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ID Date Author Type Categoryup Subject
  17910   Fri Oct 20 15:51:21 2023 JCSummaryBHDBHD Platform

The BHD platform assembly is going well. I have gotten majority of the Helicoils into all of their components. The only Helicoils I have left to insert are those of the breadboard. I have finished assembling 4 of the D220392, and 2 of the D2200409. Next I will be inserting the HeliCoils into the breadboard and working on D200400, D200405, and D200406. If lucky, I will also be able to tackle the Optic Mount Assemblies D2100200 and 2100435 on Monday afternoon as well.


I've attached a photo of the finished components.

  17912   Mon Oct 23 14:42:17 2023 JCSummaryBHDBHD Platform

Today, I spent majority of my time insterting the Helicoils for the Platform Assembly, D2100435. 181 Inserts to be exact.angry and I also got around to setting up the build for up the D2200400, 405, and 406. I expect for the assembling of the BHD platform to be maxed by Friday. (Maxed as in we need to pull parts from which are currently in Vacuum). I want OMC to be added on Friday and for us to begin the following week with alignment of the BHD Assembly.

Tasks which still need to be done

  • Assembly of D2200400, 405, and 406.
  • Bring over OMC and install onto the platform.
  • Alignment of the BHD and OMC.
  • Optic-Fibre input to the cleanroom.


  17915   Mon Oct 23 16:41:22 2023 KojiSummaryBHDBHD Platform

Thanks, JC for putting the parts together! I'll start collecting the instruments necessary for the OMC mounting / locking.

  17931   Sun Oct 29 21:01:18 2023 KojiUpdateBHDIntegration of the BHD platform and an OMC

[JC, Koji]

Integration of the BHD platform and an OMC

- Working environment: The BHD platform was placed on the optical table, and the parts and tools were placed on a wagon. (Attachment 1)

- The OMC used: OMC #1 (used OMC taken out from LLO)

- Cleanliness: HEPA booth / Particle counter borrowed from the PSL table. 0~20 count per cubic foot for 0.5um.

- OMC mounting scheme: The kinematic mount with three balls and three grooves is supposed to fix the position of the OMC once it is aligned. 

- OMC mounting procedure: Firstly, the upper parts were fixed to the OMC  (Attachment 2), while the lower parts were placed on the BHD Platform without fixing  (Attachment 3). Then, the OMC was placed on top. By jiggling the bottom parts, the grooves were aligned to the given ball positions (Attachment 4). Because the lower parts have grooves, they still can move before they are fixed keeping the tangent of the grooves and the balls. After the lower parts were aligned with the fixing thread holes well within the through holes, the hexagonal bolts were fastened with a spanner.

Using this OMC, the lower mounting parts for the second OMC slot were also aligned. They will need to be adjusted with the other OMC given later.

It is important to note that when raising or lowering the OMC from the BHD Platform, the fingers should be put on the attachment for the kinematic mounts from the bottom rather than pulling the glass breadboard up by putting the fingers on the glass breadboard.

This is to avoid extension stress on the glass mounting brackets, which can lead to epoxy delamination and/or cracking of the glass parts. Lifting the attachment for the kinematic mounts from below is safe because only compressive forces will be applied to the bonding on the breadboard surface.


  17932   Sun Oct 29 21:09:23 2023 KojiUpdateBHDOMC cable bracket delamination

[JC, Koji]

While adjusting the kinematic mount, we noticed that the OMC cable bracket was sagging from the OMC breadboard. This happened with no specific impact given.

This was the delamination of the epoxy (EP30-2) between the glass brackets and the rectangular metal shims. (Attachments)
There was no real damage to the components.

Also, a small delamination area was found on one of the mass mounting brackets (not pictured).

# This OMC was the first manufactured OMC in 2013, installed at LLO, and taken out last year. This is not the unit to be (possibly) used at Hanford.

The EP30-2 of this era had no established procedure for proper mixing yet. We've experienced frequent delamination in the OMCs and suspension assemblies.

Now that procedures for testing epoxy mixtures in a toaster oven have been established, the frequency of such delamination has decreased.

My assessment for the repair procedure:
- Remove the remaining epoxy layer on the glass side by scrubbing with a cotton swab using acetone.
- Apply EP30-2 on the cable bracket.
- Inject EP30-2 mixture to the mass mounting bracket via capillary action.

Strictly speaking, this OMC is a loan from aLIGO, so I will contact the aLIGO team to see if they have no objections to the repair before we start the work.
In the meantime, we can prepare optics for locking the OMC.

Ed (Oct 30, 2023 8AM): The rework was approved by GariLynn and Gabriele.

  17933   Mon Oct 30 13:28:28 2023 KojiUpdateBHDEpoxy removal

[JC Koji]

In the preparation of the OMC bond rework, we removed the remaining bond layer on the glass brackets.

Tools: Newly opened acetone, small glass bottle, syringes, Cotton Q-tips (wooden stick), cleaned razor blades


  • The epoxy layer stayed on the glass bracket surface.
  • We first soaked the top of the brackets with acetone, hoping the bond would start to melt.
  • We didn't see much difference after ~5 min.
  • We started scrubbing the layer with the cotton Q-tips. We hardly saw any change.
  • After struggling for ~30 min, some delaminated areas started to peel off, particularly when acetone liquid was applied. (Attachment 1)
  • Kept applying acetone while the surface was scratched with a razor blade. We try not to stress the middle part of the glass bracket as it's the most fragile part.
  • This process had the risk of being messy. Sheets of the lens cleaning paper were laid out around the cable bracket (Attachment 2).
  • All the glue on the brackets was removed. This turned the matte surface shiny and smooth.
  • Removed all the messy paper from the OMC. The fragments of the epoxy layers were removed by Kapton tape, acetone flow from syringes, and IPA wiping.
  • The result looked like Attachment 3.


  • Apply EP30-2
  • The cable bracket seems to keep its position with no position constraint. Nevertheless, we'll place some metal weights around and on the cable bracket.
  • The bracket close to the QPDs has ~50% delamination. The bond is going to be applied there also.
  17935   Mon Oct 30 15:47:16 2023 KojiUpdateBHDOMC bond rework

[JC Koji]

We successfully applied EP30-2 on the OMC #1.

