Y-End, ETM12 install in monolithic.