Violin mode measurements of ETMx monolithic silica fibers

Giles report from yesterday's work:

(Travis, Mark, Jason, Doug, Giles)

 

After leaving the PUM hanging overnight there was no further development of the crack. We then proceeded to re-lock the PUM and hang the ETM to perform modal measurements. Using the autocollimator we measured the longitudinal, pitch and yaw modes. We then setup and optical lever to measure the transverse, bounce and roll modes. Finally we measured the 4 fundamental violin modes. The modal data gathered was:         

 

Longitudinal    0.656 Hz

Pitch  1.09 Hz

Yaw  1.09 Hz

Transverse 0.656 Hz

Bounce 6.75 Hz (this will be sqrt(2) higher when the PUM is free)

Roll 9.6 Hz (this will be sqrt(2) higher when the PUM is free)

 

FR  505 Hz

FL  506.5 Hz

BR  506.5 Hz

BL  505 Hz

 

We finally installed the fibre guards and covered the entire lower stage.

Successful fiber welding of ETMx monolithic lower suspension

Giles, Travis, Betsy After discussion with SYS and SUS it was decided that we should continue using the ETM03 PUM with the fracture behind one prism, monitoring for further damage. This afternoon we proceeded with welding on the remaining fibers with no further damage observed. Mid evening saw a successful hang of the ETMx mass from the fibers. A late note from Giles describing the day: We have just returned from the end station where we hung the ETM. The differential pitch was 0.66mrad and the CoM separation 601.3mm. After 5 mins we supported the optic back on the jack and set to the starting height to relieve tension on the fibres. We then lifted the UIM springs to place 40kg onto the prism (i.e. the PUM hanging). This will be left overnight to check for crack propagation. Applying load to the PUM does not seem to close the crack, although only half the load is being applied. A total of 5 fibres were used. We also made a series of measurements of temperature of the weld mirror and prism during welding. The maximum value observed for the mirror and prism was 75 degrees centigrade. Interestingly, the prism got to this temperature before the laser beam was directed onto the mirror, suggesting radiation as being the dominant heating mechanism. During heating the crack disappeared, presumably due to thermal expansion. There was no crack line visible suggesting that the crack surfaces are intact. On cooling the crack re-appeared. Tomorrow we plan to lower the optic and measure the modal frequencies and violin modes, before installing fibre guards.

plots of dust counts

Attached are plots of dust counts requested from 5 PM June 20 to 5 PM June 21.

plots of dust counts

Attached are plots of dust counts requested from 5 PM June 19 to 5 PM June 20.

Green ALS PD in transmission recalibrated

The calibration of the green ALS PD in transmission of the arm cavity and located on ISCT1 have been remeasured. The responsitivity of the PD was changed to 0.22 A/W (from 0.755 A/W); a factor of 3.4 decrease. The beamsplitter ratio was measured to be 19% (from a theoretical 20%). The datasheet of the SM1PD1A indicated around 0.23 A/W at 532 nm.

Fiber Pulling Machine Spinning Mirror Motor Bearings Failing

Bosch 0130002090 - discontinued and out of stock so I am researching a similar product
Motor Specs:
Permanent Magnet
Torque - 1.85 Ncm
Unloaded 2850 RPM at 12vdc stock, 5.5W
 (current config Loaded: 1760 RPM - 8.55 vdc at 3.55 A)
Mounting - 2x 4mm on 46.5BC
2 bolt oval plate
shaft dia 5mm x 22.5mm

Opt Shift Summary

08:00
Laser Safe
Alarms: CDS and Dust DR #1

Pablo in H2-PSL working on PCAL
Filiberto pulling cables at End-X
Western States delivered new scissor lift
John W working at End-Y
Pablo out of H2-PSL
Jim and Cyrus at Mid-X working on fiber
Pablo in H2-PSL working on PCAL
Richard working in LVEA around dust monitor 4
Virginio taking equipment to End-X 

Helium removal

YBM turbo valved in for 6 hours today -> Started @ 9 x 10-7 torr*L/sec, ended @ 6.5 x 10-7 torr*L/sec

EX TMS Work

(Corey, Keita, Lisa, Matt, Virginio)

ISC Table Layout Has Begun

I roughly laid out the QPD Sleds, High Power Beam Dump, & Beam Diverter.  Matt & Lisa started laying out all the rest of the optics (which required brining all the hardware from the Corner Station and then building each component, and then laying it out.)  Most of the optics are now on the Table.  Matt & Lisa will finish off laying them out and then begin aligning everything next week.

Telescope:  Staging & Tooling

Virginio & I unwrapped Tooling for suspending the Telescope.  Virginio is staging to start using our alignment laser.