  • We brought a scale with 0.01g resolution from Yuta's desk.
  • The Black and Decker toaster oven was brought from the bake lab (it was already returned)
  • Made two AL cups for epoxy mixing
  • Brought an SS spatula from the bake lab.
  • Checked which bracket has the 50% delamination by lifting the OMC --> it was the one close to the QPDs (Attachment 1)
  • Used one of the EP30-2 tubes with an expiration date of Nov 1, 2023 (in 2 days!) (Attachment 6).
  • Disposed one push from the glue applicator tube into one of the Al cups. Then, poured 7g into the other Al cup.
  • Added 0.35g of silica bead powder.
  • Mixed -> painted a few drops on a shell of Al foil -> Bake in the oven at 200F for 15min.
  • JC and I confirmed the baked test piece was nicely cured. No stickiness. Very crisp.
  • Applied the bond on the side of the 50% delaminated bracket. (Attachments 2/3).
  • I could confirm that the glue was sucked into the gap somewhat. The action was still going. (Attachment 4).
  • Now, we proceeded to the cable bracket. JC applied the layer of glue to the two brackets.
  • Then, the cable bracket was placed -> We checked how the upper part was wet. It was very nicely done! (Attachment 5)
  • We've placed some weight on the cable bracket so it does not move. In reality, the bracket was well constrained by the four screws and had almost no play to slide. (Attachment 7)
  • Decided to resume tomorrow at 2:30PM
  • The exist particle counting: 0 count for 0.5um particle.
  17943   Tue Oct 31 21:09:15 2023 KojiUpdateBHDOMC bond rework

We came back to the OMC 24 hours later and found the bonding work yesterday went well.

We cleaned up the OMC further and then placed it on the BHD platform. Now it's ready for the optical action.

Entrance particle count 2 / Exit particle count 4 for 0.5um

(Bond inspection photos will be posted here by JC)

  17946   Wed Nov 1 17:02:33 2023 PacoUpdateBHDPSL power lowered

I measured 883 mW of PSL power before the PSL Shutter. I then set the waveplate AXIS 1 to 36.82 deg to make the power 93 mW.

  17972   Mon Nov 13 00:34:56 2023 KojiUpdateBHDOMC input beam alignment

The polarization and alignment of the fiber for the OMC setup were adjusted. The polarization ratio before the PBS was 50:1. Then, the P-pol was sent to the OMC via two steering mirrors.
As a result of the beam alignment, the OMC cavity is flashing with a good amount of occasional TEM00.

Fiber alignment and polarization refinement

- NPRO power ADJ was "-29". The initial fiber output was 6mW.
- The input fiber collimator and an input steering mirror were adjusted to maximize the fiber output. The output power increased to 12mW.

- Adjusted the output fiber mount to minimize the PBS reflection.
- The initial ratio of the P/S was checked. 3mW was reflected by a PBS out of 12W. (i.e. 3:1).
- Went to the PSL table and repeated 1) rotate the fiber coupler 2) maximize the input beam/coupler alignment.
- Again, adjusted the output fiber mount to minimize the PBS reflection.
- Went back to the PSL to repeat the input side adjustment.
- Determined that I could not do it better.

- Increased the NPRO power ADJ to -20, just to have more power.
  Polarization ratio was ~50:1 (Trans 43mW, Refl 0.82mW).

The beam alignment into the OMC
- Set up the steering mirrors.
- Align the input beam so that I can see the input spot on the center of the second curved mirror (CM2).
- If the alignment is perfect, the input beam should hit the center of the first cavity mirror (FM1)
- The deviation can be adjusted by the mirror/spot position on the last steering mirror.
- So: Adjust CM2 spot by the last steering mirror, Adjust FM1 spot by the penultimate steering mirror.
- This made the cavity flashing. After a bit of alignment, the TEM00 mode was visible.
- A CCD was set at the transmission of CM2

  17974   Mon Nov 13 03:14:43 2023 KojiUpdateBHDOMC input beam alignment

To Do:

  • Set up the OMC refl optical path and the refl PD
  • Set up a trans monitor PD at CM1
  • Set up a platform position marker to ensure the reproducibility
  • Moku setup:
    • Temperature sweep
    • Laser PZT sweep
    • Moku RF modulation demodulation setup for PDH locking

What we need more to make the work better/easier in/around the HEPA table:

  • Proper fiber protection
  • Proper stray beam blocks (anodized Al plates)
  • Electronics rack or shelves at the north side of the booth
  • Parts table at the south side of the booth
  • Rotate the table 180 deg and put a storage shelf beneath the table (Wire rack?)
  17982   Thu Nov 16 14:39:34 2023 JCUpdateBHDUpdate on BHD Parts and Cleanroom Accomodations

Task Completed Today :

  • D2200122 Spacer Rings have been machined and ready for C&B
  • The North siderail of the cleanroom has been raised.
  • Parts SM05RR, LMR1V, D2300352-01, -02, -03, -04 have been C&Bed.
  • A New Cart has been Cleaned and added for working purposes to the cleanroom

D2200122 Spacer Rings have been machined and ready for C&B

I walked over to the GALCIT Shop today after receiving an email notifying me that the Spacer Rings are ready. We received 5 rings instead of 4 because the machinist made a mistake on one and was a couple thousanths of an in thicker. This ring is marked red on the photo in attachment #1. I have given these rings to Maty and she will take care of the C&B process since I will be out tomorrow. She said she expect them to be done sometime early next week.

The North siderail of the cleanroom has been raised.

I raised the North Siderail of the cleanroom to give us some more freedom moving the steel cart around in the cleanroom. This also allowed me to rotate the cart and add a bit more space inside. While doing this I had the particle counter running and 0.5 Micron count < 50 and the 0.5 Micron count < 10.

Parts SM05RR, LMR1V, D2300352-01, -02, -03, -04, and D2300208, D2300209, D2300210 have been C&Bed.

SM05RR, LMR1V, D2300352-01, -02, -03, -04, D2300208, D2300209, D2300210 are ready as of today. These have been placed in a plastic box on the middle space of the newly added steel cart. The Plastic boxes have the DCC/Part number on top so you will know what parts are inside.

