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Reports until 17:19, Tuesday 21 August 2012
H1 INS
calum.torrie@LIGO.ORG - posted 17:19, Tuesday 21 August 2012 (3922)
WHAM3 MC2 BandK in chamber

WHAM3 MC2 BandK in chamber LIGO-T1200403-v1

https://dcc.ligo.org/cgi-bin/private/DocDB/ShowDocument?docid=95644

Draft
H2 TCS
jaclyn.sanders@LIGO.ORG - posted 16:57, Tuesday 21 August 2012 - last comment - 17:42, Tuesday 21 August 2012(3921)
Modal spacing with ring heater (Jax, Elli, Alberto)

This afternoon we ran the ring heater on ETMY for ~3.5 h, taking cavity scans to attempt to quantify the change in modal spacing with heating.

There's a clear change in the behavior in the 55-60 kHz region (associated with the modulation sidebands), but getting a clear signal for a higher-order cavity mode has been difficult. I also don't understand the downward slope of the phase response curve. I'm hoping to make better measurements tomorrow with a cold cavity to get consistent, clear numbers for the cavity mode frequencies, then try this measurement again.

The adoption of Phase - Phase at 30 kHz for the y-axis is purely to put the traces closer together visually for side-by-side comparisons of the sidebands. The "hot" trace starts at 166.7417, the "cold" trace starts at -162.2308.

Images attached to this report
Comments related to this report
aidan.brooks@LIGO.ORG - 17:42, Tuesday 21 August 2012 (3923)

I compared one of this afternoon's heated cavity scans with a cold cavity scan from last week. The nominal frequency of the TEM10 mode is shown (around 66kHz) [higher order frequency spacing = 28.5kHz, FSR = 37.5kHz, sum = 66kHz). There's clearly a shift in the TEM10 mode of a few hundred Hz.

Non-image files attached to this comment
LHO General
jeffrey.garcia@LIGO.ORG - posted 16:10, Tuesday 21 August 2012 (3920)
OPS Log
Kingsoft water delivery
Praxair delivery at ~10:40
Contractors on-site

Jim B. to End-Y station to reboot PEM I/O chassis
Michael R. to outbuildings to change signs for laser safety
work just north of HAM4 by Eric A.
Douglass using leak detector in OSB Optics Lab
SUS work in and around HAM3
H1 SEI
hugo.paris@LIGO.ORG - posted 15:22, Tuesday 21 August 2012 (3919)
HAM2 & HAM3 - Simulink Models Modified

DaveB, JeffG, HugoP,

Added EPICS output channels to monitor errors on IPC receiver inputs (all from SUS) of HAM2 and HAM3 models.

H1 SUS
betsy.weaver@LIGO.ORG - posted 15:05, Tuesday 21 August 2012 (3918)
HAM2 MC2 initial TFs to check for rubbing and other install work

We're going to take a few quick TFs of MC2 to check for mechanical interferences within the suspension since it has been installed.  Next up, we'll set the B&K Hammer/Laser Vibrometer equipment up on MC2 for measurements.

We have also been cleaning up grounding and cabling issues inside the chamber.  This is still ongoing and will migrate to PR2 shortly.

H1 PEM
maggie.tse@LIGO.ORG - posted 14:32, Tuesday 21 August 2012 (3917)
Effectiveness of accelerometer mounting schemes

 

During iLIGO, there were 3-axis accelerometers that were mounted on the tabletops of optics tables. This was done by bolting three accelerometers to the sides of a aluminum cube that was then bolted down to a aluminum plate, which was bolted to the table. This mounting scheme, however, introduced a ~900Hz signal, associated with the resonance of the cube and the plate, into the accelerometer channels. We investigated new mounting schemes to use during aLIGO, and compared them.