Continuing To ICS

Continue to start making Assy Loads and accounting for all parts used for this installation.

EX TMS Weather

Relative Humidity started at 30% in the morning and went to 35% in the afternoon.  We will receive desicant packs and hygrometers on Mon/Tues.

started first EX front end computer, caused DAQ problems, stopped running computer

Following the installation of timing, networking and ipc in EX, we booted the h1susauxex front end computer and started the IOP model. This caused mx-stream DAQ errors from many other front ends, including all at EY and on the LVEA test stand. Restarting the mx streamers on these front ends did not clear the problem. When h1susauxex was powered down (thereby killing the mx streaming) all the other front ends became good again with intervention needed.

We will keep EX powered down for this weekend and revisit this problem Monday or Tuesday next week.

You may be encountering problems when manually starting models
 See this wiki page https://awiki.ligo-wa.caltech.edu/aLIGO/FrontEndStart

You will see that the old scripts start_streamers.sh and start_iop_mx_stream.sh still use a single port MX stream. 
As described, modifying start_streamers.sh is easy (merely stop/start /etc/init.d/mx_stream). Discard start_iop_mx_stream.sh.

* I have tested the new startup scheme described there on the LLO DAQ test stand, but have not attempted in on L1.
The RCG 2.7 roll-out would be a good chance to do that.

Also make sure that the /diskless/root/etc/rtsystab file has been updated with a line for the new computer and IOP model.  Several startup scripts depend on it.  In particular /etc/init.d/mx_stream uses it to figure out the MX stream card and slot.

There was a configuration error on the EX DAQ switch on two ports, including the one for h1susauxex (h1seiex being the other).  It was missing the mtu setting to allow transmission of jumbo frames (the dainbramaged CLI pagination code in these switches makes this hard to see, even when expressly looking for it...).  This has been corrected, and I suspect it will work now barring any other problems, but this is yet to be tested.

Dust Monitor Y Beam Manifold Seismic Test Stand

Changed out the 9 pin cable that connects this dust monitor to the 485 loop in the hopes of reducing data problems.  The cable that was connected was twice as long and may have had too much voltage drop to properly power the dust monitor when the motor was running.

End X CDS networking has been installed.

The End-X network switches for front-end and daq traffic have been connected, allowing the front end computers for the end-x to be started when needed.  The RFM switch has also been connected between the corner and end-x.

h1pemmx has been restarted

Network reconfiguration is complete, h1pemmx has been restarted.  As a bonus, the timing master to timing slave issue has been solved, so the timing is no longer out of sync.

HEPI status

HAM HEPIs 4 and 5 were brought into run mode yesterday, June 20th. 

current HEPI Status: 

Bleed Mode	Run Mode
HAM 2	BSC 1
HAM 3	BSC 2
BSC 9	BSC 3
	BSC 6
	HAM 1
	HAM 4
	HAM 5
	HAM 6

HIFO activity

[Alexa, Chris, Matt, Kiwamu]

Currently our focus is on two main tasks : refinement of Alexa's control model and the CARM control with the PFD (Phase Frequency Discriminator).

Yesterday we did the following items :

• Transfer function measurement at EY for the PLL and PDH loop
• Increased the input gain of the PDH common mode board by 4 dB to push the UGF higher. Now the UGF is -14 dB.
• Measured the readout gain of the PFD at the floor.
  • A coarse measurement gave ~ 40 deg / V. This sounds reasonable as the number written in the schematic 36 deg / V.
• Unable to find the beatnote at the corner station
  • This was probably due to the alignment of the arm cavity as we had touched them to quiet them for the transfer function measurement. TISCThis changed the alignment of the arm transmitted ligjt at the recombine BS at ISCT1.
  • We decided to bring them back to the nominal alignment
• Realigned ETMY and ITMY based on the oplev and L2 OSEMs respectively (as the ITMY oplev doesn't look trustable).
  • We didn't get a chance to check if this alignment recovered the beatnote signal

EX TMS Work Yesterday

(Corey, Virginio)

Continue to build up the Telescope and In-Vac ISC Table assemblies.

Spent time contemplating how to make TMS Assy Loads in ICS.

Topic of humidity came up in the Weekly TMS Meeting came up yesterday---namely the negative effects of humidity on Optic coatings.  We have a Dust Monitor in the Lab, but it isn't "online".  (For a "first Humidity data point", had a humidity of 21% mid-afternoon time yesterday)  In the future, we'll be receiving desicant packs from CIT and will make "Ameristat bags/covers" for our assys with optics and place desicant within these "bags".

Lisa has completed cleaning of all 2" optics which go on the In-Vac Table.  We will gather opto-mechanical hardware for these optics & then transport this to EX.

Continue to add photos of progress here.