A New Cart has been Cleaned and added for working purposes to the cleanroom

I brought the steel cart over from the shed area. I thoroughly wiped it down with IPA after cleaning with Windex and a rag. I also used the air gun to blow of any heavy dust from the wheels. I placed foil over each level of the cart and wiped down again with IPA. After, I made some AntiStat curtain around the cart to keep out anything heavy. Here are the plastic boxes containing parts SM05RR, LMR1V, D2300352-01, -02, -03, -04, D2300208, D2300209, D2300210.


  17985   Fri Nov 17 13:06:27 2023 KojiUpdateBHDBHD Platform Inventory

I went through the inventory list and the parts in hand to figure out what was still missing

The list was made on E2200464, and the PDF snapshot was added to this entry.


  • 2" pedestal post with a bottom vent hole (QTY 1+spare 1) 1 in hand / to be drilled / to be C&Bed
  • 2.5" pedestal post with a bottom vent hole (QTY2+spare 1) 2 in hand / to be drilled / to be C&Bed
  • Thorlabs NB1-K14 mirror (QTY1 + spares 3?) 2 in hand
  • Need to find 5 Y1-1025-45P collected various 45P mirrors. In principle we have all.
  • Faraday Rotator Riser D2200378 (Already ordered by Don) To be delivered / To be C&Bed
  • D2200122 ring spacers (Coming in soon from Caltech machining shop)
    -> They are ready for C&B on Nov 16 (JC)
  • Polaris-K1-2AH on the flow bench in the C&B lab. 


  • PDR1V rotation stage -> in search
  17988   Wed Nov 22 19:55:21 2023 KojiUpdateBHDBHD Platform Inventory
  • PDR1V rotation stage was found
  • 2" pedestal post x Qty 1 / top and bottom vent holes machined -> to be C&Bed
  • 2.5" pedestal post x Qty 2 / top and bottom vent holes machined -> to be C&Bed
  17990   Sun Nov 26 16:06:22 2023 KojiUpdateBHDBHD/OMC table work

- Setup the fiber protection and stray beam shields
- Replaced brand new wedged Y1-45P mirrors used in the OMC input path with stock Y1-45S mirrors. The wedged Y1-45Ps are going to be used for the optics on the BHD platform.
  Note: 45S mirrors are the same as 45Ps, but just their coating precision was not enough for 45P. So most of the cases 45S is sufficient for 45P purpose.
- All the remaining mirrors / CCDs / a lense / an RF PD (PDA-10) were setup and aligned.

- Found a DS345 is broken. The sinusoidal output does not swing and only has weird constant offsets dependent on the setting ==> need fix.

- An old analog function generator was brought for laser PZT scan test.
- Fast PZT cavity scan test: fine alignment & prelim visibility: REFL PD DS unlocked 5.50V vs TEM00 230mV -> estimated mode matching 95~96%
- When the OMC was detached from the kinematic mount and returned to the position: Relection at TEM00 230mV -> 1V. This corresponds to ~15% degradation of the alignment.
- OMC retainer screws (white PTFE screws) to hold the OMC vertically deforms the breadboard and cause the misalignment. Use something compliant or just release the screws.

  17991   Tue Nov 28 02:01:38 2023 KojiUpdateBHDOMC locked

The OMC was locked with Moku Pro.

Attachment 1: Electrical setup. The RF part of the REFL PD signal was fed into Moku pro, while the DC part was monitored on a scope.
Attachment 2: Servo setup. The modulation amplitude is 100mV.
Attachment 3: Image rejection LPF setup
Attachment 4: Laser PZT servo during lock acquisition
Attachment 5: Laser PZT servo for stational operation
Attachment 6: Laser Temp servo setting
Attachment 7: CCD Images during lock. The REFL is still limited by the mode mismatching component.
Attachments 8/9: The REFL locked / unlocked = 340mV/5.4V = 0.06 --> Mode Matching 94%


  17995   Tue Nov 28 18:28:10 2023 KojiUpdateBHDBHD Optics Prep

Continued on the BHD Optics Prep:

The following mounts were prepared (they are not 100% tightened yet)
- OMC Refl Mirror Mounts: OMCiRj (i=1,2, j=1,2,3)
- HWP (fixed) -> a thread adapter is missing
- TFPs
- HWP Actuator

We'll extract LO3/LO4/AS2/AS3/BHDBS from the ITMY chamber.

Fixed HWP mount had very thin room at the center. I wasn't sure if I could mount the 1/2" HWP in it. Fortunately the HWP was quite thin (~1mm) and it just barely fit. (Attachments 2/3)

The fixed HWP mount had no 8-32 to 1/4-20 thread adapter.
I'm asking the C&B of the adapters. (Attachment 4)

- AS2 2" post is being C&Bed
- LO4 2.5" post is being C&Bed

- BHDBS spacer ring is coming back from C&B soon
- BHDBS 2.5" post is being C&Bed

- Faraday Rotater Base was ordered. Waiting for the delivery.

  17996   Tue Nov 28 19:47:22 2023 RadhikaUpdateBHDBHD Optics moved to BHD cleanroom

AS2/AS3/BHD BS/LO3/LO4 moved to BHD cleanroom

Attachment 1 shows the labeled optics on the ITMY table (from Koji). I recorded the initial e-bubble reading on the ITMY table: (x,y) = (0.03; 0.17). See Attachment 5 for orientation of the e-bubble (from chamber door: x-axis left to right; y-axis front to back).

I first cleared the extra steering mirrors (marked SM in Attachment 1). The e-bubble reading after clearing steering mirrors was: (x,y) = (0.03; 0.18). Note that fluctuations of 0.01 are common for the e-bubbles, so this is a negligible change. The steering mirrors were placed on the XEND flow bench [Attachment 2].

Next I removed the BHD optics, in the order of (LO4, LO3, BHD BS, AS3, AS2). This was arbitrary but made it easy to work front-to-back and remember reverse numeric order. These were placed on the BHD cleanroom table behind the OMC platform [Attachments 3, 4]. See attachments for labeled optics. 

The final e-bubble reading was: (x,y) = (0.00; 0.20). Similar (small) change in x and y directions. Final state of ITMY table in Attachment 5.

  18004   Fri Dec 1 02:16:39 2023 KojiUpdateBHDBHD Optics moved to BHD cleanroom / More OMC locking
  • AS3/LO3 were assembled (Attachment 1)
  • The BHD Platform extension plate was attached to the platform. This will be removed upon the installation into the chamber.