 

For all the tests, we used as our reference an accelerometer that was attached to the table surface with a thin layer epoxy. The hole at the bottom of the accelerometer normally used for bolting it to cubes was sealed with a set screw to avoid having epoxy seep between the threads. The epoxy was Devcon 5-minute epoxy, which was applied to the bottom of the accelerometer. Excess epoxy was scraped off using the flat side of the mixing stick, to have the layer be as thin as we could make it. The accelerometer was then placed on the table, in an area where it was not over any of the holes for bolts, and the epoxy was allowed to cure for 5 minutes before the cable was attached to it. The thickness of such a layer of epoxy is no more than 0.3mm.

---------------------

SUCCESSFUL MOUNTINGS:

 

Items Used:

- Wilcoxon accelerometer, model 731-207

- Devcon 5-minute epoxy

- Wilcoxon 1in. triaxial aluminum mounting cube, model TC1

- Glad polyethylene wrap

- Ultratape 1520CL100P3D

- 520 ft Thermax RGS-316 cable

 

Z-axis mounting:

We tried adding a layer of Glad polyethylene wrap between the accelerometer and the table. A thin layer of epoxy was first applied to the accelerometer, and a piece of wrap was pulled taut against the bottom of the accelerometer. Then another thin layer of epoxy was applied to the wrap, and then the accelerometer was pressed to the table. The purpose of adding the layer of polyethylene wrap is to isolate the accelerometer from the object it's mounted to, since a thin layer of epoxy may actually allow parts of the metal exterior of the accelerometer to come into contact with the table. The combination of the epoxy and polyethylene wrap added 0.3mm to the heght of the accelerometer (the wrap itself is ~0.5 mils thick). We found that adding this layer does not make the signal deviate too much from that of the reference (see attachment 1).

 

Triple-axis mounting:

We tried attaching an accelerometer with a layer of polyethylene wrap on the bottom (as above) to an aluminum cube using epoxy, and attaching that cube to the table using epoxy. This also does not make the accelerometer signal deviate significantly from that of the reference (see attachment 2). For actual installation of triple-axis accelerometers, we recommend first attaching three accelerometers to a metal cube using the epoxy-polyethylene-epoxy method described above, outside the LVEA. Once the epoxy has cured and the triple-axis setup is stable, one only needs to use one batch of epoxy near the table to mount the cube. We tested a similar setup but with a (non-conductive) acrylic cube instead, but found that the aluminum cubes give better performance (see attachment 3).

 

Temporary mounting:

For temporary installations, we tested 1in wide double-sided clear clean room tape. Previously, in iLIGO, double-sided Scotch tape was used, but for aLIGO we wish to use particle-free adhesives such as clean room tape. We found that this mounting allowed the accelerometer to respond to vibrations in a similar way to the epoxied reference (see attachment 4). There were two kinds of clean room tape we tried, one that had a peel-away backing, and one that did not. Since the backing is a hassle to peel off, the tape without the backing is preferred.

 

Extra long cables:

For cases where extra long cables need to be used for an accelerometer, we verified that the length of the cable does not affect the accelerometer readings. We tested a 520 ft Thermax RGS-316 cable with an accelerometer that was epoxied to the table, next to the reference, and found no effects from using a longer cable (see attachment 5).

---------------------

SUB-OPTIMAL MOUNTINGS:

 

The first mounting scheme we tested was double-sided tape, used in temporary setups during iLIGO. This kind of mounting is useful in temporary installations, not specific to optics tables. The tape used was Scotch Permanent Double Sided Tape, 0.5in wide. Two parallel, non-overlapping strips were placed across the bottom of the accelerometer, which is 1in in diameter, and the accelerometer was pressed to the table surface, again away from any holes. It was placed adjacent to the reference to avoid variations due to positioning on the table. The tape was also found to be non-conductive, so it isolates the accelerometer from the object it's mounted to. We found that when taped to the table, the accelerometer behaves very similarly to one that is epoxied to the table (see attachment 6). However due to cleanliness concerns we opted to use clean room tape for future installations.

 

Next we compared the iLIGO setup to the epoxied reference. We again found the 900Hz resonance of the cube and plate entering the accelerometer channel (see attachment 6).