Remaining things to do:

  • AS2 (DLC mount) / LO4 / BHD BS were fixed on the table but still waiting for the posts to come from C&B.
  • Waiting for the C&B
    • 2" x1 / 2.5" x2 OD1" posts
    • Thread adapter for HWP mount
    • Faraday Rotator Base (just arrived / in search)
    • #4-40 set screws to be C&Bed
    • Mighty Mouse connectors - coming out from the C&Bed  soon
  • Picomotor ball bonding (EP30-2)
  • DCPD installation
    • PD cans to be opened
  • OMC electronics function tests (PZT/DCPD/QPD)
    • External electronic units are still in prep (KA)

Tuning of the OMC locking

  • Tried to measure the open-loop transfer function of the OMC lock -> failed due to some broken instrument.
  • Added digital filter and spectrum tool on Moku Pro ("Multi Instrument" mode - Attachment 2)
  • Locking with "Multi Instrument" mode
    • Only 2 input CHs / 2 output CHs are available -> combined laser temp out and the modulation out (Attachment 3)
    • This somehow made the PZT range limited to the half of the past. The lock became a bit tricky.
  • Found that the oscillation is from 200kHz -> likely to be the PZT resonance
    • Implemented a low pass (Attachments 7/8)

The lock became less oscillative.
OMC REFL in-lock: 236mV
OMC REFL unlocked: 5.48
-> Mode-matching: 1-0.236/5.48 = 0.957

By the way, the above in-lock refl level was compared with the refl level with the cavity scan.
10Hz 800mVpp scan -> 524mV
  1Hz 800mVpp scan -> 324mV
Locked                       -> 239mV
I could be indicating the thermal effect?

A bunch of instruments are no longer functioning:

  • SR560 brought from the workbench
    • CHA and the 600Ohm output have their BNCs loose.
    • Is this unit noisy? Connecting a cable on CHB made the lock stable??? (The unit was inserted in the loop)
    • "SR560 deficit" How many functioning SR560 do we have?
  • 1201 Low noise amp (for alternative summing node)
    • The unit was brought from the cabinet -> simply broken
  • SR785 brought from the workbench
    • With nothing connected to the BNCs
    • CHA: No matter what is connected, the spectrum did not change. This channel (CH1A/B) had been labeled "FLAKY".
    • CHB showed "H.V" and was fixed at 34dBV input range -> Is it internally connected to AC???
  • DS345 shows the semi-constant voltage even though a sin wave was given.
  • Phillips function generator simply did not run.


  18005   Fri Dec 1 08:38:32 2023 JCUpdateBHDBHD Platform Parts

Productive Day for C&B

Beam Dump Bases (D1102371), PEEK Shims D1102372, Two 2.5 " pedestals, one 3" pedestal, Thread adapters #8-32 --> 1/4-20, #4-40 -1/2 Socket cap Screws, #4-40 set screws.

I have placed this on the middle stage of the outside cart. They have been labeled and placed on the center platform of the cart outside of the cleanroom.


  18006   Fri Dec 1 22:30:42 2023 KojiUpdateBHDBHD Optics moved to BHD cleanroom / More OMC locking

I've finished more BHD optic mounts:
- Downstream HWP
- Hex beam dump x2
- AS2
- LO4

The only remaining mechanics is the Faraday rotator base.

I'll start populating the optics in the mounts so that the final alignment can be done.

One issue I faced with today was that:

One of the BHDBS screws was stripped.
This pivot was supposed to swapped with a picomotor. I knew that these screws were tight and prone to strip the hex. So I carefully worked on it but it happened. crying
The other screw can still rotate. The pivot is still intact, but it'd be hard to replace it with a picomotor.

The impact is that we lost the horizontal translation of the OMC2 input beam. We have to move the OMC itself to correct the misalignment in the horizontal translation.
How much can we do that??? We inherently have no vertical translation of this beam, so it's not a big deal, maybe.
We'll face this operation when we install the second OMC.

  18009   Tue Dec 5 00:58:25 2023 KojiUpdateBHDMost of the BHD Optics populated / OMC mode matching / OMC servo actuator range

Populating the BHD Optics

  • Mounted Thorlabs NB1-K14 into OMC1R1 and OMC1R2 (Attachments 1/2)
  • Mounted CVI Y1-LW-1-1025-UV-45-P/AR into OMC1R2/3 and OMC2R2/3. (Attachments 3/4)
  • Mounted HWP and TFPs (Attachments 5)
  • 2 TFPs and 2 HWPs were aligned and adjusted to maximize the transmission.
  • OMC1R1 and OMC1R2 were aligned to take the refl beam from these mirrors.

OMC mode matching

  • OMC mode matching was <0.96.
  • Moved the last lens closer to the first lens.
  • This made the floor of the OMC refl output to be 74.4mV while the unlocked voltage was 4.78V. The dark offset was -5.4mV.
  • This gave us the mode matching of 0.983. This is close to the value I had in the OMC lab.
  • The image of the refl camera in a lock (Attachment 6) indicated that most of the mode mismatch is gone and the symmetric higher-order component remains.

OMC servo actuator range

  • Inserted Ithaco 1201 Low Noise Voltage Preamplifier after the Moku (Attachment 7). The gain was set to be 10.
  • The PZT output in Moku was set to be 0dB (instead of 14dB) and the output limitter was set to be 0~1V.
  • The gain of the digital filter (notch filter) was reduced to be 0dB.
  • This made the input swing for the PZT HV amp to be 0~10V. This is the full scale of the HV amp input range.
  • Consequently, the Moku's PZT output range was increased. This made both the lock acquision and the long term stability significantly improved.
  18015   Tue Dec 5 17:37:41 2023 KojiUpdateBHDFaraday Base issues

We got Faraday Rotator Base (D2200378) and it came back from the C&B.

I tried to build the assembly and was stunned with 2 issues.

1) The VOPO Faraday Rotator Riser (D1600160-v1) has 2" slot spacing, while D2200378 has a thread spacing of 1.5". (Attachment 1)

2) I could not manage to insert helicoils.

I made the investigation about 1). It turned out that it's a version control issue.
It seems that the riser we have is D1600160-v1 and has 2" slot spacing. DCC has this version.
However, the one in SolidWorks Vault was modified to have 1.5" slot spacing. It only exists in SW and even it claims it is V1. 😫

So our options are
a) Make the 1.5" space riser.
b) Make the 2" space base
c) Use as they are. If we rotate the base 90 deg, We can hold the riser with the base. It will become structurally weak as the riser is supported only on one side.

The issue 2) needs opinions from JC and Don. Depending on the assessment of 2), we'll decide which of a)~c) we'll do.

  13   Thu Oct 25 00:01:21 2007 ranaSoftware InstallationCDSGEO DV => LIGO DV
Martin Hewitson of GEO600 fame has modified the cool GEO DV
to work with the LIGO NDS system with some NDS advice from Rolf (who's over in Germany this week).

I've moved it onto the 40m CDS system and installed it on the AdhikariLab computer named 'django'. It worked immediately.

I modified the main .m file to include the 40m's NDS server. When you run it you have to include the path to the NDS
client written by Ben Johnson.

The attached is a screenshot of it working on a Mac; it looks as cool on Linux.

Its installed in /cvs/cds/caltech/apps/ligoDV/. In matlab you navigate to that directory and then
type addpath('/cvs/cds/caltech/apps/linux/UNIX_NDS_Client_beta2/') to add the NDS client.
On the Solaris machines, type type addpath('/cvs/cds/caltech/apps/solaris9/UNIX_NDS_Client_beta2/') instead.

Then type ligoDV to start it up. Then click away and have fun.

In the example I've selected
and plotted its specgram.

Big grin
  28   Mon Oct 29 23:25:42 2007 tobinSoftware InstallationCDSframes mounted
I mounted the frames directory on mafalda and linux3. It's intentionally not listed in the /etc/fstab so that an fb crash won't prevent the controls machines from booting. The command to mount the frames directory is:

mount fb40m:/frames/frames /frames
  144   Fri Nov 30 11:22:22 2007 ajwSummaryCDSGEO DV => LIGO DV

Martin Hewitson of GEO600 fame has modified the cool GEO DV
to work with the LIGO NDS system with some NDS advice from Rolf (who's over in Germany this week).

I've moved it onto the 40m CDS system and installed it on the AdhikariLab computer named 'django'. It worked immediately.

I modified the main .m file to include the 40m's NDS server. When you run it you have to include the path to the NDS
client written by Ben Johnson.

The attached is a screenshot of it working on a Mac; it looks as cool on Linux.

Its installed in /cvs/cds/caltech/apps/ligoDV/. In matlab you navigate to that directory and then
type addpath('/cvs/cds/caltech/apps/linux/UNIX_NDS_Client_beta2/') to add the NDS client.
On the Solaris machines, type type addpath('/cvs/cds/caltech/apps/solaris9/UNIX_NDS_Client_beta2/') instead.

Then type ligoDV to start it up. Then click away and have fun.

In the example I've selected
and plotted its specgram.

Big grin

Download and installation instructions, as well as a few examples for use
can be found here (typical lsc username and password):

  170   Wed Dec 5 19:25:07 2007 ranaDAQCDSDMF
I made a database file on C1AUX called dmf.db. It has 9 DMF EPICS channels which are also trended
so that one can now write data to those channels from a DMF Monitor and the data will be records.

New channels:

I added these to C1AUX because it doesn't do much and can be booted without having much effect.
(it controls Mech Shutters, Video, and Illuminators. It used to also do the EO Shutter but I
removed that from its startup.cmd and it will no longer load those records).
  270   Fri Jan 25 21:36:40 2008 ranaUpdateCDSmDV / channel issues
Fri Jan 25 21:30:00 2008

As it turns out, the residual problem with the mDV stuff was not to do with our button pushing episode but instead fallout from the 'turning off of the computers' during the water leak caused by the rain and construction.

The /frames partition from fb0 (the FrameBuilder) is not mounted to the control machines via vfstab; it does not remount on bootup. I originally did this because Ben Johnson and Dave Barker had warned me that during a power outage, fb0 may not come up right away. This could make the control room machines hang up for awhile. I elected to have the mount be by hand.

So the thing to do is to put the mount command into the cold start procedures (Andrey). Its in an old elog entry of mine from Feb '07.
  278   Sun Jan 27 21:44:48 2008 ranaUpdateCDSSeismic BLRMS on Matlab
I wrote a matlab script to produce band limited RMS trends from our accelerometers. It mimics the code written
by Ed Daw which makes the seismic FOMs at the sites.

Here's how it works:
  • Use mDV to get data by reading directly from frames.
  • Use the Matlab pwelch function to produce a power spectrum of the channels.
  • Use the Matlab find function and rms.m to get the RMS in user-defined frequency bands.
  • Makes a tdswrite command string which writes all the values to EPICS channels.
  • The EPICS channels are just a list of simple names in a database file.
  • The channel names are (will be) added to the C0EDCU.ini file so that its all trended.

The code is in the mDV/extra/C1 directory; its ~20 lines of code (excluding comments and spaces).

Next up is to add more DMF trend channels to the database and upgrade the code to use a .conf file
instead of hardcoded channel names. We should also evaluate if the bands I used are appropriate for the 40m;
I just used Ed's choices (0.1-0.3, 0.3-1, 1-3, 3-10, and 10-30 Hz).

In the medium term, we should make this compiled (like what RW did with the linetracker), and explore if we
want it to write values faster than 1/minute.
  356   Tue Mar 4 19:14:09 2008 ranaConfigurationCDSTDS & SVN
Matt, Rob, Rana

Today we added the TDS software to the 40m SVN repo.

First we rationalized things by deleting all the old TDS directories and taking
the tds_mevans dir and making it be the main one (apps/linux/tds).

We also deleted all of the TDS directories in the project area. It is now very
likely that several scripts will not work.
We're going to have the teething
problems of repointing everything to the nominal paths (in the apps areas).

Finally we did:
svn import tds https://40m.ligo.caltech.edu/svn/40m/tds --username rana

to stick it in. To check it out do:
svn checkout https://40m.ligo.caltech.edu/svn/40m/tds --username rana

We'll get a couple of the O'Reilly SVN books as well to supplement our verion control knowledge.
Unitl then you can use the SVN cheat sheets available at:
  383   Sun Mar 16 17:03:32 2008 robConfigurationCDSASS code change

I've updated the ass.mdl file in the directory:


to get us started in the adaptive PEM noise subtraction.