 

 


Other methods we tried were:

 

Maggie Tse, Robert Schofield

Images attached to this report
H1 SUS
jeffrey.garcia@LIGO.ORG - posted 13:34, Tuesday 21 August 2012 (3915)
H1 SUS PR2
The H1 SUS PR2 "safe" burt file was updated and committed to the "cds_user_apps" SVN repository locally in:
'/opt/rtcds/userapps/release/sus/h1/burtfiles/h1suspr2_safe.snap'

This is the file that is SVN version-controlled in the above directory.  A soft-link pointing to this particular file was created in the directory:
'/opt/rtcds/lho/h1/target/h1suspr2/h1suspr2epics/burt/'

with the name "safe.snap" for use by the startup scripts when re-booting the "h1suspr2" Simulink user model.
H2 ISC
bram.slagmolen@LIGO.ORG - posted 12:20, Tuesday 21 August 2012 - last comment - 12:31, Tuesday 21 August 2012(3912)
Arm Locking for cavity mode-scan started

[Jax, Elli, Alberto, Keita, Daniel, Bram]

After relocking the RefCav we started locking the Arm and setting alignments. Jax and Elli are running the mode-scans.

Comments related to this report
eleanor.king@LIGO.ORG - 12:31, Tuesday 21 August 2012 (3913)

The ring heater at ETMY has been turned on at 19:27:25 UTC, 12:27:25 Local time.  630mA of current is requested in both segments.  We will run the ring heater continuously for the next 3 hours.

LHO VE
kyle.ryan@LIGO.ORG - posted 11:23, Tuesday 21 August 2012 (3911)
LVEA purge air dewpoint measured to be -27C today


			
			
X1 SEI
hugo.paris@LIGO.ORG - posted 11:18, Tuesday 21 August 2012 (3909)
HAM-ISI Unit #7 - Assembly Validation Passed

HAM-ISI Unit #7 - Assembly Validation Testing was validated today. We can now proceed to storage of the unit for future insertion in HAM4 Chamber.
 

Please join me in congratulating the members of the SEI Assembly Team who successfully assembled all of our 7 aLIGO HAM-ISIs  yes
 

Reports regading the Assembly validation of previous units at LHO are available in the DCC:

HAM-ISI Unit #1 - Assembly Validation
HAM-ISI Unit #2 - Assembly Validation
HAM-ISI Unit #3 - Assembly Validation
HAM-ISI Unit #4 - Assembly Validation
HAM-ISI Unit #5 - Assembly Validation
HAM-ISI Unit #6 - Assembly Validation

Reports regading the Chamber Side testing of other units at LHO are available in the DCC:
HAM2 (HAM-ISI Unit #4) - Chamber Side Testing
HAM3 (HAM-ISI Unit #5) - Chamber Side testing

Note: Earlier this month we added an Initial In-Chamber Testing section to the HAM3-ISI Phase II - Integration Process testing report. This report has now two sections:

This report will be completed with the future tests performed on HAM3-ISI unitl the begining of Phase III - Control and Commissionning.

H1 SUS
betsy.weaver@LIGO.ORG - posted 11:05, Tuesday 21 August 2012 (3910)
WHAM3 install work

Kate and I are checking grounding on MC2.  This will require disconnecting the exterior MC2 SUS cables from the chamber feedthru briefly.

H1 SUS
jeffrey.garcia@LIGO.ORG - posted 10:23, Tuesday 21 August 2012 (3908)
H1 SUS MC1, MC3, PR3, PRM models installed on 'h1sush2a'
The Simulink models for H1 MC1, MC3, PR3, and PRM were compiled, installed, and begun on the 'h1sush2a' FrontEnd this morning during the CDS Tuesday Maintenance period.  The H1 DAQ was also re-booted to begin recording the channels for these models.  All re-boots were clean with no apparent issues to note. 
H1 PSL
michael.rodruck@LIGO.ORG - posted 09:39, Tuesday 21 August 2012 (3907)
Noise eater creating peak at ~120Hz

For future reference, the peak in the ISS_rpn spectrum at ~120Hz appears to be caused by the NPRO's noise eater. It also explains why I had to lower the reference signal to -2.5 from -1.9 to get the diffracted power to a reasonable level (33% down to 2%). This was fixed by turning the noise eater off and on. The attached plots show the noise eater noise (iss_rpn-009) and after it was reset (iss_rpn-001).