After several iterations of remote help from Alex, the code compiles and runs, receives signals from the LSC, PEM, and MC2, and communicates with the suspension controllers. I've also adapted the .par file from the code generator, but haven't got the testpoints working with the new ASS code. There are no MEDM screens yet, and Matt's adaptive filter code has not been installed (there's a matrix as a placeholder).

Putting in the adaptive code should be simple, building the MEDM screens tedious, and getting the testpoints working uncertain. I noticed that the new testpoint.par file starts at a different channel number than the previous (working) version, which is strange. I probably have a script somewhere to change all these numbers by a constant offset, but I don't know if that's the actual problem--maybe stuff just needs to be rebooted.

The code receives as input the first 24 channels from the PEM ADCU, the eight suspension control signals from the LSC, and the output of the MCL filter from MC2. It outputs to the MCL filter input of each suspension (except MC2).
  394   Sat Mar 22 22:39:02 2008 mevansSummaryCDSDirect Form 2 filters are bad
Here I show a comparison between the filter algorithm currently used in LIGO (Direct Form II), and an alternative algorithm designed to reduce numerical noise. The input signal is

x = sin(2 * pi * t) + 1e-9 * sin(2 * pi * (fs / 4) * t);

where fs = 16384 is the sample rate. The filter is a 4th order notch at 1Hz (f_poles = f_zeros = 1Hz, Q_poles = 1, Q_zeros = 1e6). It is clear that the DF2 algorithm produces a noise floor that is, for this simple filter, 1e-11 / rtHz smaller than the input drive amplitude (see plots). That should probably be scary given how many second-order-sections we run our signals through. The low-noise form does a somewhat better job. The low-noise algorithm has the same memory and computational requirements as DF2, and our CDS guys have the code in hand. I suggest we start testing soon.

(The code is included below. You will need my Matlab library to run the top level test script.)
  459   Tue Apr 29 21:09:12 2008 ranaDAQCDSFE Filters
These are new FE filters for downsampling and upsampling. We will be going from native hardware sampling rates of 64k down to 32k, 16k, and 2k.

The attached plot shows these filters. They are 3dB ripple, 40 dB stopband, 4th order elliptic filters in which I have moved the zeros around
into good places (e.g. to the Nyquist frequency).

I'm also attaching the .txt file containg the filter coefficients and the design strings. The filters are called x2, x4, and x32, for the
D2, D4, and D32 downsampling, respectively.
  1782   Thu Jul 23 07:34:45 2009 AidanUpdateCDSAdded C2 MEDM screens to 40m SVN.


See Adhikari eLOG entry: http://nodus.ligo.caltech.edu:8080/AdhikariLab/194

  1801   Tue Jul 28 18:32:21 2009 KojiUpdateCDSRCG work

Peter and Koji,

We are constructing a setup for the new 40m CDS using Realtime Code Generator (RCG).
We are trying to put simulated suspensions and test suspension controllers on a different processors of megatron
in order to create a virtual control feedback loop. Those CDS processes are communicating
each other via a shared memory, not via a reflective memory for now.

After some struggles with tremendous helps of Alex, we succeeded to have the communication between the two processes.
Also we succeeded to make the ADC/DAC cards recognized by megatoron, using the PCI express extension card replaced by Jay.
(This card runs multi PCI-X cards on the I/O chasis.)

Next steps:
- Establish a firewall between the 40m network and megatron (Remember this)
- Make DTT and other tools available at megatron
- Try virtual feedback control loops and characterize the performance
- Enable reflective memory functionalities on megatron
- Construct a hybrid system by the old/new CDSs
- Controllability tests using an interferometer

o Each cdsIPC should have a correct shared memory address spaced by 8 bytes. (i.e. 0x1000, 0x1008, 0x1010, ...)

Note on MEDM
o At the initial state, garbage (e.g. NaN) can be running all around the feedback loops. They are invisible as MEDM shows them as  "0.0000".
To escape from this state, we needed to disconnect all the feedback, say, by turning off the filters.

Note on I/O chasis
o We needed to pull all of the power plugs from megatron and the I/O chasis once so that we can activate
the PCI-e - PCI-X extension card. When it is succeeded, all (~30) LEDs turn to green.

  2045   Fri Oct 2 18:04:45 2009 robUpdateCDSDTT no good for OMC channels

I took the output of the OMC DAC and plugged it directly into an OMC ADC channel to see if I could isolate the OMC DAC weirdness I'd been seeing.  It looks like it may have something to do with DTT specifically.

Attachment 1 is a DTT transfer function of a BNC cable and some connectors (plus of course the AI and AA filters in the OMC system).  It looks like this on both linux and solaris.

Attachment 2 is a transfer function using sweepTDS (in mDV), which uses TDS tools as the driver for interfacing with testpoints and DAQ channels. 

Attachment 3 is a triggered time series, taken with DTT, of the same channels as used in the transfer functions, during a transfer function.  I think this shows that the problem lies not with awg or tpman, but with how DTT is computing transfer functions. 


I've tried soft reboots of the c1omc, which didn't work.   Since the TDS version appears to work, I suspect the problem may actually be with DTT.

  2173   Tue Nov 3 12:47:01 2009 KojiConfigurationCDS1Y9 Rack configuration update

For the CDS upgrade preparation I put and moved those stuff at the rack 1Y9:

Placed 1Y9-12 ADC to DB44/37 Adapter LIGO D080397

Placed 1Y9-14 DAC to IDC Adapter LIGO D080303

Moved the ethernet switch from 1Y9-16 to 1Y9-24

Wiki has also been updated.

  2181   Thu Nov 5 16:24:59 2009 KojiUpdateCDSETMY CDS test stuff

Joe, Peter, Jay, Koji, Rana

We put the new CDS stuff at Y end 1Y9 rack.


  • megatron
  • wireless router
  • IO chasis (black)
  • Extention cable (between megatron & IO chasis)
  • 1 ADC card
  • 1 DAC card
  • 1 BIO card
  • The adapter box for ADC
  • The adapter box for DAC
  • The adapter box for BIO
  • 2x IDC-DB37 cable for the ADC box - AA chasis
  • 1x IDC cable for the DAC box - Pentek
  • 1x DB cable for the BIO box
  • 1x +/-15V cable for the BIO box
  2233   Wed Nov 11 01:33:52 2009 peteUpdateCDSRCG ETMY code update

 I've added the side coil to the model controller and plant, and the oplev quad to the model controller and plant.  After the megatron wipe, the code now lives in /home/controls/cds/advLigo/src/epics/simLink.  The files are mdc.mdl (controller) and mdp.mdl (plant).  These RCG modules go at 16K with no decimation (no_oversampling=1 in the cdsParameters block) so hopefully will work with the old (16K) timing.

I've loaded many of the filters, there are some eft to do.  These filters are simply copied from the current frontend.  

Next I will port to the SUS module (which talks to the IO chassis).  This means channel names will match with the current system, which will be important when we plug in the RFM.

  2243   Wed Nov 11 20:46:07 2009 peteUpdateCDSRCG ETMY phase I update

The .mdl code for the mdc and mdp development modules is finished.  These modules need more filters, and testing.  Probably the most interesting piece left to do is putting in the gains and filters for the oplev model in mdp.  It might be OK to simply ignore oplevs and first test damping of the real optic without them.   However, it shouldn't be hard to get decent numbers for oplevs, add them to the mdp (plant) module, and make sure the mdc/mdp pair is stable.  In mdp, the oplev path starts with the SUSPIT and SUSYAW signals. Kakeru recently completed calibration of the oplevs from oplev cts to radians:   1403  .  From this work we should find the conversion factors from PIT and YAW to oplev counts, without making any new measurements.  (The measurements wouldn't be hard either, if we can't simply pull numbers from a document.)  These factors can be added to mdp as appropriate gains.

I've also copied mdc to a new module, which I've named "sas" to address fears of channel name collisions in the short term, and replaced the cpu-to-cpu connections with ADC and DAC connections.  sas can be the guy for the phase I ETMY test.  When we're happy with mdc/mdp, we hopefully can take the mdc filter file from chans, replace all the "MDC" strings with "SAS", and use it.

  2259   Thu Nov 12 17:24:29 2009 Koji, Joe, PeterConfigurationCDSETMY CDS test started

We started the test of the new CDS system at ETMY.

The plan is as follows:
We do the ETMY test from 9:30 to 15:00 at ETMY from Nov 12~17. This disables the ETMY during this period.
From 15:00 of the each day, we restore the ETMY configuration and confirm the ETMY work properly.

Today we connected megatron to the existing AA/AI modules via designated I/F boxes. The status of the test was already reported by the other entry.

During the test, c1iscey was kept running. We disabled the ETMY actuation by WatchDog. We did not touch the RFM network.

After the test we disconnected our cables and restored the connection to ICS110B and the AI/AA boards.

The WatchDog switches were released.

The lock of the ETMY was confirmed. The full interferometer was aligned one by one. Left in the full configuration with LA=off.

  2471   Sun Jan 3 08:23:39 2010 ranaConfigurationCDSautoburt.pl 'fixed' for post 2009 years

Tobin & Keith pointed out in the LLO ilog that there was a code bug in the autoburt.pl script for autoburts.

I edited the autoburt.pl script so that it will work from now until 2099 (by which time we may no longer be using this version of perl):

nodus:autoburt>diff autoburt.pl~ autoburt.pl
<     $thisyear = "200".$timestamp[5];
>     $thisyear = "20".$timestamp[5];

The autoburt has not been working ever since 11PM on New Year's eve.

I ran it by hand and it seems to run fine. I noticed along the way that it was running on op340m (our old Sun Blade 150 machine). The autoburt.pl was pointing at /cvs/cds/bin/perl

which is Perl v5.0. I changed it to use '/usr/bin/env' and now points at '/usr/bin/perl' which is perl 5.8. It runs fine with the new perl:

op340m:scripts>time perl /cvs/cds/scripts/autoburt.pl >> /cvs/cds/caltech/logs/autoburtlog.log
5.37u 6.29s 2:13.41 8.7%

Also ran correctly, via cron, at 9AM.

  2640   Thu Feb 25 15:49:05 2010 AlbertoAoGCDSNew IO Chassis for the new CDS
Yesterday Kiwamu and I went to Downs to take all the available parts of the IO chassis that Gary and I had put together over there.
We've got only 3 of the 5 that we need for the Upgrade. The other 2 are currently being used for some other purpose in Downs labs.
I'm not sure about what each chassis has supposed to contain. They all also look different from each other.
Anyway, it looks like there should be a sort of motherboard and an IO Chassis Interface Board (DCC# D0902029) in each of them. The IO Chassis Interface Board is just a board with a bunch of PCI slots.
This is what the 3 chassis that we've got yesterday have:
Chassis 1
- 1 very big "motherboard"
- power supply
Chassis 2
- small motherboard
- IO Interface Board (DCC# D0902029)
- power supply
Chassis n.3
- "Dolpjin" motherboard
- IO Interface Board
- power supply
Apparently 2 of these 3 chassis are still missing their IO interface boards,
Also all chassis are still missing all the connections to powering, fans, LEDs, power and reset buttons. It's not clear how these connections should be. Gary didn't know it either.
  2824   Wed Apr 21 11:32:31 2010 josephbUpdateCDS40m CDS hardware update and software requests

This is mostly a reminder to myself about what I discussed with Jay and Alex this morning.

The big black IO chassis are "almost" done.  Except for the missing parts.  We have 2 Dolphin, 1 Large and 1 Small I/O Chassis due to us.  One Dolphin is effectively done and is sitting in the test stand.  However, 2 are missing timing boards, and 3 are missing the boards necessary for the connection to the computer.  The parts were ordered a long time ago, but its possible they were "sucked to one of the sites" by Rolf (remember this is according to Jay).  They need to either track them down in Downs (possibly they're floating around and were just confused by the recent move), get them sent back from the sites, or order new ones (I was told by one person that the place they order from them notoriously takes a long time, sometimes up to 6 weeks.  I don't know if this is exaggeration or not...).  Other than the missing parts, they still need to wire up the fans and install new momentary power switches (apparently the Dolphin boards want momentary on/off buttons).  Otherwise, they're done.

We are due another CPU, just need to figure out which one it was in the test stand.

6 more BIO boards are done.  When I went over the plans with Jay, we realized we needed 7 more, not 6, so they're putting another one together.  Some ADC/DAC interface boards are done.  I promised to do another count here, to determine how many we have, how many we need, and then report that back to Jay before I steal the ones which are complete.  Unfortunately, he did not have a new drawing for the ASC/vertex wiring, so we don't have a solid count of stuff needed for them.  I'll be taking a look at the old drawings and also looking at what we physically have.