This was caused by swapping the FAST cable earlier last week. I was able to set the reference signal back to -1.9 afterwards.

Non-image files attached to this report
H1 SUS
filiberto.clara@LIGO.ORG - posted 08:12, Tuesday 21 August 2012 (3906)
SUS HAM3 PR2
Removed temporary connection used for PR2 testing and connected permanent cabling from HAM3 feedthrus to SAT Amplifiers.
H1 IOO
david.feldbaum@LIGO.ORG - posted 18:53, Monday 20 August 2012 (3903)
Optics installation into IO FI
I have put together 4 optics in the Faraday Isolator, out of 7 that should be there eventually. These include:

Ca wedge polarizer s/n 12 currently on the input side
Ca wedge Polarizer s/n 03 on the output side
TGG crystal s/n 10, presently on the "long" tube together with
Quartz rotator

Still not assembled are:

2nd TGG crystal -- will put s/n 09 in tomorrow when Al-Bronze cap is out of the C&B oven
HWP and DKDP -- don't yet have the proper mounts

To install Ca wedges I used a slightly different technique. I cut two 5 mm long sections of the Indium rod, and rolled them together into one fat 5 mm long rod. I then pressed that rod onto the setscrew, and still had enough Indium thickness to tighten on the Ca wedge.

The TGG is installed with Indium foil wrapped around the wedge. I had to roll two slices of the Indium foil together, as the lengths (or even the diagonals) of the foil squares that were delivered are shorter than the circumference of the crystal.

The Quartz is installed withOUT the foil. Instead it contains at least 3 layers of the Indium wire on the cap side to keep it in place.

More photos may be found on the Resource Space.
Images attached to this report
LHO General
patrick.thomas@LIGO.ORG - posted 18:33, Monday 20 August 2012 (3902)
plots of dust counts
Attached are plots of dust counts > .5 microns in particles per cubic foot.
Non-image files attached to this report
H2 ISC
bram.slagmolen@LIGO.ORG - posted 22:53, Thursday 16 August 2012 - last comment - 23:22, Monday 20 August 2012(3882)
FIBR Servo PZT Notch

[Daniel and Bram]

With the appearance of the laser PZT resonance in the FIBR servo loop, we made a notch filter. We measured the PZT resonance in a previous entry 3857 to be at 287.55 kHz. After some searching and going back and forth we decided to go the easy way, using a passive notch filter (schematic attached 'FIBR_PZT_NOTCH.pdf'), which Daniel already has used in the TTFSS.

By the lack of finding the right capacitors, we used a 500 pF and a 100 pF parrallel, with a 0-100 pF variable capacitor (oh and we got a 470 uH SMD inductor!). With the help of EE-Dave we managed to pack it into a pomona box.

Also attached is a discustingly bad phone photo of the measured response (the RF analyser has a naughty floppy disk drive).

All in all success. We plugged it in and it worked, we can lock the FIBR Servo with a UGF of 28 kHz (another log entry will follow when I get the data from the disk).

Images attached to this report
Non-image files attached to this report
Comments related to this report
bram.slagmolen@LIGO.ORG - 23:22, Monday 20 August 2012 (3905)

The measured open-loop response is seen in the attached tiff file.

Images attached to this comment
H1 SUS
cheryl.vorvick@LIGO.ORG - posted 17:07, Thursday 16 August 2012 - last comment - 13:11, Tuesday 21 August 2012(3875)
PR2 is in HAM3
PR2 was installed in HAM3 today, and traveled well on the Genie and Arm.  It's sitting against it's cookie cutter, and dogged down overnight.  The crew was Kurt Buckland and Scott Shankle, as well as Deepak and I
Comments related to this report
cheryl.vorvick@LIGO.ORG - 13:11, Tuesday 21 August 2012 (3914)
Pictures:
Images attached to this comment
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