I did get Jay to place the new LSC wiring diagram into the DCC (which apparently the old one never was put in or we simply couldn't find it).  Its located at: https://dcc.ligo.org/cgi-bin/private/DocDB/ShowDocument?docid=10985

I talked briefly with Alex, reminded him of feature requests and added a new one:

1) Single part representing a matrix of filter banks

2) Automatic generation of Simulated shared memory locations and an overall on/off switch for ADC/DACs

3) Individual excitation and test point pieces (as opposed to having to use a full filter bank).  He says these already exist, so when I do the CVS checkout, I'll see if they work.


I also asked where the adl default files lived, and he pointed me at ~/cds/advLigo/src/epics/util/

In that directory are FILTER.adl, GDS_TP.adl, MONITOR.adl.  Those are the templates.  We also discovered the timing signal at some point was changed from something like SYS-DCU_ID to FEC-DCU_ID, so I basically just need to modify the .adl files to fix the time stamp channel as well.  I basically need to do a CVS checkout, put the fixes in, then commit back to the CVS.  Hopefully I can do that sometime today.

I also brought over 9 Contec DO-32L-PE boards, which are PCIe isolated digital output boards which do into the IO chassis.  These have been placed above the 2 new computers, behind the 1Y6 rack.


  2826   Wed Apr 21 16:48:38 2010 josephbUpdateCDSHardware update

Alberto and myself went to downs and acquired the 3rd 4x processor (Dual core, so 8x cores total) computer.  We also retrieved 6 BIO interface boards (blue front thin boxes), 4 DAC interface boards, and 1 ADC interface boards.  The tops have not been put on yet, but we have the tops and a set of screws for them.  For the moment, these things have been placed behind the 1Y6 rack and under the table behind the 1Y5 rack


The 6 BIO boards have LIGO travelers associated with them: SN LIGO-S1000217 through SN LIGO-S1000222.

  2849   Tue Apr 27 11:16:13 2010 josephbConfigurationCDSWiki page with CDS .mdl names, shared memory allocation

I've added a new page in the wiki which describes the current naming scheme for the .mdl model files used for the real time code generator.  Note, that these model names do not necessarily have to be the names of the channels contained within.  Its still possible to make all suspension related channels start with C1:SUS- for example.  I'm also allocating 1024 8 byte channels for shared memory address space for each controller and each simulated plant.

The wiki page is here

Name suggestions, other front end models that are needed long term (HEPI is listed for example, even though we don't have it here, since in the long run we'd like to port the simulated plant work to the sites) are all welcome.

  2860   Thu Apr 29 14:37:16 2010 josephbUpdateCDSNew Channel Name to Memory Location file

Awhile back we had requested a feature for the RCG code where a single file would define a memory location's name as well as its explicit hex address.  Alex told me it had been implemented in the latest code in SVN.  After being unable to find said file, I went back and talked to him and Rolf.  Rolf said it existed, but had not been checked into the SVN yet. 

I now have a copy of that file, called G1.ipc.  It is supposed to live in /cvs/cds/caltech/chans/ipc/ , so I created the ipc directory there.  The G1.ipc file is actually for a geo install, so we'll eventually make a C1.ipc file.

The first couple lines look like:

# /cvs/cds/geo/chans/ipc/G1.ipc
desc=default entry

desc=Replaces 0x2000

desc=Replaces 0x2008


There are also section using ipcType IPC:

desc=Replaces 0x20F0
desc=Replaces 0x20F0


Effectively the ipcNum tells it which memory location to use, starting with 0x2000 (at least thats how I'm interpreting it.  Every entry of a given ipcType has a different ipcNum which seems to be correlated to its description (at least early on - later in the file many desc= lines repeat, which I think means people were copy/pasting and got tired of editing the file.  Once I get a C1.ipc file going, it should make our .mdl files much more understandable, at least for communicating between models.  It also looks like it somehow interacts with the ADCs/DACs with ipcType PCI, although I'm hoping to get a full intro how to use the file tomorrow from Rolf and Alex.

  2861   Thu Apr 29 15:48:47 2010 josephbUpdateCDSNew CDS overview diagram in wiki

I've added a diagram in the wiki under IFO Upgrade 2009-2010->New CDS->Diagram section Joe_CDS_Plan.pdf (the .svg file I used to create it is also there).  This was mostly an exercise in me learning inkscape as well as putting out a diagram with which lists control and model names and where they're running.

A direct link is: CDS_Plan.pdf

  2871   Mon May 3 15:39:39 2010 josephbUpdateCDSDaily Downs update

Talked with Jay briefly today.  Apparently there are 3 IO chassis currently on the test stand at Downs and undergoing testing (or at least they were when Alex and Rolf were around).  They are being tested to determine which slots refer to which ADC, among other things. Apparently the numbering scheme isn't as simple as 0 on the left, and going 1,2,3,4, etc.  As Rolf and Alex are away this week, it is unlikely we'll get them before their return date.

Two other chassis (which apparently is one more than the last time I talked with Jay), are still missing cards for communicating between the computer and the IO chassis, although Gary thinks I may have taken them with me in a box.  I've done a look of all the CDS stuff I know of here at the 40m and have not seen the cards.  I'll be checking in with him tomorrow to figure out when (and if) I have the the cards needed.

  2872   Mon May 3 16:53:27 2010 josephbUpdateCDSUpdated lsc.mdl and the ifo plant model with memory locations

I've updated the LSC and IFO models that Rana created with new shared memory locations.  I've used the C1:IFO- for the ifo.mdl file outputs, which in turn are read by the lsc.mdl file.  The LSC outputs being lsc control signals are using C1:LSC-.  Optics positions would presumably be coming from the associated suspension model, and am currently using SUP, SPX, and SPY for the suspension plant models (suspension vertex, suspension x end, suspension y end).

I've updated the web view of these models on nodus.  They can be viewed at: https://nodus.ligo.caltech.edu:30889/FE/

I've also created a C1.ipc file in /cvs/cds/caltech/chans/ipc  which assigns ipcNum to each of these new channels in shared memory.

ELOG V3.1.3-